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8/03/2007
sex and sexy
Kirkland does the Ragnar Relay
Go back in time with me to last Friday morning. It's 4:30 a.m. I am standing in a parking lot, watching 11 Googlers and friends adding finish decorating the mini-vans and loading coolers filled with Gatorade and snacks. We're planning to drive to Blaine (Washington) and then run 187 miles over two days, relay-style, along the coast, finishing on the south end of Whidbey island. In other words, this is the Ragnar Relay, an event that started in Utah 4 years ago, now in its first year in Washington State. Sounds crazy, huh? Fortunately, I'm working with people who consider no idea too outrageous -- not even the notion that running a multi-day relay would be "fun"!
7/21/2007
Bong da
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7/20/2007
CHAGOOGLE
Opening up Google Print Ads
Even with the growth of online news sites, Americans still read newspapers. Over the course of a typical week, nearly 3 out of 4 adults (115 million) in the top 50 markets read a copy of a daily or Sunday newspaper.* That's why thousands of businesses use print advertising every day to reach a local audience, and why we've announced that we're extending Google AdWords to newspapers for most U.S. advertisers. To learn more, visit the Google Print Ads™ site, or read about it on the Inside AdWords blog.Nonprofits mix it up with Google Apps
Your Campus in 3D winners announced
The results are in for the winners of the Build Your Campus in 3D Competition, which we announced in January. The judges chose 7 teams from among the dozens who submitted more than 4,000 buildings from colleges and universities all over North America. And the winning school teams who will be joining us in Mountain View are:...
Hosted site search for businesses
Businesses spend a lot of effort and energy creating and promoting great websites for their products and services, but quality search is often missing. As a result, businesspeople often ask us why they can't use Google to power search on their sites.
Cookies: expiring sooner to improve privacy
We are committed to an ongoing process to improve our privacy practices, and have recently taken a closer look at the question of cookie privacy. How long should a web site "remember" cookie information in its logs after a user's visit? And when should a cookie expire on your computer? Cookie privacy is both a server and a client issue.
And.............
7/06/2007
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7/02/2007
link for Today
1-800-GOOG-411: now with maps
In case you hadn't heard, a few months back we launched 1-800-GOOG-411 (1-800-466-4411) in the U.S. It's a free telephone service that lets you search for businesses by voice and get connected to those businesses for free........
Google Desktop now available for Linux
Just a few months after Google Desktop became available for the Mac, I'm happy to tell you it's now available for Linux users too. Google Desktop for Linux makes searching your computer as easy as searching the web with Google. Not only can you rediscover important...... Ga-Ga for Gadgets
Sometimes I think I know a lot. I can code like a champ and also know the difference between a Monet and a Manet. But on closer inspection, maybe I don't know very much at all. When it comes to fine wines, for instance, I can't tell the difference between Châteauneuf-du-Pape and Chateau-de-Cardboard, and if you asked me who played in the Super Bowl last year, I'd probably say the Dolphins. And lots of people at Google are like me: we know some things, and have some good ideas, but we certainly don't know everything or have all the good ideas..........A smooth Apps move
Today, it becomes a lot easier for organizations and schools to start using Google Apps email services without leaving any of their valuable email data behind. Our new self-service mail migration tools enables administrators using the Premier and Education Editions to easily copy existing mail from an IMAP server over to Google Apps. Now businesses and schools can spend less time worrying about "maintaining infrastructure" and focus more on the things that matter most to them -- like healthcare or educating students.........New dictionary translations
Google's automatic translation is handy for getting translations of complete sentences, paragraphs, and documents. But when you need to translate a single word, a bilingual dictionary can be very useful because it gives you translations for the many possible meanings a word might have. With that in mind, we've added dictionary translations to Google Translate. Now, for example, if you want to know how to say "play" in Spanish, you can use our dictionary translation and learn that depending on the context it can be "jugar", "tocar", or..........Why we're buying DoubleClick
In April we announced that we're buying DoubleClick, a leading company in the ad serving business. When we made this announcement, we gave some of our reasons. But because online advertising is complicated, I thought I'd step back a bit and offer some more context. If you're an expert, please bear with me, as some of what follows will seem elementary to those already familiar with the online advertising world. If you're not, I hope this gives you a better understanding of how advertisers, publishers, ad serving companies, agencies and other companies such as Google all fit into this exciting new mix.......... Introducing Google Earth Outreach
When Google Earth launched two years ago, it was fun to see that many people around the world used it to fly to their homes, navigate around their neighborhoods, and explore the planet. But when, in September 2005, it was used to rescue stranded victims in the aftermath of Katrina, we realized that Google Earth had the potential to be a significant tool beyond personal exploration. We began to see public-benefit KMLs created for things like environmental protection and global public health. A large number of non-profit groups started contacting us, asking good questions: can Google Earth help us illustrate our projects in a new and more compelling manner than text and slideshows? Are there methods or tools for importing our existing data into Google Earth? Can you tell us about any other non-profits who’ve been successful at using GE to reach a new audience, raise awareness, gain volunteers, inspire people into action, and create a tangible impact?More organizing tools
