Sept., I9I4-] Dyar: New York Slug-Caterpillars. 225 



Affinities, Habits, Etc. 



The larva belongs to the " tropic spined Eucleids " section 2, type 

 3 of my synopsis (Journ. N. Y. Ent. Soc, VII, 236), nearly allied 

 to Adoneta, Euclea and Sihinc. The spine-patches are present as in 

 these genera, both the caltrope spines of the lateral horns and the 

 terminal patches of Euclea and Sihine. The coloration is a rather 

 subdued warning color, more conspicuous than in Euclea but less so 

 than in Parasa indetermina, to which it is more nearly allied in 

 pattern. An unexpected modification is seen in the length of the 

 horns, which are all equal, not irregularly shortened, as in the genera 

 cited. This might appear at first sight a character of generalization, 

 allying the species to lower forms such as Natada and Sisyrosca, but 

 this relationship is negatived by the structures above cited and the 

 equality of the horns is undoubtedly secondarily acquired. 



But by far the most remarkable character is that of the eggs. 

 These are typically those of the Megalopygidse and not those of the 

 family Cochlidiidse at all. All our other Cochlidiid^e have flat, trans- 

 parent, wafer-like eggs, similar to but flatter than those of the Tor- 

 tricidae. The Megalopygidse, however, have eggs of appreciable thick- 

 ness covered with hairs, exactly like those of Monolenca. The 

 Megalopygidae are evolutionally a much lower group, from which the 

 Cochlidiidse may be directly derived. The Megalopygid type of tgg 

 has been supposedly already replaced by the new type in the original 

 ancestor of the Cochlidiidse, and its sudden reappearance in one 

 species of Cochlidiidse high on a specialized branch of the genealogical 

 tree is certainly surprising. 



Very little is known about the life history of Monolcnca semi- 

 fascia. I have never seen a larva in nature, and the late Dr. Riley, 

 who appears to have been the only person known to have seen one, 

 failed to record the food plant on which it was sent to him.^ My 

 larvse fed readily on nearly every leaf offered them and were mostly 

 bred on wild cherry and persimmon. It is presumable that the larvas 

 are semi-gregarious when young, scattering when older, much as with 

 Sibine, and that they will feed on many bushes or low-growing trees 

 with smooth leaves. There is but one brood a year, the adults emerg- 

 ing from overwintering cocoons about the middle of July, the larvae 



1 Very recently a specimen has been received from Rosharon, Texas, bred 

 from pecan by Mr. G. W. Coles. 



