Several species of spectacular butterflies flying and courting in full HD slow motion at the Cockrell Butterfly Museum in Houston.
707-451-3985
Sunday, February 26, 2023
Thursday, February 23, 2023
Flea Fossil History
Fleas likely descended from fluid feeding insects that probably fed on plants. Fossils of large, wingless stem-group fleas with siphonate (sucking) mouthparts from the Middle Jurassic to Early Cretaceous have been found in northeastern China and Russia, belonging to the families Saurophthiridae and Pseudopulicidae, as well as Tarwinia from the Early Cretaceous of Australia. Most flea families formed after the end of the Cretaceous (in the Paleogene and onwards). Modern fleas probably arose in the southern continental area of Gondwana, and migrated rapidly northwards from there. They most likely evolved with mammal hosts, only later moving to birds.
Siphonaptera is a relatively small order of insects: members of the order undergo complete metamorphosis and are secondarily wingless (their ancestors had wings which modern forms have lost). In 2005, Medvedev listed 2005 species in 242 genera, and despite subsequent descriptions of new species, bringing the total up to around 2500 species, this is the most complete database available. The order is divided into four infraorders and eighteen families. Some families are exclusive to a single host group; these include the Malacopsyllidae (armadillos), Ischnopsyllidae (bats) and Chimaeropsyllidae (elephant shrews).
Many of the known species are little studied. Some 600 species (a quarter of the total) are known from single records. Over 94% of species are associated with mammalian hosts, and only about 3% of species can be considered to be specific parasites of birds. The fleas on birds are thought to have originated from mammalian fleas; at least sixteen separate groups of fleas switched to avian hosts during the evolutionary history of the Siphonaptera. Occurrences of fleas on reptiles is accidental, and fleas have been known to feed on the hemolymph (bloodlike body fluid) of ticks.
Read more, here.
707-451-3985
Monday, February 20, 2023
The History of Fleas
Between 1735 and 1758, the Swedish naturalist Carl Linnaeus first classified insects, doing so on the basis of their wing structure. One of the seven orders into which he divided them was "Aptera", meaning wingless, a group in which as well as fleas, he included spiders, woodlice and myriapods. It wasn't until 1810 that the French zoologist Pierre André Latreille reclassified the insects on the basis of their mouthparts as well as their wings, splitting Aptera into Thysanura (silverfish), Anoplura (sucking lice) and Siphonaptera (fleas), at the same time separating off the arachnids and crustaceans into their own subphyla. The group's name, Siphonaptera, is zoological Latin from the Greek siphon (a tube) and aptera (wingless).
Read more, here.
707-451-3985
Friday, February 17, 2023
The Stunning Life Cycle Of A Ladybug | The Dodo
This will change everything you thought you knew about ladybugs.
707-451-3985
Tuesday, February 14, 2023
Saturday, February 11, 2023
Behaviour of an Earwig
Most earwigs are nocturnal and inhabit small crevices, living in small amounts of debris, in various forms such as bark and fallen logs. Species have been found to be blind and living in caves, or cavernicolous, reported to be found on the island of Hawaii and in South Africa. Food typically consists of a wide array of living and dead plant and animal matter. For protection from predators, the species Doru taeniatum of earwigs can squirt foul-smelling yellow liquid in the form of jets from scent glands on the dorsal side of the third and fourth abdominal segment. It aims the discharges by revolving the abdomen, a maneuver that enables it simultaneously to use its pincers in defense. Under exceptional circumstances, earwigs form swarms and can take over significant areas of a district. In August 1755 they appeared in vast numbers near Stroud, Gloucestershire, UK, especially in the cracks and crevices of "old wooden buildings...so that they dropped out oftentimes in such multitudes as to literally cover the floor." A similar "plague" occurred in 2006, in and around a woodland cabin near the Blue Ridge Mountains, U.S.; it persisted through winter and lasted at least two years.
Read more, here.
707-451-3985
Wednesday, February 8, 2023
Sunday, February 5, 2023
What Do Crickets Eat?
Captive crickets are omnivorous; when deprived of their natural diet, they accept a wide range of organic foodstuffs. Some species are completely herbivorous, feeding on flowers, fruit, and leaves, with ground-based species consuming seedlings, grasses, pieces of leaf, and the shoots of young plants. Others are more predatory and include in their diet invertebrate eggs, larvae, pupae, moulting insects, scale insects, and aphids. Many are scavengers and consume various organic remains, decaying plants, seedlings, and fungi. In captivity, many species have been successfully raised on a diet of ground, commercial dry dog food, supplemented with lettuce and aphids.
Crickets have relatively powerful jaws, and several species have been known to bite humans.
Read more, here.
707-451-3985
Thursday, February 2, 2023
Chirping Crickets
A male Gryllus cricket chirping: Its head faces its burrow; the leathery fore wings (tegmina; singular "tegmen") are raised (clear of the more delicate hind wings) and are being scraped against each other (stridulation) to produce the song. The burrow acts as a resonator, amplifying the sound.
Most male crickets make a loud chirping sound by stridulation (scraping two specially textured body parts together). The stridulatory organ is located on the tegmen, or fore wing, which is leathery in texture. A large vein runs along the centre of each tegmen, with comb-like serrations on its edge forming a file-like structure, and at the rear edge of the tegmen is a scraper. The tegmina are held at an angle to the body and rhythmically raised and lowered which causes the scraper on one wing to rasp on the file on the other. The central part of the tegmen contains the "harp", an area of thick, sclerotized membrane which resonates and amplifies the volume of sound, as does the pocket of air between the tegmina and the body wall. Most female crickets lack the necessary adaptations to stridulate, so make no sound.
Several types of cricket songs are in the repertoire of some species. The calling song attracts females and repels other males, and is fairly loud. The courting song is used when a female cricket is near and encourages her to mate with the caller. A triumphal song is produced for a brief period after a successful mating and may reinforce the mating bond to encourage the female to lay some eggs rather than find another male. An aggressive song is triggered by contact chemoreceptors on the antennae that detect the presence of another male cricket.
Crickets chirp at different rates depending on their species and the temperature of their environment. Most species chirp at higher rates the higher the temperature is (about 62 chirps a minute at 13 °C (55 °F) in one common species; each species has its own rate). The relationship between temperature and the rate of chirping is known as Dolbear's law. According to this law, counting the number of chirps produced in 14 seconds by the snowy tree cricket, common in the United States, and adding 40 will approximate the temperature in degrees Fahrenheit.
In 1975, Dr. William H. Cade discovered that the parasitic tachinid fly Ormia ochracea is attracted to the song of the cricket, and uses it to locate the male to deposit her larvae on him. It was the first known example of a natural enemy that locates its host or prey using the mating signal. Since then, many species of crickets have been found to be carrying the same parasitic fly, or related species. In response to this selective pressure, a mutation leaving males unable to chirp was observed amongst a population of Teleogryllus oceanicus on the Hawaiian island of Kauai, enabling these crickets to elude their parasitoid predators. A different mutation with the same effect was also discovered on the neighboring island of Oahu (ca. 100 miles (160 km) away). Recently, new "purring" males of the same species in Hawaii are able to produce a novel auditory sexual signal that can be used to attract females while greatly reducing the likelihood of parasitoid attack from the fly.
Read more, here.
707-451-3985
Subscribe to:
Posts (Atom)