*4.2.2 Larger grain borer (*Prostephanus truncatus *(Horn, 1878) Coleoptera: Bostrichidae)*

*Distribution:* The larger grain borer is originated from India but now this pest is cosmopolitan in nature.

*Host range:* The main host is corn, wheat, rice, and millet.

*Bionomics:* A larger grain borer is a small, dark brown, cylindrical, with a smooth polished surface. Both larvae and adults feed on grain kernels and leave dust and thin brown shells. Females lay 2–30 eggs in clusters on kernels which are later transformed into creamy colored C-shaped grubs with a small dark head that is partly retracted into the thorax, having three pairs of small legs. Adults are brown to black cylindrical bodied pests with numerous small pits on wing covers.

*Damage symptoms:* These are notorious for the emission of sweet, musty odor during an infestation.

### **Management of grain borers:**

The most economical and efficient method of controlling this pest is the prevention of crops. One such preventive method is fumigation. Corn and other huskbearing crops should be stored in the shuck if the husk is tight, and covers the whole tip, but if all ears with loose, short, broken, damaged, or perforated husks should be shucked and stored separately in clean bins. The application of insecticides is the rapidly controlling method for immediate results.

#### **4.3 Grain moths**

Grain moths are found to damage solid, sound, and unbroken stored grains. They reduce kernels as well as grains to powder and shells. Following pests are included in the moth category:

### *4.3.1 Angoumois grain moth (*Sitotroga cerealella *Olivier, 1789 Lepidoptera: Gelechiidae)*

*Distribution:* The name Angoumois is given to this pest because it was first noticed as a pest in the Angoumois province of France in 1973.

*Host range:* It is mainly found in a warm temperate climate and attacks both stored as well as field grains. It causes huge damage to the grains of paddy, sorghum, bajra, wheat, etc.

*Bionomics:* The Angoumois grain moth is considered one of the most serious pests or internal feeders in stored grains. It is a small, yellow-brown moth that attacks all cereal grains directly in fields as well as stored ones in all parts of the world. Females lay on or inside grains, around 150–350 eggs, which are initially white and later turned into a reddish color. Eggs are hatched into white caterpillars that are voracious feeders and eat out a channel to the outside of the grain. Larva enters into the grains and starts eating and then turns about and spins a silken web over the opening from which it enters therefore it's difficult to locate the pest. Only larvae are voracious feeders and they feed on kernels. Infestation cannot be assessed in the early stages. Germination is seriously affected after infestation. It is the most devastating pest out of all Lepidopteran storage pests. White larvae are transformed into reddish-brown pupae and later emerge as moths. Adults are usually good fliers. Infestation starts in maturing cereal crops right in the field.

*Damage symptoms*: The first infestation starts when the grain is in or passing through the milk stage in the field and when only a small percent of grains is infested. By the time grains are threshed or stored infestation increases quickly. When storing the grains infestation of these pests is restricted only to the upper surface. Early infestation is difficult to detect because a hole made by young is so small that it cannot be seen. The first indication of infestation of pests is given by the appearance of moths in the stores and round holes on the grains or sometimes grains get heated up in the bin. Infested grains are hollow insides and filled with excreta or webs of larva leaving a circular opening for moths' emergence. If the pest is breeding in farm godowns, the moth is attracted by instinct to the nearby field in search of maturing grains to lay eggs.

*4.3.2 Wolf moth (*Manduca rustica *(Fabricius, 1775) Lepidoptera: Sphingidae)*

*Distribution:* The wolf moth is cosmopolitan in distribution.

*Host range:* It is mainly found in a warm temperate climate and attacks both stored as well as field grains. It causes huge damage to the grains of paddy, sorghum, bajra, wheat, etc.

*Bionomics:* Wolf moth is a small, creamy white and has a thickly mottled appearance with brown color that distinguished it from the Angoumois grain moth.

*Damage symptoms*: Infestation can be assessed during early stages with the presence of creamy-colored grubs as well as brown-colored adults.
