Response of light traps to attract various species of Scarabaeid beetles (Coleoptera: Scarabaeidae)

An experiment was carried out to study the response of light traps to attract various species of Scarabaeid beetles at Pantnagar in the Terai region of Udham Singh Nagar, Uttarakhand, during 2019 and 2020.The basis of data collected from different light traps facilitated with different type of light source bulb revealed that significantly highest number of white grub was recorded in black light trap (B LT) (7801 and 5038), followed by mercury light trap (MLT) (5302 and 3832), LED white light trap (LED WLT) (2298 and 1643) and LED blue light trap (LED BLT) (963 and 785), while the lowest number of white grub beetles was recorded in incandescent light trap (ILT) (587 and 523), respectively. Regarding the number of white grub species, the maximum number of species were recorded in the BLT (24 species) and MLT (24 species) followed by the LED WLT (21 species), ILT (13 species) and LED BLT with 9 species. The value of alpha diversity indices viz. Shannon index (H') showed a high diversity for MLT (2.80 and 2.90), followed by LED WLT (2.76 and 2.77), BLT (2.51 and 2.71), ILT (2.43 and 2.41), and LED BLT (1.94 and 1.93) during two consecutive years of study. Pielou's evenness index (J') revealed that during two consecutive years of study, specifically 2019 and 2020, the white grub population in BLT was highest (0.51 and 0.62), followed by MLT (0.69 and 0.76), LED WLT (0.75 and 0.76), LED BLT (0.77 and 0.76), and ILT (0.87 and 0.56). Evenness is high in BLT due to the highest number of individuals collected. The study revealed that a BLT and MLT is the most effective for white grub collection and the important component of insect pest management.