MONTANA INSECT PESTS 1945-1946 • IT 



WHEAT TIGER MOTH {Collarctia hlakei) . — This pest record- 

 ed in the Thirtieth Report of the State Entomologist' as attacking 

 wheat, was reported again in 1946. Specimens, collected south of 

 Gildford in Hill County, were received from County Agent R. F. 

 Rasmusson on April 9. According to the information received, the 

 larvae were first noted on range land about one-half mile from a 

 wheat field. In a few days they had reached the field and had 

 worked several rods into it, eating all of the wheat as they pro- 

 gressed. There was no further report on this infestation, although 

 information was solicited, and there is a possibility that the field 

 recovered as did the one observed in 1944 in Chouteau County. 



It appears, from scattered evidence, that the larvae overwinter 

 on rangeland, moving early in the spring to wheat fields. Injury, 

 although obvious early in the season, appears to be short-lived, and 

 with good growing conditions may be overcome by later growth. 

 Up to the present time, infestations have been spotted and not 

 widespread. 



CATTLE GRUBS (Hypoderma lineatum and H. hovis) . — In or- 

 der to best adapt control measures for these pests of cattle to Mon- 

 tana conditions, observations on their biology were begun in 1943 

 and carried through to the spring of 1946. These studies have as- 

 sisted in clarifying unknown points in the life cycles of the grubs, 

 and have allowed the establishment of a schedule of treatments for 

 cattle in the State. Although not so complete as would be desir- 

 able, these data are brought together in Montana Agricultural 

 Experiment Station Bulletin 437. 



MALARIA MOSQUITOES (AnopheUs spp.) . — The return to 

 Montana of many members of the armed forces suffering from 

 malaria, contracted in various parts of the world, has brought to 

 the fore the need of more information on the distribution of ano- 

 pheline mosquitoes in the State. The return of infected war vet- 

 erans is illustrated by the fact that in June 1946, 26 male students 

 at Montana State University and 22 at Montana State College 

 apparently harbored malaria parasites. 



As there was only scattered information on the State distribu- 

 tion of anophelines, an extensive survey was carried on in western 

 Montana in April and May 1946, by Dr. D. J. Pletsch of the Mon- 

 tana Agricultural Experiment Station. The survey indicated that 

 this genus of mosquitoes was more generally distributed in the 

 surveyed area than was previously supposed. Counties visited 

 were Deer Lodge, Flathead, Gallatin, Granite, Jefferson, Lake, 

 Lincoln, Mineral, Missoula, Powell, Ravalli, and Sanders. Ten of 

 these counties gave positive collections either of larval or adult 

 anophelines. Larvae were found in 11 of 47 larval habitats. Ano- 



»Mont. Agr. Exp. Sta. Bull. 42.5, p. 22. 



