Carrion beetles

Taxonomic position: Carrion beetles (family Silphidae) are members of the order Coleoptera. While most species in this family are scavengers, the tribe Silphini includes the genus Aclypea, which consists of phytophagous beetles that are recognized as significant pests of cultivated plants, particularly in the beet family.

Target crops and damage: The primary host plants are sugar beets, table beets, and mangolds. Both the adult beetles and their larvae cause direct damage by feeding on leaves. They typically chew irregular holes or skeletonize the foliage, often leaving only the main veins. If the infestation occurs during the seedling stage, the entire crop stand can be compromised.

Biology and lifecycle: These beetles overwinter as adults, hidden in the soil or under leaf litter. As temperatures rise in spring, they emerge and migrate to fields. Females lay eggs near the base of host plants. Larvae hatch and develop through several instars, feeding voraciously on plant tissues before pupating in the ground. The life cycle is generally univoltine, with one generation per year.

Economic impact: The damage is most critical when the plants are in the cotyledon or early true-leaf stages. Heavy feeding can lead to complete stand loss, necessitating reseeding. Even if the plants survive, the reduction in leaf surface area significantly impairs the plant's ability to accumulate sugar and grow large roots, leading to a measurable decline in total harvest yield.

Control measures: Integrated pest management is essential. Cultural practices include deep plowing to disturb pupation sites, crop rotation, and strict control of weeds that may serve as alternative food sources. When thresholds are exceeded, chemical control using approved insecticides—applied as foliar sprays during the period of peak adult activity—is the most effective method to mitigate losses.