Rhainds Marc, Cloutier Conrad, Shipp Les, Boudreault Simon, Daigle Gaétan, Brodeur Jacques
Centre de Recherche en Horticulture, Université Laval, Pavillon de l'Envirotron, Universié Laval, Québec, Québec, Canada G1K 7P4.
Environ Entomol. 2007 Apr;36(2):475-83. doi: 10.1603/0046-225x(2007)36[475:trbwft]2.0.co;2.
Modeling the effect of temperature on the sustainability of insect-plant interactions requires assessment of both insect and plant performance. We examined the effect of temperature on western flower thrips, Frankliniella occidentalis (Pergande), a generalist herbivore with a high reproductive rate, and chrysanthemum inflorescences, a high quality but relatively fixed, ephemeral resource for thrips population growth. We hypothesized that different thrips versus plant responses to temperature result in significant statistical interaction of temperature with thrips abundance and flower damage attributes over time. Experiments were conducted at five temperatures between 20.7 and 35.3 degrees C, with thrips infestation and time after infestation as main effects. Only minor, uncontrolled variations in relative humidity and light intensity may otherwise have influenced the results. High temperatures lead to an initially rapid increase in density of thrips followed by abrupt declines in abundance. The rate of floral senescence increased with temperature and thrips infestation, as indicated by a reduced fresh biomass and greater leaching of yellow pigments. Multiple regression indicated that indices of plant damage responded more directly to thrips density at low than high temperature, supporting the conclusion that temperature affected the outcome beyond what was predictable simply from differential plant and insect optima. The relative intensity of damage caused by individual thrips decreased with increasing temperature, likely caused by thrips competition and reduced survival, growth, and fecundity on depleted inflorescences. Reduced per capita damage at high temperature may be common in insects exploiting fixed plant resources that exhibit an accelerated rate of deterioration at high temperatures.
模拟温度对昆虫与植物相互作用可持续性的影响需要评估昆虫和植物的表现。我们研究了温度对西花蓟马Frankliniella occidentalis（Pergande）的影响，它是一种繁殖率高的多食性食草动物，还研究了菊花花序，这是蓟马种群增长的优质但相对固定且短暂的资源。我们假设，蓟马与植物对温度的不同反应会导致温度与蓟马数量及花朵损伤属性随时间产生显著的统计相互作用。实验在20.7至35.3摄氏度之间的五个温度下进行，以蓟马侵染和侵染后的时间作为主要因素。否则，相对湿度和光照强度只有微小的、无法控制的变化可能会影响结果。高温导致蓟马密度最初迅速增加，随后数量急剧下降。花衰老的速率随温度和蓟马侵染而增加，这表现为鲜生物量减少和黄色素浸出增加。多元回归表明，植物损伤指数在低温下比高温下对蓟马密度的反应更直接，这支持了以下结论：温度对结果的影响超出了仅根据植物和昆虫的不同最适条件所能预测的范围。随着温度升高，单个蓟马造成的损伤相对强度降低，这可能是由于蓟马竞争以及在枯竭的花序上存活率、生长和繁殖力下降所致。在利用固定植物资源的昆虫中，高温下人均损伤减少可能很常见，因为这些植物资源在高温下会加速退化。
