Gram Pod Borer (Helicoverpa armigera) is a major insect pest that infests green gram (Vigna radiata), an important pulse crop in many nations, including India. Significant production losses are caused by the larvae of this bug, which bore into the green gram pods and feed on the developing seeds. The Gram Pod Borer is a pest with a broad range of host plants: cotton, tomatoes, chickpeas, and pigeon peas.
With a 40–50 millimeter wingspan, the adult moths appear brown. The caterpillars hatch and bore into the pods within a few days of the female moth laying eggs on the host plant’s leaves and pods. The harm that the pest causes is most severe during the last stage of the larvae’s development, which involves several stages.
Multiple methods can be used to control the Gram Pod Borer outbreak in green gram. Crop rotation, intercropping, and sowing early-maturing varieties are cultural practices that can help control the pest population. Additionally, biological control agents like Bacillus thuringiensis (Bt) and pheromone traps can successfully control the pest. If the pest population is too large, chemical insecticides can be used as a last resort, but their use should be carefully controlled to avoid the emergence of resistance.
According to research, a mix of these management techniques can successfully control the Gram Pod Borer in green gram, minimizing yield losses and fostering sustainable production. To reduce chemical insecticides and encourage sustainable agriculture, it is crucial to regularly track the pest population and use integrated pest management (IPM) techniques.
Gram Pod Borer Management in Green Gram
Identification of Gram Pod Borer
Gram Pod Borer (Helicoverpa armigera) can be identified by its various life stages. The eggs are spherical and creamy white, laid singly on the leaves or pods of the host plant. The larva can vary in color from greenish to brown and has dark brown and grey lines laterally on the body with lateral white lines and dark and pale bands. The brown pupa occurs in soil, leaf, pod, and crop debris. The adult moth is a light pale brownish-yellow stout moth with grey forewings to pale brown with a V-shaped speck. The hind wings are pale smoky white with a broad blackish outer margin.
The Life cycle of Gram Pod Borer
The life cycle of Gram Pod Borer (Helicoverpa armigera) consists of different phases. The female moth lays the eggs on the leaves or pods of the host plant, and within a few days, the eggs develop into caterpillars. The damage is most serious during the last stage of the larvae’s development because they feed on the developing seeds inside the pod.
During the 20 to 25 days of larval, the larvae go through several developmental phases, shed their skin, and get bigger. Following larval development, the insect pupates for 10 to 15 days in the soil or crop debris. The adult moth emerges after the pupal period, remaining for about 5-7 days.
Causes/Conditions Favorable for Gram Pod Borer Spread in the field
The pest population and the duration of each life stage are closely linked to environmental conditions, especially temperature, and food availability. High temperatures and a lack of moisture can increase the pest population, and low rainfall can reduce the availability of natural enemies. Poor sanitation, improper crop rotation, and monoculture practices can also contribute to the spread of Gram Pod Borer.