Aphid

About: Aphid is a research topic. Over the lifetime, 11380 publications have been published within this topic receiving 229721 citations. The topic is also known as: Aphidoidea & plant lice.

Assessment of aphid colonies by hoverflies. I maple aphids andEpisyrphus balteatus (de Geer) (Diptera: Syrphidae)

Abstract: In the syrphid hoverflyEpisyrphus balteatus (de Geer), females in search of oviposition sites are assessing the qualitative and quantitative value of aphid colonies for securing the successful development of their offspring. They select small, young and “promising” aphid colonies consisting of nymphs and/or fundatrices as their oviposition sites, and neglect large, older ones including winged adults. Such “buy-futures” tactics will benefit the offspring in finding suitable and sufficient food.

Plant architecture and the foraging success of ladybird beetles attacking the Russian wheat aphid

Abstract: We examined the interaction between the fourteen-spotted ladybird beetle, Propylea quatuordecimpunctata (L.), and the Russian wheat aphid, Diuraphis noxia (Mordvilko), on two grasses with divergent leaf architectures. Like wheat, crested wheatgrass bears flat, broad leaves, whereas Indian ricegrass produces slender, tightly rolled leaves. In the absence of aphid prey, residence times and time budgets of larvae and adults of P. quatuordecimpunctata were similar on the two hosts, although larvae tended to remain longer on crested wheatgrass. When aphids were present, both predator stages dislodged, contacted, and captured aphids at higher rates on Indian ricegrass than on crested wheatgrass. Predator time budgets and behavior sequences also reflected a greater predation risk for D. noxia on Indian ricegrass, and were consistent with earlier, population-level experiments in the field. Comparisons between aphid-free and aphid-infested plants suggest that the effect of host plant in this tri-trophic system largely depended on differences in the availability of prey refuges rather than on differences in predator searching behavior; proportionally more aphids fed in exposed locations on Indian ricegrass than on crested wheatgrass. Plant architecture is likely to be an important component of the predation risk of D. noxia because of the aphid's tendency to feed in relatively concealed locations.

Reproductive strategies of the alate morphs of the bird cherry-oat aphid rhopalosiphum padi l.

Abstract: Host alternating aphids like the bird cherry-oat aphid exist in several distinct morphs (Dixon 1973). The alate morphs are difficult to separate morphologically (Rogerson 1948) but are easily separated behaviourally. The emigrants leave the primary host, bird cherry, Prunus padus L., before the end of June and colonize various grasses. The alate exules, which are then produced on the secondary hosts, spread to other grass plants. Triggered by fall in temperature and decrease in day-length in autumn, exules no longer produce more exules, but gynoparae and males instead, which finally return to the primary host on which the aphid overwinters as an egg (Dixon & Glen 1971). Each morph in the sequence that is produced in the annual cycle of a host alternating aphid has a different function to perform. Associated with their different functional roles it is acceptable that these morphs also exhibit different reproductive strategies. It is the aim of this paper to describe these differences in the reproductive behaviour of all the alate female morphs of Rhopalosiphum padi L. and to relate the differences to the aphid's way of life.

Attraction of the specialist parasitoid Cotesia rubecula to Arabidopsis thaliana infested by host or non‐host herbivore species

Abstract: In this study we investigated whether in a two-choice set-up the parasitoid Cotesia rubecula (Marshall) (Hymenoptera, Braconidae) distinguishes between volatiles emitted by Arabidopsis thaliana (L.) Heynh. (Brassicaceae) infested with its host, Pieris rapae (L.) (Lepidoptera: Pieridae) and Arabidopsis infested with non-host herbivores. Four non-host herbivore species were tested: the caterpillars Plutella xylostella (L.) (Lepidoptera: Plutellidae) and Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae), both chewing insects, the spider mite Tetranychus urticae (Koch) (Acari: Tetranychidae), which punctures parenchymal cells, and the aphid Myzus persicae (Sulzer) (Hemiptera: Aphidoidea), which is a phloem-feeder. Compared with undamaged plants, C. rubecula females were more attracted to Arabidopsis plants infested by P. rapae, P. xylostella, S. exigua, or T. urticae, but not to plants infested by M. persicae. The parasitoids preferred host-infested plants to spider mite- or aphid-infested plants, but not to plants infested with non-host caterpillars (P. xylostella or S. exigua). The data show that when Arabidopsis plants are infested with a leaf tissue-damaging herbivore they emit a volatile blend that attracts C. rubecula females and the wasps only discriminate between a host and non-host herbivore when the type of damage is different (chewing vs. piercing). When Arabidopsis is infested with a herbivore that hardly damages leaf tissue, C. rubecula females are not attracted. These results may be explained by differences in the amount of damage and in the relative importance of different signal-transduction pathways induced by different types of herbivores.