Скачать или смотреть Control of rice stem borer/Daily Zarat

Symptoms are similar to those of other rice stem borers. Newly hatched larvae tunnel down the plant between the leaf sheaths, killing the shoot and causing 'deadhearts'. The stems are easily pulled out. Later, the feeding at the base of the panicles may prevent emergence, or result in white unfilled grain of those that have emerged, a symptom called 'whitehead. Scirpophaga innotata is a tropical species, occurring in regions with distinct dry and wet seasons.

The eggs are laid in groups of about 100 near the tip of the leaf blade and covered with hairs from the tip of the abdomen. A week later the eggs hatch and the off-white larvae have a faint dark line along the back and brown heads. The larvae are at first greyish-white, and when fully grown are white to yellowish, 25 mm long. During diapause the larvae move down into the plant base, most reaching 3-5 cm below ground. Development takes from 20-30 days. Pupae are white, and pupation takes from 6 to 9 days. Adults are white; male wingspan is 18-22 mm, whereas the female wingspan is up to 33 mm. They are nocturnal.
The use of insecticides risks destroying natural enemies. Use only as a last resort:

Use abamectin, a natural fermentation product from a bacterium.
In Fiji, diazinon and bifenthrin are recommended for (unspecified) stem borers.
Chlorpyrifos and fipronil, have also been recommended (for all stem borers), but note that chlorpyrifos is an organophosphate insecticide, and is a potent nerve agent; the World Health Organization (WHO) considers chlorpyrifos to be moderately hazardous (Class II). The use of fipronil is under review in Australia by the APVMA because of environmental concerns. A report is expected in 2020. Reviews on the use of chlorpyrifos are on-going in Europe, USA and Australia.
All synthetic products are likely to reduce the impact of natural predators and parasitoids against this moth, and can only be recommended as a last resort.
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