Comparative Biology and Life Tables of Sugarcane Aphid Melanaphis Sacchari (Hemiptera: Aphididae) From Guanajuato, Mexico, at Different Temperatures

Abstract

The Sugarcane aphid, Melanaphis sacchari (Zehntner, 1897) is the most important pest in sorghum crops of USA and Mexico. In northern Mexico and other regions, as Guanajuato and Morelos, reduced over 30% of the cultivated area of sorghum between 2016 and 2019. This study provides basic information that supports the Integrated Management of this insect. Research used biological material (parthenogenetic forms) from Guanajuato, Mexico; reared in foliar agar-disc of Sorghum bicolor VAR. UPM-219, at bioclimatic chamber under different temperatures: 5, 10, 15, 20, 25, 30, 35 and 40°C. The highest mortalities occurred in extremes temperatures: 5°C (35%), 35°C (45%) and 40°C (100%). At low temperature (5°C) there was no reproduction and the pre-reproductive period continued 62.5 days, allowing the insects to survive on average 88.2 days. At the highest temperature (40°C), nymph 1 died in 0.9 days. While at 20°C, M. sacchari produced a supernumerary N5 stage that prolonged the development to 7.1 days. The longest reproductive period was 33.2 days (0.6 nymphs/day) to 10°C, in contrast to 4.1 days (0.4 nymphs/day) to 35°C; the longest post-reproductive period (22.4 days) was obtained at 10°C and the smallest (4.2 days) at 35°C. Highest average fertility (79.06 nymphs) was reached at 25°C. Theoretical thermal thresholds was 2.0° and 40°C; and the heat units t required for each generation were 158.9. Population parameters show that 25°C is the optimal temperature for this aphid Ro (79.06) and Rm (0.44) T (10.01) DT (1.59 and λ (1.55).