Storage pests of Sweet Sorghum: Saw Toothed Grain Beetle (Oryzaephilus surinamensis)

There are two types of saw toothed grain beetle that affect the stored grains,

1. Saw toothed grain beetle

2. Merchant grain beetle

Nature of damage:

Adults and larvae cause roughening of grain surface and offensive odor. Grains with higher percentage of brokens, dockage and foreign matter sustain heavy infestation, which leads to heating.

Grains attacked:

The insect causes damage in the grains of rice, wheat, maize, oil seeds and dry fruits.

Identification:

• It is narrow and flattened.

• Length ranges from 2.5 to 3.0 mm.

• Thorax has six teeth like serrations on each side.

• Antennae clubbed.

• Elytra cover the abdomen completely.

Other information:

The female lays eggs in cracks of storage receptacles or godowns. At 30°C temperature and 75 per cent relative humidity, the life cycle of the insect takes about 3 weeks. Maximum longevity of the adult is about 3 years. Generally, it survives for about 6-10 months. Multiplication is faster in the rainy season.

Fig. 1 : Damage of saw toothed grain beetle