Corcuera Pablo, Valverde Pedro Luis, Jiménez-Salinas Everardo, Vite Fernando, López-Ortega Gerardo, Pérez-Hernández Marco Aurelio
Department of Biology, University of Notre Dame, Notre Dame, IN 46556, USA.
Environ Entomol. 2010 Apr;39(2):320-7. doi: 10.1603/EN09205.
Peucetia viridans (Hentz) lives almost exclusively on Croton ciliatoglandulifer (Ortega) in the dry forests of western Mexico. This spider is usually found on pubescent shrubs. Within their host plants, P. viridans has been associated with plant height and cover, as well as with number of flowers or inflorescences in anthesis. Flowers can be used as cues of good habitat conditions or because they attract prey detected by the spider. In this study, we assessed the importance of flowers, plant cover, and plant exposure (sun/shade) on the spider distribution in five 50-plant transects. In a field experiment, we also compared the number of spiders between controls, plants from which inflorescences were removed, and plants with artificial inflorescences. The results from the transects indicate that, when the number of flowers per spider is high, spiders were more abundant in exposed locations, which presumably offer better microclimatic conditions; when flowers become scarce, food may be more difficult to find and the spider distribution become strongly associated with the number of flowers, where they are more likely to find prey. Spider abundances on the experimental plot decreased on plants from which flowers were removed in comparison to control plants. Spider abundance increased on those in which artificial inflorescences were added. The similarity between plants with natural and artificial inflorescences suggests that spiders use flowers as cues of good microhabitats instead of prey visitors, which are significantly less abundant on artificial inflorescences.
绿蟹蛛（Peucetia viridans (Hentz)）几乎仅栖息于墨西哥西部干旱森林中的腺毛巴豆（Croton ciliatoglandulifer (Ortega)）上。这种蜘蛛通常在长有柔毛的灌木上被发现。在其寄主植物中，绿蟹蛛与植物高度、覆盖度以及开花期的花朵或花序数量有关。花朵可作为良好栖息地条件的线索，或者是因为它们能吸引蜘蛛察觉到的猎物。在本研究中，我们在五条各有50株植物的样带中评估了花朵、植物覆盖度和植物受光情况（向阳/背阴）对蜘蛛分布的重要性。在一项田间实验中，我们还比较了对照组、去除花序的植物以及带有人工花序的植物上蜘蛛的数量。样带研究结果表明，当每只蜘蛛对应的花朵数量较多时，蜘蛛在光照充足的位置更为丰富，这些位置大概能提供更好的微气候条件；当花朵变得稀少时，食物可能更难找到，蜘蛛的分布就与花朵数量紧密相关，因为它们更有可能在那里找到猎物。与对照植物相比，实验地块上去除花朵的植物上蜘蛛数量减少。添加人工花序的植物上蜘蛛数量增加。带有自然花序和人工花序的植物之间的相似性表明，蜘蛛将花朵用作良好微生境的线索，而非猎物到访的线索，因为人工花序上的猎物到访者明显较少。
