SLUG CATERPILLARS ON ORANGE. 



141 



Fig. 58. — Laijoa opcrcularis, co- 

 coon. (Original.) 



whicli is readily piislied opea from witiiin by the escapiug moth, but 

 does uot yield to pressure from without, and is so accurately fitted that 

 no tell-tale crack can be discerned. Upon the 

 back of the cocoon is an elevation formed by the 

 meeting of several folds and ridges, forming a 

 marvelously exact imitation of a winter bud. 

 The ends of a lock of hair from the body of the 

 caterpillar counterfeit the down which in nature protects the dormant 

 bud. The substance of which the cocoon is made is a tough parchment, 

 composed of agglutinated silk, in which is felted the long, hairy cover- 

 ing of the larva. Its color is a neutral brown, closely approximating to 

 that of the bark upon which it is placed. The entire arrangement is a 

 most successful representation of the stump of a small branch broken 

 off near its junction with the main stem, 

 and upon which is plainly shown the 

 swelling of a bud. 



The ])erfect insect (Fig. 59) is a moth 

 with a very wooly body, pale yellow, 

 tinged with brown. The fore wings 

 are umber-brown at the base, fading to 

 pale yellow outwardly; the surface is 



Fig. o9.—Lagoa opercularis, tuotb. 

 inal.) 



(Orig 



marked with fine wavy lines of silver 

 gray, and the fore margins are nearly black. The legs are yellow, with 

 dusky feet. The wiugs of the male moth spread about one inch ; those 

 of the female an inch and a half. 



Life-history. — The larva is a very general feeder, and although the 

 Oak appears to be its principal food plant, it is occasionally injurious to 

 the Orange. It never injures the bark or tender shoots, but subsists only 

 upon the mature leaves. 



There are two broods, one in early summer and the other in the fall. 

 The larvte of the second brood form their cocoons in November or De- 

 cember, and in them pass the winter, not changing to pupa until'the 

 following March or April, or about. two weeks before the moths ap])ear. 



Parasites. — The same parasites have been bred from Lagoa as from 

 tlie Orange Dog. Tachina flies issued in June from a cocoon found on 

 Orange in ]\Iarch. The hymenopterous parasite Chalcis rohusta issued 

 September 15 from a cocoon collected August 27. 



THE SADDLE-BACK CATERPILLAR. 



[Empretia stimulea Clemens.) 



[Figs. GO and Gl, and Plate XI, Fig. 3.] 



The caterpillar of this species, also a general feeder, is short and 

 thick, and very strangely marked with a large, quadrate i)atch of ^reen, 

 in the center of which is an oval spot of purjile, so that the animal 



