Journal Article

Larvicidal, growth inhibitory and biochemical effects of soil bacterium, Pseudomonas sp. EN4 against Spodoptera litura (Fab.) (Lepidoptera: Noctuidae)

Sharma, Geetika, Devi, Meena, Mahajan, Rohit, Sarkhandia, Sunaina, Kaur, Sanehdeep, Chadha, Pooja, Saini, Harvinder Singh

2023

Overview

Background Spodoptera litura  (Fabricius) (Lepidoptera: Noctuidae) also known as tobacco caterpillar, is one of the most serious polyphagous pests that cause economic losses to a variety of commercially important agricultural crops. Over the past few years, many conventional insecticides have been used to control this pest. However, the indiscriminate use of these chemicals has led to development of insecticide resistant populations of S. litura in addition to harmful effects on environment. Due to these ill effects, the emphasis is being laid on alternative eco-friendly control measures. Microbial control is one of the important components of integrated pest management. Thus, in search for novel biocontrol agents, the current work was carried out with the aim to evaluate the insecticidal potential of soil bacteria against  S. litura . Results Among the tested soil bacterial isolates (EN1, EN2, AA5, EN4 and R1), maximum mortality (74%) was exhibited by  Pseudomonas  sp. (EN4). The larval mortality rate increased in a dose-dependent manner. Bacterial infection also significantly delayed the larval development, reduced adult emergence, and induced morphological deformities in adults of S . litura . Adverse effects were also detected on various nutritional parameters. The infected larvae showed a significant decrease in relative growth and consumption rate as well as efficiency of conversion of ingested and digested food to biomass. Histopathological studies indicated damage to the midgut epithelial layer of larvae due to the consumption of bacteria treated diet. The infected larvae also showed a significantly decreased level of various digestive enzymes. Furthermore, exposure to  Pseudomonas  sp. also caused DNA damage in the hemocytes of  S. litura  larvae. Conclusion Adverse effects of Pseudomonas  sp. EN4 on various biological parameters of S. litura indicate that this soil bacterial strain may be used as an effective biocontrol agent against insect pests.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Agricultural pests / Agricultural practices / Analysis / Animals / Bacteria / Bacterial diseases / Bacterial infections / Biochemical analysis / Biochemical assays / Biological control / Biological Microscopy / Biomedical and Life Sciences / Biopesticides / Confidence intervals / Control / Crops / Damage / Deformation effects / Developmental stages / Digestive enzymes / DNA damage / Economic impact / Environmental effects / Genotoxicity / Growth / Hemocytes / Identification and classification / Infections / Insect pests / Insecticidal potential / Insecticide resistance / Insecticides / Insecticides - metabolism / Insecticides - pharmacology / Insects / Integrated pest management / Larva / Larvae / Larval development / Lepidoptera / Life Sciences / Methods / Microbiology / Microorganisms / Midgut / Morphology / Mortality / Moths / Mycology / Noctuidae / Nutritional physiology / Parameters / Parasitology / Pest control / Pesticides / Pests / Physiological aspects / Pseudomonas / Pseudomonas sp / Side effects / Soil bacteria / Soil microbiology / Soil microorganisms / Soil structure / Soil testing / Soils / Spodoptera / Spodoptera litura / Tobacco / Toxins / Virology