336 



THE GYPSY MOTH. 



sexes found to be parasitized was 9.7 per cent, of the males 

 and 7.5 per cent, of the females. This does not agree with 

 observations previously made, where the larger per cent, 

 parasitized were found to be females. The greater part of 

 the parasitized pupae were brought in, and many were found 

 to contain Dipterous larvae. In most cases no parasite ima- 

 goes were obtained from these pupae, although some of the 

 Dipterous maggots have not yet transformed^ 



The Imago. 



The Process of Emerging, 

 The emerging of the imago from the pupa is accom- 

 plished as follows : when the insect is fully developed and 

 ready to come forth, it forces off the cap on the anterior 

 ventral part of the pupa, comprising the antennte, head and 

 leg shields, and through the opening thus formed the antennae 

 appear, and then the first two pairs of legs are drawn out. 

 The cap is attached to the rest of the pupa at its apex, and 

 its larger anterior end is pushed away from the body by 

 means of the feet. The legs at first are stiff at the joints 

 between the tibiae and tarsi. JsText, the juncture of the wing 

 covers on the top of the back splits, then the posterior 

 margin of the wing covers comes off, and the insect crawls 

 up and out of the pupa-case, the hind legs coming out at the 

 same time as the wings. This process requires from five 

 minutes to five hours, according to the resistance of the pupa- 

 case and the vigor of the enclosed imago. When the moth 

 first emerges it is quite moist, but soon dries off. From 

 twenty minutes to two hours are required for the develop- 

 ment of the wings. 



Descrvption of the Imago, 

 The following description was made from thirty males and 

 thirty-seven females. The males (Plate I, Fig. 3) measure 

 from 37 to 50 mm. (one and one-half to two inches) be- 

 tween the tips of the expanded wings. The ground color 

 of all the wings is brownish yellow, varying in intensity in 

 different examples, but somewhat lighter beneath. The 

 head, thorax, antennae and upper side of the palpi are 



