NYMPIIALINAE : BASILARCIIIA ARCHIPPUS. 279 



prisoned Ilyinenoptcra make their escape. One June 25 I was examining 

 a wintered chrysalis given me by Mr. L. Trouvehit, when it suddenly began 

 to swarm witli these little parasites. Instantly upon emerging from little 

 holes wliich tiiey had bitten out near the ti[)s of the wings, they began to 

 pair, the males awaiting the females at the edge of the opening. They 

 ran rapidly upon and about the chrysalis and made short, hopping flights 

 of a little more than a centimetre in distance. All but two specimens were 

 secured and I was surprised to find the proportion of males to females less 

 than one to six, the total number being 17 males and 108 females. All 

 had emerged within half an hour of the appearance of the pioneer. 



The wintering caterpillar is also attacked l>y Apanteles limenitidis, a 

 larger hymenopterous parasite, whicli stings a single larva while very 

 young, emerging from its host while it is in the second stage and spinning 

 its cocoon beside the larva upon the silk which had afforded it a foothold. 

 One may sometimes find these cocoons on the eaten leaves just before the 

 time for the caterpillar to seek winter quarters. Limneria limenitidis 

 (88 : 5) and Ichneumon caliginosus, also among the larger forms, are 

 further enemies of the caterpillar, and Riley states that he has often 

 noticed the eggs of one of the Tachinid flies "fastened transversely on the 

 back of the neck of the larva," though none has ever been reared. Nor is this 

 all ; the egg also has its perils. Miss Guild discovered late in July one 

 or two specimens of a leaden hue, which upon examination proved to be 

 empty, the parasites having escaped through an almost imperceptible hole 

 in the bottom of the egg ; within was a sort of hardened, gummy nidus of 

 caked yelk, covered over wdth a thin layer of spun silk, but no pellicles 

 of chrysalids coidd be seen. Mr. Riley has since been more fortunate, 

 having obtained a parasite and described it under the name of Tricho- 

 gramma minutum. Out of about two hundred eggs of this buttei'fly ob- 

 tained in a single spot fully one-half were parasitized, from four to six flies 

 escaping from each egg. I have since found others late in June similarly 

 attacked, which belong to a second species of the same genus, T. minutissi- 

 mum. I have also more than once found the base of an eaten egg, on an 

 untouched leaf, showing the presence probably of spiders which had 

 snatched away the little caterpillar before its second meal. 



Desiderata. It is essential to note the comparative abundance or ab- 

 sence of this insect in every possible northern locality in order to determine 

 its exact limit ; to record also the exact time at which the caterpillar leaves 

 its hibernaculum on each kind of tree ; how many times tlie larva moults 

 before constructing its winter residence and whether the stage is invariably 

 the same ; whether the summer caterpillars c\ or liibernate after the manner 

 of Nymphalis ; how commonly it winters in the imago state and whether 

 such hibernation is common to both sexes ; and finally in wliat features the 

 flight of this buttei-fly differs from that of its congeners. 



