Chemical-treated soil or physical barriers have been the most commonly used approach for termite management. We hypothesized that a barrier of soil incorporated with oven-dried Lantana camara L. tissues could prevent ...Chemical-treated soil or physical barriers have been the most commonly used approach for termite management. We hypothesized that a barrier of soil incorporated with oven-dried Lantana camara L. tissues could prevent termite infestation. We first examined the antitermitic effects of the dried tissues from two cultivars （＇Mozelle＇ and ＇New Gold＇） on the subterranean termite, Reticulitermes virginicus （Banks） （Isoptera： Rhinotermitidae）. Results show that all of the tissues of Mozelle had greater antitermic activity than corresponding tissues of New Gold, and leaves had greater termiticidal effects than flowers and stems. When termites were exposed to the test materials in a no-choice bioassay, the 24-day test resulted in a significant reduction of survival （52.5%-88.6%）, running speed （18.2%-37.3%）, live weight （21.8%-53.5%） and body water content （33.2%-56.2%） compared to the control. The consumption of leaves and flowers was exiguous. When used as 25% tissue mulch-barrier, the oven-dried lantana tissues decreased termite tunneling and wood consumption and increased termite mortality. The decreased survival, vigor, and low consumption indicate a toxic and anti-feeding property of the materials tested. The results therefore support our hypothesis that the dried lantana tissues possess antitermitic activities.展开更多
The effects of elevated CO2 on foliar chemistry of two tree species （Populus pseudo-simonii Kitag. and Betula platyphylla） and on growth of gypsy moth （Lymantria dispar L.） larvae were examined. Furthermore, we fo...The effects of elevated CO2 on foliar chemistry of two tree species （Populus pseudo-simonii Kitag. and Betula platyphylla） and on growth of gypsy moth （Lymantria dispar L.） larvae were examined. Furthermore, we focused on the comparison of results on the growth responses of larvae obtained from two methods of insect rearing, the nochoice feeding trial performed in the laboratory or in situ in open-top chambers. On the whole, both primary and secondary metabolites in the leaves of the two tree species were significantly affected by main effects of time （sampling date）, CO2 and species. Elevated CO2 significantly increased the C： N ratio and concentrations of the soluble sugar, starch, total nonstructural carbohydrates, total phenolics and condensed tannins, but significantly decreased the concentration of nitrogen. Higher contents of total phenolics and condensed tannins were detected in the frass of larvae reared in elevated CO2 treatments. Overall, the growth of gypsy moth larvae were significantly inhibited by elevated CO2 and CO2- induced changes in leaf quality. Our study did not indicate the two methods of insect rearing could influence the direction of effects of elevated CO2 on the growth of individual insects; however, the magnitude of negative effects of elevated CO2 on larval growth did differ between the two insect rearing methods, and it seems that the response magnitude was also mediated by larval age and host plant species.展开更多
文摘Chemical-treated soil or physical barriers have been the most commonly used approach for termite management. We hypothesized that a barrier of soil incorporated with oven-dried Lantana camara L. tissues could prevent termite infestation. We first examined the antitermitic effects of the dried tissues from two cultivars （＇Mozelle＇ and ＇New Gold＇） on the subterranean termite, Reticulitermes virginicus （Banks） （Isoptera： Rhinotermitidae）. Results show that all of the tissues of Mozelle had greater antitermic activity than corresponding tissues of New Gold, and leaves had greater termiticidal effects than flowers and stems. When termites were exposed to the test materials in a no-choice bioassay, the 24-day test resulted in a significant reduction of survival （52.5%-88.6%）, running speed （18.2%-37.3%）, live weight （21.8%-53.5%） and body water content （33.2%-56.2%） compared to the control. The consumption of leaves and flowers was exiguous. When used as 25% tissue mulch-barrier, the oven-dried lantana tissues decreased termite tunneling and wood consumption and increased termite mortality. The decreased survival, vigor, and low consumption indicate a toxic and anti-feeding property of the materials tested. The results therefore support our hypothesis that the dried lantana tissues possess antitermitic activities.
基金Acknowledgments This study was financially supported by the National Natural Science Foundation of China （30670306 ＆ 30970515） and Special Research Funds for Public Welfare Sectors （Forestry）, State Forestry Administration of China （200804023）.
文摘The effects of elevated CO2 on foliar chemistry of two tree species （Populus pseudo-simonii Kitag. and Betula platyphylla） and on growth of gypsy moth （Lymantria dispar L.） larvae were examined. Furthermore, we focused on the comparison of results on the growth responses of larvae obtained from two methods of insect rearing, the nochoice feeding trial performed in the laboratory or in situ in open-top chambers. On the whole, both primary and secondary metabolites in the leaves of the two tree species were significantly affected by main effects of time （sampling date）, CO2 and species. Elevated CO2 significantly increased the C： N ratio and concentrations of the soluble sugar, starch, total nonstructural carbohydrates, total phenolics and condensed tannins, but significantly decreased the concentration of nitrogen. Higher contents of total phenolics and condensed tannins were detected in the frass of larvae reared in elevated CO2 treatments. Overall, the growth of gypsy moth larvae were significantly inhibited by elevated CO2 and CO2- induced changes in leaf quality. Our study did not indicate the two methods of insect rearing could influence the direction of effects of elevated CO2 on the growth of individual insects; however, the magnitude of negative effects of elevated CO2 on larval growth did differ between the two insect rearing methods, and it seems that the response magnitude was also mediated by larval age and host plant species.
