NYMI'IIAUXAK: roLVdOXIA IX TKKItCX i AI'lOXIS. 331 



thing apparently goes on well, and the caterpillar assianes the (;hry8alis 

 state, but by and by, instead of a butterfly, out comes, through a hole in 

 the side, a swarm of tiny flies. W it were not for these creatures the 

 caterpillar would soon become a formidable and destructive pest" (Rep. 

 Ent. soc. Ont., 1872, 32). Mr. Edwards has had a worse experience: 

 "When it is considered how many eggs are laid, and that so short a time 

 inter\cnes l)et\^•een the egg and the imago, it is surprising how few butter- 

 flies of this species are the result. From eggs that were laid on my vines in 

 July and August, amounting, 1 am sure, to many hundreds, very few larvae 

 were hatched, and gradually these became more and more scarce, so that 

 at last I could with difficulty discover a single one. The eggs are destroyed 

 by spiders and various insects by wholesale. I have had the contents 

 of one of my kegs swept away in a night, leaving not atraceof shell behind, 

 and in the same way I have lost scores of small larvae. . . . Finally after 

 the larvae have escaped all ap[)arent danger and have changed to chrysalids, 

 the imago therein is often destroyed by ichneumon flies. So that it is doubt- 

 ful if nuich more than two per cent of the eggs laid produce butterflies." 

 (Butt. N. A., i, Grapta 5.) Hoplismenus morulus (88:9) isalsoafoeto 

 this caterpillar, which changes to chrysalis with the parasite Avithin the 

 body ; the latter makes its escape later by decapitating the chrysalis (88 : 16) , 

 as shown by a specimen received from Rev. Mr. Bethune. The eggs are 

 often destroyed by a minute [)arasite, Telenomus graptae How. (89:9), a 

 dozen or moi-e of which will issue from a single egg a dav or two after 

 others laid at the same time have given birth to caterpillars. Accord- 

 ing to Mr. Gentry, either the caterpillar or the butterfly (he does not 

 say which, but Ave presume the latter) is devoured by the Avood pcAvee, 

 Contopus virens (Linn.). 



Desiderata. Tiie time of appearance of this insect in the NeAv Eng- 

 land states is not yet determined Avith sufficient exactitude, the account 

 given here requiring complete verification ; the haunts of the butterfly, its 

 mode of flight as contrasted Avith the other species of the genus, and the 

 question of its hibernation, all demand examination ; and what relation the 

 tAvo forms of the perfect insect bear to the seasons or the different localities 

 in Avhich they occur needs the Aery closest investigation. Is it anvAvhere 

 single brooded, and if so, Avhich form prevails ? Does the hibernating 

 brood ever contain any butterflies of the form umbrosa V Is there any 

 evidence of the slightest constant or comparative difl'erence betAveen the 

 two forms in such habits or peculiarities as vary in the different species ? 



LIS T OF ILL US TEA TIOXS.—POL 17V OXIA IX TERR GA TIOXIS. 



General. 89 : 3. Pteromalus vaiiessae, a parasite. 



PI. 20, fig. 3. Distribution in North America. 9. Telenoniu>graptae, an egg parasite. 



88:9. Hoplismenus morulus, a parasite. E(ig. 



16. Cbrysalis of r. interrogationis as p|. (U, lig. 10. Columns of eggs, 

 cut by Hoplismenus morulus in escaping. 17, Single egg, colored. 



