Impact and management of damage caused by the infestation of Mulberry leaf (Morus alba L.) by Spilosoma obliqua defoliator insect pests

Abstract

A significant polyphagous defoliator pest, Spilosoma obliqua (Walker), often called the Bihar hairy caterpillar, causes severe damage to mulberry plants, especially during the rainy and winter months (August through January). The larvae eat voraciously and target the foliage, resulting in significant quantitative and qualitative losses in leaf yield, which has a direct effect on silk production and silkworm rearing. Sericulture is an agro-based industry that is also a significant branch of agricultural entomology. There are four varieties of silk made in this industry, including mulberry, muga, eri, and tassar. One of these is mulberry silk, which is highly sought after in the global agricultural market. The Bombyx mori mulberry silkworm (Order: Lepidoptera & family: Bombycidae) produces this mulberry silk. Only the mulberry tree (Morus alba L) sustains the mulberry silkworm (Bombyx mori). For a full successful rearing of the mulberry silkworm (Bombyx mori), the host plants are extremely important. However, a variety of insect pests infest the host plant severely. The most significant insect pest of the mulberry plant among them is the defoliator. They have an impact on different aspects of the plant, including the leaf, bud, stem, and others. The development of afflicted plants is halted, and their leaf output is reduced. Additionally, silkworms cannot survive on infected leaves. The primary emphasis of this review is on mulberry plant defoliators (Orders Lepidoptera, Orthoptera, and Coleoptera), the harm they cause, and how to control them. According to the study area, various pests are harming the mulberry crop, which is causing significant financial harm to sericulture farmers and breeders. Among the insect fauna, Hemipterans, Thysanopteran, Homopteran, and Lepidopteran species were observed. The fact that insect pests are found in a variety of locations proves that the incidence of two Hemipterans, specifically the Jassid and pink mealybug, one Thysanopteran, namely thrips, one Homopteran, namely whitefly, and four Lepidopterans, specifically the leaf-eating caterpillar, leaf roller, wasp moth, and Bihar hairy caterpillar, is increasing. The harm caused by S. obliqua results in a large decline in the quantity and quality of mulberry leaves. This loss has a direct impact on silkworm rising, which results in lower cocoon output.