i8o 



ENTOMOLOGY 



their conspicuous and usually showy hind wings concealed under the pro- 

 tectively colored front wings. The caterpillars of Basilarchia ar chip pus 

 and Papilio thoas, as well as other larvae and not a few moths, resemble 

 closely the excrements of birds. Numerous grass-eating caterpillars are 

 striped with green, as is also a sphingid species (Ellema harrisii) that lives 

 among pine needles. The large green sphinx caterpillars perhaps owe 

 their inconspicuousness partly to their oblique lateral stripes, which cut a 

 mass of green into smaller areas. The caterpillar of Schizura ipomcece 

 (Fig. 243), which is green with brown patches, rests for hours along the 

 eaten or torn edge of a basswood leaf, in which position it bears an ex- 



FIG. 243. Caterpillar of Schizura ipomcea clinging to a torn leaf. Natural size. 



tremely deceptive resemblance to the partially dead border of ,a leaf. 

 The weevils that drop to the ground and remain immovable are often 

 indistinguishable to the collector on account of their likeness to bits of 

 soil or little pebbles. Everyone has noticed the extent to which some 

 of the grasshoppers resemble the soil in color; Trimerotropis maritima 

 is practically invisible against the gray sand of the seashore or other 

 places to which it restricts itself; and Dissosteira Carolina, which varies 

 greatly in color, ranging from ashy gray to yellowish or to reddish brown, 

 is commonly found on soil of its own color. 



Adventitious Resemblance. If, instead of hastily ascribing all 

 cases apparently of protective resemblance to the action of natural 



