OAK INSECTS. The insect fauna of oak is very extensive. Between 500 and 600 species of insects have been recorded that live upon the dif ferent species of Querens, and there are in ad dition many other species which live in decaying oak wood and oak stumps. In Germany 531 species of insects of all orders have been recorded by Kaltenbach as preying upon the oaks of that country. It has been estimated that it is not improbable that 1000 species of oak in sects exist in the United States. The roots of the live oak, and probably of the water oak, are infested by a great longico•n bore• (.1/a//odon in(/onopits) by which the trees are pe•mmanently dwarfed and their growth arrested. There are several species which burrow into the trunk, the most prominent being the caterpillar of the car penter moth (Priono.rystus robinia), which oc curs from New England to Texas and honey combs the wood with large black burrows. Sev eral flat-headed borers (1 luprestithe) and many bark-boring beetles (Curculionidie) affect oak.
The oak-prliner (Ebsphillion rillosuml and the periodic:d cicada (see CICADA) (•111 off the twigs and small limbs. The leaves Of Va rifillti oaks are eaten by many specieP, of lepidopterous larva., the most prominent being the forest tent-cater pillar (C/isiocomr(1 disstria) and the large black and red striped :piny caterpillar• of .1 niRota sow toria. These two caterpillars in the Atlantie and Central States, as a ride, do more harm to oak forests than all other spec•ies combined.
Several species of leaf-rolle•s (q.v.) are found upon oak, and leaf-miners (q,v.) frequently dis figure the leaves. There are also plant-liee and
which are confined to the trees of Ibis kiwi, and the so-called gloomy seals (Aspidi otus brivosus) frequently endangers the life of half-grown trees, while the imported oak-scale (.nstoodiaspis qucroicola ) enfeebles the trees in many localities, disfiguring the smaller branches by pitting the tender bark with its peculiar de pression,.
A striking characteristic of the insect fauna of oak is the occurrence of many kinds of galls produced mainly by gall-tlies of the hymenopter ous family Cynipidie. One hundred and eight distinct species of gall-flies live upon oaks in the United States, each species making its characteristic gall either upon the roots, the twigs, the buds, or the leaves. Sonic of the most striking of the oak galls are: The oak potato-gall, the large, hard. uneven swelling resembling a potato in shape, growing upon white oak twigs and attaining a length of two inches or more: the wool-sower gall. which con sists of a round mass resembling wool, from the size of a walnut to that of a goose-egg, growing on the silt of or surronnding white oak twigs in June. pure white in color tinged or speckled with rose-red; and the oak cup-gall, which con sists of a very curious swelling on the acorn cups. terminating in a bunch of curly, woolly fibres. Several galls are made by dipterous in sects of the gall-mid:re family, Cocidoinyihke.
Consult Packard, h Bcpari, railed Stales Entomologist COM iss ion ( Wash ington, 1890 ) .