POTENTIAL AND ACTUAL POPULATIONS OF GRASSHOPPER NYMPHS IN TILLED AND UNTILLED CEREAL GRAIN FIELDS
- 1 July 1964
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Plant Science
- Vol. 44 (4) , 365-375
- https://doi.org/10.4141/cjps64-070
Abstract
The within-season trends of grasshopper abundance in cultivated habitats were investigated during seven years between 1943 and 1960, in southwestern Saskatchewan and southern Alberta. In unfilled cereal grain fields, the numbers of grasshopper eggs declined by 0 to 67% from late fall to early spring. Tillage seldom affected this decrease substantially. Of the eggs surviving in the spring, a few studies showed 7 to 64% producing nymphs that emerged. Tillage between egg-laying and emergence sometimes further reduced emergence. At the mid-point of nymphal development, when most eggs were hatched, nymphal mortality had further reduced the population, to 2 to 20% of the eggs present earlier in the same spring. The most reliable effect of tillage as a control measure was the destruction of food plants, prior to grasshopper hatching, in the preparation of summerfallow. Of the surface-tilling implements, one-way disks were most effective, but implements preferred for preserving trash cover, such as blade and duck-foot cultivators, were also effective if used under conditions conducive to complete killing of food plants.This publication has 3 references indexed in Scilit:
- Note on Destruction of Grasshopper Eggs by the Field Cricket Acheta assimilis luctuosus (Serville) (Orthoptera: Gryllidae)The Canadian Entomologist, 1959
- PARASITES OF NYMPHAL AND ADULT GRASSHOPPERS (ORTHOPTERA: ACRIDIDAE) IN WESTERN CANADACanadian Journal of Zoology, 1958
- Observations on Internal Parasites (Hymenoptera: Scelionidae) of Eggs of Pest Grasshopper Species in the Prairie Provinces of CanadaThe Canadian Entomologist, 1953