About the Alfalfa Weevil
Hypera postica, commonly known as the alfalfa weevil, is a species of weevil; it can be found in alfalfa fields throughout Europe. Considered a destructive threat to alfalfa production in North America, several accidental introductions have been successfully countered though the use of a variety of biological control species.
The alfalfa weevil grows to a length of about 4 to 5.5 mm (0.16 to 0.22 in). The rostrum or beak is short and broad. The frons is half as wide as the rostrum while the pronotum is broadest in the centre. The general colour of the insect is brown, with a dark mid-dorsal stripe. The larva has a distinctive black head and no legs; it is yellowish-green, with a white dorsal stripe and faint white lateral stripes. It is about 1 cm (0.4 in) long just before pupation. It pupates in a white, pea-sized cocoon made of loosely-woven silk. It resembles the clover leaf weevil (Hypera punctata), but that species is nearly twice as large, the larvae have tan heads and they seldom cause much damage to alfalfa crops.
In Illinois, some eggs are laid in the late fall or the winter, when weather conditions permit. Adults also overwinter and become... Wikipedia →