Synonyms and other taxonomic changes
The taxonomy of the family is in flux; a number of species have been moved to different genera or tribes(1)(2)
Explanation of Names
Mordellidae Latreille 1802
just over 200 spp. in 17 genera north of Mexico; ~1500 spp. in 100 genera worldwide(3)(4)(5)
; 56 spp. in Canada(6)
, 43 in NH(7)
, 38 in FL(8)
, 26 in CA(9)
All NA species are members of the subfam. Mordellinae (the sole member of another subfamily lives in S. Africa)(3)
Overview of our fauna
1.5-15 mm (usually 3-8 mm)
Body humpbacked, more or less wedge-shaped; broadest at front; head is bent forward, attached ventrally; abdomen pointy, extending beyond elytra. Hind legs enlarged. They kick and tumble about when disturbed. Black or gray, some brown; hairy, sometimes light patches of hair form pattern. Antennae short to moderate, threadlike, sawtoothed or clubbed. Tarsal claws often bilobed or comblike.
Identification beyond family often involves the number of ridges on the hind tibia and tarsi (see photo below); try to photograph these parts
The most comprehensive work for our area is Liljeblad's 1945 Monograph(10)
, but the taxonomy used there is obsolete
Common on flowers and foliage; sometimes on dead trees and logs. Larvae occur in dead or dying hardwoods, in pith of weeds or in bracket fungi.
Larvae are believed to eat plant material in decaying wood, etc. Some are leaf and stem miners. Some are predaceous. Adults visit flowers.
small, wedge-shaped beetles; body arched, head bent downward; abdomen usually prolonged into a style or pointed process; hind legs in most species very long and stout, fitted for leaping; antennae long and slender; thorax as wide at base as the elytra. The body is densely covered with fine silky hairs, usually black, but often very prettily spotted or banded with yellow or silvery hues. The adults occur on flowers or on dead trees and are very active, flying and running with great rapidity and in the net or beating umbrella jumping and tumbling about in grotesque manner in their efforts to escape. The larvae live in old wood or in the pith of plants, and those of some species are said to be carnivorous in habit, feeding upon the young of Lepidoptera and Diptera which they find in the plant stems.(11)
In addition to the characters mentioned the Mordellidae have:
maxillary palpi 4-jointed, the last joint variable in form
head vertical and applied closely to the prosternum in repose, suddenly constricted immediately behind the eyes
antennae slender, 11-jointed, inserted at the sides of the front
thorax strongly narrowed in front, its lateral suture distinct
elytra narrowed behind, not truncate, leaving exposed the tip of the abdomen, the latter with five or six ventral segments
front legs short, hind ones usually long; front coxae large, conical, contiguous, without trochantins, the cavities open behind
hind coxae flat, contiguous, very large in most of our species
hind tarsi long, compressed
tarsal claws either simple or cleft to the base, with the upper portion comb-toothed in most species
Ford E.J., Jackman J.A. (1996) New larval host plant associations of tumbling flower beetles (Coleoptera: Mordellidae) in North America. The Coleopterists Bulletin 50: 361-368.