How do you control Helicoverpa armigera?
Control of H. armigera has mostly depended on chemical insecticides and BT cotton (Guo, 1997; Ahmad et al., 1999; Wu and Guo, 2005). As a result of the continuous and widespread use of Bt cotton and long-term, large-scale, and indiscriminate chemical pesticide use, H.
Which of the following can be used against Helicoverpa armigera?
The results suggested that HaNPV can be used in combination with spinetoram and emamectin benzoate for the management of resistant population of H. armigera.
What is the economic importance of Helicoverpa armigera?
Economic importance: The damage caused by H. armigera is annually estimated, world-wide, to exceed US$2 billion, and the bollworm is listed as an A2 quarantine pest by EPPO. In the Middle East it is a major pest of cotton, tomatoes and other solanaceous crops, legumes like peas and beans, and maize (corn).
How do you control borer pods?
Apply biopesticides such as Bt or neem products. They usually give good control of pod borers, provided they are applied to pods before the young caterpillars enter into the pods. Once the caterpillars have entered the pods they are difficult to control and by then they have caused damage.
Which is the damaging stage of Helicoverpa armigera?
armigera can cause significant reductions for soybean in Brazil, and it is necessary to intensify monitoring and use of efficient and alternative control methods for the use of insecticide. In conclusion, our study shows that growth stage R5. 1 is more sensitive to damage by H. armigera than the R2 stage.
Why is Helicoverpa a major pest?
It is a multivoltine with diapause, highly fecund and capable of moving long distances as adults (Fitt, 1989). Thus, they can rapidly exploit host crops, particularly monocultures. Another important factor contributing to its pest status is the relatively large size and quick development.
How do I identify my Helicoverpa armigera?
They are white, later becoming greenish. The larvae take 13 to 22 days to develop, reaching up to 40 millimetres (1+1⁄2 in) long in the sixth instar. Their colouring is variable, but mostly greenish and yellow to red-brown. The head is yellow with several spots.
What is the damaging stage of Helicoverpa armigera?
Damage after full-pod stage leads to reduced potential to compensate for the damage. H. armigera feeds mostly in the middle third of soybean plants. The rate of seed-yield loss at R2 growth stage was 7.7 g per larva and 10.6 g per larva at R5.
Which stage of Helicoverpa armigera is used to cause damage to the crops?
H. armigera caused more injuries in the middle part of the plant, followed by the upper and lower third. The rate of seed-yield loss at the R2 growth stage was 7.7 g per larva, significantly lower than the rate of loss at the R5. 1 stage (10.6 g per larva).
How can you tell if a pod is a borer?
- Larva – Greenish white with brown head. It has two pairs of dark spots on the back of each segment.
- Adult – Forewings – light brown colour with white markings; Hindwings – white colour with brown markings at the lateral edge.
How can you tell if a bean pod is a borer?
Look for frass – faecal matter and chewed remains of the pods – around entry holes. Look for caterpillars inside the damaged pods: they are pale with two rows of black markings on their backs. The moth is brown with a white patch on the front wings. Bracon parasitoids have been recorded in Fiji.
What flare square symptoms?
Explanation: Flare square is a characteristic symptom of Spotted bollworm. It is caused by Earis insulena/vitella. In the attacked bolls the lint is spoiled by larval feeding.
What is the common name of Helicoverpa armigera?
Helicoverpa armigera is a species of Lepidoptera in the family Noctuidae. It is known as the cotton bollworm, corn earworm, Old World (African) bollworm, or scarce bordered straw (the lattermost in the UK, where it is a migrant). The larvae feed on a wide range of plants, including many important cultivated crops.
How do I find my Helicoverpa?
Eggs are 0.5 mm in diameter and change from white to brown to a black head stage before hatching. Newly hatched larvae (neonates) are light in colour with tiny dark spots and dark heads. As larvae develop they become darker and the darker spots become more obvious.
At which stage of gram crop is damaged by Helicoverpa armigera?
The correct answer is Early stage.
In which crop the insect pod borer is commonly found on?
Maruca vitrata is a pantropical insect pest of leguminous crops like pigeon pea, cowpea, mung bean and soybean. Its common names include the maruca pod borer, bean pod borer, soybean pod borer, mung moth, and the legume pod borer. The species was first described by Johan Christian Fabricius in 1787.
How do you prevent bean pod borers?
Fall plowing to at least 8 inches deep can help destroy overwintering populations. Early year planting can help the crop achieve maturity before pod borers attain high densities. Crop rotation also is recommended where lima bean pod borers are a problem. Insecticides used for corn earworm also control this insect.
How do Americans control bollworms?
Spray using Neem-based products max 3 times (usually 2.5-3 litres/ha or 50-60 ml /20 litres water, or 20 – 50 g neem seed cake or powder / litre water, but double-check with product labels). Spray to cover fruits and entire plants. This is used to control small 1st -2nd instars of larvae (when they are < 1.5 cm long).
What season is the Helicoverpa eggs are active?
armigera and H. punctigera take 4-6 weeks from egg to adult in summer, and 8-12 weeks in spring or autumn. The helicoverpa lifecycle stages are egg, larva, pupa and adult (moth) (Figure 6). Fertile eggs hatch in about three days during warm weather (250C average) and 6–10 days in cooler conditions.
Which of the following insect is known as pod borer?
Maruca vitrata is a pantropical insect pest of leguminous crops like pigeon pea, cowpea, mung bean and soybean. Its common names include the maruca pod borer, bean pod borer, soybean pod borer, mung moth, and the legume pod borer.