862 IiKPOTJT OF THE DKPART^[F.XT OF ExTOMOLOGV OF THE 



juries to the fruit and foliage and to reduce to the smallest pos- 

 sible numbers the insects that would seek to hibernate in the soil, 

 all of the plats were sprayed with nicotine extract and soap. The 

 larvae are very readily killed on Kieffer pears, and with the ex- 

 ception of small numbers of them that were feeding along the 

 rolled edges of the unfolding leaves very few escaped the treat- 

 ment. The damage to the foliage by the remaining larvae was 

 unimportant. 



THE EFFECTS OF SPRAYING MIXTURES ON FOLIAGE. 



^Notwithstanding the repeated sprayings in a short space of time, 

 in none of the experimental plats did the applications of the nico- 

 tine extracts, in combination with soap or kerosene emulsion in 

 the proportions as given, cause any injuries to the tender unfold- 

 ing leaves. Throughout the attacks by the young and old thrips 

 the foliage of the trees in the sprayed plats presented for the most 

 part a fresh and healthful appearance which contrasted strongly 

 with that of the untreated trees. There was also no apparent 

 checking of the new growth, which appeared to be of normal vigor 

 and amount. In some orchards kerosene emulsion when used 

 alone in strong mixtures caused considerable injury both to the 

 foliage and bark of the young wood. The emulsions were appar- 

 ently stable, but they proved, in spite of the great dilution, to be 

 the least safe of the spraying mixtures when used in quantities to 

 drench the trees, as is necessary for the successful control of the 

 thrips. 



DISCUSSION OF RESULTS. 



In its appearance and habits the thrips is quite different from 

 all other insects which the pear growers in this State have been 

 accustomed to combat. It also has the reputation of being a very 

 difficult species to control satisfactorily, which has been well borne 

 out in this season's work. The insect is more susceptible to spray- 

 ing than any other measure, but it is a formidable pest to combat 

 by even these means because it works rapidly and the prospects of 



