Thrips and Cannabis
Thrips are tiny (less than 0,06" in length), winged insects that feed on the juices of the cannabis plant by puncturing the plant and sucking up the contents within. Although they wear wings, they are poor flyers and depend on the wind to carry them from venue to venue. Their bodies are cigar shaped, with six legs and pointed butts.
The damage seen with thrips is evidenced by silver or bronze colored scars on the leaves and/or stems; wherever they have chosen to invade. The leaves will be deprived of chlorophyll, turn brown, dry and crumbly. Typically, they feed on developing flowers; this is where the damage to cannabis most occurs. Thrips are known vectors for plant viruses, which is cause for concern.
Thrips are more of a threat to greenhouse gardens than those grown outdoors. In either setting, they prefer the cannabis buds as the place to conduct their living habits. If you see burned looking edges, you have a colony of thrips at work. Shaking the plant will dislodge them and send them packing.
Predatory mites and parasitic wasps are natural deterrents to thrips attacking your marijuana plants. Applying good compost mixture to the soil before planting will contain beneficial nematodes which attack any pupae that may fall to the ground. Thrips are not a major threat in cannabis plants grown outdoors. Use neem oil or predatory mites to get rid of them.