Topgrid Pest Specialist

Stored product Insects

Species commonly found in Singapore

1. Indian meal moth

2. Almond moth

3. Cigarette bettle

4. Flour beetle

5. Sawtoothed grain beetle

6. Foreign grain beetle

7. Rice weevil

Indian Meal Moth

(Plodia Interpunctella) – Pantry Moth

A mature female lays 100 to 300 eggs on food material. Eggs are grayish colour and 0.3 to 0.5 mm. Larvae possess a dark brown head, cream-coloured / yellowish-green / pinkish shades, depending on the food source. Pupae are pale brown, 6 to 11 mm long. Adult wings generally gray but the rear half of the wings are rusty brown or bronze. They are general feeding on grain products, dried fruits, pasta, powdered milk, nuts, seeds etc.

Interesting facts about Indian Meal Moth

  • The larvae usually spin a web as they become completely grown and leave behind the siken threads wherever they crawl.
  • Foodstuffs are contaminated with frass, cast skins, pupal cases and dead moths.
  • Large quantities of silk bind together and foul foodstuffs.
  • Active during night time, flying in a zigzag pattern instead of maintaining a direct flight line.
  • At rest, the wings are held roof-like over the body.
  • Adults do not feed and normally rest during the day in shaded areas.

Almond Moth

(Cadra Cautella) – Common in Warehouses
A female almond moth lays about 200 to 400 small white eggs on or near to their eventual food source. A full-grown adult has a size range from 13mm to 20 mm with it’s upper half wing yellowish-grey in colour with a dark band or stripe at the intersection between two. Webbing is present on pupal cases. These moths feed on a variety of nuts, including almonds, walnuts, peanuts, hazelnuts, dried fruits, grains, seeds etc.

Interesting facts about Almond Moth

  • The larvae create matted webbing during feeding. They pupate in a silk cocoon, and they are able to diapause if the conditions are unfavourable for development.
  • Adult moths are seen flying around areas where their food source is stored, more active during dawn and dusk.
  • Foodstuffs are contaminated with frass, cast skins, pupal cases and dead moths.
  • Large quantities of silk bind together and foul foodstuffs.

Cigarette Beetle

(Lasioderma Serricorne) – Stored product pest that can be found worldwide

Cigarette Beetle undergo a complete metamorphosis. Females lay eggs in or on the food material. The larvae hatched are creamy white and in worm-like shape. Fully-grown larvae pupate in silk-like cocoon covered with materials they have infested. Adults are shiny, small, stout, yellowish to reddish-brown. Body is round, oval and covered by golden hairs. The head is concealed by the pronotum (bent down) and barely visible from above. Infest a wide variety of products such as flour, cereals, spices, and pasta.

Interesting facts about Cigarette Beetle​

  • Adult cigarette beetles are strong fliers.
  • Active in the late afternoon and on cloudy days.
  • Hide in dark and shaded places during daytime.
  • “Play dead” for a few seconds when disturbed.

Flour Beetle

Commonly are Confused Flour Beetle (Tribolium Confusum) and Red Flour Beetle (Tribolium Castaneum)
Small, about 3 to 6 mm in length, reddish-brown in colour. Undergo complete metamorphosis. Female adults lay small and white eggs loosely in flour or other material. The larvae are worm-like larvae that are slender and cylindrical. During pupation, the pupae are white, gradually change to yellow and brown. Known for attacking flour, grain, dried fruits, cereals, nuts, spices.

Interesting facts about Flour Beetle

  • Confused flour beetles are named so as they are easily confused with the red flour beetles.
  • Food are contaminated with their feeding damage, dead bodies, fecal pellets.
  • They usually create a pungent smell and cause the growth of mold in food.

Sawtoothed Grain Beetle

(Oryzaephilus Surinamensis)

Adults possess 6 saw-like “teeth” on each side of prothorax. Larvae are yellow-white with brown heads, feeding on broken kernels. They create a cocoon from food materials during pupation. A fully grown adult is about 2.5 to 3 mm long. Their small size allows them to penetrate cracks and crevices in the food packages. They commonly bait on grain, cereal, flour, pet food, fruit, chocolate, nuts etc.

Interesting facts about Sawtoothed Grain Beetle

  • Are not attracted to light.
  • Adults possess wings but do not fly.
  • The tiny saw-like teeth on the prothorax giving them the name sawtoothed beetle.

Foreign Grain Beetle

(Ahasverus Advena)

Foreign Grain Beetle are about 2 mm long, reddish-brown, and three-segmented antennal club. Live in damp areas where fungus grows. These species are scavenger, hence they feed on fungus or moldy food products and food materials such as cereal, flours, grains, nuts, figs etc.

Interesting facts about Foreign Grain Beetle​

  • Good fliers, manage to gain access through windows.
  • Closely associated with moisture areas which allow fungus or mildew to grow, for example, building with poor ventilation and water leaks.

Rice Weevil

(Sitophilus Oryzae)

Adults about 2 mm long with a long snout, brown or black body. Attack several crops, including wheats, rice, barley, maize, corn, cereals and oats. Female adults bore a small hole into the kernel or seed to lay an egg inside, sealing it with a gelatinous material. The hatched larvae develop and consume within the kernel and eventually hollow it out.

Interesting facts about Rice Weevil

  • Strong fliers
  • Infested grains have exit holes as the adults emerge from the kernels.
  • Adults can live up to 6 months.