20 MONTANA EXPERIMENT STATION BULLETIN 504 



Entomologist, have requested and received co-operation from the Soil Con- 

 servation Research Branch, Agricultural Research Service, to carry on the 

 work necessary to continue this project. At the time of writing, only pre- 

 liminary phases of this work are underway. 



Elsewhere in Montana the mosquito problem persists as usual. Five 

 mimicipalities requested information and aid in carrying on mosquito control 

 work. Four others merely requested information but did not initiate an 

 active control program. Because of this apparent interest a rather compre- 

 hensive publication is planned which \vill outline the best methods of 

 mosquito control. 



CATTLE GRUBS (Hypoderma lineatum and Hypoderma hovis) 



Data gathered from within the state and from other sources indicate 

 that chemical control of this pest leaves much to be desired. All controls 

 have heretofore been directed at the grub in the animal's back— at a time 

 when the damage has already been done. It was thought that by killing 

 these grubs the populations could be reduced in futiire generations. In 

 some instances, where cattle have been treated for a number of years, the 

 current population of warbles is the same as before the treatment was 

 started. Tn the light of this evidence many stockmen have discontinued treat- 

 ment for this pest. 



CATTLE LICE (Orders: Mallophaga and Anoplura) 



Cattle lice continued to be a problem throughout the state especially 

 during the winter months. Since treatment for lice involves a good deal of 

 hand labo'-, a research program using the self-applicating type of back 

 rubber will be carried out. During the biennium another species of louse, 

 Solenopotes capillatus, was found to occur in the state. This brings the 

 number of species to four. The other three are: Haematopinus eurj'stenius, 

 Linognathus vituli, and Bovicola bovis. 



SHEEP TICKS (Melophagus ovinus) 



This parasitic fly occiu-s state-wide wherever sheep are raised. A 

 rotenone spray is the most practical method of combatting this insect. 



HORN FLIES (Siphona imtans) 



The incidence of horn flies appeared to be about normal during the 

 biennium. In 1953, however, the season extended longer than normal 

 because of the warm, open fall. Aerial application of insecticide to range 

 cattle was attempted during the summer of 1953. The animals were first 

 bunched by plane and then sprayed with DDT. Excellent control was 

 achieved for a month at a cost of about 40 cents per head. The back-rubber 

 type of applicator appears to work quite well when it is in a convenient, 

 readily accessible location and when there is little competition from brush 

 or other objects which can be used for rubbing. 



