Population fluctuation, hosts, fecundity and life cycle of the yellow aphid [Melanaphis sacchari (Zehntner)] in sorghum [Sorghum bicolor L. Moench] in Nicaragua

Abstract

Sorghum (Sorghum bicolor) belongs to the Poaceae family, produced by small and medium producers in Nicaragua; in 2016 it was attacked by the sugarcane aphid (Melanaphis Sacchari Zehntner), a recently introduced pest to the country, in this same year it caused losses between 30 and 40%. This study was carried out with the objective of determining the biological and ecological behavior of the sugarcane aphid in the cultivation of Sorghum. It was carried out between the months of July to October 2017, at the El Plantel Experimental Center, where a test of 36 m X 24.8 m was delimited, placing six traps of two colors (yellow and red), at three different heights (0.5 m, 1.0 m and 1.50 m) on each of the four sides of the plot obtaining a total of 24 traps, weed weeds were sampled to determine the alternate hosts of the aphid, taking three points at a distance of five meters from the plot In each of the geographic coordinates, likewise 100 sorghum plants were sampled to determine the population fluctuation of the yellow aphid and its natural enemies. The results indicated that the yellow traps are the ones that caught the most insects and fly indistinctly at the different heights evaluated. The main natural enemies associated with the yellow sorghum aphid found are: species of the Syrphidae family, Chrysoperla externa, Cycloneda sangunea and Ceraochrysa sp. The predominant host weed was Sorghum halepense. Large populations of M. sacchari appeared at 72 days after planting. M. sacchari reached a daily fecundity of one to 17 individuals per female with a total progeny of 63 to 86 nymphs which go through five nymphal stages, their entire life cycle lasts from 22 to 24 days.