"defoliated" - 1 õppematerjal

The control of forest insects: general considerations

Fifth level FOOD SUPPLY Food supply Food material is an important factor in bringing about the increase or decrease of an insect species. Many forest insects are capable of attacking and feeding upon healthy trees. Other insects can only feed on deceased or damaged trees. Food Supply Mature Timber ­ overmature, decadent and suppressed trees usually offer susceptile material for barkbeetle attack. Defoliated Trees ­ trees that have stripped of their leaves by defoliating insects. Diseased Trees ­ diseases that defoliate trees may render them susceptile to the attacks of cambiumfeeding insects. Lightingstruck Trees ­ coniferous trees struck by lighting appear to be very attractive to bark beetles. Windfall and Snowbreak ­ a number of severe epidemics of bark beetle can be traced to windblown timber. Slash ­ includes all the trash in the woods left on the ground by cutting of trees.