title: Reproduction and Population Dynamics as Biotypic Markers of Russian Wheat Aphid Diuraphis noxia (Kurdjumov).
abstract: Russian wheat aphid Diuraphis noxia (Kurdjumov) is widely established in wheat-growing countries where it causes significant economic losses. The development and use of Russian wheat aphid (RWA)-resistant wheat varieties has been constrained by the variation in resident RWA populations and the evolution of virulent biotypes. An experiment was set up at the Kenya Agricultural and Livestock Research Organization (KALRO), Njoro, to characterize RWA populations based on phenotypic characteristics of reproduction, development and population dynamics. RWA populations from the regions of Eldoret, Mau Narok and Njoro were used in the study. A factorial experiment was set up in randomized complete block design replicated eleven times. A single day-old nymph was placed on a new, fully-open leaf in a 0.5 cm-diameter clear plastic straw leaf cage and observed daily for its entire lifetime. The results showed that there were variations in aphid lifespan, reproductive longevity and aphid fecundity between populations, indicating that the phenotypic markers used to determine biotypes were good enough to show distinct biotypes among populations of the RWA in Kenya. Further, the study concluded that the use of phenotypic life and reproductive markers was a valid way of characterizing biotypes of RWA worldwide.
authors.affiliation: Department of Crops, Horticulture and Soils, Egerton University, Egerton 536-20115, Kenya. watsonngenya24@gmail.com.|Kenya Agricultural and Livestock Research Organization, Food crops institute, Kitale 450-30200, Kenya. watsonngenya24@gmail.com.
authors.forename: Watson
authors.initials: W
authors.lastname: Ngenya
authors.affiliation: Kenya Agricultural and Livestock Research Organization, Food crops institute, Kitale 450-30200, Kenya. joycemalinga@kalro.org.
authors.forename: Joyce
authors.initials: J
authors.lastname: Malinga
authors.affiliation: Department of Crops, Horticulture and Soils, Egerton University, Egerton 536-20115, Kenya. immtabu@yahoo.com.
authors.forename: Isaiah
authors.initials: I
authors.lastname: Tabu
authors.affiliation: Department of Crops, Horticulture and Soils, Egerton University, Egerton 536-20115, Kenya. masinde.emily11@gmail.com.|Kenya Agricultural and Livestock Research Organization, Food crops institute, Kitale 450-30200, Kenya. masinde.emily11@gmail.com.
authors.forename: Emily
authors.initials: E
authors.lastname: Masinde
keywords: Diuraphis noxia; population; preference; reproduction