Scientific name：Dichromothrips corbetti Priesner
This kind of thrips commonly appears on Vanda orchids and Cattleya orchids. Adults and larvae cluster on the overlapping petals and the affected flowers have obvious faded spots or brown stripes, which cause flowers to lose their beauty and value.
They tend to lay eggs on petals or inside stems and leaves. Both larvae and adults are lively and active, constantly crawling and sucking plant juices. It happens more often in warmer seasons, when the leaves of the plants are kept dried for a long period of time.
They mainly cause harm to flowers, stems and leaves of a plant. Adults and larvae ruin flowers during the flowering stage, especially like to inhabit at the flower center or at the overlapping part of the petals and flowers. The affected petals have gray spots. Sprouts or leaf sheaths are also susceptible to larval infestation. The stems and leaves were yellowed and withered after being damaged.
The flowering part of the orchid is often attacked, and there are brown patches at the overlapping parts of the petals. It can be found that a large number of adults and larvae gather together, and the damaged flowers lose bright colors and its beauty.
This species of thrips generally occurs in the flowering stage of all kinds of orchids. Adults and larvae have serious and significant damage to flower parts. Damaged petals show brown patches and wither, which not only affects their beauty, but also damages the commercial value.
1. Remove unnecessary flower spikes when the plants are divided, to avoid breeding of thrips.
2. Spray the systemic insecticide on the surfaces of stems and leaves to reduce the density of thrips prior to flowering.
3. When the condition is severe during flowering period, spray the insecticide if need be, but at this time, the dilution factor of the insecticide should be reduced so as not to cause phytotoxicity in the flower part.
4. The surface of potted plants may be given insecticidal granules so that the pharmaceutical ingredients are absorbed through the roots and then run to the stems and leaves.
5. Use insecticidal fumigant or ultra-fine particle spray in a confined greenhouse and spray thoroughly with flowers, sprouts, leaves, etc., so that the liquid can reach the hiding place of the thrips.