Okra
Red Cotton Bug
Dysdercus cingulatus
Insect
In a Nutshell
- Feeding damage on cotton bolls.
- Premature opening and shedding of the boll.
- Stained cotton fibers.
- Adults are red-orange colored, with two black spots on their forewings.
- Nymphs also red with black and white dots.
Okra
Symptoms
Both adults and nymphs feed on flower buds and on closed or partially-opened cotton bolls. They bore through the fibers and feed on the seeds. The damaged tissues are colonized by microorganisms that cause boll rot and discoloration. Boll abortion, premature opening and early shed are common. Further symptoms are smaller seeds with reduced oil content, stained fibers and lower germination rate. These seeds are not fit for sowing. D. cingulatus is not bound to a single plant and may migrate to other young bolls. A high infestation can cause a severe loss in quality due to the stained lint.
Recommendations
Organic Control
Foliar sprays with diluted neem oil have shown to be effective against this pest.
Chemical Control
Always consider an integrated approach with preventive measures and biological treatments if available. The foliar application of insecticide formulations containing chlorpyrifos, esfenvalerate or indoxacarb works against the pink bollworm and has shown to reduce red cotton bug population as well. However, in case of late infestation, chemical control is often not feasible because of the residues still present on the bolls during harvest.
What caused it?
The damage is caused by the nymphs and adults of Dysdercus cingulatus. Adults may reach a length of 12-13 mm and are of a distinct red-orange color. Head is red with a white collar, abdomen is black and forewings have two black dots. Males are smaller than females. Females can lay up to 130 bright yellow eggs at a time in the soil, nearby the host plants. After an incubation period of 7-8 days, nymphs hatch and start to feed on cotton plants. They are also red and have three black dots on the abdomen and three pairs of white dorsal spots. The development period lasts 50-90 days in total, depending on the climate. Infestation occur towards the end of the season, when the first bolls are opening. Alternative hosts include okra, hibiscus and citrus.
Preventive Measures
- Monitor fields for signs of the pest.
- Remove the insects by hand, if populations are still small.
- Remove alternative hosts, such as Bombax trees, and other wild plants of the malvaceae family (Hibiscus asper, H.
- cannabinus and H.
- trionus).
- Sow trap crops such as bhendi and collect the insects there.
- Hang moistened trap seeds at different places in the field where bugs congregate.
- Control insecticide use to avoid the development of resistance in the insect.
- Pick up cotton bolls as and when they open.
- Remove and destroy all standing cotton plants as soon as the cotton has been picked.
- Plow the soil deep after harvest to expose the buried eggs to sunlight and predators.
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