Biology and Life Table of Melanaphis sorghi (Theobald, 1904) (Hemiptera: Aphididae) on Sweet Sorghum Hybrids (Sorghum bicolor)

Abstract

The aphid Melanaphis sorghi is an economically significant pest of sorghum (Sorghum bicolor), a crop with potential for bioenergy production and food use. This study evaluated the biology and life table of M. sorghi on ten sweet sorghum hybrids to identify resistant and susceptible genotypes. The biological parameters assessed included pre-reproductive, reproductive, and post-reproductive periods, longevity, fecundity, and daily nymph production. Additionally, life table parameters were calculated, such as the net reproductive rate (R₀), intrinsic rate of increase (Rₘ), finite rate of increase (λ), and population doubling time (DT).  The results showed that genotype 202224B017 was the most susceptible, with the highest values of R₀ (18.92 ± 0.48 females), Rₘ (0.40 ± 0.00 females/day), and λ (1.49 ± 0.00), along with the shortest population doubling time (DT = 1.74 ± 0.01 days). In contrast, genotype CMSXS5039 exhibited greater resistance, with the lowest values of R₀ (2.34 ± 0.08 females), Rₘ (0.11 ± 0.00 females/day), and λ (1.12 ± 0.01), as well as the longest DT (6.11 ± 0.27 days). Survival analysis indicated that CMSXS5039 had the lowest proportion of surviving nymphs (0.20), while 202224B017 had the highest (0.78). These findings suggest that CMSXS5039 possesses mechanisms that hinder aphid development and reproduction, whereas 202224B017 favors pest population growth and is considered more susceptible.