OBSERVATIONS ON THE BIONOMICS OF THE DARK-SIDED CUTWORM, EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE), IN ONTARIO

Abstract

The dark-sided cutworm, Euxoa messoria (Harris), has a North American distribution and is commonly found in tobacco fields in Ontario. It has one generation a year, and overwinters as an egg in the soil. Hatching takes place in early April and the young larvae feed on the rye rotation crop; later they attack newly transplanted tobacco seedlings. Head width measurements of larvae collected from the field show seven instars, but individual rearing data of E. messoria larvae reveal that small numbers pass through six and an occasional larva passes through eight; however, the eighth instar has the same head width as the seventh. Pupation occurs from late July to mid-August in the soil. The adult emerges from mid-August to October, and oviposition occurs in this same period. Eggs are completely developed before winter. Behaviour and duration of the different stages are described. Natural mortality factors of the species are given.

Prey characteristics of upland-breeding Red-winged Blackbirds, Agelaius phoeniceus

“…Dark-sided Cutworms were as common as larvae of the Clover Leaf Weevil in quadrat samples from an alfalfa and clover field although none of the former and many of the latter were recovered from neckcollar samples taken in or near this field. Clover Leaf Weevil larvae pass the day in the crown of alfalfa and clover whereas the Dark-sided Cutworm was found on the soil surface and may in fact pass the day below the soil surface (Cheng 1973). Since no sub-surface sampling was done, Dark-sided Cutworms may have been more abundant than the quadrat sampling indicated.…”

THE RESPONSE OF FLAX TO DIFFERENT POPULATION DENSITIES OF THE RED-BACKED CUTWORM, EUXOA OCHROGASTER (GN.) (LEPIDOPTERA: NOCTUIDAE)

“…Further, our observations showed that the early instars of E. ochrogaster, like E. messoria (Harr.) (Cheng 1973), climb plants and feed mainly on leaves. Consequently, plant losses prior to the larvae reaching the fifth instar were considered few and of minimal importance in this study.…”

BIOSYSTEMATICS OF THE GENUS EUXOA (LEPIDOPTERA: NOCTUIDAE): VII. EGGS OF THE SUBGENERA CHORIZAGROTIS, CRASSIVESICA, LONGIVESICA, OROSAGROTIS, AND PLEONECTOPODA

“…The messoria egg has been described in general terms by Crumb (1929), Seamans (1933), and Syme (1961); the latter authors included line drawings of the micropylar area and adjacent chorionic reticulation. Peterson (1964) and Cheng (1973) have provided low magnification photographs of the eggs together with descriptions. E .…”