Search results
Results from the WOW.Com Content Network
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.
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 aphids migrate back to primary hosts in August and overwinter as eggs on weeds. In North America they are heavily parasitized by the braconid wasp Aphidius nigripes , which lays its eggs in the aphid nymphs, and these are eventually killed by the wasp larvae developing inside them.
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]
Macrosiphum rosae, the rose aphid, is a species of sap-sucking aphids in the subfamily Aphidinae. [1] [2] They have a world-wide distribution and infest rosebushes as the main host in spring and early summer, congregating on the tips of shoots and around new buds. Later in the summer, winged forms move to other rose bushes, or to a limited ...
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.
Winged aphids can then colonize other host plants. Pea aphids also show hereditary body color variations of green or red/pink. The green morphs are generally more frequent in natural populations. [8] Acyrthosiphon pisum is a rather large aphid whose body can reach 4 millimetres (5 ⁄ 32 in) in adults. [8]