A preliminary study of variation and inheritance of life-history traits and the occurrence of hybrid vigour in Sitobion avenae (F.) (Hemiptera: Aphididae)

Abstract

AbstractClones of Sitobion avenae (F.) collected in southern England in 1983 and 1984 were subjected to sexual-inducing conditions in the laboratory (12 L:8 D photoperiod at 15°C and/or 8 L:16 D photoperiod at 12°C). Most clones were continuously parthenogenetic under these conditions; some clones produced males only (androcyclic), and the same behaviour was observed under field conditions in the autumn of 1983. In contrast, over 90% of the clones collected from Scotland in 1984 were holocyclic (i.e. cyclically parthenogenetic). Fundatrices from intra- and interclonal matings were obtained. Those from interclonal matings were significantly more fecund than fundatrices from intraclonal matings. Examination of the descendants of these fundatrices indicated that both life-history strategy and migratory tendency were genetically-determined.