Yellow stem borer

The yellow stem borer Scirpophaga incertulas is common in Southeast and East Asia, China, the Indian continent, and Afghanistan. It attacks rice throughout its growth period.

The eggs of the yellow stem borers are laid near the tip of the leaf blade.

The eggs, which hatch in 8 days, are laid in oval masses of 50-200 eggs each. They are covered with hairs from the anal tufts of the female moth.

The body of the larva is cream colored and the head  is reddish brown.

The pupa is yellowish white with a tinge of green. It turns dark brown just before adult emergence. The pupal stage takes place inside the stem, and often below the soil surface.

The adults show sexual dimorphism, or differences in form or color between the sexes.  The males and females are often mistaken as 2 species. The male is light brown with numerous small brownish dots, along the subterminal area and near the tip of the forewing. The female is yellow, the color deepening toward the tip, and there is a very distinct black spot in the center of each forewing. The hindwings are pale and straw-colored.

The yellow stem borer requires about 46 days to complete development. Adults can emerge through the water.