Effect of herbivory on preference and performance of heterospecific herbivores mediated by Cucumber Plant
عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران
نویسندگان
چکیده
Plant responses to herbivory and its effect on subsequent herbivores through plant-mediated effects are important to understanding; how plants response to initial herbivores, and how these responses affect other members of the community. As well as its importance in agriculture; indirect interactions mediated by plants can affect food webs and ecological communities. We conducted a series of separate experiments in order to understand whether preference and performance of Trialeurodes vaporariorum, Tetranychus urticae and Aphis gossypii are affected by the previous herbivory of each other’s on the cucumber plant; and whether these effects are local or systemic. The fourth leaf of cucumber seedlings was confined by ventilated clip cages and herbivore were released in the cage. After 48 hours, initial herbivores and deposited eggs or nymphs were removed. Seven days after initial herbivory, the second herbivore from other species (Receiver) was introduced on the plant. Another series of receiver herbivores were transferred to the fifth leaves of cucumber plants, whose fourth leaves had been previously exposed to initial herbivory to assess the systemic effect. Performance parameters were measured for herbivores on local and systemic treatments. The performance parameters of herbivores on cucumber plant with no previous herbivory considered as control.
The effect of the previous herbivory on host-plant preference was examined with two-choice tests in which studied organisms are allowed free access to two leaves from different treatments (Control vs. Local or systemic). Cucumber plants used in preference experiments treated same as performance experiments. Results indicated that herbivory of T. vaporariorum, T. urticae, and A. gossypii can affect preference and performance of receiver herbivores. In none of the experiments, a positive effect on the performance parameters was observed and influences of initial herbivory on subsequent herbivores varied from negative to neutral depending on the performance parameters and the studied level (local or systemic). Preference experiments indicated that all three organisms studied here are able to detect the previous herbivory and prefer to settle and produce offspring on control leaves to evade the detrimental effect of the previous herbivory. Regards to the detrimental effect of herbivory on T. urticae, it seems that T. urticae are the most sensitive to change in the quality of host and more precise for host selection. It can be concluded that conducting preference experiments along with performance experiments, not only elucidate herbivores interactions but also reveal the sensitivity of herbivores to changes in the host plant.
The effect of the previous herbivory on host-plant preference was examined with two-choice tests in which studied organisms are allowed free access to two leaves from different treatments (Control vs. Local or systemic). Cucumber plants used in preference experiments treated same as performance experiments. Results indicated that herbivory of T. vaporariorum, T. urticae, and A. gossypii can affect preference and performance of receiver herbivores. In none of the experiments, a positive effect on the performance parameters was observed and influences of initial herbivory on subsequent herbivores varied from negative to neutral depending on the performance parameters and the studied level (local or systemic). Preference experiments indicated that all three organisms studied here are able to detect the previous herbivory and prefer to settle and produce offspring on control leaves to evade the detrimental effect of the previous herbivory. Regards to the detrimental effect of herbivory on T. urticae, it seems that T. urticae are the most sensitive to change in the quality of host and more precise for host selection. It can be concluded that conducting preference experiments along with performance experiments, not only elucidate herbivores interactions but also reveal the sensitivity of herbivores to changes in the host plant.
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