412 THE BUTTERFLIES OF XEW ENGLAND. 



deadly foe. lliis insect was first made known tome by ]\lr. \\\ Saunders, 

 who sent, me from Ontario three cater[)inars of Y. antiopa, eacli of whicli 

 proved to have been stuni>- by it, for on arrival the caterpillars were dead 

 and three tachinid pupae lay at the bottom of the box. It is then proba- 

 ble that in this case the female Phorocera laid but a sing-le c":"- in each cat- 

 crpillar, and as it effected its death, we can readily imagine, knowing how 

 prolific flies arc, what a devastation of antiopas this insect may create. 

 The larvae emerged from the caterpillars of antiopa between July 3 and 

 10, and broke the pupa shell on jNlay 4 of the following year. It there- 

 fore hibernates in tlie pupa state. But this parasitic fly probably some- 

 times lays more than one egg in a caterpillar, or a catci-pillar may be 

 attacked by more than one fly ; for, judging from specimens and notes in 

 Dr. Harris's collection, he obtained two flies from a single chrysalis ; and 

 Mr. J. Pettit of Grimsby, as I learn from Dr. Packard, found three dip- 

 terous larvae (of some kind) in a chrysalis, "which thev had eaten to the 

 shell." 



These are all the parasites as yet known ; but Gentry relates, in a pas- 

 sage already referred to, hoAv a score of the carabide beetle, Calosoma 

 scrutator, discovering an abundance of these "harmless though terrible 

 looking caterpillars" "were waging a desperate encounter with them,'" caus- 

 ing "destruction on a singularly grand scale." And Abbot records that 

 in Georgia "the large red wasps are great enemies to this species, seizing 

 on a cater|)illar and cutting it to pieces to make into a lump the better to 

 cari'v it to their nest to feed their younir with." 



Desiderata. With regard to the diflcrcnt broods of this insect we need 

 much more definite information over a wide extent of country before we 

 can determine the limits within which it is single, double, or triple brooded ; 

 probably these variations in its annual history will be found to correspond 

 to the Canadian, Alleghanian, and Carolinian faunas, so that observations 

 should be principally directed toward the boundaries of these districts. In 

 the Canadian faima particular attention should be i)aid to the hibernation 

 of the insect, for it is not impossible that the August brood of butterflies 

 may lay eggs and die the same season, while their progeny pass the winter 

 as chrysalids and so produce an early crop of butterflies ; thus making the 

 species double-brooded, as farther south, but by a difterent process. The 

 same cpiestion of hibernation in the Alleghanian fauna needs careful exam- 

 ination, as will be seen from the preceding observations. It is quite possi- 

 ble that the habit of wintering as chrysalids may obtain in one place and 

 not in another. Investigations upon the sounds })roduced by our butter- 

 flies can l)cst be undertaken upon this species. 



