Visual Generalist With Visual Specialist Phytophagous Insects: Host Selection Behaviour and Application to Management

Abstract

Our findings suggest that Hoplocampa testudinea adults (apparently monophagous) and Rhagoletis pomonella flies (oligophagous) are more specific in orientation to hue and/or form of feeding, mating, or oviposition sites on a common host (apple) than are Lygus lineolaris adults (polyphagous) on apple. We speculate that subject to varying influence by host plant chemical stimuli, many monophagous --oligophagous insects may tend to be visual specialists in comparison with polyphagous insects, especially those polyphagous species whose preferred feeding, mating, or oviposition sites within an individual plant are of diverse physical characteristics. They may tend more toward being visual generalists. Visual traps incorporating the synthetic equivalents of comparatively specific host plant visual stimuli should prove useful in monitoring and possibly even directly controlling a number of monophagous-oligophagous insects on crops.Aspects of the process by which insects select plants as feeding, mating, or oviposition sites have been recently and excellently reviewed by Dethier (1973), Beck (1974), Chapman (1974), Markl (1974), Hedin et al. (1977, Kogan (1977), Schoonhoven (1977), and St/idler (1977).One general conclusion is that the process usually involves a constellation of interacting stimuli, often including olfactory and visual stimuli.Considerably more research attention is presently being given to the olfactory basis of whole plant or plant part selection than to the visual basis. The reasons are several, one being the stimulating effect of the appreciable literature (summarized by Hedin et al., 1977;Kogan, 1977; St/idler, 1977) indicating that a variety of phytophagous insects are attracted to specific sorts of volatile chemicals, usually in appropriate blend, emanating from their respective hosts. In contrast, the literature (reviewed by Markl, 1974; St/idler, 1977) provides fewer examples of phytophagous insects attracted to plants or plant parts on the basis of comparatively specific sorts of visual characters.Here, we focus on aspects of host selection by: tarnished plant bug adults, Lygus lineolaris (P. de B.); European apple sawfly adults, Hoplocampa testudinea Klug.;

Responses of Neomegalotomus parvus (Hemiptera: Alydidae) to color and male-lured traps

“…White, red and blue traps captured significantly more N. parvus males than black probably due to greater contrast with the soil surface. Low captures in aluminum traps corroborated information of the mimicry of sun polarized light determining lack of attraction (Prokopy and Owens, 1978). Contrast perception was reported in the host plant selection for the fruit fly Rhagoletis pomonella (Walsh.)…”

“…Contrast perception was reported in the host plant selection for the fruit fly Rhagoletis pomonella (Walsh.) (Tephritidae) (Prokopy and Owens, 1978).…”

“…Lygus lineolaris (P. de B.) adults are not visually oriented toward the hue of apple structures on which they feed or rest (Prokopy and Owens, 1978).…”

Response by Specialist and Generalist Natural Enemies to Agroecosystem Diversification: A Selective Review

“…However, evidence for distant (> 10 m) olfactory orientation to plants is controversial for herbivores (Finch & Skinner 1982), and is entirely lacking for enemies. Specialist herbivores appear to use more specific chemical and visual cues than generalists in orienting to host plants (Stadler 1977, Prokopy & Owens 1978; this may be true for enemies as well (Vinson 1976). Furthermore, when specific plant cues are used by insects to locate plant June 1986 SHEEHAN: NATURAL ENEMIES AND ACROECOSYSTEM DIVERSIFICATION 459 patches, the presence of other plants in close association with these plants may disrupt orientation to the patch.…”

Empoasca leafhoppers attack wild tobacco plants in a jasmonate-dependent manner and identify jasmonate mutants in natural populations

“…Host-plant selection by insects involves complex behavioral responses to a variety of physical and chemical characteristics of the host plant that operate at different spatial scales and include long-range olfactory (e.g., plant-derived volatiles perceived by odor receptors) and visual (e.g., plant shape, size, and color) cues and short-range chemotactic and gustatory (e.g., surface metabolites perceived by chemoreceptors) cues (1)(2)(3). The physical and chemical characteristics of plants that insects use for host selection depend on the feeding guild and the dietary behavior (e.g., polyphagy or oligophagy) of the insect species (4). For example, Drosophila melanogaster flies (order Diptera) use a wide range of olfactory cues such as methyl-, ethyl-, and propyl esters of short-chain fatty acids generated by microorganisms growing on decaying fruit (5), whereas Drosophila sechellia flies use a specific molecule (methyl hexanoate) emitted by its exclusive food plant, Morinda citrifolia (6).…”