02611nas a2200169   4500008004100000020001400041245008100055210006900136260001200205300001200217490000800229520203500237653001902272100002302291700002302314856010402337       2010                        eng d  a0029-854900aElevated CO2 and aboveground-belowground herbivory by the clover root weevil0 aElevated CO2 and abovegroundbelowground herbivory by the clover   cJanuary  a209-2160 v1623 aPredicted increases in atmospheric carbon dioxide (CO2) concentrations are expected to increase primary productivity in many terrestrial ecosystems, which could lead to plants becoming N limited. Studies suggest that legumes may partially overcome this by increasing biological nitrogen fixation. However, these studies have not yet considered how these changes may be affected by the altered dynamics of insect herbivores feeding on the plant. This study investigated how elevated CO2 (700 [mu]l l-1) affected the clover root weevil (Sitona lepidus), a significant pest of white clover (Trifolium repens). Adults feed on leaves aboveground where they lay eggs; soil-dwelling larvae initially feed on root nodules that house N2-fixing bacteria. Foliar C:N ratios rose by 9% at elevated CO2, but the biggest responses were observed belowground, with increases in root mass (85% greater) and nodule abundance (220% more abundant). Root C:N ratios increased significantly from 10.95 to 11.60 under elevated CO2, which increased even further to 13.13 when nodules were attacked by larval S. lepidus. Adult S. lepidus consumed significantly more leaf tissue at elevated CO2 (0.47 cm2 day-1) compared with ambient CO2 (0.35 cm2 day-1), suggesting compensatory feeding, but laid 23% fewer eggs at elevated CO2. Even though fewer eggs were laid at elevated CO2, 38% more larvae were recovered suggesting that larval survival was much better under elevated CO2. Increased larval abundance and performance at elevated CO2 were positively correlated with the number of nodules available. In conclusion, reduced foliar quality at elevated CO2 was generally disadvantageous for adult S. lepidus living aboveground, but extremely beneficial for S. lepidus larvae living belowground, due to the enhanced nodulation. Climate change may, therefore, enhance biological nitrogen fixation by T. repens, but potential benefits (e.g. provision of N without chemical fertilizers) may be undermined by larger populations of S. lepidus larvae belowground.10aSitona lepidus1 aJohnson, Scott, N.1 aMcNicol, James, W.  uhttps://weevil.myspecies.info/elevated-co2-and-aboveground-belowground-herbivory-clover-root-weevil02878nas a2200217   4500008004100000020001400041245012200055210006900177260001200246300001000258490000700268520209800275653001902373100002302392700002302415700002302438700002102461700002002482700002302502856013502525       2010                        eng d  a0929-139300aEffects of soil conditions and drought on egg hatching and larval survival of the clover root weevil (Sitona lepidus)0 aEffects of soil conditions and drought on egg hatching and larva  cJanuary  a75-790 v443 aSoil-dwelling insect herbivores are significant pests in many managed ecosystems. Because eggs and larvae are difficult to observe, mathematical models have been developed to predict life-cycle events occurring in the soil. To date, these models have incorporated very little empirical information about how soil and drought conditions interact to shape these processes. This study investigated how soil temperature (10, 15, 20 and 25 [degree]C), water content (0.02 (air dried), 0.10 and 0.25 g g-1) and pH (5, 7 and 9) interactively affected egg hatching and early larval lifespan of the clover root weevil (Sitona lepidus Gyllenhal, Coleoptera: Curculionidae). Eggs developed over 3.5 times faster at 25 [degree]C compared with 10 [degree]C (hatching after 40.1 and 11.5 days, respectively). The effect of drought on S. lepidus eggs was investigated by exposing eggs to drought conditions before wetting the soil (2-12 days later) at four temperatures. No eggs hatched in dry soil, suggesting that S. lepidus eggs require water to remain viable. Eggs hatched significantly sooner in slightly acidic soil (pH 5) compared with soils with higher pH values. There was also a significant interaction between soil temperature, pH and soil water content. Egg viability was significantly reduced by exposure to drought. When exposed to 2-6 days of drought, egg viability was 80-100% at all temperatures but fell to 50% after 12 days exposure at 10 [degree]C and did not hatch at all at 20 [degree]C and above. Drought exposure also increased hatching time of viable eggs. The effects of soil conditions on unfed larvae were less influential, except for soil temperature which significantly reduced larval longevity by 57% when reared at 25 [degree]C compared with 10 [degree]C (4.1 and 9.7 days, respectively). The effects of soil conditions on S. lepidus eggs and larvae are discussed in the context of global climate change and how such empirically based information could be useful for refining existing mathematical models of these processes. [copyright] 2009 Elsevier B.V. All rights reserved.10aSitona lepidus1 aJohnson, Scott, N.1 aGregory, Peter, J.1 aMcNicol, James, W.1 aOodally, Yasmina1 aZhang, Xiaoxian1 aMurray, Philip, J.  uhttps://weevil.myspecies.info/effects-soil-conditions-and-drought-egg-hatching-and-larval-survival-clover-root-weevil-sitona-lepid01557nas a2200205   4500008004100000020001400041245009600055210006900151260000800220300001200228490000800240520087400248653001901122100001901141700001801160700001701178700002001195700002301215856011301238       2010                        eng d  a0007-485300aThe bionomics of an invasive species Sitona lepidus during its establishment in New Zealand0 abionomics of an invasive species Sitona lepidus during its estab  cJun  a339-3460 v1003 aThe egg, larval, pupal and adult abundance of the clover root weevil Sitona lepidus Gyllenhal (Coleoptera: Curculionidae) was monitored at three sites for the first ten years following the discovery of this exotic pest in the Waikato region of New Zealand. The species went through an initial boom and bust cycle at two sites, with populations reaching up to 1800 larvae m-2. Thereafter, winter larval populations were relatively stable, ranging between 450-750 m-2. Unlike in the Northern Hemisphere, S. lepidus was found to have two generations a year in the Waikato region of New Zealand. Pasture white clover content at the time of peak adult numbers was positively related to the subsequent peak larval populations for each generation. The factors contributing to the emergence of S. lepidus as one of the most important pasture pests in New Zealand are discussed.10aSitona lepidus1 aGerard, P., J.1 aGoldson, S.L.1 aHardwick, S.1 aAddison, P., J.1 aWilloughby, B., E.  uhttps://weevil.myspecies.info/bionomics-invasive-species-sitona-lepidus-during-its-establishment-new-zealand