The active immature stage of an insect, and usually the stage where the greatest damage is done to plants, as the maximumoccurs at this time.
Gardeners use the terms larva, caterpillar, grub or maggot somewhat loosely, making them interchangeable. The entomologist, however, refers to the larva of a moth or butterfly as a caterpillar, that of a sawfly, e.g. apple sawfly, plum sawfly (both important fruit tree pests), as a false caterpillar. A beetle or weevil larva is called a grub and a two-winged fly larva, e.g. leather-jackets, ‘bluebottles’ and stable flies, a maggot.