Rutherglen Bug

Nysius vinitor

Family: Lygaeidae

Order: Hemiptera

Description:

Adult

Colour - Grey to dull brown with transparent wings

Body - Up to 5 mm long and 1.5 mm wide. Slender.

Wings - 2 Pairs, both used in flight. Held flat and overlapping position when at rest. Coupled. Transparent. Wing-span 2 mm. Nymphs have no wings.

Mouthparts - Stylet. Sucking. Near rear of head.

Antennae - 3-10 segments. Set well below the eyes.

Eyes - 2. Compound. 2 simple.

Legs -Feet (Tarsi) have 4 segments.

Head -Wedge shaped

Thorax - 3 segments.

Abdomen - Eight pairs of spiracles on underside.

Egg - ovoid. Whitish.

Habits - Can't fly when cold or windy. Give of an odour when crushed. Irritate eyes. Rise in clouds of insects when disturbed. Tend to congregate in swarms.

Nymphs

Similar to adults. Reddish brown and pear shaped and wingless. They usually have 5 stages (instars).

Biology:

Life Cycle:

Adults over-winter in litter or herbage. In spring and early summer large numbers of eggs are laid in grass, sow thistle, cudweed or other flower heads and leaves. These hatch in 6 days to produce nymphs that grow quickly and moult 5 times. They look and behave similarly to the adult. In 3-4 weeks they have reached full size. Often develop into large numbers in hot dry summers.

Rutherglen bugs colonise capeweed at flowering in spring and leave 6-10 weeks later to move onto sunflowers over summer then onto wireweed in February 1320

Habitats:

Origin and History:

Distribution:

Significance:

A native insect. Major pest of sunflowers, grapes tomatoes and potatoes. Pest of beans, cauliflowers, cabbages, canola, cut flowers and young eucalypts. Suck sap causing wilting of soft growth. Fruit and grapes may be dried out, a leathery layer beneath the skin formed or exudates may appear on the skin. Immigrate in spring and summer from inland infestations to attack crops in the agricultural area. Feed on cruciferous plants such as canola, radish, turnip and mustard and a range of vegetable and other plants.

Heavy and prolonged infestations can reduce canola pod set, fill and grain quality and viability.

Rutherglen bug is an occasional pest of Sorghum in Queensland.

Management and Control:

Spaying is economic on some crops. Several days of continuous rain usually stops an epidemic. If large numbers of bugs are seen on weeds and herbage in spring then a serious out break may occur.

Thresholds:

Canola

If there are more than 10 adults or 20 nymphs per Canola plant and the crop is moisture stressed then it is usually worth spraying. Under good growing conditions higher numbers are well tolerated. When infested, spray before windrowing to reduce damage in the windrow. Inspect crops from flowering to windrowing. Pay special attention to areas bordering Capeweed pastures as the bugs will move onto the crop as the pasture dries.

Sorghum

When there are 30 adults and nymphs per head it is usually worth spraying because this will build up to over 100/head which causes grain pinching (Qld DPI, 2005). Nymphs are often difficult to control because they are protected within the sorghum head. Densities of less than 30 adults per head don't usually cause yield loss.

Sunflower

10-15 per plant at budding on dry land crops. 20-25 per plant at budding on irrigated crops.

After flowering spray if there are more than 20-25 per flower head.

Related Species:

Similar Species:

Leafhoppers or Jassids

Aphids

Lucerne flea.

References:

CSIRO. The Insects of Australia. Melbourne University Press. (1991) p108, 502.

Child, J.C. Australian Insects. Periwinkle Books. p37.

Goode, J. Insects of Australia. Angus and Robertson. p68.

Jones, D. & Elliot, R. Pests Diseases and Ailments of Australian Plants. Lothian Publishing Co. p51.

Victorian Department of Agriculture. Insect Bulletins. p48.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.