Insect Pests of Maize

Insect Pests of Maize the insects which cause infestation and damage to maize plants in the field of Bangladesh are fall armyworm (Spodoptera frugiperda), aphid (Rhopalosiphum maidis), shoot fly (Atherigona orientalis), cutworm (Agrotis ipsilon), common cutworm (Spodoptera litura), climbing cutworm (Mythimna separate), stem borer (Chilo partellus), pink stem borer (Sesamia inferens), European corn borer (Ostrinia nubilalis), earworm (Helicoverpa armigera), looper (Trichoplusia sp.) and grasshopper (Oxya sp.). Among these insects, the fall army is the most destructive to maize plants and is referred to as a major pest. In storage, the maize weevil (Sitophilus zeamais), rice weevil (Sitophilus oryzae), and lesser grain borer (Rhyzopertha dominica) may appear as serious pests whether the maize grains are left unprotected. The fall armyworm is a new invasive pest identified in Bangladesh for the first time in late 2018 following an incursion from Africa and southern India. Fall armyworm has already been spread out in about 48 districts of the country, causing an infestation in about 35% of maize cultivating lands. The larvae are harmful to crops, and they attack more than 80 species of plants in 26 families. The larva feeds on leaf and fruit, and its full-grown stage is highly voracious, which consumes 50 times higher than the initial stage, and can destroy all the plants on land overnight. This polyphagous insect has four stages in its life, namely egg, larva, pupa, and adult moth. The adult moths are 32 to 40 mm long, having a brown or gray forewing and a white hindwing. Female moths lay dome-shaped eggs on the underside of the leaves, and a female moth can lay up to 1500 eggs in her life. The eggs hatch into larvae within 3 to 4 days. The full-grown larvae are green to a black color and 35 to 50 mm long. They pupate underground for 7 to 37 days in a cocoon. The adults live for 10 to 20 days, and this pest can produce more than six generations per year. This quarantine pest's egg, larvae, and pupae can be disseminated through the soil, and different plant materials, especially seedlings, saplings, and bulbs. Adult moths are rapid flyers, and they can move several hundred kilometers with a storm. [Md. Ruhul Amin]