Tumbling flower beetle—Mordella hubbsi
Tumbling flower beetle (family Mordellidae) adults chew and feed on the flowers of various plants. In California, buckwheat (Eriogonum fasciculatum) is a common host. The beetle's plant damage is minor, and it is a beneficial pollinator of the blossoms.
Identification
The adult is an iridescent blackish beetle with thin antennae and silvery coloration on the sides and underside of its abdomen. Adults are 1/4 inch long when measuring from the head to the tip of where the abdomen protrudes to a point beneath the rear of the wing covers. Adults can be very active. When disturbed they commonly jump, turn, and tumble, which is the source of the common name of their family.
At least 6 other similar-looking Mordella species occur in California. Mordella hubbsi can be distinguished from these by the reddish brown color of the femur (swollen, basal segment) of its front and middle legs.
Larvae are white, elongate with distinct segments. They grow to about 1/4 inch and occur hidden in decaying wood or the stem pith of various plants.
Life cycle
Tumbling flower beetles develop through four life stages: egg, larva, pupa, and adult. Adults are present mostly during June and July. The larvae are present from late summer through spring. Several sources suggest the larvae are predaceous on immatures of flies and moths that also colonize plant pith, but the biology of Mordella species is not completely understood. Pupation occurs in April or May. There is one generation per year.
Damage
Adult tumbling flower beetles feed mostly on nectar and pollen but also chew flowers. This damage is generally minor, and in the process of feeding and moving among blossoms the beetles pollinate the flowers.
Solutions
Management is not recommended or known.
Adapted from Monograph of the Family Mordellidae (Coleoptera) of North America, North of Mexico, University of Michigan. |
