home Home | contact Contact | Sitemap Sitemap userHello Guest | Login FacebookTwitterGoogle+YouTube
Indian Pest Control Association

Drugstore Beetle

drugstore beetleThe drugstore beetle (Stegobium paniceum) is the most omnivorous of the storage pests. It is rust-brown in colour and grows to a length of 3 mm. The females lay about a hundred eggs, from which the adult insects develop in two to three months. The white maggots or larvae pupate in an oval cocoon spun from particles of food. The fully grown beetles live for one to two months.

The drugstore beetle is considered as omnivorous because it infests a broad range of vegetable and animal products. As well as bakery products it will eat soup cubes, chocolate, animal food and dried fish. Now and again it will eat savoury biscuits, and even develop a taste for chilli powder. Their presence can be detected from pinhead holes in the infested items. Packaging materials such as paper and cardboard are also attacked. Since the drugstore beetle can fly well, the source of infestation is often hard to find.

Because it is 12 to 18 mm long the yellow mealworm (Tenebrio molitor) is hard to overlook when it is crawling around in snow-white flour. The freshly hatched beetle is brown at first, and then turns black with light stripes on its wing cases. The females lay 150 to 200 sticky eggs in the food. The hatched larvae are the familiar mealworms, with a length of up to 28 mm. It may take a year and a half before the mealworms turn into beetles. Massive infestation is therefore fortunately rare. The adult beetles live for about 4 to 6 weeks.

Drugstore beetles and mealworms not only eat any pastry and bakery products, they also soil them as well. The flour turns lumpy and smells mouldy. They prefer leftover wheat and flour waste. Mealworms can also eat holes in planks and beams. In addition they can cause parasite infections - mealworms transmit parasite worms among other things.

Preventive measures and control

  • Keep food cool and dry
  • Immediately remove and destroy infested foods, and if it looks alright keep it in a deep freezer for three days
  • Vacuum-clean storage cupboards thoroughly (the cracks and crevices especially)
  • Keep new stores in sealed containers (jars, boxes)

The basis rule is:
Do not use insecticides in storage cupboards especially if food items are still in.