BIOLOGY OF LIMNERIUM VALIDUM. 



83 



to disease, and the experiment was closed without any conchisive 

 evidence being gained, although the inference may be drawn that 

 Limnenmn valid um is not adapted to the gipsy moth. 



EXPERIMENTS WITH OTHER HOSTS. 



Several experiments were also started with caterpillars of the com- 

 mon tussock moth {Ilemerocampa leucostignui Smith and Abbot) 

 and of the mourning-cloak butter- 

 fly {Euranessa ant'ioiKi Linnaeus), 

 but for various reasons they furnish 

 no satisfactory evidence to show 

 whether these hosts can be- para- 

 sitized successfully by Limnerium 

 validum. It is rather unfortunate 

 that the experiment with the 

 Hernerocampa did not give any 

 results on account of disease prev- 

 alent among the caterpillars, in view of the fact that this species 

 of Limnerium has been reared by Dr. L. O. Howard from the tussock 

 moth at Washington, D. C. In Massachusetts, however, it has never 

 been surely reared from this host, although large numbers of the 

 tussock moth have been collected in various parts of the State and 

 carefully studied at the Gipsy Moth Parasite Laboratory. It seems 

 likely^ therefore, that the Limnerium varies "in habits in different 

 parts of the country, or this apparent difference in host relationship 



may be ascribable merely to 

 changes in its seasonal his- 



FiG. 33. — Limnerium validum: Egg. En- 

 larged about 120 times. (Original.) 



tory brought 

 colder climate. 



about by a 



NOTES ON DEVELOPMENT 

 AND ANATOMY OF THE 

 LARVA. 



THE EGG. 



Pig. 34. — Limnerium validum: Eclosion of larva, 

 Enlarged about 120 times. (Original.) 



The Qgg (figs. 33, 34) of 

 Li7nnerium validum is elon- 

 gate kidney-shaped or subcylindrical and rather convex on the dorsal 

 side, slightly concave ventrally, with both poles bluntly rounded. 

 The chorion is heavily chitinized, comparatively thick and resistant, 

 and with a perfectly smooth surface. Its color is pale brown, or 

 sometimes nearly Avhite in the case of freshly deposited eggs, but not 

 always, as fully colored eggs may be found in the oviducts of dis- 

 sected females. In size the egg is about 0.35 to 0.41 mm. long and 

 0.13 to 0.14 nnn. in transverse diameter. 



