The Variable Coloration of the Acridoid Grasshoppers

The Evolution of Color Polymorphism: Crypticity, Searching Images, and Apostatic Selection

“…There are cryptic polymorphic spiders (Bonte & Maelfait 2004, Oxford & Gillespie 1998, crustaceans (Devin et al 2004, Hargeby et al 2004, Merilaita et al 2001, and even vertebrates (Olendorf et al 2006, Wente & Phillips 2003. Examples occur throughout the Acridid and Tetrigid grasshoppers (Figure 2) (Dearn 1990, Nabours et al 1933, where many species are so variable that color is wholly inadequate as a basis for classification (Rowell 1971). Many mantids (Edmunds 1976) and katydids (Owen 1980) are polymorphic, as are water boatmen (Popham 1941), walking sticks (Sando-val 1994), and spittlebugs (Halkka & Halkka 1990).…”

“…The number of morphs can range from perhaps three or four to dozens, as in grouse locusts (Acrydium arenosum) (Figure 2) (Nabours et al 1933), land snails (Cepaea nemoralis) (Cain & Sheppard 1954), or underwing moths (Catocala micronympha) (Barnes & McDunnough 1918). Such generalist polymorphisms are mainly associated with relatively homogeneous but visually complex environments, such as temperate grasslands, exposed rock and soil, leaf litter, or beach gravel (Clarke et al 1978, Dearn 1990, Rowell 1971, Whiteley et al 1997. These habitats tend to be fine grained (Levins 1968), in that there are no large patches of distinctive substrate, but the visual complexity enables a range of diverse forms to be equally difficult to detect.…”

“…Because diversity is limited by the number of substrate types, specialist polymorphisms generally involve fewer, more distinctive forms, often only green and brown (Dearn 1990, Edmunds 1976, Owen 1980, Poulton 1890, Wente & Phillips 2003 or dark and light (Kettlewell 1973). In many cases, the dimorphism is genetically determined; in others, it is a polyphenism, a developmental difference in color pattern cued by physical or chemical signals (Edmunds 1976, Greene 1996, Rowell 1971. Because each morph specializes on a particular substrate type, these species may be highly selective in choosing a resting location, actively avoiding nonmatching backgrounds (Edmunds 1976, Owen 1980, Sargent 1981.…”

Characterization and immunological analysis of insecticyanin from the hemolymph ofagrius convolvuli

“…The hemolymph of some insects such as Orthoptera, Lepidoptera, Coleoptera and Diptera have a green or blue color, suggesting the presence of a biliverdinbinding protein in these insects (Ohtaki and Ohnishi, 1967;Rowell, 1971;Tobin et al, 1971;Kayser and Dettner, 1984). Generally in hemimetabolous insects, biliverdin IXa is typically detected (Kayser and Dettner, 1984).…”

Why are individuals so different from each other?

“…East African Acridoid grasshoppers deposit black melanin in their cuticle if the reflectance of the ground is low when they hatch out, as it would be after a savannah fire (Rowell, 1971). As a consequence of this mechanism, most grasshoppers are green in periods without fires and most are black in periods after fires when the savannah is blackened.…”