2[7] Riptortus spp [EIFS

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This leaflet is produced by the Ministry of Agriculture & Livestock, Solomon Islands, with support
from IPPSI: Improved Plant Protection in Solomon Islands, a project financed by ACIAR, the
Australian Centre for International Agricultural Research, Canberra. Authors: Helen Tsatsia, MAL &
Grahame Jackson, TerraCircle.

Extension Fact Sheet 18:

Bean Pod Sucking Bug

Common name: Bean pod-sucking bug

Scientific name: Riptortus serripes & Riptortus linearis.

Hosts: These bugs (photo, left) attack legumes, such as long bean, soybean, and mung
bean. They may also attack rice and clover.

Damage

Damage is done by adults and nymphs (they look like ants) feeding on the pods and
seeds (photo, lower right). The feeding causes the pods to rot, or to develop without
seeds inside. This insect can cause a lot of damage to bean crops.

Biology and Life Cycle

Riptortus lays its eggs on the bean leaves and other plants; usually the eggs are laid
singly. Both adult and nymphs sting the beans in the pods and suck their juices, so
that the beans cannot mature. The pods turn brown, shrivel and die.

Detection and Inspection

Look at the pods and under the leaves; look for ant-like bugs (photo, top right). Look
closely for small holes and damaged, shrivelled pods.

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Management

Cultural control:

Plant long beans near Bixa (photo, right), a
method recommended by a farmer on Malaita
(see flyer: What is the pest spoiling your long
beans?). Bixa is known as the Lipstick Tree,
because of its seeds. They are deep red, soft,
and children use them to paint their faces, lips
included. When the fruits open, they attract
large numbers of Riptortus. The insects feed on
the seeds, preferring them to the seeds of
beans. In this way, the insects are ‘trapped’ on
the Bixa, and attack on long beans is reduced.

Chemical control:

• Insecticides have not been tested against Riptortus in Solomon Islands. It is likely

that synthetic pyrethroids would be effective, such as lambda cyhalothrin or
permethrin. See your MAL extension officer for details.

• A variety of Derris, brought many years ago from Papua New Guinea, may be

effective as a spray. It contains rotenone, an insecticide. Plants are being
multiplied by MAL and KGA for evaluation by growers. Contact those
organisations for plants to test.