Ecological specialization of the aphid Aphis gossypii Glover on cultivated host plants

Abstract

Many plant-feeding insect species considered to be polyphagous are in fact composed of genetically differentiated sympatric populations that use different hosts and between which gene flow still exists. We studied the population genetic structure of the cotton-melon aphid Aphis gossypii that is considered as one of the most polyphagous aphid species. We used eight microsatellites to analyse the genetic diversity of numerous samples of A. gossypii collected over several years at a large geographical scale on annual crops from different plant families. The number of multilocus genotypes detected was extremely low and the genotypes were found to be associated with host plants. Five host races were unambiguously identified (Cucurbitaceae, cotton, eggplant, potato and chili- or sweet pepper). These host races were dominated by asexual clones. Plant transfer experiments using several specialized clones further confirmed the existence of host-associated trade-offs. Finally, both genetic and experimental data suggested that plants of the genus Hibiscus may be used as refuge for the specialized clones. Resource abundance is discussed as a key factor involved in the process of ecological specialization in A. gossypii.

Maintaining genetic diversity and population panmixia through dispersal and not gene flow in a holocyclic heteroecious aphid species

“…About 4700 described species exist (Blackman and Eastop, 2006;Peccoud et al, 2010), some of which represent diverging populations, host races, biotypes, or other potential forms of incipient speciation (Van Emden and Harrington, 2007;Carletto et al, 2009;Peccoud et al, 2009). Aphids also vary in important life-history characteristics such as reproductive mode and host specificity (Moran, 1992;Blackman and Eastop, 2006).…”

Genetic structure of populations of Aphis gossypii (Hemiptera: Aphididae) on citrus trees in Northern Iran

“…The relationship between the genetic diversity of A. gossypii and different host plants has been revealed by the use of polymorphic microsatellite markers, which indicate that one of three predominant multilocus genotypes is associated with each of the three plant families, Cucurbitaceae, Solanaceae and Rutaceae (Charaabi et al, 2008;Carletto et al, 2009). Further examples of such host plant-genetic diversity correlations are reported for other species of pest aphid, like the grain aphid, Sitobion avenae (F.) on wheat and cocksfoot grass (Sunnucks et al, 1997) and different grasses and cereals.…”

A laboratory and field condition comparison of life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae)

“…Hibiscus syriacus L., Catalpa bignoïdes Walter and some other ligneous plants act as hosts (Carletto et al 2009). Rose of Sharon, H. syriacus, is a common garden hibiscus.…”