We collaborate using Google Docs & Spreadsheets so often at work that I now have more than 300 online documents. My project teams create shared documents and spreadsheets for everything: taking notes in meetings, planning product launches, analyzing usability studies, and much more. I also share docs with friends at work to plan baseball outings, and my fiancée and I are using a shared spreadsheet to help manage the guest list for our upcoming wedding. In other words, I'm one of many with a desperate need to organize all my online documents. Thankfully, I got the chance to design a new interface for Google Docs & Spreadsheets that includes folders and some convenient ways to quickly manage and access all my documents (and if you're like me, your own collection of online docs and spreadsheets is growing daily).......Put your photos on a map, and Picasa on your phone
If you've ever seen a great picture and wondered where it was, wished you could visit that exact spot yourself, or found yourself itching to share a great photo with somebody -- but you were away from a computer, we've got two new features on Picasa Web Albums to help you out. First, we're excited to let you know about 'Map My Photos' -- it lets you show exactly where you took your favorite snapshots. When you share an album with friends, they can see your best photos arrayed on a map (or even Google Earth). It's the perfect way to showcase a memorable road trip or a globe-trotting vacation.......9,000 and counting
This month, we passed the 9,000 mark for enterprise buyers of the Google Search Appliance and the Google Mini. That's a great beginning, but we want to reach out even farther, which is why we're embarking on a partnership with Ingram Micro, one of the largest global distributors of technology products in the world. Ingram has extensive reseller relationships that can help us deliver the power of search behind the firewall to businesses of all sizes, more efficiently and at a larger scale than we could on our own.New advisory group on health
Every day, people use Google to learn more about an illness, drug, or treatment, or simply to research a condition or diagnosis. We want to help users make more empowered and informed healthcare decisions, and have been steadily developing our ability to make our search results more medically relevant and more helpful to users..........Ga-Ga for Gadgets
Sometimes I think I know a lot. I can code like a champ and also know the difference between a Monet and a Manet. But on closer inspection, maybe I don't know very much at all. When it comes to fine wines, for instance, I can't tell the difference between Châteauneuf-du-Pape and Chateau-de-Cardboard, and if you asked me who played in the Super Bowl last year, I'd probably say the Dolphins. And lots of people at Google are like me: we know some things, and have some good ideas, but we certainly don't know everything or have all the good ideas.......6/22/2007
6/21/2007
Website 64 tỉnh thành - 64 Provinces and Cities in Vietnam
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6/18/2007
A NEW SPECIES OF SALAMANDER, - genus Tylototriton (Urodela: Salamandridae), from Northern Vietnam
Wolfgang Böhme, Thomas Schöttler, Nguyen Quang Truong & Jörn Köhler
Abstract. We describe a new species of Tylototriton from lowland forest of Bac Giang Province in northern Vietnam. The new species is mainly characterized by skin covered with relatively small warts and glands, flattened head, dorsal colour uniformly greyish tan or light brownish in life without larger orange or red dorsal markings. The species presumably reproduces in forest ponds during the rainy season. Records of Tylototriton asperrimus from northern Vietnam are briefly discussed. Key words. Amphibia: Urodela: Salamandridae: Tylototriton; new species; Vietnam.
Introduction
Within the last decades the herpetofauna of Vietnam has received considerable attention from native and foreign researchers. As a result, the number of known species has increased remarkably. New records and species discoveries are the almost inevitable result of every scientific expedition to remote forest areas (e.g. INGER et al. 1999, ZIEGLER et al. 2000, 2004). Concerning salamanders, four species have so far been reported for the country: Paramesotriton deloustali (BOURRET, 1934), Paramesotriton guanxiensis (HUANG, TANG & TANG, 1983), Tylototriton verrucosus ANDERSON, 1871 and Tylototriton asperrimus UNTERSTEIN, 1930 (NGUYEN & HO 1996, ORLOV et al. 2002, SELGIE et al. 2003, NGUYEN et al. 2005). However, there are frequent anecdotal reports of supposedly undescribed species from northern Vietnam which sometimes occur in the pet trade (e.g. HERRMANN 2005). Recent field work of two of the authors (T. SCHÖTTLER and Q. T. NGUYEN) discovered the existence of one of these forms in Bac Giang Province, northern Vietnam (SCHÖTTLER 2003). Our investigations revealed that it indeed represents an unnamed species of the genus Tylototriton which we describe herein.
Material and methods
Specimens examined are deposited at Zoologisches Forschungsmuseum Alexander Koenig (ZFMK). Terminology and description of characters follow STUART & PAPENFUSS (2002). Abbreviations used are as follows: SVL = snout-vent length measured from tip of snout to anterior edge of vent; TTL = total length; TAL = tail length measured from posterior edge of vent to tail tip; TAD = maximum tail depth; HL = head length measured from posterior edge of parotoid to snout tip; HW = maximum head width; EN = eye-nostril distance measured from anterior corner of eye to nostril; IN = internostril distance; AL = anterior limb length measured from point of body insertion to tip of longest toe; PL = posterior
limb length measured from point of body insertion to tip of longest toe. Skeletal characters were assessed using X-ray photography at ZFMK.
Results
Tylototriton vietnamensis sp. n.
Tylototriton asperrimus asperrimus: FLECK, 2003:3 (non UNTERSTEIN, 1930) 216 WOLFGANG BÖHME et al. Tylototriton sp.: SCHÖTTLER, 2003:23; HERRMANN, 2005:21.Echinotriton asperrimus (partim): NGUYEN et al., 2005:9 (non UNTERSTEIN, 1930). Holotype: ZFMK 80637, adult male (Figs. 1- 2), from vicinity of Dong Vanh Village, Luc Son Commune, Luc Nam District, Bac Giang Province, northern Vietnam (21°12' N, 106°40' E, approximately 250-300 m a.s.l.), collected on 23 June 2003 by T. Q. NGUYEN and T. SCHÖTTLER. Paratypes: ZFMK 82971-972, two adult males, from type locality, collected in July 2004 by T. Q. NGUYEN and T. SCHÖTTLER. Referred specimens: ZFMK 82973-75, three larvae, from type locality, collected in July 2004 by T. Q. NGUYEN and T. SCHÖTTLER.
