Behavioural responses of four generalist pests to crops and exotic weeds for their sustainable management.

Abstract

Leaf epicuticular waxes play a crucial role in host selection of Spilosoma obliqua, Amsacta albistriga, Spodoptera litura, and Spilarctia luteum. The leaf epicuticular waxes of groundnut, soybean, mikania, and parthenium indicated the presence of 25 different n-alkanes (C₁₄ to n-C₃₆) and 15 free fatty acids (FFAs) (C_12:0 to C_22:0). All the chemical analysis and bioassays were conducted by using the standard protocols. The attraction index (AI %) and oviposition preference index (OPI %) of each pest species towards the combined-synthetic-mixtures of respective leaf wax chemicals (4 n-alkanes [n-C₁₆, n-C₁₈, n-C₂₀, n-C₂₂] + 4 FFAs [C_14:0, C_16:1, C_16:0, C_20:0]) were more preferred due to respective wax chemicals. The AI (%) and OPI (%) towards the said mixture (C3) of the selected host plants (groundnut > soybean > parthenium > mikania) were in the order of S. obliqua > S. litura > S. luteum > A. albistriga for better survival and growth of their neonates because of the respective amounts of leaf wax chemicals including other phytoconstituents. The said synthetic mixture in respective leaf equivalent amount (µg leaf^-1) acted as the most preferred lure to develop baited trap and or groundnut as trap crop for soybean to support integrated pest management of such crops (groundnut and soybean). It also supports the use of such pest species as biocontrol agent for the exotic weeds (mikania and parthenium). This finding promotes sustainable pest and weed management for climate smart agriculture to maintain and sustain quality of our planet in the near future.