THE GREEN STINK BUG GENUS CHLOROCHROA STÅL (HEMIPTERA: PENTATOMIDAE) IN CANADA

This paper reviews the occurrence of the genus Chlorochroa Stål in Canada. It is shown that 10 species occur in this country, namely C. belfragii (Stål), C. faceta (Say), C. congrua Uhler, C. granulosa (Uhler), C. ligata (Say), C. opuntiae Esselbaugh, C. persimilis Horvath, C. rossiana Buxton and Thomas, C. uhleri (Stål), and C. viridicata (Walker). Chlorochroa sayi (Stål) does not occur in Canada. The published records of C. sayi as a pest of agricultural crops and ornamentals in Canada refer to C. uhleri.

DAMAGE TO WHEAT BY SAY STINK BUG, CHLOROCHROA SAYI

Wheat grown in a growth chamber was infested at various stages of growth with adults of Say stink bug, Chlorochroa sayi Stål (Hemiptera:Pentatomidae). Feeding during the boot stage stunted the plants, and feeding just before heading reduced the numbers of kernels in the heads. Damage after heading varied directly with duration of feeding and numbers of insects but inversely with development of the kernels. Damage consisted of reduced numbers of kernels per head, lowered mean weights of kernels, or discolored kernels. Yield was reduced by more than 75% when wheat was fed upon just before, or 5 days after, the heads emerged. When the feeding occurred in the dough stage, damage was slight.

THE EFFECT OF SAY STINKBUG FEEDING ON WHEAT

Say stinkbug, Chlorochroa sayi Stal, is a comparatively new pest of wheat and other seed crops in Western Canada. In the past ten years it frequently has caused severe damage to wheat in many localized areas.

SAY'S GRAIN BUG, CHLOROCHROA SAYI STAL, IN CANADA

Say's grain bug, Chlorochroa sayi Stal, made its initial appearance in Alberta, in appreciable numbers, during the season of 1935. The history of the recorded damage by this insect is available in the publication by Caffrey and Barber (U. S. D. A. Bul. 779). This publication is the only adequate treatise to date on this pest of economic grains. The first recorded damage was reported by farmers from Gila and Salt River Valleys of Arizona in 1903. Further outbreaks were recorded in the southern states of New Mexico, Arizona, Texas and Colorado, reaching the peak of depredation during the period, 1915 to 1919. Its first occurrence in Montana was noted during the years 1931 and 1932. where it has been causing considerable losses to the farmers in the northern part of that state ever since. Localized outbreaks were reported in Utah during this same period.