Sap beetles
Carpophilus species

Order: Coleoptera
Family: Nitidulidae
Acronym: CAR

Ecology

The Nitidulidae is a large family of beetles with approximately 3000 species world wide. 120 species are estimated to be in Canada. They are referred to as sap beetles. They feed on a wide variety of food sources but mostly on decaying and fermenting fruit, fungi and carrion. They are attracted to moulds and yeasts growing on potential food sources. They are major pests of fruit production and minor pests of stored grain. Warm and damp conditions favor rapid development of sap beetle populations. Sap beetles are found in recently harvested grain, grain residues, empty granaries, compost heaps, factories and warehouses. They feed on ripe and decomposing fruit in the field, dried fruit, stored grain, corn, wheat, oats, rice, nuts, spices, flour and sugar.

Damage

Larvae and adults are both generalist feeders and do not create any distinctive damage. In high value fruit crops, the presence of adults, larvae and cast skins has a more detrimental effect on product quality than their actual feeding. The larvae require a moist food source. The larvae may burrow into soft mouldy fruit or grain residues. Signs of infestation are liquids oozing from entrance sites on fruits and insect frass. The beetles may transmit mould spores, bacteria and yeasts, which can cause smut and spoiling of fruit.

Life history

The adult sap beetle is very distinct in appearance. It is oval and flattened. It is approximately 2 – 4 mm long. The adult may range from light brown to black in colour. Some species have spots on their elytra, which may be yellow, red or brown in colour. The adult has clubbed antennae. The elytra are shortened, exposing the last two to three segments of the abdomen. The adult is a strong flyer and long lived. Adult longevity may be 5 to 7 months.

The female can lay between 500 – 1000 eggs. She deposits her eggs singly in among the food source. The optimum temperature for development ranges from 18°C to 34°C, and is species dependant. Relative humidity for development ranges from 50% - 90%.

The larva is translucent and very active. It is 6 – 9 mm long. It has two tail-like appendages, called urogomphi, on the last abdominal segment. It will moult 4 times. The development time ranges from 18 days to 125 days. The larva pupates in the food source or below the soil surface.

Control

Controlling insect infestations

Images

Adult: Sap beetle - Carpophilus hemipterus

Larva: Sap beetle - Carpophilus hemipterus