Bark And Ambrosia Beetles

Scolytidae and Platypodidae. Spanish: Taladrillos (Argentina).

Bark beetles (Scolytidae) and ambrosia beetles (Platypodidae) are all small (BL 1—5 mm) and uniformly black, dark brown, or light brown in color. They are cylindrical in shape and often have strongly punctate or apically sculptured wing covers. The short, elbowed antennae, tipped with a knob composed always of only the three terminal segments, are also characteristic. The two families are closely related and are distinguished only by minute structural differences; the head of platypodids is normally wider than the thorax and more exposed dorsally than in scolytids. Tarsal segment 1 in platypodids is as long as segments 2—5 combined, while in scolytids, segments 1—3 are about equal in length.

The larvae all are small, white, and legless. The body is arched slightly and the anterior end somewhat larger in diameter than the posterior. The head is lightly sclerotized.

All are borers in woody plants, both as adults and larvae. Biologically, however, they may be divided into two types, not corresponding directly with the taxonomic families: the so-called bark beetles feed directly on wood, both as larvae and adults (most scolytids); the ambrosia beetles cultivate special types of fungi in their tunnels and feed on these (many scolytids and all platypodids). The latter predominate in the lowland tropics of the New World,

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