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The galls occur when female aphids lay a single egg on the underside of the sumac leaf, inducing the leaf to form a sac over the egg. [5] According to Hebert et al, the eggs "give rise to a series of parthenogenetic generations, which remain within the gall. Winged females leave the gall in late summer and fly to moss, where they establish ...
A female aphid lives for 9 to 25 days and can produce from 25 to 125 young during its life. There may be up to twenty generations in the year. By November winged forms have developed and eggs are laid before winter sets in. [6] In warmer climates, parthenogenetic reproduction takes place throughout the year.
These aphids follow the general life cycle of most other aphid species. [2] First generation females can lay around 100 eggs. Eggs of R. oxyacanthae will appear small, oval and shiny. The eggs are green but are difficult to differentiate between other species of aphid eggs. [2] Eggs are laid on branches and will typically hatch before other ...
Aphid giving birth to live young: populations are often entirely female. In autumn, aphids reproduce sexually and lay eggs. Environmental factors such as a change in photoperiod and temperature, or perhaps a lower food quantity or quality, causes females to parthenogenetically produce sexual females and males. [56]
The production of female offspring by parthenogenesis is referred to as thelytoky (e.g., aphids) while the production of males by parthenogenesis is referred to as arrhenotoky (e.g., bees). When unfertilized eggs develop into both males and females, the phenomenon is called deuterotoky. [22]
Stegophylla essigi, also known as the California woolly oak aphid, is a species of North American aphid. [1] It had been found on many California oaks, including blue oaks, valley oaks, Oregon white oaks, coast live oaks, interior live oaks, California black oaks, and scrub oaks. [2] Woolly oak aphids overwinter as eggs.
Female aphids reproduce by parthenogenesis, males have never been observed in the wild but have been produced under laboratory conditions. [10] Females may be wingless or winged ( alate ), the production of the alate form occurs a higher rate in those regions where it is necessary for oleander aphid to migrate each year on to temporary hosts.
The fundatrix, or parthenogenetic female aphid produced on the primary host plant from an overwintering fertilized egg, is pale green; these individuals allow the second generation alatae to form within the gall. [5] The galls typically mature in late August to early September and change color from green to red over the course of maturation.