Diagnosis: The new species is diagnosed by the following combination of characters: relatively stout body; head flattened, broader than body; parotoids large, elongated; dorsal skin covered with relatively small warts and glands, three tubercular dorsal ridges; slightly flattened rib nodules, moderately developed; dorsal and ventral tail fin developed; tongue pad lacking a free posterior margin; dorsal colour uniformly greyish tan or brownish in life; venter tan in life; rib nodules slightly orange tan in life; ventral tail fin yellow-orange in life; tips of fingers and toes yellow-orange in life. Comparisons: Tylototriton vietnamensis differs from T. kweichowensis FANG & CHANG, 1932 and T. shanjing NUSSBAUM, BRODIE & YANG, 1995 by a more slender body and by lacking orange or yellow tails and a dorsum with orange-yellow markings. Furthermore, T. verrucosus differs from the new species by its larger size, head shape, and by exhibiting orange or yellowish colour on dorsum, tail and flanks. Tylototriton taliangensis LIU, 1950 mainly differs from T. vietnamensis by head shape, a more slender, elongated body and red flecks at the posterior corner of the Fig. 1. Male holotype of Tylototriton vietnamensis sp. n. (ZFMK 80637) in life. Fig. 2. X-ray photograph of the preserved holotype of Tylototriton vietnamensis sp. n. (ZFMK 80637). 217
A new species of Tylototriton from Vietnam parotoids in adults. In external characters, the new species appears most similar to T. asperrimus, T. hainanensis FEI, YE & YANG, 1984 and T. wenxianensis FEI, YE & YANG, 1984. However, T. vietnamensis differs from T. wenxianensis in the following characters (characters of T. wenxianensis in parentheses): greyish to brownish tan dorsal colour (black), truncate snout in dorsal view (rounded), and moderately large, slightly flattened rib nodules forming lateral ridges (rib nodules and ridges indistinct). In contrast to T. vietnamensis, T. asperrimus exhibits black dorsal colour, very prominent rib nodules, a rounded snout and more prominent bony ridges on head. Tylototriton hainanensis differs by larger size, head much wider than long, black dorsal colour and a more rounded snout.
Description of holotype: Habitus moderately stout; head broader than body. Head slightly sloping in profile. Skull broad with maxillaries oriented angular to body axis. Snout short, truncate in dorsal view, rounded in profile and protruding beyond lower jaw. Nostrils close to snout tip. Upper lips thick, fleshy and overlapping lower lip under eye region. Vomeropalatine teeth in two rows beginning just posterior to the last maxillary tooth at the medium level of the choanae, Fig. 3. Larva of Tylototriton vietnamensis sp. n. collected at the type locality in June 2003 (total length 45 mm).
Fig. 4. Habitat of Tylototrit on vietnamensis sp. n.at the type locality in Bac Giang Province, Vietnam. Fig. 5. Schematic map of Vietnam showing the known distribution of Tylototriton vietnamensis sp. n. in respective provinces: (1) Bac Giang Province (type locality); (2) + (3) Cao Bang Province; (4) Nghe An Province. Question mark indicates locality for Tylototriton cf. vietnamensis in Lao Cai Province (see text for more precise locality data). Stippled lines indicate limitations of provinces. 218 WOLFGANG BÖHME et al. diverging from one another. Tongue with poorly developed tongue pad, lacking a free posterior margin. Thirteen trunk vertebrae (Fig. 2). A low vertebral tubercular ridge, extending from top of head to base of tail. Two lateral rows of larger warts, extending from insertion of forearms to base of tail. Glands and warts relatively small, covering most of dorsal surfaces; venter almost smooth. Parotoids greatly enlarged, slightly projecting backwards. Gular fold absent. Fingers without webbing, toes with basal webbing. Tail laterally compressed; dorsal and ventral tail fin moderately developed; tail tip acuminate in profile. For measurements see
Table 1. In alcohol, dorsal and ventral surfaces brownish tan. Finger and toe tips cream coloured. Tail brownish tan with ventral tail fin being creamy yellow. Cloacal region bordered with cream-yellow. Life colouration differs only by stronger orange-yellow colour of respective body parts.
Variation: There are no obvious differences in coloration and body proportions between the three male specimens. However, the two male paratypes seem to exhibit more extensive webbing on toes. In life, specimens caught from ponds exhibited considerably lighter dorsal colour (Fig. 1) compared to specimens captured from the forest floor (see FLECK 2003:Fig. 6, as Tylototriton a. asperrimus). Natural history: Specimens were found in ponds within dense bamboo vegetation in secondary forest. One larva collected in June 2003 had a total length of 45 mm (Fig. 3). At the type locality, larvae were found from June to July in 2003 and 2004. However, in June 2005 only a few males were observed in the ponds, whereas no larvae were present. According to information provided by local scientists, larvae collected in October had almost finished metamorphosis. At that time adults already left the ponds. Presumably, mating and reproduction take place within these ponds (Fig. 4) during the rainy season.
Distribution: So far, the new species is known from four localities in northern and north-central Vietnam (Fig. 5). In addition to the type locality these are: Quang Thanh Commune (22°38' N, 105°55' E) and Thank Cong Commune (22°48' N, 105°44' E), Nguyen Binh District, Cao Bang Province; Pu Hoat Forest, Dong Van Commune, Que Phong District, Nghe An Province (T. SCHÖTTLER pers. obs.). Specimens from Nam Tha Commune (21°55' N, 104°22' E, 850 m a.s.l.), Van Ban District, Lao Cai Province (NGUYEN et al. 2005, T. SCHÖTTLER pers. obs.) exhibit some slight morphological differences and are here tentatively regarded as T. cf. vietnamensis (see discussion). Tylototriton vietnamensis probably also occurs in adjacent southern China and eastern Laos. Etymology: The new species is named after the country of its origin, Vietnam.
