Corpus allatum

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In insect physiology and anatomy, the corpus allatum (plural: corpora allata) is an endocrine gland that generates juvenile hormone; as such, it plays a crucial role in metamorphosis. Surgical removal of the corpora allata (an allatectomy) can cause an immature larva to pupate at its next molt, resulting in a miniature adult. [1] Similarly, transplantation of corpora allata from a young larva to a fully mature larva can greatly extend the larval stage, resulting in an equivalent to gigantism. [2]

In many Diptera species, the corpus allatum is fused with the corpus cardiacum, forming a "ring gland", also known as Weismann's ring. [3]

In Lepidoptera species, the corpus allatum acts as a release site for prothoracicotropic hormone which is generated by the brain. [4]

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<span class="mw-page-title-main">Lepidoptera</span> Order of insects including moths and butterflies

Lepidoptera is an order of insects that includes butterflies and moths. About 180,000 species of the Lepidoptera are described, in 126 families and 46 superfamilies, 10 percent of the total described species of living organisms. It is one of the most widespread and widely recognizable insect orders in the world. The Lepidoptera show many variations of the basic body structure that have evolved to gain advantages in lifestyle and distribution. Recent estimates suggest the order may have more species than earlier thought, and is among the four most species-rich orders, along with the Hymenoptera, Diptera, and Coleoptera.

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<i>Calliphora vomitoria</i> Species of fly

Calliphora vomitoria, known as the blue bottle fly, orange-bearded blue bottle, or bottlebee is a species of blow fly, a species in the family Calliphoridae. Calliphora vomitoria is the type species of the genus Calliphora. It is common throughout many continents including Europe, Americas, and Africa. They are fairly large flies, nearly twice the size of the housefly, with a metallic blue abdomen and long orange setae on the gena.

<i>Agrotis ipsilon</i> Species of moth

Agrotis ipsilon, the dark sword-grass, black cutworm, greasy cutworm, floodplain cutworm or ipsilon dart, is a small noctuid moth found worldwide. The moth gets its scientific name from black markings on its forewings shaped like the letter "Y" or the Greek letter upsilon. The larvae are known as "cutworms" because they cut plants and other crops. The larvae are serious agricultural pests and feed on nearly all varieties of vegetables and many important grains.

Insect physiology includes the physiology and biochemistry of insect organ systems.

<span class="mw-page-title-main">Juvenile-hormone esterase</span>

The enzyme juvenile hormone esterase (EC 3.1.1.59, systematic name methyl-(2E,6E,10R)-10,11-epoxy-3,7,11-trimethyltrideca-2,6-dienoate acylhydrolase, JH esterase) catalyzes the hydrolysis of juvenile hormone:

<i>Mythimna unipuncta</i> Species of moth

Mythimna unipuncta, the true armyworm moth, white-speck moth, common armyworm or rice armyworm, is a nocturnal agricultural pest belonging to the family Noctuidae. This moth is also commonly referred to by the scientific name Pseudaletia unipuncta. The species was first described by Adrian Hardy Haworth in 1809. Mythimna unipuncta is found in the Americas and in parts of Europe, Africa and Asia. Its original distribution is North and South America. It has been introduced to other places from there. They are known as armyworms because the caterpillars move in lines as a massive group, like an army, from field to field, damaging crops.

Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered.The chemical symbol for prothoracicotropic hormone is (C64H102N16O19S2). It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922) and Vincent Wigglesworth (1934), who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects.

<span class="mw-page-title-main">Insect morphology</span> Description of the physical form of insects

Insect morphology is the study and description of the physical form of insects. The terminology used to describe insects is similar to that used for other arthropods due to their shared evolutionary history. Three physical features separate insects from other arthropods: they have a body divided into three regions, have three pairs of legs, and mouthparts located outside of the head capsule. It is this position of the mouthparts which divides them from their closest relatives, the non-insect hexapods, which includes Protura, Diplura, and Collembola.

Neurosecretion is the storage, synthesis and release of hormones from neurons. These neurohormones, produced by neurosecretory cells, are normally secreted from nerve cells in the brain that then circulate into the blood. These neurohormones are similar to nonneural endocrine cells and glands in that they also regulate both endocrine and nonendocrine cells. Neurosecretion cells synthesize and package their product in vesicles and exocytose them at axon endings just as normal neurons do, but release their product farther from their target than normal neurons, typically releasing their neurohormones into the circulatory system to reach their distant targets.

Aedes taeniorhynchus, or the black salt marsh mosquito, is a mosquito in the family Culicidae. It is a carrier for encephalitic viruses including Venezuelan equine encephalitis and can transmit Dirofilaria immitis. It resides in the Americas and is known to bite mammals, reptiles, and birds. Like other mosquitoes, Ae. taeniorhynchus adults survive on a combination diet of blood and sugar, with females generally requiring a blood meal before laying eggs.

Juvenile hormone acid O-methyltransferase (JHAMT) is a ~33 kDa enzyme that catalyzes the conversion of inactive precursors of Juvenile hormones (JHs) to active JHs in the final stages of JH biosynthesis in the corpora allata of insects. More specifically, the enzyme catalyzes the transfer of a methyl group from S-adenosyl-L-methionine (SAM) to the carboxylate group of JH precursors.

References

  1. Vitamins and Hormones: v. 14: Advances in Research and Applications, edited by Richard Harris, 1956, from Elsevier
  2. Insect Hormones Archived 2010-01-03 at the Wayback Machine at John W. Kimball's Biology-Pages.info
  3. THE HOMOLOGIES OF THE RING GLAND OF DIPTERA BRACHYCERA, Annals of the Entomological Society of America, Volume 36, Number 1, March 1943, pp. 1-10, by M.F. Day
  4. Insect Hormones, page 13, by H. Fredrik Nijhout, 1994, Princeton University Press