In spite of their toughness and their terrible weapons, the stinging Hy- 

 menoptera are preyed on by a good many birds; and though as a rule not 

 counter shaded, they are furnished with bold obliterative patterns of many 

 sorts. The predominant type, perhaps, is a system of sharp transverse bars 

 of dark and light, by which the insect is 'cut up' as the zebra is by his bands. 

 Yellow and black are the prevailing colors of these patterns— though white 

 and buff often take the place of yellow, and fuscous, tawny brown, and olive 

 (plant-shadow colors) the place of black. Such markings are fundamentally 

 and very potently obliterative against their wearers' average backgrounds 

 of green vegetation in sunlight and shadow, and also amidst yellow flowers. 

 Sometimes the pattern is simplified to a 'ruptive' one of two or three broad, 

 unmarked patches of black and yellow, or black and orange— as on some 

 of the bumblebees,— or still further simplified to a nearly monochrome cos- 

 tume of mingled plant- and shadow-like greenish yellow. Some wasps and 

 bees, again, are uniformly almost black, and do not seem to have obliterative 

 devices of any kind— except in the cases where the black is transfused with 

 metallic color* On the other hand, the transverse 'secant' pattern is often 

 highly elaborated, consisting of many narrow, sharply defined, contrasting 

 stripes, varied on the thorax and head by more broken and irregular mark- 

 ings. Such is the case with certain wood wasps or hornets, e. g., the common 

 "Yellow Jacket" (Vespa vulgaris). Among the "sawflies" and "borers" 

 {SiricidcB, etc.), there is much variety in coloration as well as form. Glossy 

 black, varied to steely blue, is perhaps the most characteristic color of these 

 insects' bodies, but with it are often combined red, orange, yellow, brown, 

 etc., in comparatively simple 'ruptive' and 'secant' obliterative patterns. 

 Though lacking finer 'bark-pictures,' as well as counter shading, some of 

 these borers, etc., are very inconspicuous when seated on the trunks of trees. 



The wings of most Hymenoptera—zs those of most of the other aerial 

 insects mentioned in this chapter— are transparent, and hence essentially 

 inconspicuous at all times, except when they brightly 'shine'— as a glass 



* See footnote, p. 204. 

 205 



