A Closer Look at the White Pine Cone Beetle

Abstract

Conophthorus coniperda (Coleoptera: Curculionidae; Schwarz), known as the white pine cone beetle, is a pest in white pine seed orchards. The insect was primarily studied in the United States of America during the late 1960s to 1992. No contemporary studies have been performed since, despite the devastating damage the beetle causes to white pine seed orchards, and the seeds they produce for reforestation purposes. To help future research on potential biological control, this work revisits the ontogeny of the white pine cone beetle. The biology of the insect was studied over two years in 2022 and 2023 in a seed orchard (Quebec, Canada). Observations were complemented with data collected from the same orchard and other sites in 2009 and in 2012. Except in 2022, the emergence of the insect occurred around 53.6 {+/-} 1.98 {degrees}C.d above a threshold of 6.5 {degrees}C. A shorter developmental cycle was observed compared with the ones described in 1965 and 1976. The relationship between cone size and the number of insects per cone was statistically significant but explained only a small proportion of the variance and showed high variability. These results will help improve survey timing and sampling strategies for this species.