EXPERIMENT STATION REPORTS. 85 



words most of the river woods have been drained at trifling expense by 

 this department and the Department of Forestry, by means of open ditches 

 following, as far as possible, the natural outlets. These pools were exten- 

 sive breeding places for mosquitoes and, as they lie to the south and east 

 of the campus, the pests are driven in by the winds in great numbers. 

 It also is probable that the pools in the vicinity of the athletic field will 

 be drained during the summer, thus adding much tillable land to the farm 

 on which they lie. This will take away considerable breeding space and 

 render the work much easier next season. 



The wet weather that prevailed during the season of 1902 and which 

 seems about to be repeated this year, has made plant-lice numerous and 

 kept the grasshoppers down. The Hessian fly is becoming less destruc- 

 tive as we are approaching the bottom of the wave of destructiveness. 

 It is to be looked for again in a few years, however late sowing will 

 retard the wave and render the next incursion less disastrous. 



A disease of the California apricot scale has just been found working 

 in our orchards and vinej-ards. It is hoped that it will be well established 

 before long. 



An accident to myself has rendered it impossible to do as much travel- 

 ing as I should like, but I, hope to be in better condition soon. 



During the winter, the entomologist, at the request of Professor U. P. 

 Hedrick, advised with him in relation to the spraying of the elms on the 

 campus, and also kept the records of the applications and treatment as 

 a whole. It may truthfully be said to have been a success, although the 

 scales still exist in many places on the trees. It is utterly impossible to 

 eradicate them in one or two years. Owing to wind conditions, many 

 trees were sprayed on one side only, and in other cases, the spray of 

 lime, salt and sulphur was found to be inefficient, owing probably to too 

 long a time elapsing between the preparation and application of the 

 spray. At the same time, the trees have been greatly benefited as can 

 readily be seen, and probably they will show still greater improvement 

 later in the season. Lime, salt and sulphur is said to be very slow in its 

 action while fairly certain in its results. 



An extended experiment bearing on the question of broods and time 

 for spraying for the codling moth has been started. It has required and 

 will require from now on, a great deal of field work, but the question is 

 of such interest that it is deemed time and labor well expended. It is 

 expected that the time of egg laying for .the second brood may be de- 

 termined and possibly the existence or absence of the third brood may 

 be demonstrated. 



A fumigation house has been built for the purpose of experimenting 

 with hydrocyanic acid gas in the control of forcing-house pests as well 

 as the pests of roses, carnations, chrysanthemums, etc. Little has been 

 done along this line, and the writer is constantly asked for information 

 relative to the control of mealy bugs in cucumber houses, etc. This house 

 and its accessories furnishes a complete outfit for the fumigation of 

 nursery stock, cuttings, etc. 



Several oily compounds are at hand which are to be tested compara- 

 tively for their effects on mosquitoes. 



The work on scale insects of the more difficult species is going on as 

 opportunity offers. The reason for this work, being little understood, it 

 may be of interest to some to know that the identity of many of the 

 fleshy scales can at the present time merely be guessed at. Their charac- 



