MONTANA ESrSECT PESTS 1945-1946 9 



TABLE III— SUMMARY OF GRASSHOPPER CONTROL PROGRAM 



Cool weather in the spring of 1946 delayed and caused an ir- 

 regular hatch of grasshopper eggs. In the late summer, adults and 

 first and second instar nymphs were observed in the same areas. 



The first grasshopper nymphs were observed May 15. The 

 hatch was about 50 per cent complete by June 7, and on June 14 

 approximately 75 per cent of the eggs had hatched. Hatching was 

 not completed until August 9. By July 22 it is estimated that less 

 than 5 per cent of the 'hoppers had reached the adult stage. Egg 

 deposition was noticed for the first time about August 15. Light, 

 milling grasshopper flights of a local nature occurred in the eastern 

 part of the State almost daily during the first part of August, re- 

 sulting in increased field populations and general dispersal from 

 right of ways, fence rows, ditch banks, etc. 



Fungus or bacterial diseases were responsible for population 

 decreases of 5 per cent to 10 per cent in some localities in the eastern 

 part of the State and the Triangle area. Sarcophagid flies were not 

 so much in evidence as in previous years. It is estimated that ap- 

 proximately 10 per cent of the egg pods were parasitized by blister 

 beetle, carabid, and bee fly larvae this fall. Cold, wet weather this 

 fall was not favorable for egg laying, and it is felt that this may 

 bring about a reduction in populations in some areas next year. 



In spite of the fact that weather conditions were unfavorable 

 for control work during the early and late parts of the season, the 

 program was quite successful. The results of baiting in alfalfa 

 fields, along ditch banks, right of ways, fence rows, etc., where 

 there was rank vegetative growth, were disappointing. With the 

 exception of alfalfa, farmers were able to protect their crops from 

 grasshopper damage by baiting. 



Although the amount of bait spread this year was 557 tons 

 less than was put out last year, the estimated crop saving in 1946 



