REPORT OP COMMITTEE ON PUBLICATION . 215 



Mating. The mating habits of these beetles are conspicuous because 

 they appear to copulate during most of the time they are on the vines, 

 beginning soon after partaking of the first food and extending for several 

 weeks. Unlike most beetles they can be picked off the flowers and upon 

 being placed in a vial will continue to copulate, at least, for a short time. 



SUMMARY OF THE LIFE CYCLE. 



The life of one of these beetles occupies a period of about 13 months of 

 which almost 11 months are passed in the larval stage. The egg stage lasts 

 about two weeks, the pupal stage two weeks and the life of the adults about 

 one month. The adults die the latter part of July and early August. 



NATURAL CONTROL. 



The most important natural means of holding this insect in check appear 

 to be two: the few eggs laid by the females and the destruction of the larvae 

 by ground beetles species of the family Carabidae. The abundance of these 

 beetles in soil infested with grubs of the rose chafer led the writer to place 

 them in cages with larvae of the latter insect and here one species of Carabid 

 beetle ate the grubs. Harpalus pennsylvanicus was seen eating grubs in one 

 of the cages but the abundance of other species in the soil infested with 

 larvae of the rose chafer would lead us to expect to find that some of the 

 other species are also enemies of this pest. As this investigation is in 

 progress at the present time we hope to be able to report the same in a 

 later publication. 



ARTIFICIAL CONTROL. 



Various methods for the control of this pest have been advocated; three 

 of these appear to be the most practical. They are (1) spraying with 

 arsenical poisons, (2) hand picking, and (3) cultivation during the pupal 

 stage. 



Spraying. Entomologists have recommended various poison sprays for 

 this insect but the use of bordeaux mixture and arsenate of lead has been 

 the one most widely used. This material acted more as a repellent than as a 

 poison and while good results have been claimed from its use by some, 

 other workers have failed to control the beetles if numerous. For this reason 

 the rose chafer has always been considered a difficult pest to kill at least in 

 time to save the crop. The use of the sweetened sprays has been attended with 

 success during the past six years and they are the only ones recommended. 

 The mixture consists of cheap molasses (1 gal.), arsenate of lead (6 Ibs.), 

 and water (100 gals.), and should be used as soon as the beetles appear on 

 the vines. It may be necessary to make a second application within a week 

 after the first one if the insects continue to reinfest the vines. As mentioned 

 previously all sprays containing molasses must be applied so as to avoid 

 rains, and should rain occur the application must be repeated if the beetles 

 have not been poisoned. 



Hand Picking. Sometimes the beetles are collected by hand. This is 

 effective but expensive. A practical method is to shake the beetles into a 

 cloth, shaped much like an umbrella and having a can attached to the apex 



