April, '12] PARROTT: PEAR THRIPd 187 



is actually increasing in clestructiveness. Future observations may- 

 lead to this conclusion. Prolonged droughts for successive years and 

 an abnormally early development of fruit buds during 1910 afforded 

 perhaps exceptional conditions for its destructive work that yeav, 

 which eventually led to its detection. The question may well be 

 asked as to whether the insect has been lately introduced or is a well- 

 established species which has recently emerged from a state of obscurity 

 and has risen at last to a position of first prominence. 



Control of Thrips by Spraying. The Station conducted a number of 

 experiments with various spraying mixtures, largely according to the 

 directions of Foster and Jones, which have recently given such prom- 

 ising results in their work in California. The standard nicotine prep- 

 arations with either soap or kerosene emulsion proved exceedingly 

 satisfactory sprays, for they killed all the insects wetted by them. 

 To destroy the thrips buried in the substance of the bud or in the 

 compact blossom clusters the use of the oil emulsion with the tobacco 

 extract is perhaps to be preferred; but when the thrips are in exposed 

 positions a combination of the nicotine spray with soap was surprisingly 

 effective. Both of the above combinations proved to be very safe 

 to the foliage and, notwithstanding the fact that the trees were sprayed 

 from three to four times on successive days, there was no material 

 injury to the leaves. As recommended by the above writers, the 

 Station will advise the growers of this State to make at least two appli- 

 eations for the adults to protect the expanding buds and blossom 

 clusters, and one or two treatments to destroy the larvae. In the 

 spraying of pear orchards the young thrips were very susceptible to 

 treatment. The accumulative effects from a systematic spraying of 

 the trees each year must be considerable, and the applications to kill 

 the larvae appear to be a very important consideration in the spraying 

 schedule. 



Injuries to Pears by Other Species. Two other species of thrips 

 w;hich may be observed on fruit trees in New York are Euthrips tritici 

 Fitch and Thrips tabaci Lind. During some seasons both species are 

 very common, but the former appears to be usually more numerous 

 than the latter. Ordinarily they do not seem to cause any appreciable 

 damage to fruit trees, and only once in the writer's experience have 

 they proven very destructive in orchards. This outbreak occurred 

 during the spring of 1909 and marked damage was done in pear orchards 

 in western New York, principally about Ransomville, Burt and Mid- 

 dleport. The varieties sustaining the greatest losses to the blossoms 

 were Bartlett, Kieffer and Dutchess. The effects of the work of 

 these thrips w^ere not unlike those of pyri, except that the damage 

 was not so extensive. The injured blossom clusters similarly turned 



