Carpophilus Beetle

Description

Larvae are yellowish with a brown head and forked tail measuring 5 mm when fully grown. Adult beetles are oblong shaped and small, measuring 3 mm in length. They have short wings and clubbed antennae and range from black, brown or mottled yellow in colour.

Adult beetles are strong fliers and can travel long distances in search of hosts. Optimal breeding conditions occur in wet summers in the presence of rotting fruit where beetles lay their eggs. Larvae emerge from the fruit and pupate in the soil. Adult beetles develop from the pupae and begin attacking fruit during late spring and summer. Carpophilus beetles can overwinter in tree cracks, under bark or in mummified fruit if no hosts are available. The lifecycle of CB takes about a month, consequently several generations can occur every year.

Adults directly feed and damage ripening almonds and stone fruit. Beetles enter by burrowing into the fruit near the stem end suture line, and via splits and mechanical damage to fruit. In contrast, in other fruit trees including citrus, apples and figs, only fallen fruit are attacked and therefore yield is not impacted.

Carpophilus beetles are a vector for brown rot which can be spread by the beetles as they burrow through damaged fruit. Spores of brown rot stick to their bodies, which can then be spread from orchard to orchard.

Control

As an introduced pest into Australia CB has no known natural enemies, therefore control relies heavily on cultural and chemical methods. Good orchard hygiene is imperative through the removal of rotten or damaged fruit from the orchard and near packing sheds, which reduces the accessibility of breeding spots.

Given their ability to fly long distances, co-operation from neighbouring orchard owners who also maintain good orchard hygiene will result in the most effective control.

Susceptible crops may require additional methods of control. A trapping method is commercially available and often used for monitoring and management of the beetles. These traps attract and kill the adult beetles assisting in keeping numbers low.

Orchards should be monitored regularly, particularly leading up to harvest, as mature fruit, is more susceptible to attack from CB. Foliar insecticide sprays can be applied to fruit and foliage prior to the beetles reaching damaging levels. However, due to the migratory nature of CB, insecticides will not provide long term protection.

Vayego® is a powerful insecticide providing antifeeding and residual activity. Registered for the control of CB (including C. near dimidiatus) in almonds. Vayego should be applied at early mid hull split if CB numbers reach damaging levels. In stone fruit, Vayego is registered for the suppression of CB species and is best applied prior to CB reaching damaging levels.

References

Bugs for Bugs (2015), ‘Carpophilus beetles’, Bugs for bugs, https://bugsforbugs.com.au/whats-your-pest/carpophilus-beetles/

Fox, R (2017) ‘Carpophilus beetle – a serious pest ’, Tree Fruit, https://www.treefruit.com.au/orchard/crop-protection/pests/item/773-carpophilus-beetles-a-serious-pest

Fox, R (2017) ‘Carpophilus beetle – a serious pest (part 2)’, Tree Fruit https://www.treefruit.com.au/orchard/crop-protection/pests/item/781-carpophilus-beetles-a-serious-pest-part-2

Fox, R (Viewed May 2021) ‘What you need to know about the Carpophilus beetle’, Fruit Growers Vitoria, http://www.fgv.com.au/grower-services/latest-updates/technical-articles/468-what-you-need-to-know-about-the-carpophilus-beetle

Learmonth, L. and Woods, B (2020) ‘Dried Fruit Beetle (Carpophilus) – pest of stone fruit’, Department of Primary Industries and Regional Development (DPIRD), https://www.agric.wa.gov.au/citrus/dried-fruit-beetle-carpophilus-pest-stone-fruit