PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 625 



-what these factors are, efforts will again be made this year to find these 

 out, so as to be able to have ready a large number of live adults for in- 

 oculating the first brood caterpillars in the chaur early in the season. 

 The object in view may also be accompUshed by work in another Une 

 and that h by first ascertaining if the Agrotis ypsilon caterpillars, which 

 are reported to be found in the Hills during the rains, are parasitized 

 there and, if so, by introducing a large number of affected caterpillars 

 from the Hills in August and September and rearing them out for use 

 in the chaur. Work on this line will be taken up this year along with 

 the trial in the Insectary for carrying through the local parasite during 

 the aestivating period. 



28.— CONTROL OF THE MELON-FLY IN HAWAII BY A 

 • PAEASITE INTRODUCED FROM INDIA. 



By David T. Fullaway, Honolulu, H.I. 



The Hawaiian Islands are situated in the midst of a vast ocean. 

 They are completely isolated from the continent, so that insects de- 

 trimental to agriculture cannot easily reach them. But with the de- 

 velopment of trade on the Pacific, the Islands have become a commer- 

 cial crossroads, a day seldom passing without a steamer putting into our 

 main port, and despite the strict inspection and quarantine of horti- 

 cultural products a serious pest now and then does slip in. Our equable 

 climate permitting almost continuous breeding, an excessive multipli- 

 cation and rapid spread of the pest soon result. Thus it was that 

 the melon-fly {Chcetodacus cucurbitae) gained access to the islands about 

 1895, and thereafter melons of any sort could not be grown successfully. 

 A somewhat similar experience later with a more destructive insect, 

 the Mediterranean fruit-fly, aroused public interest to the extent of in- 

 ducing the Government to experiment with the possibility of controll- 

 ing the injuriousness of the fly by searching out and introducing its para- 

 sites, that is to say, other insects that were known or could be ascertain- 

 ed to live at the expense of the first. Parasitism among insects is a. 

 very common phenomenon, which even the layman to-day is acquainted 

 with, and the check which this parasitism exerts on the multiplication 

 of insects is also well-known. It should be pointed out here that the 

 same circumstances which prevent the migration of injurious insects 

 to our isolated islands, also prevent beneficial insects from reaching us. 

 Likewise, the same causes which lead to the rapid spread and excessive 

 multiplication of injurious introductions, operate equally on the bene- 

 ficial ones that prey upon them. In other words, the method of con- 

 trolling injurious immigrant insects by the introduction of their para- 



o2 