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Discussion
Tylototriton vietnamensis is the fifth known species of salamander and the third known species of Tylototriton from Vietnam. NGUYEN & HO (1996) reported T. asperrimus from Mau Son and Lang Son areas in northern Vietnam. We have seen photographs of T. ZFMK ZFMK ZFMK 80637, 82971, 82972, male, male, male, holotype paratype paratype SVL 50.1 48.3 53.6 - TTL 119.5 113.9 121.8 - TAL 63.9 62.4 63.1 - TAD 8.0 6.6 7.5 - HL 18.6 17.6 15.3 - HW 16.7 15.7 17.0 - EN 4.0 4.0 4.4 - IN 5.4 5.5 6.1 - AL 16.0 18.7 19.8 - PL 21.3 20.6 20.1 Tab. 1. Measurements of the type series of Tylototriton vietnamensis sp. n. in millimetres (mm). For abbreviations see text. A new species of Tylototriton from Vietnam asperrimus -like living specimens from the nearby Tam Dao area in northern Vietnam and concluded that they display some characters unusual for T. asperrimus: a very stout body shape and a very broad head with very well-developed bony crests. These characters are generally much more developed in T. hainanensis than in T. asperrimus (FEI et al. 1984). Thus, it may not be excluded that some records of T. asperrimus by NGUYEN & HO (1996) actually correspond to T. hainanensis. The geographical distance between Hainan Island and northern Vietnam is less than 400 km and therefore the presence of T. hainanensis in northern Vietnam seems at least possible and respective populations deserve further study. Recently, NGUYEN et al. (2005) reported T asperrimus (as Echinotriton asperrimus) from several localities in northern Vietnam. In a colour photograph, NGUYEN et al. (2005:147) figured a specimen from Lao Cai Province, northern Vietnam. This specimen is very similar to T. vietnamensis in its general habitus, size, flattened head and colouration. However, the dorsal skin appears to be more warty and darker. These slight differences probably display seasonal variation, since individuals in their aquatic phase were found to exhibit relatively smooth dorsal skin and light colouration, whereas specimens caught from the forest floor showed darker dorsal colour and somewhat more warty skin (see paragraph on variation). However, here we tentatively refer to this population as Tylototriton cf. vietnamensis unless more specimens from this population become available. In conclusion, we may suspect that several Vietnamese records referred to as Tylototriton asperrimus (or Echinotriton asperrimus) in the literature are likely to include other taxa like e.g. T. cf. hainanensis (NGUYEN & HO 1996) or T. vietnamensis (FLECK 2003, NGUYEN et al. 2005). ZHAO & HU (1988) suggested that Tylototriton asperrimus should better be placed in the genus Echinotriton based on the sharptipped ribs which may penetrate the skin at their apices and because of a reproductive mode with terrestrial egg deposition (compare NUSSBAUM & BRODIE 1982). NUSSBAUM et al. (1995) provided convincing arguments for transferring the species again to Tylototriton and this is also corroborated by recent genetic studies (LARSON et al. 2003). As mentioned above, Tylototriton vietnamensis shares some external characters with T. asperrimus, but its general habitus appears quite different. It does not exhibit extraordinarily sharp-tipped ribs and penetration of the skin could not be observed in the specimens studied by us. The relationships of T. vietnamensis remain unknown at this stage, however, both species might be related.
Acknowledgements
We are indebted to NGUYEN VAN SANG (Institute of Ecology and Biological Resources) who first found the new species in Bac Giang, as well as to RAOUL BAIN (American Museum of Natural History), NGUYEN MANH HA (Center for Natural Resources and Environment Study) and THOMAS ZIEGLER (Zoologischer Garten Köln) for providing the map and unpublished information. Furthermore, we thank DUONG XUAN BANH (Deputy Director of Bac Giang Forest Protection Department) for valuable help with research permits for the Bac Giang Province and KLAUS BUSSE (ZFMK) for helping to prepare the X-ray photograph.
SEARCH FOR THE INSECTS IN VIETNAM
(More than 1000 species of insects in Vietnam) | ||||||||||||||||||||||||||||
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SEARCH FOR THE FLORAS IN VIETNAM
SEARCH FOR THE FLORAS IN VIETNAM (More than 3000 species of floras in Vietnam) | ||||||||||||||||||||||||||||
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SEARCH FOR THE FAUNAS IN VIETNAM
SEARCH FOR THE FAUNAS IN VIETNAM (More than 2000 species of faunars in Vietnam) | ||||||||||||||||||||||||||||
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THE BUTTERFLY LIFE CYCLE - From egg to adult
Paul Smart – The illustrated encyclopedia of the Butterfly world |
Butterflies are examples of endopterygotes: insects which characteristically undergo a complete change or metamorphosis during the course of their development. Their life cycle includes both a larval and a pupal stage before the adult insect or imago emerges. The larva is completely different from the adult both in appearance and habits. The pupa is an inactive, non-feeding stage which gives rise to the adult. In grasshoppers, cockroaches and earwigs, which are examples of exopterygote insects, development is much more gradual with a series of young stages or nymphs which all resemble the adult and become progressively more like it at each successive stage. In these insects there is no pupal stage.
