*4.1.4 Coffee-bean weevil/nutmeg weevil (*Araecerus fasciculatus *(De Geer, 1775) Coleoptera: Curculionidae)*

*Distribution:* The coffee-bean weevil (Coleoptera: Brenthidae) is cosmopolitan in nature.

*Host range:* Its main hosts are dried fruits, coffee, corn, cornstalks, seeds, and seed pods.

*Bionomics:* The coffee-bean weevil is very active, dark brown in color, with mottled light and dark-brown pubescence, robust beetle. It can be seen in cornfields where they fly here and there. They are usually seen inside soft seeds than hard seeds so they can damage a little to the stored grains gravid females lays eggs inside soft kernels of corn holes.

*Damage symptoms:* Coffee-Bean weevil can be seen flying in cornfields as well as both larvae and adults inside containers or bins containing grains.

#### **Management of grain weevils:**

Freezing is one traditional method in which stored grains are stored in freezing conditions to increase their shelf life free from infestation. Vacuum cleaning is another traditional method in which any stage of any pest can be pulled from any surface with the vacuum cleaners by sucking all of them. Sun drying of grains is also beneficial. Cleaning, damp-proofing, and heating arrangements should be made possible before storing grains in storehouses or godowns. Corn and other husk-bearing 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. Placing neem leaves inside grain containers is also recommended. Chemical control can be performed by applying 5% BHC at the rate of 0.15% by weight. Before storage of grains, godowns, containers, and bins should be sprayed with 0.02% Malathion or 0.4% BHC or DDT. Fumigants such as methyl bromide, ethylene dibromide, phostoxin tablets, and HCN are also used for fumigation for 18 h in the closed godowns.

#### **4.2 Grain borers**

Grain borers can bore into almost anything such as fabrics, furniture, paper, seed kernels, and seeds.

### *4.2.1 Lesser grain borer (*Rhyzopertha dominica *(Fabricius, 1792) Coleoptera: Bostrichidae)*

*Distribution:* This pest is originated in India but now this pest has spread all around the world. After rice weevil lesser grain borer is considered as second in importance as a destroyer of stored grains.

**Figure 4.** *Dorsal view of adult of* Rhyzopertha dominica.

*Host range:* Initially, it was mainly found to invest wheat packings but now it's found to be a pest of all cereals. It's mainly found in warmer areas of the world and damages mainly wheat, barley maize, paddy, sorghum, and other crops. It causes its damage by mainly boring into the wood in both larval and adult stages.

*Bionomics:* Lesser grain borer or Australian wheat weevil are cosmopolitan, small, cylindrical-shaped, dark brown or black in color, roughened surface bodied entities. The head of lesser grain borers are turned down under the thorax and are armed with powerful jaws for cutting and piercing the wood (**Figure 4**). Adults and larvae, both are causing serious damage in warm climates than in cold climatic conditions. Gravid females lay 300–500 eggs loosely or in clusters in the grains. After hatching small, whitish grubs are emerged and voraciously feed on the seeds. Inside grains, these larvae are transformed into pupae and later into adult beetles that came out of the grain through holes.

*Damage symptoms:* Both larvae and adults of this pest cause serious damage. Highly infested grains become completely hollow inside and only the outer thin shell remains intact. Almost four beetles can be present in bigger grains such as maize. Adults are mostly good fliers so they can easily migrate from one godown to other. Adults produce a considerable amount of frass, spoiling more than what they eat.
