The damage status of L. invasa on different Eucalyptus varieties( clones) were surveyed in the field,and effects of Eucalyptus varieties on fitness,development and reproduction of this pest were studied in the study. ...The damage status of L. invasa on different Eucalyptus varieties( clones) were surveyed in the field,and effects of Eucalyptus varieties on fitness,development and reproduction of this pest were studied in the study. Results showed that:( 1) Most of the major Eucalyptus varieties( clones) could be attacked by L. invasa in Fujian Province,and galls formed on E. urophylla × E. camaldulensis DH201-2,E. gradis QG3,E. dunnii,E. urophylla cU6,E. grandis × E. urophylla GL9,E. robusta and E. exserta; L. invasa could develop and complete its life cycle on above varieties.( 2) The damage degree of different Eucalyptus varieties( clones) was different from fitness degree to L. invasa. L. invasa had different selection frequency,fecundity and number of larvae per gall on different Eucalyptus varieties( clones).( 3) In addition to little difference in female ratios,L. invasa feeding different Eucalyptus varieties( clones) had extremely significant differences in the indicators such as number of emerged L. invasa,body mass of female adult,fecundity,longevity,etc.( 4) According to the fitness index( FI),the host plants of L. invasa were divided into 4 types by cluster analysis: suitable host,moderately suitable host,less suitable host and unsuitable host; the fecundity of each female was more than 70 eggs in suitable host,which was adequate to lead to potential population outbreak of the pest. Host fitness index could be used as a comprehensive evaluation index for screening of resistant varieties( clones) in production.展开更多
Symbiotic associations between microbes and insects are widespread, and it is frequent that several symbionts share the same host individual. Hence, interactions can occur between these symbionts, influencing their re...Symbiotic associations between microbes and insects are widespread, and it is frequent that several symbionts share the same host individual. Hence, interactions can occur between these symbionts, influencing their respective abundance within the host with consequences on its phenotype. Here, we investigate the effects of multiple infections in the pea aphid, Acyrthosiphon pisurn, which is the host of an obligatory and several facultative symbionts. In particular, we study the influence of a coinfection with 2 protective symbionts： Harniltonella defensa, which confers protection against parasitoids, and Rickettsiella viridis, which provides protection against fungal pathogens and predators. The effects of Hamiltonella-Rickettsiella coinfection on the respective abundance of the symbionts, host fitness and efficacy of enemy protection were studied. Asymmetrical interactions between the 2 protective symbionts have been found： when they coinfect the same aphid individuals, the Rickettsiella infection affected Hamiltonella abundance within hosts but not the Hamiltonella-mediated protective phenotype while the Hamiltonella infection negatively influences the Rickettsiella-mediated protective phenotype but not its abundance. Harboring the 2 protective symbionts also reduced the survival and fecundity of host individuals. Overall, this work highlights the effects of multiple infections on symbiont abundances and host traits that are likely to impact the maintenance of the symbiotic associations in natural habitats.展开更多
基金Supported by Key Project of Fujian Department of Science and Technology(2012N0008)Science and Technology Project of Fujian Department of Forestry(MLK[2005])
文摘The damage status of L. invasa on different Eucalyptus varieties( clones) were surveyed in the field,and effects of Eucalyptus varieties on fitness,development and reproduction of this pest were studied in the study. Results showed that:( 1) Most of the major Eucalyptus varieties( clones) could be attacked by L. invasa in Fujian Province,and galls formed on E. urophylla × E. camaldulensis DH201-2,E. gradis QG3,E. dunnii,E. urophylla cU6,E. grandis × E. urophylla GL9,E. robusta and E. exserta; L. invasa could develop and complete its life cycle on above varieties.( 2) The damage degree of different Eucalyptus varieties( clones) was different from fitness degree to L. invasa. L. invasa had different selection frequency,fecundity and number of larvae per gall on different Eucalyptus varieties( clones).( 3) In addition to little difference in female ratios,L. invasa feeding different Eucalyptus varieties( clones) had extremely significant differences in the indicators such as number of emerged L. invasa,body mass of female adult,fecundity,longevity,etc.( 4) According to the fitness index( FI),the host plants of L. invasa were divided into 4 types by cluster analysis: suitable host,moderately suitable host,less suitable host and unsuitable host; the fecundity of each female was more than 70 eggs in suitable host,which was adequate to lead to potential population outbreak of the pest. Host fitness index could be used as a comprehensive evaluation index for screening of resistant varieties( clones) in production.
文摘Symbiotic associations between microbes and insects are widespread, and it is frequent that several symbionts share the same host individual. Hence, interactions can occur between these symbionts, influencing their respective abundance within the host with consequences on its phenotype. Here, we investigate the effects of multiple infections in the pea aphid, Acyrthosiphon pisurn, which is the host of an obligatory and several facultative symbionts. In particular, we study the influence of a coinfection with 2 protective symbionts： Harniltonella defensa, which confers protection against parasitoids, and Rickettsiella viridis, which provides protection against fungal pathogens and predators. The effects of Hamiltonella-Rickettsiella coinfection on the respective abundance of the symbionts, host fitness and efficacy of enemy protection were studied. Asymmetrical interactions between the 2 protective symbionts have been found： when they coinfect the same aphid individuals, the Rickettsiella infection affected Hamiltonella abundance within hosts but not the Hamiltonella-mediated protective phenotype while the Hamiltonella infection negatively influences the Rickettsiella-mediated protective phenotype but not its abundance. Harboring the 2 protective symbionts also reduced the survival and fecundity of host individuals. Overall, this work highlights the effects of multiple infections on symbiont abundances and host traits that are likely to impact the maintenance of the symbiotic associations in natural habitats.
