Locusts are actually grasshoppers belonging to Superfamily Acridoidea.  They develop gregarious characteristics and their control is critical to food security worldwide.

Image: A. miliaris

During the COVID-19 pandemic lockdown situation in April, communities of Uttar Lambari village Taknaf, Cox’s Bazar, a southeastern District of Bangladesh have faced a crisis in the form of Aularches miliaris (Family: Pyrgomorphidae) an insect species, locally called ‘Barmachandali’. In 1990, A. punctatus [A. miliaris] was recorded from he country previously. It is a minor insect pest of more than 30 economic crops and causing occasional economic damage to these and many other crops.
Common name of A. miliaris is Coffee spotted grasshopper, Ghost grasshopper, Northern spotted grasshopper and Foam grasshopper. It was reported from Bangladesh, Cambodia, Laos, Indonesia: Java; Sumatra; Sulawesi, Myanmar, Nepal, Pakistan, Sri Lanka, Thailand, China; Tibet, South Vietnam, West Malaysia, Maldives Island, Philippines, Papua, Papua New Guinea, Solomon Islands, Christmas Islands.
Image: A. miliaris

The specimens of this species have been found in long green grasses, pastures and fruit orchards, and mainly causing damage to grasses. Also, A. miliaris swarms in October, the mating and egg-laying season, collecting on bushes and grasses. It is heavy and sluggish, able to make only short leaps, very visible on vegetation. Outbreaks leading to this species damaging cultivated crops are uncommon.

A. miliaris passes through a series of stages in their life cycle, from egg to nymph to adult.  From the egg, a nymph emerges and goes through several rounds of molting before becoming an adult. The brightly coloured adults lay up to 80 eggs in egg pods inserted into the soil during September-November. Eggs are largely confined at the bottom of the egg pod, stacked one over the other, and these egg pods measured 5-7 cm). Egg-laying takes place mostly in uncultivated patches in and around the cultivated area. The incubation period is about 5 months. Hatching occurs in February-March, at the beginning of the summer season. Nymphs are blackish with yellow markings and undergo six instars before becoming adults in three months. Nymphs of Aularches miliaris defoliate host plants but nymphs are highly polyphagous. Populations of this species fluctuate widely in numbers from year-to-year.

Although these grasshoppers are not a major pest, this outbreak could be due to i) ecological disruptions such as the effect of relatively prolonged hot weather allowing an increased number of generations per season; (ii) incessant and indiscriminate pesticide use affecting the natural enemies causing a phenomenon known as a ‘natural enemy ravine’; (iii) changes in the soil (where grasshoppers lay eggs) and crop practices or husbandry (e.g. dense crop canopy or density; pruning rounds) and (iv) any evidence of migration from other areas.  Likewise, the change in agricultural practices from mixed cropping and crop rotation to monocropping are leaving significant areas of the farm unattended. This favours the soil-incubating eggs of hoppers, and they hatch together in favourable conditions.

Integrated control measures recommended for A. miliaris  control. In a localized outbreak situation, an eco-friendly management strategy involving the mechanical collection of the grasshoppers and destruction of egg-laying sites by tillage, handpicking of l larvae and imagos and their destruction by burning are advised, rather than intervention using insecticides. Destruction of eggs by digging up and exposing the egg pods for desiccation in the sun was recommended as an effective alternative to chemical control. For hoppers dusting with BHC 10% powder at the rate of 40 kg/ha of cardamon plantation was prescribed and using insecticides. Botanicals like neem (Azadirachta indicamixed with soap, and entomopathogenic fungus (Beauveria bassianacould be effective.

Also, the chemicals which are low in toxicity and registered in-country are suggested for the pest above threshold levels. Insectivorous birds, snakes, lizards, skinks and many other free-ranging animals find these grasshoppers a tasty meal, so maintaining the natural balance of predators and prey is key to controlling pests.  



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