400 ENTOMOLOGICAL SOCIETY 



Among the Batrachia the Bufonidae are occasionally found in 

 fested with Dipterous larvas in Europe. The subject has recently 

 received treatment at the hands of Dr. Fr. Meinert, who has de 

 scribed the larva of a Lucilia found in the eyes of a toad. The 

 eggs had been laid upon the back of the head, and the larvas had 

 evidently made their way from that point to the eye. This was 

 a case of parasitism of a healthy toad, but previous writers have 

 assumed that in similar instances the eggs have been laid upon 

 injured individuals, in sores or cancerous spots. 



OTHER CLASSES. The Worms, the Radiates, and the Mollusks 

 are measurably free from insect parasites, though one of the marine 

 mites, Atax bonzi, was found by Claparede to live within the 

 shell of a fresh-water mussel, whether as a commensal or as a 

 true parasite does not appear. 



ARTHROPODS. Representatives of nearly all orders of insects 

 are affected by parasites of their own class. Aquatic insects are 

 less affected than terrestrial, but even here there is a group of well- 

 known water mites (Hydrachna) which attack various aquatic 

 species. I have recorded 15 different species of Hymenopterous 

 and Dipterous parasites reared from Hyphantria cunea and 14 

 from Leucania unipuncta, and these are the highest numbers 

 recorded on any one insect in America ; but in Europe, in 

 addition to a number of Diptera, as many as 63 species of 

 Hymenopterous parasites are recorded as attacking a single 

 species, viz., the " Winter Moth" {Cheimatobia brumata}. In 

 all these cases, however, the hyper-parasites are included with 

 the true parasites. It is usually the larva of the insect which is 

 attacked, but both the egg and the pupa state are also affected, 

 while occasionally the parasitized individual succeeds in attaining 

 the imago state before succumbing to the parasite. Even the 

 imago is sometimes attacked, and this is especially true in the 

 Orthoptera, the attacks of Tachinids being more frequent on the 

 imagines than on the adolescent states. Mites, especially those of 

 the genera Uropoda and Gamasus and the larval form of Trom- 

 bidium, attack many insects in all states but the egg. 



DEFINITIONS. 



A preliminary definition of the scope and intent of the terms 

 used always helps and, in fact, is often absolutely necessary to 



