Visual Detection of Plants by Herbivorous Insects

Abstract

INTRODUCTIONThere are hundreds of thousands of insect species for which plants provide a variety of resources such as adult food, mating encounter sites, oviposi tional sites, food for immatures, shelter from harmful biotic or abiotic agents, or transport (90,149,181). Yet our understanding of the process by which an insect detects a resource-furnishing plant is not well developed. This is particularly true for the visual aspects of plant detection by insects.To date, studies of this aspect have focused on the visual location of fl owers by pollinators (80). Visual location of plants by herbivores, parasitoids, or predators has received no more than marginal or scattered attention (6,64,79,82,88,98,100,104,151,152,156,162,169).Before focusing attention exclusively on insect vision, it is useful to briefl y review some general aspects of animal vision. Here, vision is defi ned as the ability to perceive spatial patterns. The physical stimulus that defines a pattern can be regarded as a spatiotemporal distribution of photo fl ux that differs in total energy and frequency composition, and thus provides the visual color cues of brightness (intensity of perceived reflected light), hue (dominant wavelength of reflected light), and saturation (spectral purity of reflected light). The spatial distribution of photon flux provides information on shape, size, distance, and motion. Visual patterns depend upon the nature of the viewed surface, the optical background, the illuminant, and 337 0066-4170/83/0101·0337$02.00 Annu. Rev. Entomol. 1983.28:337-364. Downloaded from www.annualreviews.org by Stanford University -Main Campus -Lane Medical Library on 09/28/12. For personal use only. Quick links to online content Further ANNUAL REVIEWS 338 PROKOPY & OWENSthe viewer's angle and sensitivity. As an active, complex process, vision depends not only upon events in the entire visual fi eld but also upon patterns of expectation in the visual processing system itself, some of which are established through prior visual experience.Description and analysis of the natural optical environment in terms of the visual system of an animal is known as visual ecology, which presumes that specialized visual systems are of adaptive advantage to the animal possessing them. Visual ecologists quantify physical attributes of optical patterns in the environment, particularly those of resource items. How animals solve common visual problems is best understood when data on the physical environment is combined with data on animal behavior and on the morphology and physiology of visual systems.The visual ecology approach was formulated during studies of sea fishes (94,96,113) and has subsequently been adapted to studies of land-dwelling animals (56,96,147), including insects (80).Our review is concerned primarily with the visual ecology of herbivorous insects. Accordingly, we deal with the following elements that, in combina tion, comprise a visual ecology approach: the evolutionary history of plants and insects; the visual properties of natural illuminan...

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

“…1 Tentative spectral sensitivities of three modelled types of photoreceptors of Myzus persicae. Model after Stavenga et al (1993) There is still very limited information on photoreceptor sensitivities in herbivorous insects, as already lamented by Prokopy and Owens (1983). A reason for the scarcity of physiological information on aphids, in particular, is that the appropriate techniques are difficult to apply because the animals are so small and soft, which makes inserting microelectrodes into single cells of their eyes exceptionally difficult.…”

“…Probings on grey paper after walking on coloured paper have been assigned to a negative sign, probings on coloured paper without prior colour stimuli to positive sign, in order to mark the different experimental approaches. Further explanations see text (Section 'From photoreceptor spectral sensitivity to behavioural responses to colour') Arthropod-Plant Interactions (2007) 1:3-16 7 the higher reflectance in the green spectral domain of yellow than of green (Prokopy and Owens 1983). However this is unlikely to explain the phenomenon accurately.…”

“…However, it might well be that yellow preference of some aphid species and morphs is non-adaptive and that yellow just represents a 'supernormal foliage stimulus' for the herbivorous insects (Prokopy and Owens 1983). The proximate perspective on this interpretation is the mechanistic explanation given above-that if green-ness of leaves is assessed by an opponent mechanism described in Eq.…”

Evaluación del color y la posición de trampas en la captura de cicadélidos en Gaultheria phillyreifolia (Ericaceae) afectadas por fitoplasmas

“…que puede estar directamente relacionado con la longitud de onda refl ejada entre los 500-600 nm, siendo la longitud de onda en la cual el pico de refl ectancia en la plantas suele ocurrir. Aparentemente, los cicadélidos pueden aceptar o discriminar (< 500 nm y > 580 nm) longitudes de onda y por lo tanto, detectar características similares a follaje en algunos colores (Prokopy & Owens 1983, Mensah 1996. El color amarillo representa hojas muy brillantes que refl eja esas ondas de energía, actuando como un estímulo supernormal (Prokopy & Owens 1983) o puede representar un comportamiento adaptativo que ayuda al insecto en la búsqueda de hojas nuevas o en desarrollo, las cuales, aún no poseen todas las defensas fi sioquímicas (Kursar & Coley 2003).…”

“…Aparentemente, los cicadélidos pueden aceptar o discriminar (< 500 nm y > 580 nm) longitudes de onda y por lo tanto, detectar características similares a follaje en algunos colores (Prokopy & Owens 1983, Mensah 1996. El color amarillo representa hojas muy brillantes que refl eja esas ondas de energía, actuando como un estímulo supernormal (Prokopy & Owens 1983) o puede representar un comportamiento adaptativo que ayuda al insecto en la búsqueda de hojas nuevas o en desarrollo, las cuales, aún no poseen todas las defensas fi sioquímicas (Kursar & Coley 2003). Pero también, la preferencia al color amarillo puede estar directamente relacionada con los problemas de clorosis en los tejidos enfermos, lo cual puede favorecer aquellas especies vectores de enfermedades (Weintraub & Beanland 2006).…”