TWENTY-NINTH REPORT OF THE STATE ENTOMOLOGIST 17 



1 part of cottonseed oil injected at the rate of about Vi ounce per 

 ear, with a warm syringe, is recommended by Imes This mixture 

 kills the parasites present and protects against reinfestation for 

 about a month. In cases where an infestation is suspected, the 

 animals should be examined, and if no ticks are visible the ear 

 should be probed with a piece of bailing wire. A loop should be 

 formed in the end of the wire to prevent injury to the ear. 



Montana records are all from the southeastern part of the 

 State, Park City, Biddle, Custer, and Mission. 



MISCELLANEOUS RECORDS AND OBSERVATIONS 



SAY'S sttnkbug. — This large, green stink bug, (Chlorochroa 

 sayi Stal) has been locally abundant in the State for the last ten 

 years, and has caused considerable local and sporadic damage to 

 wheat. In 1940 it was seen in numbers as far east as the North 

 Dakota line, but in 1941 and 1942 it was conspicuously rare over 

 much of the previously infested territory. During the past year 

 but one specimen was seen on the study plots at the North Mon- 

 tana Branch Station near Havre. 



In June, 1941, some terminal growth of potato vines in Yellow- 

 stone County suffered from the attack of Say's stinkbugs. As 

 many as ten specimens per plant were noted. No similar infesta- 

 tions were found in the same area during 1942. 



corn leaf aphid.— During the late summer of 1941 the corn 

 leaf aphid (Aphis maidis Fitch) was sent in from Glasgow and 

 Hardin, and was seen in other areas in the eastern part of the State. 

 In the infested fields this bluish-green plant louse was very abun- 

 dant on leaves, causing considerable curling. Apparently it was 

 not a problem during the 1942 season. 



This pest attacks corn, millet, broom corn, sorghum, and Sudan 

 grass. In the southern part of the United States it winters on bar- 

 ley, but it is not known where the winter is spent in our area, nor 

 has its life history been worked out completely. It is usually not 

 an important pest, and adequate control measures are not known. 



THE POTATO AND TOMATO psyllid.— The 1941 adult popula- 

 tions of this pest (Paratrioza cockerelli Sulc.) were alarmingly high 

 in early potatoes until checked by very high temperatures from 

 July 16-19. Slight reductions in yield resulted in some areas. 

 Growers have gradually become less 'psyllid-conscious' since the 

 outbreak of 1938 and reduced yields are commonly attributed to 

 other causes. 



Early season populations of psyllids were low in 1942. In the 

 Yellowstone Valley potato fields planted during April and the first 

 half of May showed symptoms of psyllid yellows by early July, and 

 some reductions in yield resulted. A general outbreak was ap- 

 parentlv checked by high temperatures in July, when half the 



