THE MONTHLY BULLETIN. 



to 



The Pear Thrips. 



Figure 7 gives the reader an idea as to the appearance of the pear 

 thrips. It passes tlie winter in the resting stage in the ground and the 

 adult emerges early in the spring, laying its white bean-shaped eggs in 

 the tender tissues of the host. The adult and young attack the tender 

 flowers and leaf buds. In badly infested orchards the buds fail to open 

 and the trees have a brown, dead appearance. 



The pear suffers the most. Besides this host, prunes, plums, peaches, 

 apricots, almonds, apples, cherries, figs, grapes and English walnuts 

 are often attacked.* 



The best spray to use against the pear thrips is known as the Gov- 

 ernment formula and consists of three per cent distillate oil emulsion 

 to which is added nicotine sulphate (Black-leaf 40) in the proportions 

 of one part to fifteen hundred to two thousand of the spray mixture.! 

 Spray at the time the thrips are present. 







1|- 



Fig. 7. — The pear thrips; adult female and nymph. (After Moulton. ) 



Potato Eelworm. 



The eelworm is not an insect but belongs to a lower class of animals. 

 It infests over four hundred and eighty species of plants which includes 

 most of our general garden crops, as well as fruit trees and field crops. 

 It is a microscopic, almost transparent eel-like creature, which causes 

 what is known as root-knot on nursery trees, galls on tomato vines and 

 the warty surface on potato tubers. Soils which contain infested crops 

 must be either sterilized to prevent new crops becoming infested or 

 rotated to crops which are not attacked by the nematode. Sterilization 

 of the soil by steam or formaldehyde, one part to 100 parts of water 

 is practical only when a small lot of soil is handled, as in greenhouses. 



*E. O. Essig, "Injurious and Beneficial Insects of California," p. 36. 

 tG. E. Merrill, Mo. Bui. Cal. Hort. Com., Vol. I, No. 2, p. 54. 



