March, 1S96.] DvAR AND Morton, New York Slug Caterpillars. 3 



conversion of the primitive setae into urticating spines on the two upper 

 rows of warts and in the development of certain detachable specialized 

 skin spines in the last stage.* 



Affinities, Habits, Etc. 



The genus Sibine contains but one species in North America, north 

 of Mexico, though represented by several in Central and South 

 America, with most interesting larvae, to judge by Sepp's figures. 

 Our larva is nearly allied to Eiiclea, Adoneta and Parasa, possessing 

 in common with them most of the special structural characters de- 

 scribed above. It is the most specialized larva of its group («• type 2"). 

 This is one of our most common species of Eucleidffi, and has a wide 

 range of food plants; basswood, cherry, chestnut, oak, corn leaves and 

 Caiina indica being a few among its many favorites. The young larvae 

 feed indifferently on the upper or underside of the leaf, consuming all 

 but a thin skin, and Vi\\\\\.& y-inversa, feeding around themselves, leav- 

 ing irregular patches on the surface where they have fed (Plate I, fig. 21) 

 until they reach the third stage, when the whole leaf is devoured in 

 large holes, either on the edge or in the body of the leaf. 



The species is single brooded, the moths (Plate I, fig. 15) appear- 

 ing in July. The males fly, seeking their mates in the early twilight, 

 and on favorable nights (warm and damp with a slight breeze) come 

 in swarms to the cages, their wings fluttering and dancing rapidly over 

 the surface of the gauze wire, where the females are confined, or dart- 

 ing in circles about the cages seeking an entrance. The couples remain 

 paired usually until the same hour the next evening, though occasion- 

 ally they separate earlier. The females lay their eggs during the night, 

 in patches of from thirty to fifty, on the upper side of the leaf. The 

 eggs hatch in ten days, but the larvae develop slowly, maturing in Sep- 

 tember or even not until October. The larva of stimuka is well known 

 for its stinging properties; the nettle-like spines being capable of inflict- 



*We conceive the "caltropes" (Plate I, fig. 5) to be modified skin spines and 

 the long spines (Plate I, fig. 7) to be modified " caltropes." We trace the following 

 series. In Euclea in deter mitia there are no detachable spine patches, but only 

 "caltropes." E. pcemdata {elliotii) has one pair of patches; E. delphinii two 

 pairs, but smaller and less developed than in Sibine. The spines also are smaller 

 and have a swollen base, looking like elongate " caltropes." We expect to figure 

 them when we reach Euclea. The caltropes are about the same size in all 

 (0.068 mm. ), but the spines becor.^e larger as they are belter developed. In pcznti- 

 lata their length is 0.28 mm.; m delphinii, 0.56 mm. and in stimulea 0.89. 



