DESCRIPTION
Larvae are very small (1 to 2 mm long). They can be yellowish or orange. Adults are hard to see as they fly when disturbed. The dots of black excrement and the damage they cause are usually more visible than the thrips themselves.

DAMAGE
Thrips feed on a variety of houseplants, vegetables and ornamentals, particularly roses, peonies, gladiolus and chrysanthemums. Both larvae and adults feed by rasping plant tissue and sucking the juice, causing a silvery appearance on leaves, tattered or streaked flowers and deformed fruit. Thrips usually cause little damage, however severe infestations can stunt plants, shorten bloom period, prevent flowers from opening and reduce crop yields. Thrips may also transmit virus diseases from plant to plant.

LIFE CYCLE
Most thrip species overwinter as pupae in the soil, with adults emerging to feed about the time leaves on Linden trees start to open. Adult females insert several hundred eggs into stem, leaf or flower tissue. Larvae hatch in 3 to 5 days, feed for several weeks and then drop to the soil to pupate. Adults emerge 1 to 2 weeks later. There are between 1 and 8 generations per year, with the life cycle taking only 3 weeks for some species.

CONTROLS
• Hang blue or yellow sticky cards on susceptible plants and inspect frequently for insects, damage or excrement. Water thoroughly when irrigating to drown pupae in soil.
• Apply pesticides to affected plants.
• Keep a pest journal for next year, recording host plants, controls used and when you first noticed pest in relation to another plant in bloom.

PESTICIDES
• Chemical-Diazinon, Latox or Cygon at label rates.
• Alternative-Pyrethrin, Safer’s Soap or Trounce at label rates. Dust plants and soil around affected plants with diatomaceous earth.