Adult forms of caterpillars have the ability to fly and thus invade the greenhouse from weeds and other infested plants outside. In the control section for each pest, a few of the many registered and effective pesticides will be listed. For a complete listing please consult the references at the end of this report. The list given in this section should be used only as a guide to the sensitivity to pesticides. Symptoms - Infestations are easy to detect because worms, their excrement and the damage they cause, are usually quite visible to the unaided eye.
Damage appears as holes in the center or along the edges of leaves.
If leaves have been fed upon while in the rolled stage the damage appears as a line of equally spaced holes once the leaf opens. Damage by worms is often confused with slug or snail damage. The only way to determine which pest is involved is to find a specimen. The adults have long bead-like antennae and their legs hang down as they fly. The larvae spin webs on the soil surface which resemble spider webs.