Black & Green Gram
Black & Green Gram
Symptoms are observed on buds, flowers, and pods. During the flowering stage, leaves, flowers and pods are webbed, intertwined through the excrement of the larvae. New shoots and buds appear to be dry. Feeding holes are located in the pods to reach the seeds. By boring in the leaf stems, the spotted pod borer causes drying of branches.
Damage is caused by larvae of the spotted pod borer. The adult moth has white crossbands on the dark fore wings and a dark border on the white hind wings. The female lays eggs singly or in small clusters on the leaves, buds and flowers. The greenish-white dark spotted brown-headed larvae have short dark hairs on black warts of the body, pupates in the soil or in leaf webbings. Larvae are nocturnal and attack stems, peduncles, flowers and pods of various hosts, e.g. gram, lablab, chill, peanut, tobacco and cotton, soybean, sesame, sugarcane, castor, Hibiscus, and wild hosts. After rolling and webbing, the leaves M. vitrata continues feeding in the inside. Infestation occurs during seedling until podding stage, preferring temperatures between 20 - 28°C. Yield losses caused by spotted stem borer are estimated to be 20 - 50%.
Spotted pod borer can largely be controlled by natural enemies. Members of parasitoid flies (Tachinidae) and wasps (Braconidae & Ichneumonidae) are able to limit pest population. In combination with predators (Lacewing, ladybird beetle, spider, red ant, dragonfly, robber fly, reduviid bug and praying mantis), M. vitrata can diminish the infestation up to 98%. As biological pesticides, neem oil based EC containing azadirachtin or Bacillus thuringiensis can be applied as foliar sprays. These should be applied at the beginning of flowering until harvesting. Neem oil or BT formulations are recommended only once at the beginning of the crop season or as soon as an infestation is noticed.
Always consider an integrated approach with preventive measures and biological treatments, if available. You may apply systemic or contact pesticides when it exceeds the economic threshold of 3 larvae per 1 squaremeter. Choose chemical control agents carefully so that they do not disrupt the population of beneficial insects. Apply systemic or contact pesticides like azadirachtin (1500 ppm) @ 5 ml/litre on the onset of pest attack. Other insecticides based on chlorantraniliprole 18.5 EC (0.3 ml/lit), chlorpyrifos 20 EC (2 ml/lit), profenophos 50 EC (2 ml/lit), Spinosad 45 SC (0.3 ml/lit), Emamectin benzoate + lambda-cyhalothrin 5 EC or flubendiamide 39.35 SC (0.2 ml/lit) are also effective to control this pest.