The egg
Female butterflies usually lay their eggs on or very near to the food plant on which the larva feeds. The oviposition site is carefully chosen, and touch, smell, taste and sight are probably all involved in its selection. Most species lay their eggs singly and cement them to the plant by a sticky secretion. The eggs are usually laid on a particular part of the plant, for example, on the leaves, flower heads or in crevices in the bark. Most frequently they are laid on the under surface of the leaf; the female alights on the upper surface and curves her abdomen under the leaf until a suitable position is found. Here the eggs are protected from rain and sunshine and to some extent from predators. However, a large number of eggs are laid by a single female to ensure that at least some will hatch successfully. The large white (Pieris brassicae) often lays clusters of one hundred or more eggs, whilst a few others lay smaller batches of 5-15 eggs. The arrangement of the eggs varies, they may form regular bands around twigs or pendant strings of eggs. A small number of species merely scatter their eggs at random as they fly over vegetation (usually grassland).
Butterfly eggs are commonly yellow or green in colour although they may darken just before hatching. The shape of the egg varies in different species and may be spherical or oval and flattened. The shell is often elaborately sculptured with regular ribs or pits (reticulations). At the top of the egg is a slight depression within which is a minute opening or micropyle. The micropyle marks the entry point of the male sperm into the egg, and once the egg is laid, air and moisture pass to the developing embryo through this pore. Food is contained inside the egg in the form of yolk and this is gradually consumed as the young larva develops.
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Just before hatching the fully formed embryo can be seen curled up within the transparent egg shell or chorion. The young larva gnaws its way through the shell and after hatching continues to eat the shell until only the base is left. In the large white butterfly, where the eggs are laid in dusters, a newly hatched larva may also eat off the tops of other unhatched eggs. The shell contains valuable nutrients and is immediately available to the larva. After this the food plant on which the egg was laid will be devoured.
The larva
Butterfly larvae, or caterpillars as they are commonly called, are quite variable in colour and in shape, although their basic structure is relatively constant. The larva has a head followed by 13 trunk segments of which the first three are regarded as the thorax and the remainder the abdomen. The larval skin or cuticle is soft and flexible., though spines or bristles (setae) which arise from surface tubercles may be present. These are particularly characteristic of the family Nymphalidae.
The head is a hardened round capsule with a completely different array of structures to the adult butterfly. The larvae feed on plant material which is relatively tough to a small insect. Consequently, the mouth parts are modified for biting and chewing. There is a prominent pair of toothed jaws or mandibles which bite off fragments of food and shred them into fine pieces. The maxillae (which form the proboscis in the adult) are very small and used to guide the food into the mouth. The other main mouth part (the labium) is modified to form the spinneret which is used in silk production.
Compound eyes are lacking in the lava, the main visual organs being the lateral ocelli. These are arranged in two groups of six, one group on either side of the head. The ocelli in many ways resemble the single optical unit or ommatidium of the adult's compound eye. Each ocellus has a lens and receptive part or retina. It seems that they are unable to create an image of their visual field and probably only detect the difference between dark and light. The lateral ocelli can therefore be of little use in the location of food, the senses of touch and smell being more important in this context. The head also bears a pair of short, stubby antennae.
The three segments of the thorax each have a pair of short jointed legs which end in a single claw. The abdomen has ten fleshy rings or segments, five of these bearing a pair of false legs or prolegs. These are soft structures, without joints, present on the third to sixth segments. A final pair on the last segment are called claspers, and some larvae will be tom in half rather than release their hold with them. The end of each proleg is flattened and has a series of hooks or crochets which help the larva in locomotion. When not being used the prolegs can be withdrawn into the body. The arrangement of the hooks on the prolegs is a useful guide in the classification of larval types.
Since the skin of the larva is so it is not able to provide a suitable skeleton for the attachment of muscles (as the exoskeleton does in the adult). Consequently the body has to be kept turgid by the pressure of the body fluid (haemolymph) rather like an earthwonn. The characteristic crawling movement consists of a co-ordinated interaction between the muscles of the body wall and the internal pressure of the haemolymph.
As the larvae grow they entirely fill their skin, which becomes very tight. In order that a further size increase may occur this skin is shed from time to time, exposing a new and larger one which has formed beneath it. Rapid expansion of the 'new' larva occurs before the skin becomes toughened. This shedding of the skin is known as moulting or ecdysis and usually takes place four or five times before the larva is full grown. Each growth stage between moults is known as an instar. Moulting in insects is very carefully and precisely controlled by hormones, although environmental conditions and the availability of food may cause variations in the duration of the instars.
The larvae feed mainly on the leaves of flowering plants and trees. Ferns or mosses appear never to be eaten. They’re extraordinarily specific in their feeding habits and will usually only feed on a small number of closely related plant species. If a suitable food plant is not available then larvae will starve to death rather than eat something else. A larva recognizes its food plants by certain aromatic vegetable oils which they contain. It is generally thought that selection may depend upon the detection of chemical attractants in the food species and of repellents in other plants.
The larva is the main feeding stage in the life cycle, and when they are present in sufficient numbers caterpillars can defoliate large areas of vegetation. This means that those butterfly species whose larvae feed on agricultural crops can be a serious pest. Single larvae may consume an entire leaf before moving on to the next, but more often only a part of the leaf is eaten. The way in which a larva tackles a leaf is often characteristic of the species ; some eat holes in the leaf, whilst others attack the leaf margin. In some species feeding occurs at night and in others by day. Generally periods of active feeding alternate with periods of rest. Feeding ceases a day or so before a moult, but is resumed as soon as the new skin is fully developed. A diet of plant leaves, in addition to requiring mouth parts for chewing the food, necessitates some modifications of the digestive tract. A large quantity of food is passed through the alimentary canal which is consequently a wide straight tube. The stomach is the largest region and has muscular walls which maintain continual churning movements, causing thorough mixing of the food material.
