Twenty larvae per ear have been reported from Nebraska. Unlike corn earworms, western bean cutworms are not cannibalistic so several larvae may feed in the same ear. The 4th and 5th instars may leave the ear tip and cut entrance holes through the husks and feed on the developing kernels through the 6th or 7th instar. Newly-hatched larvae feed on the tassel, corn pollen, tissue behind the leaf sheaths, and silks. Moths are most attracted to cornfields with tassels just beginning to emerge for egg laying. In the midwest, adult flight usually begins in the later part of June and continues through August. One to five days after mating, females lay their eggs mostly on the upper surface of the flag leaf. There are 6, and occasionally 7, larval stages. Mature larvae have a broad, faint tan stripe along the back, no distinctive spots, an orange head, and the pronotum has two broad brown stripes, which are good characteristics to distinguish it from other corn caterpillars. Newly-hatched larvae are a dull orange color with black heads, a black pronotum (hardened plate immediately behind the head) and 8-10 black spots on each body segment. They are white when first laid and turn dark purple a day or two before hatching. They are laid in tightly packed clusters from 21–195 eggs, and average 52. It was collected for the first time in Illinois and Missouri in 2004, and in Indiana, Michigan and Ohio in 2006.Įggs are nearly round with small ridges from the top to the bottom. Beginning in 2000, economic damage was found in Iowa and Minnesota. Prior to 2000, economic damage was confined to the western Corn Belt states, and several mountain states where dry beans also were grown. The western bean cutworm is native to North America. The presence of the western bean cutworm has been confirmed in Arizona, Colorado, Idaho, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, New York, North Dakota, Ohio, Pennsylvania, South Dakota, Wisconsin, and Wyoming. Include in email: 1) Pest Alert name, 2) number of packs desired (only available in packs of 50) and, 3) the date they will be needed.Ĭlick to download a PDF version of this publication.ĭistribution of Western Bean Cutworm in North America Western Bean Cutworm Striacosta albicosta (Smith) Contact free printed copies.
0 kommentar(er)
