20 



mend the preparation in the spring of a series of plats, separated 

 by walls through which the worms cannot pass, for these experi- 

 ments. As this worm infests to a serious extent nearly all of our 

 common garden vegetables, it will be an easy matter to obtain 

 material for experimentation. 



The work upon wire-worms is still in progress. Several species 

 have been reared to the adult state, and experiments have been 

 tried to determine the value of the growing of buckwheat, and of 

 mustard, on infested lands in order to starve the worms. I am 

 not yet ready to announce any definite results ; but our experi- 

 ments seem now to indicate that the importance of this remedy has 

 been greatly over-estimated. 



Much attention is being given, especially by several of the agri- 

 cultural students, to the study of greenhouse pests. One of these 

 pests, which occurred in great numbers both in the Insectarj^ and 

 in the plant-houses of the Horticultural Department, is a species 

 which has not previously been mentioned as occurring in this 

 country, although it is a well known European pest. It is in its 

 early stages a scale-like insect, infesting the lower surface of the 

 leaves of various plants. In the adult state it is a minute fly, 

 which is very conspicuous on account of a white, mealy powder 

 with which the body and wings are covered ; it is known to ento- 

 mologists as Aleyrodes vaporioruni. Two of the agricultural stu- 

 dents are making studies in the Insectary upon mealy bugs, upon 

 which they are to write their theses. I confidently expect that 

 conclusions will be reached by them which will be of practical im- 

 portance. 



The preparations for the study of hop insects are now completed ; 

 as our hop-yard is well established, and the hop Aphis appeared 

 in it last fall. 



The experience of the past year has realized our expectations in 

 regard to the value of an Insectary. This building has proved 

 indispensable to our work ; and the importance of such a building 

 is being appreciated elsewhere, for similar structures have been 

 erected at two other Stations. 



I am your obedient servant, 



J. H. COMSTOCK, 



. Entomologist. 



