vi HETEROCERA LIMACODIDAE 403 



the integument are much changed, so that in the adult 

 larva (Fig. 199) the spines have subsided into the condition 

 of mere prominences, different in colour from the rest of 

 the surface. These larvae appear to be destitute of a head, 

 but there really exists a large one which is retracted, except 

 during feeding, into the body ; the five pairs of abdominal feet of 

 the larvae of allied families are replaced by sucker-like structures 

 on the first eight abdominal segments. The spinneret of the 

 mouth is not a pointed tubular organ, but is fish-tailed in shape, 

 and hence disposes the silky matter, that aids the larva in mov- 

 ing on the leaves, in the form of a ribbon instead of that of a 

 thread. It has been stated that these peculiar larvae " imitate " 

 the coloured galls frequently found on the leaves of trees. The 

 North American forms of this family have very varied and most 

 extraordinary larvae. 1 In the pretty and conspicuous larva of 

 Empretia stimulea, the tubercles or processes of the body are, in 

 the later stages, armed with hairs, that contain a poisonous or 

 irritating fluid, said to be secreted by glands at the bases of the 

 processes. These hairs are readily detached and enter the skin 

 of persons handling the caterpillars. The larva of the North 

 American Hag-moth, Phobetron pithecium, is a curious object, 

 bearing long, fleshy appendages covered with down. Hubbard 

 makes the following statement as to the instincts of this larva : 2 - 

 " The hag-moth larvae do not seek to hide away their cocoons, 

 but attach them to leaves and twigs fully exposed to view, with, 

 however, such artful management as to surroundings and har- 

 monising colours that they are of all the group the most difficult 

 to discover^ A device to which this Insect frequently resorts 

 exhibits the extreme of instinctive sagacity. If the caterpillar 

 cannot find at hand a suitable place in which to weave its 

 cocoon, it frequently makes for itself more satisfactory surround- 

 ings by killing the leaves, upon which, after they have become 

 dry and brown in colour, it places its cocoon. Several of these 

 caterpillars unite together, and selecting a long and vigorous 

 immature shoot or leader of the orange tree, they kill it by 

 cutting into its base until it wilts and bends over. The 

 leaves of a young shoot in drying turn a light tan-color, which 



1 See Packard, P. Amer. Phil. Soc. xxxi. 1893, pp. 83, 108, Plates. (He uses 

 the terra Cochliopodidae instead of Liruacodidae) ; also Dyar, as above. 



2 Insects affecting the Orange, Washington, 1885, p. 143. 



