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Alate

About: Alate is a research topic. Over the lifetime, 642 publications have been published within this topic receiving 13385 citations.


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Book ChapterDOI
TL;DR: This chapter is concerned with aphids that have served as material for experimental work and exhibit morphological transformations that are continued over several successive generations.
Abstract: Publisher Summary Polymorphism in aphids is an expression of the multiple developmental potentialities inherent in the egg, the embryo, and the young larva. Polymorphism is frequently of the “alternative” type. Competence to differentiate along different alternative routes often arises sequentially during development. This chapter is concerned with aphids that have served as material for experimental work. These species are few in number and belong almost entirely to the most specialized family, the Aphididae. In monoecious aphids the successive “decisions” comprise the determination of sex (presumably at the oocyte stage); the determination of young female embryos as virgin oparae or oviparae; and finally, the determination of alate embryos as alate or apterous virgin oparae. In heteroecious aphids the production of oviparae takes place in two stages and requires the intermediary of an additional morph, the gynopara. The choice of pathway depends on the operation of a series of switch mechanisms which are often maternal (invariably so in the case of oviparae) but are sometimes postnatal. Timing mechanisms are also of great importance inform determination. In addition, aphids exhibit morphological transformations that are continued over several successive generations. The final target both of the environmental cues and of the maternal switch mechanisms is the endocrine system of the embryo or young larva.

360 citations

Journal ArticleDOI
TL;DR: It is concluded that most invertebrate-eating mammals choose prey based on availability and other aspects of prey biology and not on gross nutritional factors, and the problems associated with eating ants and termites are discussed.
Abstract: Water, ash, total nitrogen and fat contents were determined for the worker and soldier castes of nine species of central Brazilian termites. These values were then compared with those from other species of termites, ants and 22 other species of terrestrial invertebrates. In comparison with most other invertebrates, termite workers and soldiers tend to be high in ash, low in fat and about equal in water and nitrogen. In contrast, alate ants and termites and most larval or pupal insects have much higher percentages of fat. It is pointed out that most protein and total energy values for arthropods are of limited use because the assays used incorporate the nitrogen present in the indigestible chitin exoskeleton. It is concluded that most invertebrate-eating mammals choose prey based on availability and other aspects of prey biology and not on gross nutritional factors. The problems associated with eating ants and termites are discussed and include low nutritional value of prey, small prey size and forms of defense relying on the sociality of the prey.

272 citations

Journal ArticleDOI
TL;DR: Odors of certain nonhost plants masked the attractiveness of the host plant leaves, but tansy and summer savory volatiles repelled B. brassicae andA.
Abstract: Alate and apterous virginoparae ofAphis fabae Scop, and alate virginoparae ofBrevicoryne brassicae (L.), walking in a linear track olfactometer, were attracted by odor from leaves of their host plants.A. fabae responded to odor from undamaged but not damaged bean leaves. Gynoparae (autumn migrants) ofA. fabae, however, did not respond to their host plant (spindle,Euonymus europaeus) odor. Odors of certain nonhost plants masked the attractiveness of the host plant leaves, but tansy (Tanacetum vulgare) and summer savory (Satureja hortensis) volatiles repelledB. brassicae andA. fabae, respectively. 3-Butenyl isothiocyanate attractedB. brassicae andLipaphis erysimi (Kalt.), the latter species being more sensitive in both behavioral and electrophysiological studies. Isothiocyanate receptors were found on the antennae ofA. fabae, which was repelled by these compounds, 4-pentenyl isothiocyanate being the most active.

244 citations

Journal ArticleDOI
TL;DR: This work focuses on the characteristics of fission in the phylogenetically primitive ants Ponerinae in which both ergatoid queens and gamergates occur.
Abstract: ▪ Abstract Social Hymenoptera show two contrasting strategies of colony reproduction. A reproductive female can raise the first generation of brood alone (independent foundation), or a colony can divide into autonomous parts in which the reproductive female is helped by sterile relatives (fission, budding, swarming). In independent-founding ants, queens can histolize their flight muscles after dispersal; in many species, large flight muscles and metabolic reserves reduce or eliminate the need for risky foraging trips during the vulnerable solitary stage. Colony division is a derived strategy, and we review the selective pressures leading to its occurrence in the different social taxa. In various ants, fission coexists with independent foundation, and alate queens are retained. However, in ants exhibiting obligate fission (e.g. all army ants and many Ponerinae), queens are permanently wingless (ergatoid), or the queen caste is missing altogether. When reproductive females are flightless, dispersal distance...

227 citations

Journal ArticleDOI
TL;DR: The experiments indicate that aphids respond to the presence of a predator by producing the dispersal morph which can escape by flight to colonize other plants, but this shift in prey morphology does not lead to better protection against predator attack, but enables aphids to leave plants when mortality risks are high.
Abstract: Aphids exhibit a polymorphism whereby individual aphids are either winged or unwinged. The winged dispersal morph is mainly responsible for the colonization of new plants and, in many species, is produced in response to adverse environmental conditions. Aphids are attacked by a wide range of specialized predators and predation has been shown to strongly influence the growth and persistence of aphid colonies. In two experiments, we reared two clones of pea aphid ( Acyrthosiphon pisum ) in the presence and absence of predatory ladybirds ( Coccinella septempunctata or Adalia bipunctata ). In both experiments, the presence of a predator enhanced the proportion of winged morphs among the offspring produced by the aphids. The aphid clones differed in their reaction to the presence of a ladybird, suggesting the presence of genetic variation for this trait. A treatment that simulated disturbance caused by predators did not enhance winged offspring production. The experiments indicate that aphids respond to the presence of a predator by producing the dispersal morph which can escape by flight to colonize other plants. In contrast to previous examples of predator-induced defence this shift in prey morphology does not lead to better protection against predator attack, but enables aphids to leave plants when mortality risks are high.

217 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202317
202261
202110
20207
20197
201816