Helicoverpa or Heliothis Budworms

Helicoverpa or Heliothis Budworms

Heliothis and Helicoverpa species

Family: - Noctuidae

Order: - Lepidoptera

Description:

Adult
Night flying moths with eyes that reflect orange light. Attracted to lights.
Colour - 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
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 -
Habits - Can't fly when cold.
Caterpillar -
Colour - Brown, green or pinkish with a broad pale bands down each side and dark flecking. 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:

Moth flies by night and lays eggs on plants. Caterpillars remain close to where eggs were laid. Small caterpillars eats soft plant tissue, larger one burrow into the plant leaving a hole about 3mm wide. Pupa lives in soil beneath the plant. In Victoria there are 3 generations in a year.

Habitats:

Origin and History:

Distribution:

Significance:

Some species are cosmopolitan and others native to Australia. 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 (Helicoverpa punctigera and H. armigera) are major pests of cotton, sunflower, lupins, linseed, tomatoes, beans, peas, lucerne, maize and tobacco.
Some of these species 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.

Management and Control:

A number of strains have become tolerant of common insecticides, which can make control very difficult.
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.
Higher numbers, earlier in the season, appear to have little effect on the yield of Faba Beans or Chickpeas, if seasonal conditions result in low numbers at podding.
See Pest Susceptibility of Lupin Varieties for ranking of common Lupin species and varieties.
In Faba Beans they are hard to find and 2 grubs in 20 sweeps (taken at the beginning of podding) is usually worth controlling. Spray at the commencement of podding. A single spray at this time is usually sufficient.
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.

Acknowledgments:

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