Rutherglen bug and grey cluster bug







Nysius vinitor

milkweed bugs, seed bugs


There are two species which are virtually identical- the rutherglen bug (Nysius vinitor) and the grey cluster bug (Nysius clevelandensis). Both are grey and black in colour, with some brown markings. They are very difficult to tell apart but under magnification the Rugherglen bug is smooth whilst the Grey cluster bug is hairy. Nymphs are wingless, pear shaped, reddish brown and look a little like an aphid.

Adult size: 5 mm

Out and about

Both are about in spring and summer, and are often seen together. They like hot dry conditions and are often seen in cane mulch, usually in great numbers. Both of these species are native to Australia. The Rutherglen bug is widespread throughout the country but the Grey cluster bug is only in the north-eastern areas. There are at least 100 species in this genus worldwide. There are at least 100 species in this genus worldwide.

Reproduction and Life cycle

The eggs are laid on the surface of the soil or on flower heads. They are about 1 mm long and a creamy colour, turning brown before hatching. The adults will shelter over winter and emerge in spring to breed on a wide range of native and weed plants. The time frame from egg to adult is 3-4 weeks and the female can lay up to 400 eggs at a time. There can be as many as eight generations produced in the year, so numbers can explode very quickly.

To deter

To control

- Keep the area clean from weeds - Spray with pyrethrum - Spray with neem

Plants to repel

Plants to attract


Parasitoid wasp, although bug numbers are often too high for them to have an impact
Why they are a Pest
These bugs are sap suckers and get into fruit and the heads of flowers. In our garden they were in the broccoli heads which became quite deformed as they grew. They breed up in weeds over spring and, as these die off, they move over into nearby crops in summer. Crops affected include sunflower, legumes and grains.