Clay colored weevil

Clay colored weevil, Otiorhynchus singularis (CCW), can be damaging to ornamental plants. It is considered a cool season weevil, with key activity in the spring and fall. First emergence of the new adults is in the early spring, often in March. This is quite early compared to black vine weevil, our more common root weevil in nursery production. Like black vine weevil, CCW are all female. Egg laying or oviposition tends to be bi-modal beginning in mid-May, ending in late June and beginning again in September, lasting into October. Not as fecund as black vine weevil which can lay approximately 200-to-400 eggs per season/adult, CCW will lay much fewer eggs, around 30 eggs per season/adult. While not prolific, they tend to escape most weevil management activities which are generally timed for black vine weevil control and too late to break the life cycle of this early season weevil. Most of the research on this weevil has occurred in small fruit production.

Websites with more information and images:

Clay colored weevil. Northwest Berry Foundation.

Raspberry weevil. BugGuide.

Tanigoshi, L.K. and J.R. Bergen. 2002. Managing root weevils in Washington State raspberries. Tanigoshi, L.K. and Bergen, J.R. (2002). Acta Hortic. 585, 309-314, DOI:10.17660/ActaHortic.2002.585.50 <1 May 2018>

Clay colored weevil

Photo: Rosetta