368 



AN ATTEJIPT TO CONTROL tNSECT PESTS 



sequence of parasites iu certain localities. Japan is one locality in which 

 the moth is supposed to be coatrolled, and they give a table as follows : — 



Parasites. 



Egg. 



Larval istagics. 



Pupal Stagks. 



H 



P 

 < 



(So 





If 



o ^ 



Is 



If 



43 ^ 



if 









li 





A:?tastatti!i h'tfasclatU6 ... 

 Schedius kuvanae 

 Apaiiteles fulvipcs, 1st 



generation. 

 Apaiitelcs fidrqies, 2nd 



generation. 

 Ci'ossocosiula fiericavlae.. . 

 Tacliina japonlua 

 Chalets obsctirata 



1 































i 

























1 





















""" 











1 





















1 



In this table the vertical columns indicate the various stages in the 

 development of tiie moths, with their duration. The dotted Hue following 

 the name of the parasite shows the stages during which the moth is likely to be 

 attacked by that parasite, while the solid line indicates the stages during which 

 it is likely to contain this parasite in its body. Six other species, indicated by 

 the authors as probably unimportant, have been omitted from the table, which 

 shows a complete sequence of attack. 



In Kussia, it was found that in some areas parasites were plentiful, while iu 

 others parasites were few, but that an epidemic of disease had very much reduced 

 the pest. 



In France, the parasitism of the gipsy moth was found tu be nnicli less than 

 was anticipated, ranging only from 25 to 40 per cent., but the conditions of the 

 insects' life were so adverse otherwise that this was not considered surprising. 

 It is urged that this difference in the conditions, with the resulting alteration in 

 the habits of the moth, as compared with what obtains in the United States, 

 does not permit of the deduction that parasitism would be ineffective in the 

 latter country. 



One is impressed with the desire of the authors to reconcile facts with hopes, 

 rather than to base their hopes on the facts. They endeavour to account for 

 the poverty of parasitism and come from their explanations with renewed hope. 



Brown-tail moth parasites were studied from Europe only, where it is less 

 checked by parasites than gipsy moth. A disease attacks this species, which 

 may be of importance, and which already occurs in the United States. A 

 sequence is given for its parasites. 



Gipsy moth parasites in America are discussed in detail. Tacliina i/iulla, 

 Wlk., is interesting, being a fly which lays eggs on the caterpillars. The fly 

 larvae frequently fail to live and the moth emerges ; this may be due to one of 

 the following causes : — f 1) absorption of the larvae, on penetrating the skin, by 

 phagocytes ; (2) the larva penetrates and lives in a funnel formed under the 



