Functional response
Polynomial logistic regression analysis of proportion of prey consumed (Ne/N0) to the initial prey density (N0) was resulted in significant negative linear parameters (P1 < 0) and confirmed the type-II response for all the predatory stages against B. tabaci nymphs (Table 2), pupae (Table 3) and adults (4). The line fitted with Roger’s model and Hollings model exhibited a characteristic polynomial decelerating type-II curve for all predatory stages of C. sexmaculata against B. tabaci nymphs (Fig. 1–6), pupae (Fig. 7–12) and adults (Fig. 13–18). The curves displayed the increased in predation with the increased in prey density until reaching the satiation for all the stages of predator. Roger’s random attack equation revealed that the coefficient of attack rate (a’) was the highest for the female (4.65) followed by fourth instar grub (4.43), adult male (1.94), third instar grub (2.14), second instar grub (2.87) and first instar grub (1.52) and the handling time (Th) of adult male (0.02) was substantially the lowest followed by female (0.05), fourth instar grub (0.06), second instar grub (0.08), third instar grub (0.09) and first instar grub (0.19) against the B. tabaci nymphs. The AIC’s values for Roger’s equation were 119.9, 113.0, 96.5, 103.5, 154 and 126.4 respectively for first instar grub, second instar grub, third instar grub, fourth instar grub, female and male against the B. tabaci nymphs. However, Holling’s Disc equation for coefficient of attack rate (a’) was the highest for second instar grub (1.63) followed by third instar grub (1.62), fourth instar grub (1.26), male (1.19), first instar (1.05) and female (0.0.87), and the handling time (Th) for the female was substantially the lowest (0.01), followed by male (0.03), fourth instar (0.05), third instar (0.07) second instar (0.07) and first instar grub (0.18) against the B. tabaci nymphs. The AIC’s values for Holling’s equation were 119.9, 109.5, 98.3, 107.0, 155.1 and 135.6, respectively of first instar grub, second instar grub, third instar grub, fourth instar grub, female and male against the B. tabaci nymphs. However, the maximum predation/day (Tt/Th) was 7.1, 9.48, 19.3, 31.3, 37.5 and 28.4, respectively against the first instar grub, second instar grub, third instar grub, fourth instar grub, female and male of C. sexmaculata against the B. tabaci nymphs (Table 5).
In case of B. tabaci pupae Roger’s random attack equation revealed that the coefficient of attack rate (a’) was the highest for fourth instar grub (2.72) followed by first instar grub (1.86), male (1.85), female (1.50), second instar grub (1.10) and third instar grub (0.72), and handling time (Th) of adult female (0.058) was substantially the lowest followed by male (0.059), third instar grub (0.06), fourth instar grub (0.07), second instar grub (0.10) and first instar grub (0.21) of C. sexmaculata against the B. tabaci pupae. The AIC’s values for the first instar grub, second instar grub, third instar grub, fourth instar grub, female and male were 98.6, 109.3, 116.7, 100.7, 117.5 and 98.2, respectively against the B. tabaci pupae with Roger’s equation. However, in case of Holling’s disc equation coefficient of attack was the highest of fourth instar grub (1.30) followed by first instar grub (1.26), adult male (1.01), female (0.98), second instar grub (0.79) third instar grub (0.53), and handling time (Th) of adult female (0.04) was substantially the lowest followed by male (0.05), third instar grub (0.05), fourth instar grub (0.06), third instar grub (0.10) and first instar grub (0.20) against the B. tabaci pupae. The AIC’s values were 98.4, 108.9, 116.8, 99.2, 117.5 and 96.4, respectively against the first instar grub, second instar grub, third instar grub, fourth instar grub, female and male against the B. tabaci pupae. The maximum predation/day (Tt/Th) was 9.15, 11.89, 21.44, 33.41, 38.18 and 30.64, respectively against the first instar grub, second instar grub, third instar grub, fourth instar grub, female and male against the B. tabaci pupae (Table 6).
In case of B. tabaci adults Roger’s random attack equation coefficient of attack rate (a’) was highest for female (6.87) followed by adult male (3.96), first instar grub (1.80), second instar grub (1.21) third instar grub (1.04), fourth instar grub (0.69), and handling time (Th) for the fourth instar grub (0.01), was substantially the lowest followed by adult male (0.02), female (0.07), third instar grub (0.08) second instar grub (0.10), and first instar grub (0.18) against the B. tabaci adults. The AIC’s values for Roger’s equation were 88.0, 96.3, 108.7, 178.0, 117.2 and 111.08 for the first instar grub, second instar grub, third instar grub, fourth instar grub, female and male respectively against the B. tabaci adults. However, Holling Disc equation for coefficient of attack rate (a’) was the highest for female (1.38) followed by first instar grub (1.19), adult male (1.07), second instar grub (0.79), third instar grub (0.72), fourth instar grub (0.50), and the handling time (Th) for the female (0.01) and fourth instar grub (0.01) was same followed by adult male (0.05), third instar grub (0.07) second instar grub (0.09) and first instar grub (0.18) against the B. tabaci adults. The AIC’s values Hollings equation were 88.6, 96.34, 108.8, 178.0, 120.6 and 111.3, respectively for the first instar grub, second instar grub, third instar grub, fourth instar grub, female and male against the B. tabaci adults. The maximum predation/day (Tt/Th) were 10.1, 13.1, 23.8, 41.7, 39.1 and 33.2, respectively for the first instar grub, second instar grub, third instar grub, fourth instar grub, female and male against the B. tabaci adults (Table 7).