Desert locust and its management in Nepal: a review

Abstract

Locusts are among the most dangerous agricultural pests. They are a group of short horned grasshoppers belonging to Acrididae family and are hemimetabolous insects. This group of grasshoppers have a unique character of changing habits and behaviors when they aggregate in a group and this habit is catalyzed by different environmental factors. In the adult stage, gregarious locusts migrate from one place to another in a swarm. Desert Locust, Schistocerca gregaria (Forksal), is one of those locusts which cause damage to different types of crop which fly in the direction of wind up to a distance of 150 km. Because of polyphagous feeding habits and swarming in a plague (large group of adults), this pest is considered as the hazardous migratory pest. These pests entered Nepal for the first time in 1962 and then in 1996. In 2020 the pest entered the country from India on three different dates 27th June and continued till 29th (5 districts), 12th July (1 district), and 16th July (2 districts). The swarms migrated to 53 districts and caused the considerable loss in agricultural and field crop in 1118 hectare. These pests are monitored on the basis of environmental factors and many tools and practices such as eLocust3, SMELLS (Soil Moisture for Desert Locust Early Survey), P-locust and SUPARCO Disaster Watch Desert Locust Situation Alert are being used. Their control is critical to food security. Many tools and techniques are integrated for prevention and management of these pests to minimize damage in the existing crops where they migrate. These are physical methods, cultural methods, use of botanicals, green muscle, PAN (phenylacetonitrile) and chemicals. Effective preventive management strategy relies on an improved knowledge of the pest biology, more efficient monitoring and control techniques.

Desert locust (Schistocerca gregaria Forskal) and its management: A review

“…Desert locusts are polyphagous insects which feed on various parts of plants such as leaves, shoots, flowers, fruit, seeds, stems, and even bark (Shrestha et al, 2021). The damage and loss to crops are severe when desert locusts occur in a plague (gregarious phase).…”

“…Similarly, electronic devices which produced ultrasound help to reduce swarms of the desert locust. Likewise, nets that are sprayed with garlic or neem can help to repel different locusts and grasshoppers in small nurseries and kitchen gardens (Shrestha et al, 2021). The pathogenic fungi Metahizium anisopliae var.…”

Limitations of Remote Sensing in Assessing Vegetation Damage Due to the 2019–2021 Desert Locust Upsurge

“…Desert locusts (Schistocerca gregaria) (DL) are considered one of the most dangerous migratory pests on the planet (Cressman, 2016;Gómez et al, 2018;Shrestha et al, 2021). They typically inhabit the arid regions stretching from West Africa to the Indian subcontinent and exist in a relatively unremarkable solitary phase (Cressman, 2016;Gómez et al, 2020;Shrestha et al, 2021). However, under favorable climatic conditions, DL can phase change into gregarious swarms, breeding, and devoring vegetation at massive scales (Pener, 1991;Sword et al, 2010).…”

Desert Locust Stopped by Tibetan Highlands during the 2020 Upsurge

“…This country was invaded in three successive waves, on 25-29 June, 12 July, and 16 July. The swarms then spread over much of Nepal in about 10 days [31,32] (Figure 1). This Himalayan region on the southern border of Tibet has four valleys (ChenTang, Gama, Zhangmu, and Jilong) leading into Nepal and of relatively low altitude.…”