Cryptic coloration

Brandon, R. A. Huheey, J. E. 1975. Diurnal activity, avian predation, and the question of warning coloration and cryptic coloration in salamanaders. Herpetol, 31, 252—255. 

Pyrrolizidine alkaloids are feeding deterrents and insecticidal for many species of insects (Schneider, 1987 Wink, 1993b). Some insects, such as Melanchra persicariae and Spodoptera littoralis feed on Senecio vulgaris, which contains pyrrolizidine alkaloids, but do not sequester the alkaloids. The larvae are cryptically colored (Schneider, 1987). Certain insects appear to be able to excrete these alkaloids without harm. For example, senecionine (5), its A -oxide, and hydrolytic products, including retronecine (1), were found in the honeydew of the aphid Myzus persicae when this insect fed on Senecio vulgaris (Molyneux et al., 1990). 

At the present time, extracts from some forty-five species of dendrobatid frogs have been examined, but detailed analyses have been carried out and published for only about one-half of these species. Sites of collection of various species of Phyllobates and Dendrobates for analysis of skin extracts are shown in Figs. 1 and 2. The five species of the genus Phyllobates all contain batrachotoxins (797, see Table 3). Certain Phyllobates species also contain pumiliotoxins and histrionicotoxins (797, unpublished results). The some thirty species of the genus Dendrobates whose skin extracts have been examined contain only the simpler dendrobatid alkaloids, that it is the pumiliotoxins, the histrionicotoxins, the gephyrotoxins, and related compounds 80, 187-190, unpublished results see Table 22). As yet, dendrobatid alkaloids have not been positively identified in skin extracts from ten species of a third genus of dendrobatid frogs, the usually cryptically colored Colostethus. 

The cryptic talmudic comparisons of the color of tekhelet to that of grass, trees, the sea, and the sky is understood now as reference to the chromatic sequence that occurs in nature when the colorless mucus from the snail, upon exposure to the elements, first becomes yellow, then gradually changes to green, followed by blue, and finally becomes violet (15). 

Other lysine-derived alkaloids known as coccinellines (42-47) occur in many members of the family Coccinellidae (ladybugs or ladybird beetles) (Fig. 29.15). Many of these insects are also wamingly colored. Cryptic members of the same groups usually do not contain the alkaloids (Jones and Blum, 1983). These alkaloids also have been isolated from a soldier beetle, Chauliognathus and from the boll weevil Anthonomus grandis. Coccinellines are highly repellent to... 

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