Insects in commodities
Types of Pest
The most important type of pest is the commodity feeder. This type of pest feeds directly on commodities and can be divided into:Primary pests: those that infest intact commodities.Secondary pests: require the commodity to be damaged before they can infest it.
Distribution
Most species have a worldwide or a pan-tropical distribution. Comments on geographical distribution are provided with each pest described. Many tropical species not established in temperate areas are often intercepted there on infested imports.
Identification
For each pest described, the common and scientific name is given including family names, if available. Major features used for identification are indicated; however, as a basic field guide, only those characteristics that are easily visible with a hand lens or basic binocular microscope are emphasized.
Commodities preferred
With each pest, details are given of the commodities that they infest. Secondary pests usually infest a wider range of commodities and many can feed on almost any dry material of animal or plant origin.
| Type of pest | Primary pest |
| Distribution | Tropical |
| Identification | Adult - 3 -5mm, globular, long legs and antennae, elytra patterned with light and dark patches giving checkered appearance. Last three segments of antennae formless club. Larvae - scarabaeiform, legs party developed. |
| Similar species | Bruchids |
| Commodities infested | Cocoa, coffee, dried cassava and yams, maize, groundnuts, Brazil nuts, nutmegs. |
| Type of pest | Secondary pest |
| Distribution | Worldwide, warm temperate to tropical |
| Identification | Adult - labial palps short and cured upwards. Forewing ( 7- 9mm ) grey with darker markings. Larvae - 15 -20mm. white to pink with black spots ( at base of hairs ), rim of abdominal spiracles evenly thickened. |
| Similar species | Hofmannophila, corcyra, plodia, distinction from Ephestia spp only reliable by examination of genitalia |
| Commodities infested | Dried material of plant origin, especially cereal products, oilseeds, cocoa, chocolate, spices, nuts, dried fruit, and processed food |
| Type of pest | Secondary pest, mould feeder |
| Distribution | Worldwide, varies |
| Identification | Adult - 2 -4mm, Oval, flattened, light brown to black. Elytra short leaving two to three segments of abdomen exposed. Elytra often with one or two yellow, reddish or brown spots. Antennae with three segmented globular club C. hemipterus is distinctive, having a large triangular yellow spot on each Elytra. Larvae - campodeiform |
| Similar species | Histeridae |
| Commodities Infested | Dried and ripening fruit, newly harvested and damp grain, grain residues, compost heaps |
Primary Storage Pest
Primary pests attack and breed in previously undameged commodities. They do not attack milled or ground foodstuff. They are more destructive than secondary pests.
Grain Moth
Damages
Paddy, Maize, Jowar, Barley and Wheat
Granary Weevil
Damages
Rice, Wheat, Sorgham, Barley and Maize
Cigarette Beetle
Damages
Wheat Flour, Cereal Bran, Peanuts, Cocoa, Beans, Cotton Seeds, Spices, Giner, Turmeric and Chilly.
Pulse Beetle
Damages
Pulses, Bean and Gram
Potato Tuber Moth
Damages
Potato Stock.
Lesser Grain Borer
Damages
Rice, Wheat and Maize.
Khapra Beetle
Damages
Wheat, Maize, Jowar, Rice, Pulses, Oil Seeds and Oil Cakes.
Sweet Potato Weevil
Damages
Sweet Potato Stock
Rice Weevil
Damages
Wheat, Rice, Jowar and Paddy.
Peanut Bruchid
Damages
Groundnut, Tamarind and Legumes
Drugstore Beetle
Damages
Turmeric, Coriander and Ginger.
Secondary Storage Pest
They attack only materials that have been previously damaged either by primary pests or by poor handling and storage. They also attack processed items like flour or milled rice.
Red Flour Beetle
Damages
Grains and Milled Products
Confused Flour Beetle
Damages
Grains, Cereals, Millets and Milled Products
Long Headed Flour Beetle
Damages
Grains and Milled Products
Rice Moth
Damages
Rice, Jowar, Millets, Whole Cereals, Cereal Products, Pulses, Oil Seeds, Nuts, Dry Fruits and Milled Spices
Flat Grain Beetle
Damages
Rice, Wheat, Maize, Flour and Ground Nuts.
Almond Moth
Damages
Grains, Cereals, Millets and Milled Products
Saw Toothed Grain Beetle
Damages
Rice, Wheat, Maize, Ceareal Products, Oil Seeds and Dry Fruits.
Mediterranean Flour Moth
Damages
Flour, Nuts, Seeds and Grains.
Merchant Grain Beetle
Damages
Cereals, Dry Fruits, Chocolate, Rice, Bran and Oats.
Indian Meal Moth
Damages
Maize, Cereals, Dry Fruits, Ground Nuts and Cereal Products.