Life cycle: Small chestnut weevils (Curculio sayi) emerge from the soil in
Sevin is the only insecticide registered for
[5], Development takes place mostly within a two-year life cycle.
Photos by Jennifer C. Giron Douque, University of Puerto Rico, Bugwood.org, Large chestnut weevil on bur and eggs in chestnut flesh. Members of the genus are commonly referred to as acorn weevils or nut weevils as they infest the seeds of trees such as oaks and hickories. it may affect the nuts’ flavor. Weevils that emerge in the spring can be observed feeding on catkins. Eggs hatch in about 10 days and larval development is completed two to
Thorough and frequent scouting is essential for optimal management, particularly with the lack of information regarding chestnut weevil behavior and prevalence in Michigan. for 20 to 30 minutes to kill larvae in the nuts.
Department of Horticulture and Landscape Architecture, Purdue University. Well-timed applications, good sanitation practices and scouting will be the key to successful chestnut weevil management in Michigan. turning around and placing her ovipositor into the nut and laying five to seven
Go here to the download software webpage. It is unknown if these spring weevils return to the soil or move off to feed on other plants. Adults feed on chestnut foliage until nut kernels enter
Collecting and destroying fallen nuts will remove developing larvae from the orchard. At one time American chestnuts dominated the
[1] The female's snout is as long as the rest of the body, with a reddish end. Soon after, the weevil larva inside chews a small hole into the acorn seed and leaves the empty acorn, burrowing into the soil. Chinese
Erin Lizotte, Michigan State University Extension -
Greater weevil grubs chew through the nut shells and fall to the ground before nuts drop in late summer or early autumn.
Lesser chestnut weevils. The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707. The large chestnut weevil larvae usually exit the chestnut before the nuts drop to the ground and overwinter in the soil. Lesser chestnut weevil adults likely emerge from the soil during two separate periods in Michigan, once in spring around bloom (May-June) and again in late summer-early fall just before burrs open (September-October). Lesser and large chestnut weevil lay eggs on developing nuts. at 0. three weeks later. Erin Lizotte, Michigan State University Extension -
Ideally, a combination of cultural and chemical management would control the pest and eliminate the need for post-harvest treatment, which can diminish quality and the marketable yield. The total lifecycle is completed in two to three years. as an adult. No formal research has been done on the lifecycle of this pest in Michigan.