Insect Signs of Damage (1)

go to main menu

A closer look at the damage caused by a particular insect gives us a general idea of which kind of insect has caused the damage. The signs as a result of an insect with piercing-sucking mouthparts look very different from the feeding traces of an insect with chewing mouthparts. Chewing mouthparts result in parts of the plant being chewed or torn off so that there is for instance a hole in a leaf. This type of damage is most likely to be caused by caterpillars of moths and butterflies, by maggots of flies and wasps or by adult beetles or their grubs. Insects with piercing-sucking mouthparts like hemipteran bugs or mites pierce parts of their host plant, causing the affected area to become brown or resulting in wilt or a tumour-like growth, but there is never any part of the plant missing. Insect signs such as cocoons, larval skins, eggs or silk shelters are another indication of the kind of insect responsible for particular damage and are also very helpful to determine the causal agent. Generally insect damage and signs are divided into four categories, however, the damage seen will rarely fit exactly into one of the categories, more often it is a combination of two categories:

• leaf damage
• seed and cone damage
• shoot, twig, trunk and root damage
• insect signs

back to previous page
go to glossary
go to main menu

© Michael F. Schneider, 1999