The droppings of the larvae are discrete oval structures and are referred to as frass. Since much of the plant material consists of indigestible celulose a large amount of frass is produced and may even form a distinct layer under small trees or shrubs on which many larvae have been feeding.
The internal organization of the other systems closely resembles that found in the adult insect. However, the salivary glands, which In the adult produce substances to accelerate digestion, take on a new role in the larva, that of silk production. Several species are known to produce silk to make webs or cocoons. The silk is manufactured in the salivary glands which are a pair of long tubes, particularly conspicuous in the Satumiid moths. The spinning apparatus lies in the spinneret (part of the labium) and consists of a silk regulator and a directing tube. The characteristic side to side movement of the head of the larva draws the silk out into a fine thread which adheres to the substrate wherever it is touched by the directing tube. During spinning silk is continually passed from the regulator to the directing tube and hardens on exposure to the air. The silk net forms a protection for the larva, especially when it pupates.
Butterfly larvae are rather inactive sluggish creatures and this together with the soft outer covering makes them an ideal target for a wide range of predators. To protect themselves the larvae have evolved various structures and habits to either serve as camouflage or to make them appear unattractive or unpalatable to a would be predator. Some of these devices will be discussed in mote detail in later chapters.
The pupa
The end of larval life is marked by another moult which gives rise to a pupa or chrysalis. Fully grown larvae often select special sites to undergo this transformation and may for. example leave their food plant and enter the soil. The digestive tract is emptied and the larval skin shrivels and eventually splits to expose the pupa. During the pupal period much of the larval tissue is remoulded to give rise to adult structures, particularly the wings, mouth parts and reproductive organs.
The pupa is immobile and neither eats nor drinks since the mouth and anus are sealed over. The only functional openings in the pupal case are the spiracles which permit the exchange of respiratory gases. The legs and antennae are firmly stuck down and cannot be moved. Externally the pupa usually appears brown or green, and the abdominal region, with prominent segmental rings and tapering posteriorly, is very distinct from the thoracic part. All the major features of the adult can be seen within the pupal skin, but one. specialized structure is to be found' at the end of the abdomen, where a number of hooks form the cremaster. This is used for the attachment of the pupa to the substrate.
It is often desirable to distinguish the sex of a pupa before the adult emerges, and this is not usually difficult. In the male there is a single genital opening on the ninth abdominal segment whilst in the female there are two such openings, one on the eighth and another on the ninth segment of the abdomen.
Since the pupa is immobile it is particularly vulnerable to attack by predators and frequently pupation proceeds within a silken cocoon. This may take the form of a hollow of earth lined with silk, or a roll of leaves fastened together with silk threads (eg Hesperiidae and some Satyridae). Silk cocoons are generally much better developed among moths. In some butterflies the pupa is naked but it is then usually protectively coloured. The naked pupa may hang upside down attached only by the cremaster (many Satyridae and Nymphalidae) or it may be attached by the terminal cremaster but also supported head upwards by a silken girdle (Lycaenidae, Pieridae and Papilionidae). In each case the larva spins a little silken pad into which the hooks of the cremaster are firmly embedded..
The adult
The emergence of the adult or imago is preceded by the colour pigment appearing in the wing scales, so that the wing patterns of the adult can be seen through the pupal case. The skin of the pupa splits behind the head, the insect first frees its legs and antennae and after a short while withdraws the rest of its body. Those species pupating within a cocoon have to free themselves from this as well as the pupal skin. In some Saturniid moths there may be a special arrangement of the silk to facilitate this, whilst in others a special softening fluid is produced.
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Immediately after emergence the wings are soft and crumpled. The butterfly moves to a place from where its wings can hang downwards and blood is forced into them. The wings expand by the flattening of the numerous tiny folds and soon become the typical sheets supported by hollow veins. Once they have reached their full size the insect holds them apart until they are completely dry and hardened. The excretory material which has accumulated in the dosed digestive tract during the pupal period is ejected from the anus. The time of adult emergence varies, it may occur early in the morning or in the evening; in the latter case they rest until the next day before becoming active.
Interruption of the life cycle
The duration of the life cycle varies in different species. Some may have a single complete generation in a year whilst others have two or even more. Unfavourable climatic conditions such as the winter in temperate regions or the dry season in the tropics often necessitate an interruption in the life cycle. Any of the developmental stages - egg, larva or pupa - may enter a period of arrested development (or diapause). This delay in development is induced by environmental conditions such as day length, but cannot then be terminated until a pre-determined period has passed. This ensures that the insects do not emerge too- early during temporary favourable periods only to be caught out by a resumption of harsh conditions. The eggs and pupae are protected by their outer shell or skins respectively, whilst the overwintering larvae usually shelter at the base of their food plant or in a specially produced larval cocoon formed from plant leaves and silk. The stage in the life cycle which regularly undergoes hibernation (or aestivation in the tropics) varies in different species and also within the same species in different parts of its geographical range.
THE BUTTERFLY BODY
Adult butterflies are built on the same general plan as their other insect relatives such as the wasps, bees and beetles. The body is protected by an armour of chitin (forming the exoskeleton) and this is arranged in a series of rings or segments separated by flexible membranous zones which allow movement to take place. The body consists of three main regions, the head, the thorax and the abdomen, all with a specialized structure to equip them for different functions in the life of the insect. Each part is covered in a layer of minute scales which are responsible for the soft, downy appearance of the body as well as the frequently vivid coloration so characteristic of butterflies.
The head
The head is a small spherical capsule which bears the feeding apparatus and sensory structures.' Adult butterflies feed mainly on nectar from flowers, although honey dew (the sweet secretion produced by aphids), decaying fruit, the sap exuding from damaged trees, excrement or the juices of carrion are examples of other butterfly foods.
