Toxicity and insect growth regulatory activities of medicinal plant, Withania somnifera, in flesh fly, Sarcophaga ruficornis (Diptera: Sarcophagidae)

Sandeep Kumar Gaur,Krishna Kumar

doi:10.1186/s41936-020-00154-2

Sandeep Kumar Gaur, Krishna Kumar

Open Access

https://doi.org/10.1186/s41936-020-00154-2

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Abstract

BackgroundThe flesh fly Sarcophaga ruficornis is well known for its medical and veterinary importance in causing myiasis in humans and animals. The conventional use of chemical pesticides for controlling insect pests has resulted in environmental pollution besides posing serious hazards to non-target organisms and the development of pest resistance against these compounds. Considering the various harmful and adverse effects of chemical pesticides, an alternative and safe approach for the pest management has to be explored. The plant extracts derived from plants are eco-friendly in nature, easily biodegradable, and can be used as botanical pesticides.ResultsExtracts from root of the medicinal plant Withania somnifera were assessed for their toxicity and insect growth regulatory activity when administered to larvae of S. ruficornis. Topical administration of root extracts of W. somnifera to 0–3-day-old third instar larvae of S. ruficornis resulted into severe disruption of development, moulting, and metamorphosis producing several detrimental effects such as toxicity, prolongation of larval life, ecdysial stasis, abnormal pupariation, reduced normal pupariation and adult emergence, and development of pupal-adult mosaics and adultoids. The LC50 values in topical application of root extracts of W. somnifera were 28.19, 43.49, 47.48, and 48.16 g/μL against S. ruficornis third instar day 0, 1, 2, and 3 larvae, respectively.ConclusionThese effects are similar to those observed as a consequence of the administration of juvenile hormone analogs (juvenoids) and may be due to interference with the normal hormonal mechanism of moulting and metamorphosis. This clearly demonstrates that the root extracts of W. somnifera may be used as an insect growth regulator for the control and management of S. ruficornis along with other bio-rational approaches in integrated pest management programs.

Highlights

The flesh fly Sarcophaga ruficornis is well known for its medical and veterinary importance in causing myiasis in humans and animals
Topical administration of different doses of root extracts of W. somnifera to third instar day 0, 1, 2, and 3 larvae of S. ruficornis resulted into larval and pupal mortality, delay in larval-pupal ecdysis, abnormal pupariation, suppression of adult emergence, and formation of pupal-adult mosaics and adultoids
Mortality Topical administration of root extracts of W. somnifera to third instar 0–3-day-old larvae of S. ruficornis resulted into larval and pupal mortality in a dose-dependent manner showing a significant positive correlation in all the treated groups (Table 1)

Summary

Introduction

The flesh fly Sarcophaga ruficornis is well known for its medical and veterinary importance in causing myiasis in humans and animals. Contamination of air, water, and soil has already adversely affected ecosystem and human health, disrupted the dynamics of the food web in the community, destroyed beneficial organisms, and led to the development of pest resistance (Zacharia, 2011). Considering these harmful effects of chemical pesticides, a safe and environmental friendly approach for insect control is desired. These plant derivatives are eco-friendly with target specificity, biodegradable, economically feasible, devoid of toxic residues, and with the least chances of development of pest resistance (Pant et al 2016; Rajapakse et al 2016)

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