Species diversity of different insect families trapped under beer-based volatile fermentation

Insect species composition is an important phenomenon playing a significant role in the ecosystem. Chemical control of insects and pests releases toxic materials to the environment. These chemicals are dangerous to human populations. In this situation, there is a dire need to develop strategies to overcome the haphazard use of chemicals. The present investigations were carried out to explore the diversity of different insects attracted through bait fermentation.

The traditionally prepared bait fermentation was used to attract different insect populations both in treated (traps installed near field crops) and control traps (traps installed near invasive weed). Abundance, evenness, richness and equitability of these trapped insects were calculated. The chemical screening of bait fermentation was done using Gas Chromatography and Mass Spectrometry (GC-MS).

Significant difference (P < 0.05) in abundance of insect populations was found in treated compared to control trap. The insects of Noctuidae family recorded high Shannon- Wiener's diversity index followed by Muscidae. Margalef's index was recorded maximum in the treated traps (10.77) compared to those of control (8.09). The yielded index indicated that maximum richness was found in bait treated compared to control. The Shannon's equitability's values were investigated higher in Noctuidae (1.48), while, maximum evenness was observed in Muscidae (2.05) in treated trap. This fermentation was dried at room temperature and ground at 0.1 micron size. Our result showed significant (P < 0.05) effects of extraction times, with high yield in first extraction by polar solvents. Co-efficient of determination (R ² = 0.87) recorded similar results in both extractions, however high root mean square error (0.97) recorded with bait + distilled water solvent showed linear arc line gave better performance. Finally, this fermentation was analyzed using GC-MS and recorded volatile compounds that were involved in the attraction of major and minor pests.

Fermentation can help for the attraction of different families of insects of various crops. The field experiment suggested that this fermentation is economical, easily installed and consumed only 0.64 RMB/0.09 USD, including infrastructures per location. Bait fermentation is safe biochemical constituents and did not spread any toxic chemicals to the environment.