NINETEENTH REPORT OF STATE ENTOMOLOGIST 21 



An idea of the work carried on nnder the county insect pest law 

 since its passage can be had by an examination of the tables printed 

 in this report regarding the grasshopper campaigns during 1921-22, 

 and the map, figure 3, which shows the high proportion of counties 

 which used the law during these years. 



INSECT PESTS OF 1921 

 SNAILS (MOLLUSCA) 

 Gray Garden Snail {Agriolimax agrestis Linn.). This snail, some- 

 times referred to as the garden ''slug," has continued to cause dam 

 age to tomatoes, lettuce, turnips, and other garden truck in a few 



localities. 



MITES AND TICKS (ACARINA) 



Pear-Leaf Blister-Mite {Eriophyes pyri Pgst.). See page 17. 



THRIPS (THYSANOPTERA) 



Thrips (Frankliniella tritici Fitch). Damage to alfalfa seed and 

 the honey flow by thrips continued this season but did not prove to 

 be as serious as in 1920. 



In some orchards of the Bitter Root Valley fully 25 per cent of 

 the apples showed an unusual abundance of white blotches on the skin 

 similar to injury attributed to the egg-laying punctures of a thrips 

 by E. J. Newcomer, U. S. Bureau of Entomology, Yakima, Washing- 

 ton. This injury was particularly noticeable and annoying when at- 

 tempting to select show fruit. 



GRASSHOPPERS, CRICKETS (ORTHOPTERA) 



Mormon Cricket {Anabrus simplex Hald.). The appearance of 

 this insect in considerable numbers in Toole and Teton counties has 

 been the cause of some conjecture among the farmers as to the dam- 

 age which may occur next season. We have no record of this insect's 

 occurrence in these localities before. It was reported by the farmers 

 that the crickets came in from the northwest. This is a common in- 

 sect in the mountains and valleys in some parts of the State but has 

 never been observed so far east of the mountainous section before. 



Warrior Grasshopper {Camnula pellucida Scudd.). This species 

 was the chief one concerned in grasshopper outbreaks in Flathead, 

 Sanders, Missoula, and Beaverhead counties. It was also present in 

 great numbers through central Montana along with the two following 

 species. (See general discussion on page 3.) 



