Genetic analysis of larval host‐plant preference in two sibling species of Helicoverpa

Abstract

The genetic basis of larval host-plant preference was investigated in reciprocal F 1 , F 2 , and backcrossed generations derived from hybrid crosses between the generalist species Helicoverpa armigera (Hübner) and the closely related specialist species Helicoverpa assulta (Guenée) (Lepidoptera: Noctuidae). Host-plant preference for cotton [ Gossypium arboreum L. (Malvaceae)] and pepper [ Capsicum frutescens L. (Solanaceae)] of fifth-instar caterpillars was tested by using a two-choice leaf-disk assay. Helicoverpa armigera and H. assulta were significantly different in their feeding preferences, but the difference was not significant in the reciprocal hybrids, which showed there were no maternal/cytoplasmic effects. Comparisons of feeding preference between different groups of females or males demonstrated that the trait was not controlled by sex-linked loci. The distributions of feeding preference index values for crosses that carried similar complements of autosomal genes were not significantly different, whereas crosses with different complements of autosomal genes were associated with significantly different feeding preferences, indicating that feeding preference of the two species for cotton and pepper, respectively, is controlled by autosomal genes. It was found that one major autosomal locus affected this feeding preference, with the H . armigera -derived alleles being partially dominant to those carried by H. assulta . The genetic analysis of hybrids contributes to understand the evolution of feeding preference in these closely related species.

Identification of the Larvae of Helicoverpa assulta and H. armigera (Lepidoptera: Noctuidae) Through Morphological Difference and DNA Barcoding

“…However. But both of they often appeared at the same time on tobacco (Tang et al, 2006;Zhao et al, 2006). Therefore, the host range and feeding preferences is helpless, this is confusing to distinguish them.…”

“…2), visual in image, and the color is rich, all of them has a strong visual impact, and given the sufficient and necessary complement for some important morphological structure of the larvae. In addition, some researchers also refer to the feeding preferences and host range of larvae to distinguish (Powell et al, 1998;Tang et al, 2006). H. armigera is polyphagous pest, they can harm more than 30 families and 200 many kinds of plants, such as malvaceae, solanaceae, leguminosae.…”

Genetic diversity assessment using RAPD primers in insecticide resistant populations of diamondback moth Plutella xylostella (Linn.)

“…The high degree of migration, indiscriminate pesticide application by farmers and innate ability of the insect to quickly develop resistance to applied insecticides have been considered as factors responsible for this pest to attain the status of key pest (Sivapragasam et al 1996, Ferre andVan Rie 2002). However, the possibility of differential susceptibility status in P. xylostella due to widespread mixing of population through migration, a common feature in this insect (Tang et al, 2006), cannot be over ruled. Molecular markers are ideal choices for studying genetic differences among individuals of different regions.…”

Complex inheritance of larval adaptation in Plutella xylostella to a novel host plant

“…The genetics of host plant adaptation or host-associated performance have been studied in several insects and a range of genetic architectures have been observed: Hawthorne and Via (2001) detected polygenic inheritance in pea aphids, whereas in other cases evidence for the influence of a limited number of genetic factors (oligo-to monogenic inheritance) was found (Jones, 1998;Sezer and Butlin, 1998;de Jong et al, 2000). For the mode of inheritance, a general pattern seems to apply: genes affecting larval performance consistently map to the autosomes (Tang et al, 2006). Genes controlling oviposition preference are less consistent: they are sex-linked in Papilio butterflies (Thompson, 1988), but autosomal in moths, Heliothis virescens and H. subflexa (Sheck and Gould, 1995), and Yponomeuta species (Hora et al, 2005).…”