Native Budworm

Native Budworm

Helicoverpa punctigera

(formerly Heliothis punctigera)

Family: - Noctuidae

Order: - Lepidoptera

Description:

Adult

Night flying moths with eyes that reflect orange light. Attracted to lights.

Colour - Cream, brown or grey. Often with zig zag marking on wing.

Body - Medium size. Stout. Long hair scales.

Wings - 2 Pairs. Membranous. Hairy. Wing-span 20-45mm. Front wings are lighter than rear wings which may be almost white with a dark patch at the extremities.

Mouthparts -

Antennae - 3 segments.

Legs - Broad overlapping scales. Feet (Tarsi) have 5 segments.

Head - Broad overlapping scales. Large rounded compound eyes.

Thorax - Broad overlapping scales. 3 segments. Front segment much smaller. Hairy

Abdomen - Broad overlapping scales. 7-11 segments. Spiracles on segments 1-7. Hairy

Egg - small white.

Habits - Can't fly when cold. Fly very swiftly.

Caterpillar -

They are 1.5 mm long with dark heads and dark spotted whitish bodies on hatching. Young ones are 10-20 mm long and pale yellow, greenish or brownish with dark heads, hairs on their upper body and often have dark narrow stripes along the backs and sides of the body.

Mature caterpillars are as below;

Colour - Brown, green or pinkish with a broad pale bands down each side and dark flecking. Often has a cream line bordered by a black line down the middle of its back. Markings depend on the plant that it is feeding on.

Body - Fleshy. Cylindrical. Slightly hairy. Spiny skinned 20-40mm long, 3-10mm wide.

Mouthparts - Chewing.

Antennae - Short. 3 segments.

Legs - 5 segments. Single claw on end.

Head - Hard.

Thorax - 10-11 segments. Spiracles on segments 1 to 8. Prolegs on segments 3-6 and 10.

Abdomen -

Habits - Herbivorous. Curls up when disturbed.

Pupa - In soil, in a silken cocoon.

Biology:

Life Cycle:

The moths fly by night and lay stalkless eggs on plants shoots or fruit. They are often attached to the hairs on small legume pods. Moths flights are strongly influenced by low and mid level wind patterns. Caterpillars remain close to where eggs were laid and emerge about a week after the eggs are laid. Small caterpillars eats soft plant tissue, larger one burrow into the plant leaving a hole about 3mm wide. They feed for about three weeks then pupate. The pupa lives in soil beneath the plant for a few days to a few months depending on the season. In Victoria and W.A. there are 3 generations in a year. The spring generation is usually the most damaging. In spring conditions in the wheatbelt the life cycle is about 7 weeks.

Larvae from eggs laid in winter in cool temperatures take longer to develop than those laid in warmer conditions.

There are 6 instars.

Instar	Size mm	Day to develop
1	1.5	13-21
2	3	16-21
3	7	8-11
4	13	~7
5	23-28	~7
6	28-31	~7

Habitats:

Breeds in native vegetation and in the pastoral areas and migrates south into the agricultural areas.

Origin and History:

Australian native insect.

Distribution:

Throughout the agricultural and pastoral areas of WA.

Significance:

Caterpillar is a pest of a wide variety of crops and plants including mallows. Eats buds, flowers, fruits and young leaves usually making a characteristic round hole. Caterpillars are often seen with their heads buried in this hole. Budworms are major pests of cotton, sunflower, lupins, linseed, canola, tomatoes, beans, peas, chickpeas, lucerne, Persian clover, Balansa clover, subterranean clover, medic, serradella, maize and tobacco. Occasionally cereals are attacked as caterpillars move out of drying pastures.

Some may migrate over considerable distances. This may carry insecticide tolerant strains into susceptible populations or dilute tolerant populations with susceptible strains.

Orius flower bugs eat the eggs of Budworms.

Grain legume crops attract the moths at egg laying and may protect nearby crops such as canola.

Heavy aphid infestations favour budworm infestations because the egg laying moths are attracted by the honeydew excreted by aphids as a supplementary food source for nectar and the aphids are alternative prey for predators of budworm eggs. Hot dry weather also favours infestations because it reduces parasitic wasps. (Hart et al, 1995)

Caterpillars less than 10 mm long rarely cause economic loss because they feed on foliage rarely attack pods of canola or lupins. Occasionally they can cause damage in windrowed canola.

Management and Control:

A number of strains have become tolerant of common insecticides which can make control very difficult.

A number of parasites, predators and diseases together with the weather often help control outbreaks. So, dense flights of moths don't always result in high infestations of caterpillars and crop damage. For winter crops, unless there is a major moth flight (and egg laying) before the end of September then the crops mature before the caterpillars gain sufficient size to cause economic damage.

Control is made difficult because they breed in bush and are very mobile.

Budworms will damage Chickpea and Faba Bean pods as soon as they are formed so spraying should not be delayed. In lupins damaged usually occurs much later and spraying is often delayed.

Thresholds:

Start monitoring from flowering.

Spray from the first pod onwards in grain legumes.

As a rule of thumb, 1 large budworm/m2 at podding in Lupins causes $1/ha of damage. In peas, chickpeas and faba beans 1 large budworm/m2 causes a $2/ha loss.

Insects are commonly counted by collecting the crop from 1 square metre and shaking it onto a white sheet or tray to determine the larvae per square metre or by using sweep nets.

In grain legumes it is usually economic to apply insecticides if 1 small caterpillar is collected for each 3 sweeps of on insect net or if 1-2 large or up to 10-15 small caterpillars per square metre are found.

Spraying thresholds for Grain Legumes over the podding period.

Crop	Budworms per 10 sweeps of insect net.	Expected yield loss kg/ha/day
Lupins	5	7
Peas	1	50
Chickpea (Desi)	1	30
Vetches	4	10
Faba Bean	1-2	70
Lentil	1-2	60
Canola	4	6

Spraying is usually profitable if Budworm numbers are more than above. Check from flowering onwards and spray as required. Normally only a single spray when the threshold is reached is required in grain legumes. Spray before larvae enter the pod. Once inside the pod they are very difficult to control.

In Faba Beans they are difficult to find.

In Canola treatment is usually worth while if the caterpillars are starting to chew on the pods and there is 5-10 caterpillars longer than 10 mm per square metre. In thin canola stands the Budworms may be found by placing a white bag on the ground then shaking the crop. In denser stands 10 - 20 sweeps with and insect net near the edge of the crop is preferred.

Serradella is sensitive to budworm and should usually be sprayed as soon as budworm are detected.

In WA, growers and Agriculture WA maintain a trapping grid for moths to predict likely problems. Seasonal information is available on Pestfax at www.agric.wa.gov.au.

Related Species:

Armyworm, Bogong moth, Cluster caterpillar, Common Armyworm, Corn Earworm, Cutworms, Helicoverpa, Heliothis, Inland Armyworm, Loopers, Native budworm, Southern Armyworm.

Similar Species:

References:

CSIRO. The Insects of Australia. Melbourne University Press. (1991) p489, 829, 912, 948, 969, H. armigera 38f2.9, 107, 108, 914, H. punctigera 108, 914

Jones, D. & Elliot, R. Pests Diseases and Ailments of Australian Plants. Lothian Publishing Co. p116-117.

Victorian Department of Agriculture. Insect Bulletins. p25-27.

WADA. Insects and Allied Pests of Extensive Farming. Department of Agriculture - Western Australia Bulletin No. 4185. p52.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 for more information.