Butterflies have no jaws and must always take the food in liquid form using a specially modified 'tongue' or proboscis. This is a long, hollow tube which is coiled like a watch-spring and tucked under the head when not in use. It can be quickly unrolled to probe deep into flowers; this extension being brought about by an increase in blood pressure. This feeding tube is composed of two parts which are grooved on their inner surface and joined along their length by tiny interlocking spines. The liquid food is sucked up the central channel between the two parts and there is a special type of pump in the head to assist in this. The continuous passage of sticky fluid tends to clog the channel and so the proboscis has to be cleaned periodically.
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Since butterflies never bite or chew their food, jaws or mandibles are absent. A pair of sensory palps or feelers (labial palps) are present instead, one on each side of the proboscis. These palps are densely covered with scales and sensory hairs and serve to test the suitability of the food source. Some species of butterflies actively drink water, by using their proboscis, and the enormous congregations on muddy river banks are a notable feature of the tropics.
The antennae are typically dub-ended in butterflies. Each antenna consists of a series of rings or segments and both the number of, segments and size of the club varies in different families, the skippers (Hesperiidae) for example, often have very pronounced 'hooks' . The antennae are sense organs which are responsible for balance and smell. The base of the antenna houses a specialized organ, Johnston's organ, and it is this which is of value in sensing the insect's orientation, particularly during flight. The smell receptors are scattered over the entire surface of the antenna.
The eyes of butterflies are conspicuous hemispherical swellings on the top of the head. They are called 'compound' eyes because each eye is composed of a large number of optical units or ommatidia. The individual ommatidium resembles a simple eye with a lens and a light receptive region, and each one is capable of forming its own visual image. Each ommatidium is sheathed by a layer of pigment which serves to separate it from its neighbours. A butterfly therefore sees its surroundings as a complex mosaic of tiny pictures, each picture being eated by a single ommatidium. Although butterflies can readily detect the movement of objects, the acuity of their vision is much inferior to that of man. They are able to detect a limited number of different colours by discriminating between light sources
of different wavelengths. This simple colour vision may be illustrated by the fact that certain types of butterfly will frequent flowers of a particular colour ; for example, swallowtails (Papilionidae) regularly visit red flowers. Butterflies are also capable of detecting ultra-violet light, which is invisible to humans, and this suggests they may well see the colour of flowers in quite a different way to us. Other light sensitive structures known as the dorsal ocelli occur on the top of the head between the large compound eyes. These ocelli are very small and play little part in the vision of adult butterflies.
The thorax
The middle zone or thorax of the body is the locomotory region, where both the legs and wings are located. The head is joined to the thorax by a flexible neck or cervix. The thorax is composed of three segments and each carries a pair of legs adapted both for walking and clinging. Each leg consists of several regions, the basal joint (coxa), the thigh (femur), the shank (tibia) and the foot (tarsus). The coxa and femur are joined by a small triangular segment, the trochanter. The foot commonly has five joints and ends in a pair of claws. In the Nymphalidae the front legs are very short and held close to the body, giving the odd appearance of an insect having only four legs.
The shank or tibia of the fore leg in some species has a mobile spur or epiphysis which is armed with a brush of hairs and is used to clean the antennae. Surprisingly butterflies also use their feet to taste their food, so there are numerous sense organs on the tarsi.
The two pairs of wings belong to the second and third thoracic segments (meso- and meta-thorax). The delicate wings consist of an upper and lower membrane with a framework of hollow tubes between the layers. These supporting tubes are called veins and. they are arranged in a very precise way. The overall pattern or venation is often a diagnostic feature of a group of butterflies and consequently wing venation is an important tool in classification. The principal veins are given names according to their position on the wing.
At the base of the wings are some small structures known as sclerites which form a flexible articulation between the wings and the thorax. These permit the beating 'of the wings in flight and also allow them to be folded away when at rest, in the upright position characteristic of butterflies. During flight the wings are regularly moved up and down and the movements of the two wings on each side are coupled or linked together in a special way. Usually the hind wing has a lobe which presses against the fore wing, thus ensuring that wing movements are synchronized to give maximum efficiency. The wing movements are created in two ways : firstly by muscles acting at the base of the wing and secondly by distortion of the thorax brought about by the thoracic musculature which is particularly well developed in the wing-bearing segments. During flight the orientation and balance of the insect is controlled by special sense organs. Butterflies are typically active during the day (diurnal) and most species only fly in bright sunshine. The height at which they fly varies some merely skim across the surface of low vegetation whilst others fly very much higher.
The colour patterns on the wings are due to the covering of scales (see Coloration). The scales overlap each other in a regular fashion resembling tiles on a roof. Each scale is more or less racquet shaped and has a small projection or stalk at its base which fits into a minute socket on the wing membrane. The handling of specimens damages this delicate articulation and the scales easily rub off. To the naked eye the scales look like coloured dust. Pigments contained within the scales give rise to the colour of some butterflies, whilst in others, microscopic ridges or striae on the surface break up the light falling on them and so produce the metallic colours of the blues and coppers.
Scattered among the scales are specialized scent scales known as androconia (vảy cách ở bướm đực) which are peculiar to the males. At the base of these scales is a small gland which produces an aphrodisiac to excite the female during courtship. The volatile secretion passes up the hollow stalk of the scale and is disseminated by the fine hair-like processes or plumes at its tip. These scent scales may be scattered over the upper surface of the wing or collected into special patches called scent brands, as in the fritillaries, where they are visible as thickenings on the veins. During courtship the male often flutters around the female waving his wings and attempting to stimulate her by his scent. In some butterflies, although the scent producing area is in the wings, the dissemination takes place by means of the hair pencils which are associated with the terminal abdominal segments. These hair brushes consist of a small sac which is pushed out by blood pressure during courtship. At the end of each sac is a tuft of hairs. During scent dissemination the wings are outspread and the hair brushes brought into contact with the scent producing areas on them. The hair brushes are then expanded fully to disperse the scent.
