ditions when there is no possibility of drift onto nearby plants. 

 Tomatoes, grapes, and roses are particularly susceptible to injury. 

 Applying a dilute spray using nozzles that deliver large, coarse 

 droplets and low pressure reduces the possiblity of drift. 



Clean the sprayer thoroughly after using it to apply 2,4-D be- 

 cause trace amounts of this herbicide can injure sensitive crops. 

 In fact, it would be best not to use the same sprayer for other 

 crops. If this is unavoidable, rinse thoroughly with clean water 

 and then fill the tank with a solution of 1 part household ammonia 

 to 99 parts water and allow it to remain for 24 hours. Then pump 

 some of this solution through the system, drain, and rinse again. 

 A quicker method is to fill the tank 1/3 full of water and add 1/4 

 pound of activated charcoal and 2 to 4 ounces of laundry detergent 

 for each 10 gallons. Agitate the mixture and swirl it around in 

 the tank for at least 2 minutes so that it reaches all parts of the 

 tank. Pump some through the system, drain, and rinse with clean 

 water. 



Where broadleaf perennial weeds are a problem in established 

 strawberry beds, 2,4-D can be useful for their control, but it 

 must be used with extreme caution because of the possibility of in- 

 jury from drift onto nearby sensitive plants and the need for re- 

 moving every trace of it from application equipment. 



*************** 



THE PLUM CURCULIO: AN INTRODUCTION AND SUMMARY OF PRELIMINARY 



FIELD OBSERVATIONS, 1976 



Karen I. Hauschild and Ronald J. Prokopy 

 Department of Entomology 



The plum curculio is one of the most serious pests of apples 

 in Massachusetts. It is a native species, originally found on 

 wild plums, crabapples, and hawthorn; however, with the past cen- 

 tury, it has adapted to most tree fruits as they have become in- 

 troduced from Europe. Here we outline the life history as known 

 from the literature, and discuss some of the results of our first 

 year (1976) of research studies. 



Dr. Whitcomb, of the Waltham Experiment Station, conducted 

 an extensive study of the biology of the plum curculio in Massa- 

 chusetts in the 1920' s. He found that in some years a few adult 

 curculios arrive on apple trees as early as the pink stage. Ac- 

 cording to his study, feeding punctures can be found from the 

 last week in May, while oviposition (egg-laying) occurs from late 

 May to mid-July. Mating, he found, occurs prior to, or during the 



