Geometric morphometry and life table studies on Diamondback moth Plutella xylostella L Lepidoptera Plutellidae and screening of botanicals using insilico approach for its management

Abstract

The diamondback moth, Plutella xylostella also known as the cabbage moth, belongs to the genus Plutella. It is a serious pest and a widely distributed species that has a broad ecological host range. Cauliflower belonging to brassica is an important vegetable consumed throughout the world. P. xylostella adversely affects the cauliflower yield worldwide and causes greater economic loss. This study aims to use plant phytochemicals to control the pest. Host plants affect survival, reproduction and insect development. Geometric morphometry study (Rohlf, 2018) was used to diffentiate male and female individuals. The wing images were converted to the tps format using the tps-util program. The study revealed that the wings had variations in the middle region. The life table parameter studies showed that the egg duration was 6-8 days. It had four larval instars lasting for about 9-12 days. The pupation period was 3-4 days and the adult life span was 6-9 days. Three plants, Trachyspermum ammi, Zingiber officinale and Syzygium aromaticum were selected and the phytochemistry of these plants were analyzed using GC-MS, that confirmed the presence of hydrocarbon, methyl, hydroxyl, carbonyl and carboxylic acid functional groups. Of these, three ligands namely Acetylmarinobufogenin, Tetrahydropapaveroline and Chondrillasterol were subjected to insilico docking studies with Ryanodine receptor using the software Schrodinger suit. Among the three ligands Acetylmarinobufogenin showed higher affinity to the receptor with a glide score (-10.37), while Tetrahydropapaveroline had (-8.83) and Chondrillasterol had (-7.82). Thus Acetylmarinobufogenin can be suggested to be used as a botanical insecticide after assessing the safety levels since it is a bioinsecticide and is free from environmental hazards. newlineKeywords: Plutella xylostella, Cauliflower, Geometric morphometry, Larvicidal activity, In silico studies newlinei) Major objectives: newlineand#61656; To study the shape variation of female and male wings of P. xylostella using landmark distances.