368 NATURL SCIENCE. May. 



point for a change in the race. When we consider the vast numbers 

 of the lepidoptera, and the structural modifications which they have 

 undergone, their generally faithful adherence to a vegetable diet 

 (mostly leaves, rarely wood) is remarkable. The clothes-moths 

 (Tineids) have invaded our dwellings and found a congenial food-stuff 

 for their larvae in our garments. A few small species of the same 

 group [Ephestta) are reared in meal and other human food-stores, 

 while the caterpillars of some pyralid moths [Asopia, Aglossa) feed 

 upon kitchen refuse. Two species of crambid moths [Aphomia sociella 

 and Galleria melonella) find a home in bee-hives, where their cater- 

 pillars feed upon the wax, while the waxy secretion from the body of 

 the great American lantern-fly (Fulgora candelaria) serves both as 

 shelter and food for the caterpillar of the moth Epipyrops anomala. 

 Very few caterpillars have developed a thoroughly carnivorous habit. 

 Cosmia trapezina feeds on oak and other leaves, but devours smaller 

 caterpillars which happen to get in its way, and if shaken from 

 the tree, eats other larvae while climbing the trunk. Xylina ornithoptis 

 and a few other species are said to be always carnivorous when 

 opportunity offers ; the small looping caterpillar of a "pug"-moth 

 {Eupithecia coronata) has been observed to eat a larva three times as 

 big as itself. The caterpillars of Ovthosia pistacina live together in 

 peace while their food is moist, but devour each other when it dries 

 up ; this is true cannibalism — a term which should not be applied to 

 the habit of preying on another species. Dr. Seitz remarks that in 

 vertebrate animals also, thirst is more maddening than hunger. Canni- 

 balism has been observed in a few other cases. Patagonia yields several 

 examples of carnivorous caterpillars, as might be expected from the 

 poverty of its flora. A few carnivorous caterpillars do not attack 

 other caterpillars, but prey upon insects of different kinds ; among 

 these Fenescia tarquiniiis, which eats aphides, and Erastria scitiila, 

 which feeds upon scale insects, must be reckoned as benefactors to 

 mankind. 



The life-history of the latter moth has lately been worked out in 

 detail by Dr. H. Rouzaud, and is described (6) by Professor V. Riley. 

 It inhabits the shores of the Mediterranean, and its caterpillar 

 devours the coccids upon various fruit-trees, specially the black- 

 scale {Lecanium olece) of the olive. The moth, which is a small noctuid, 

 the white markings on whose wings give it the appearance of a bird- 

 dropping when at rest in the daytime, appears in May, and lays her 

 eggs, singly and far apart, upon the trees infested by the coccids. 

 When hatched, the young caterpillar selects a large female coccid, 

 eats its way through the scale, and devours the insect beneath ; 

 having done this it makes its way to a fresh victim. As it increases 

 in size it forms a case for itself made of the scales of its victims, 

 excrement, etc., bound together by silk which it spins, and, protected 

 by this covering, which closely resembles the smut-covered bark of 

 the tree, it roams about during its later stages, devouring several 