The abdomen
The abdomen is much softer than the head and thorax and consists of ten rings or segments of which only seven or eight can be easily seen. The end segments are specialized for reproductive purposes and are generally known as the genitalia. In the male there is a pair of claspers which grip the female during mating and surround the central ejaculatory organ. The presence of a pair of claspers at the hind end of the body is a simple and reliable way to distinguish the sexes . In the female some fusion of the terminal segments occurs to give rise to an egg laying tube or ovipositor. The ovipositor is normally telescoped inside the body of the female. There is usually a special opening which receives the sperm from the male.
The female also produces a scent and this is attractive to the males of the species. The glands responsible for this are at the tip of the abdomen. The scent producing area is exposed by the extension of her abdomen. These substances are extremely effective in attracting the males and one female is able to lure vast numbers of males to her vicinity from great distances. These substances are known as pheromones and play an important communication role in the social behaviour of many groups of animals. Once both sexes have been stimulated by the respective scents, courtship is complete and the couple is ready for pairing. The female settles and the male grasps the end of her abdomen with his claspers. Pairing takes some time and the two insects may remain together for an hour or so. The male passes his sperm to the female in a package called a spermatophore which she retains inside her body until egg laying begins. If the couple are disturbed during pairing they will take to flight with one partner (usually the male) being dominant and dragging the other after it. A male is capable of mating with several females.
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Internal structures
Within the toughened exoskeleton of an insect the internal organs are bathed in blood. Unlike humans the blood system does not consist of veins and arteries but instead the whole of the body cavity is one large blood filled space (the haemocoel). Circulation of the blood is maintained by a long, tubular heart which lies along the back of the insect (dorsal surface. The heart has muscular walls which con tract rhythmically and push the blood or haemolymph forwards into the blood space. On its return from the body tissues the blood re-enters the heart via small pores or ostia.
The digestive system is specially designed to cope with a liquid diet. The base of the 'tongue' or proboscis opens into a spherical muscular region (pharynx.). This region is often referred to as a sucking pump, since it is responsible for drawing liquids up the long proboscis. The sucking action is brought about quite simply by a change in volume of the pharynx. The enlargement of the pharynx creates within it a partial vacuum and the liquid in the proboscis is drawn upwards and into the pharynx. The muscular walls then contract and this serves to push the meal into the oesophagus, which is the next region of the alimentary canal. During this contraction of the pharynx there would also be a tendency for the fluid to flow back down the proboscis, but this is prevented by a shutter-like valve which closes the entrance to the proboscis. Once inside the digestive tract the food may be stored in a small reservoir (the crop) until it is needed. The actual digestion of the food takes place in the stomach and any unsuitable material is passed into the hind intestine and is voided as faeces, via the anus. The digested food is absorbed into the blood and is stored as fat in a structure known as the fat body until it is needed. The fat body takes the form of sheets of fatty tissue which either underlie the outer integument of the insect or surround the digestive tract. The fat body is usually better developed in the female since it is also needed to provide nourishment for her developing eggs.
Excretion is performed by structures known as malpighian tubules. In their mode of functioning they closely resemble kidneys although in appearance they are very different. The tubules are long filaments attached to the alimentary canal at the beginning of the hind gut. They float freely in the haemocoel and extract waste products from the circulating blood. These substances (collectively referred to as urine) are passed through the tubules and into the hind gut, from here they leave the body with the faeces.
The nervous system is composed of nerve cells or neurones and these are grouped together in nerve centres or ganglia. One of these is situated in the head and is generally referred to as the brain. The brain is connected to a nerve cord which lies under the digestive tract and passes to the hind end of the body. The nerve cord has a number of subsidiary nerve centres or ganglia along its length. Most butterflies have two ganglia in the thorax and four in the abdomen. From these centres smaller nerves pass to all parts of the body. Special nerve cells (visceral (thuộc nội dung) nerves) are associated with the digestive system and reproductive system whilst others (peripheral nerves) innervate the surface of the body.
The internal reproductive organs of insects consist of a pair of gonads and a system of tubes or ducts to carry their products (either sperm or eggs) to the outside of the body. In the female each ovary consists of four egg tubes or ovarioles. Each contains a large number of eggs at various stages of development. There is a special sac-like storage chamber (bursa) which retains the sperms until the eggs are ripe and about to be laid, only then are they fertilized. The female also has accessory glands associated with the reproductive system which secrete a sticky substance used for cementing her eggs to the substrate on which they are laid. The male has a pair of testes which are fused together in some butterflies. Sperm reservoirs are also present which store the sperm prior to pairing.
In many animals, including humans, oxygen is carried around the body by the blood but in butterflies (and other insects) the organs of the body are separately supplied with oxygen by a system of 'air tubes' or tracheae. These open to the atmosphere through special apertures in the exoskeleton called spiracles, of which there are nine pairs in butterflies. The actual exchange of gases takes place by simple diffusion at the ends of the tracheae, where the tubes become very narrow. In active insects the diffusion of oxygen into the body and the passage of carbon dioxide out is speeded up by ventilatory actions of the body comparable with our own breathing movements. Even so the system is relatively inefficient and the amount of oxygen available to the insect is quite small. This crucial point represents one of the main limitations on the size of butterflies, and without a major redesign of their whole system they cannot ever be more than relatively small creatures.
Paul Smart – The illustrated encyclopedia of the Butterfly world
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