Weevils - Entomological Society of Canada

protective cover or fluid is placed over the egg. The incubation period is
not known. Upon hatching, the larvae tunnel into the wood. The
galleries are nearly straight across the grain of the wood. The larva
keeps the tunnel clean by pushing the boring dust out through the hole
made by the female to deposit her egg. Most larvae develop in living
trees, but some are found to mature in trees that have been dead for at
least 2 years. Larvae can be so numerous that the wood is rendered
commercially useless. Pupation takes place within the gallery, but the
length of the pupal period has not been determined. In addition to oak
(Quercus species), specimens have been found in paper birch (Betula
papyrifera), elm (Ulmus species), basswood (Tilia americana), poplar
(Populus species), and beech (Fagus species).
Family Apionidae
This is a large family, with more than 1500 species around the world.
Approximately 300 species in three genera occur in North America. The
taxonomy of this group poses formidable difficulties. In addition to the
large number of species, the individuals are small, usually 1.0-3.0 mm
long, and diagnostic taxonomic characters are difficult to observe. The
present treatment recognizes species in three genera that occur or
probably occur in Canada and Alaska.
Description. Body robust to moderately slender, usually black;
appendages may be lighter. Pubescence sparse. Head with gular sutures
fused; pregular sutures absent. Rostrum usually longer in female than
in male. Maxillary palpus rigid, 2-segmented; lacinia distinct; labrum
absent. Antennae straight, moniliform (except Nanophyes); antennal
club distinct, compact. Legs with trochanter elongate, cylindrical;
femur attached to apex of trochanter (Fig. 20). Abdomen with first and
second visible sternites connate.
Comments. Kissinger (1968) reviewed the entire family for
North and Central America. He provided keys and descriptions for all
species, and his monograph should be consulted for further information.
Key to genera of Apionidae in Canada and Alaska
1. Antennae geniculate; scapes very long, slender (Fig. 19). Elytra
nearly monochromatic, pale. Pubescence consisting of small,
sparse, fine, recumbent scales. Interstria 8 smooth on basal quarter.
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