This paper presents a sampling procedure for estimating larval populations of the alfalfa snout beetle, Otiorhynchus ligustici. The method is based on counts of the larvae taken in 16 x 16 cm quadrats of soil during early fall when the grubs are in their final two instars and feeding just below the crowns of the plant. Analysis of sampling variability showed that 200 quadrats per field are necessary to obtain adequate precision for intensive population studies but that 50 quadrats are sufficient for survey work. The pattern of counts was overdispersed but conformed to the negative binomial distribution.
Harcourt, D. G. and Binns, M. R.
"Sampling Technique for Larvae of the Alfalfa Snout Beetle, Otiorhynchus Ligustici (Coleoptera: Curculionidae),"
The Great Lakes Entomologist, vol 22
Available at: https://scholar.valpo.edu/tgle/vol22/iss3/3