308 ANNUAL REPORT. 



The pupa case consists of the shrunken and hardened skin of the mature larvje^ 

 and the fly issues by a sort of trap door at the upper end. The four winged para- 

 sites include a great number of very diverse forms, all bearing more or less resem- 

 blance to bees and wasps which are among their near relations. The females are 

 furnished with bristles or horny organs at the tip of the abdomen which are of a 

 great variety of shapes and lengths. These are the oviparitors, by means of which 

 they can place their eggs in the bodies of caterpillars, worms and boring grubs 

 which they cannot closely approach. Some of these flies like the larger Tchneu- 

 monidae, are so large that a great caterpillar such as the Polyphemus or Cecropia, or 

 some of the grape vine or tomato vine Sphinxes, are only suSicient for food for a 

 single larva;. Others are so small that a hundred or more will be nourished on the 

 fatty parts of a single worm. Some have oviparitors four or five inches long by 

 which they are able to find the borers in trees and place in their bodies an egg 

 from which hatches a sort of insect cancer for which there is no cure. By some 

 strange instinct these parasitic larv« avoid the vital pans of their victim which 

 feeds languidly and lives along until its tormenting guests have completed their 

 growth and are ready for transformation. 



We have all seen large sphinx worms on the grape or tomato or tobacco whose 

 bodies were covered with tiny white cocoons, like grains of rice set on end, which 

 were still alive though punctured in a hundred places where the little parasites had 

 cut their way but. It is unfortunate that the "first law of nature" enables us to 

 look with satisfaction on such barbaric and pitiless processes, but if insects did not 

 prey upon each other in the ways I have mentioned man would never be able to 

 hold his own against them. The multiplication of the vegetable feeding species is 

 so rapid and excessive on all our most important plants that were it not for the 

 assistance we receive from the small, but not insignificant allies, whose vigilance 

 far surpasses our own, they would soon take complete possession of our fields and 

 orchards and leave us penniless and disheartened. 



It is most desirable that all should learn to aistinguish the beneficial from the 

 injurious species, that the former may be exempted from the death sentence which 

 we are very apt to execute without any form of trial, and in so doing often destroy 

 a friend instead of a foe. This is a branch of economic entomology that should 

 receive especial attention at our agricultural colleges and at all meetings that have 

 for their object the promotion of practical agricultural science. 



BLACKBERRY CULTURE. 



On motion of Mr. Cutler, Mr. C. H. Hamilton was requested to give 

 the Society some of the results of his experience in blackberry culture. 



Mr. Hamilton. Mr. Pre.sident, I did not come here with anyinten- 

 tions of making a speech, and I hardly know now where to begin on 

 this blackberry question. I will state to you, in the first place, that 

 we are quite extensively engaged in cultivating blackberries; also 

 other small fruits, but we are making a speciality of blackberries. 



I think it was about eight years ago there was some three acres 



