October Pest of the Month: Black bean aphid

Thursday, 1 October 2020

Name: Black bean aphid (Aphis fabae)

This species is not present in Australia and can quickly develop heavy populations that can become debilitating to infested plants. This species is also a vector of a number of viral diseases, including Beet mosaic virus and Potato leafroll virus.

It has in excess of 82 know host plants including a wide variety of vegetable crops, ornamental plants and weeds but is a major pest of faba bean, soybeans and sunflower. It has been recognised as being a medium risk to the Australian grains industry if it becomes established.

Similar to: Cowpea aphid and Cotton aphid

Description: These are a soft-bodied insect that have specialised piercing and sucking mouthparts used to suck the juice from plants.

A lifecycle can take as little as 5 to 6 days at ideal temperature (approx. 28oC) but can take up to 22 days in cool temperatures (approx. 12oC). Young are produced sexually and asexually.

In the warmer months live young are produced and in the cooler month eggs are produced for overwintering in cold climates. Can be wingless (aptery) or winged (alates).

Winged adults are produced when the colony is too big or there is a shortage of food when migration to other plants occur. All stages may be present in aphid colonies.

Eggs: Small, black and laid in cracks of older bark. Can survive sub-zero temperatures.

Immatures: Small (1 mm long), look similar to adults. They grow through four nymph stages.

Adults:  About 2mm long with small head and bulbous abdomen, blackish or dark green in colour.

Winged forms are longer and more slender and have a shiny black body. Membranous wings are held angled over the body.

The antennae are less than two thirds of the length of the body. Both antennae and legs are pale yellow in colour with black tips. Cornicles or siphunculi are slender and elongated.

Damage: Large numbers of aphids cause yellowing and curling of leaves, stunting of the plants, distorted stems, aborted flowers due to the action of the toxic saliva injected by the aphid to improve the flow of sap, harmful viruses are transmitted and aphid residues may contaminate the crop.

The production of honeydew, secreted by the aphids, attracts ants and adheres to plants where it promotes the growth of sooty mould, which interferes with photosynthesis.

For further information, please refer to the Pest ID Tool at: https://pestid.com.au/pest-insect/bean-aphid-black-bean-aphid-beet-leaf-aphid-blackfly

Note that the Pest ID tool is now available with free access to industry.

An initiative of the Nursery Levy funded National Nursery Industry Biosecurity Program (NY15004) and ‘Building the resilience and on-farm biosecurity capacity of the Australian production nursery industry’ Project (NY15002)