Host finding by aphids in the field

Abstract

Aphis fabae gynoparae occurred in the same large proportion in simultaneous collections of all aphids alighting and probing on, and taking off from, a host plant (spindle) and a non-host (peach), and behaved similarly when approaching and leaving them in the same conditions. Most alighters took off again from leaves of both kinds within a few minutes, staying longer and probing more times on the host. In atmospheric conditions favouring local 'hovering' instead of dispersal, flying and alighting aphids became concentrated around host plants, not through any specific attraction to them, but apparently because more aphids had accumulated upon them and were now taking off.Brevicoryne brassicae occurred in the same large proportion in simultaneous collections of aphids alighting on a host plant (cabbage) and a non-host (sugar beet). No satisfactory evidence was found of preferential alightment on cabbage and there were indications of preferential alightment on the non-host. A very small minority of the A. fabae and B. brassicae that alighted on their hosts stayed there long enough to larviposit. This minority was rather larger among alighters late in the day, but in the absolute sense, more colonization occurred during earlier periods when more aphids arrived.The intensely dispersive type of host-finding behaviour in Myzus persicae, A. fabae and B. brassicae may be common among Aphididae. It seems ideal for the dissemination of non-persistent plant viruses, more particularly among the lessfavoured host plants of each aphid. The tendency to commensal association between virus and vector provides an ecological framework which may govern the incidence of virus-vector specificity and symbiosis.

Visual ecology of aphids—a critical review on the role of colours in host finding

“…In terms of green leaves, the question is whether there is a specific adaptation of aphid visual system to optimise the spectral discrimination between their (green-leafed summer) hosts and non-host plants, or put slightly differently, if host plants can be discriminated from non-hosts by their colour. Prokopy and Owens (1983, p. 357) conjectured that 'with few exceptions ... it is unlikely that plant spectral quality constitutes a hostplant specific character for herbivorous insects because of its similarity among most plants'; see also Kennedy et al (1961). However, from an evolutionary viewpoint, the mentioned dissimilarities between different aphid species in their response to coloured stimuli might be explicable by assuming adaptation of their visual preferences to a specific task, possibly host finding.…”

“…Because young (yellowish) leaf tissue as well as autumnal yellow leaves tend to have a higher flow of aphid accessible nitrogen sources in the phloem, this was seen as a point for explaining ultimate causes of yellow preference in certain aphids by some authors (Kennedy et al 1961;Dixon 1985). Total leaf nitrogen levels on the other hand, tend to be associated with lower overall reflectance in the insect visible spectrum (Judkins and Wander 1950;Serrano et al 2000).…”

Efeito da aplicação de maravilha (Mirabilis jalapa L.), primavera (Bougainvillea spectabilis L.) e isolados de Trichoderma na produção de alface

“…Constatou-se que as maiores revoadas de afídeos ocorreram nos primeiros trinta dias após a introdução das mudas de alface no campo, fato já observado em tomateiro, pois neste período a coloração menos intensa das mudas proporcionam comprimentos de ondas maiores que 500 ìM (faixa amarelo/verde), o que atrai diversas espécies de afídeos (Kennedy et al, 1961).…”

Influence of Host Plant Species and Flush Growth Stage on the Asian Citrus Psyllid, <i>Diaphorina citri</i> Kuwayama

“…Control measures with suitable insecticides on these alternate hosts and also on citrus trees may help in eliminating the psyllids and thereby check the spread of greening disease by the vector. Although feeding, nutrition and the chemotactic basis for host plant selection have been extensively investigated in a closely related family, the Aphidae (Auclair, 1963;Kennedy et al, 1961), nothing is known about host choice in the Psyllidae. The lack of response of the psyllids to chemical extracts may be an indication that nutritive factors in the leaves play a role in host plant selection (Gerling, 1990) in this species.…”