Depto. Agronomia; Área de Fitossanidade, Universidade Federal Rural de Pernambuco, 52171-900 Recife, PE, Brazil.
Exp Appl Acarol. 2012 Mar;56(3):233-46. doi: 10.1007/s10493-012-9515-3. Epub 2012 Jan 24.
Several predatory mites have been found in association with the coconut mite, Aceria guerreronis Keifer, in northeast Brazil. However, the latter still causes damage to coconut in that region. The objectives of this work were to compare the frequencies of occurrence of Neoseiulus (Phytoseiidae) and Proctolaelaps (Melicharidae) species on standing and aborted coconuts in coastal Pernambuco State, northeast Brazil and to analyze their possible limitations as control agents of the coconut mite, based on evaluations of the restrictions they may have to access the microhabitat inhabited by the pest and their functional and reproductive responses to increasing densities of the latter. Neoseiulus baraki (Athias-Henriot) was found mostly on standing coconuts whereas Proctolaelaps bickleyi (Bram) was found mostly on aborted coconuts. Measurements of the entrance to the microhabitat occupied by the coconut mite, between the bracts and the subjacent fruit surface, showed that this different pattern of predator prevalence could be related to predator sizes, although other environmental factors could not be disregarded. Progressively higher predation rate of N. baraki was observed up to an experimental density that corresponded to 1,200 coconut mites per fruit, which is close to the average number determined in northeast Brazil, reducing slightly afterwards. Predation rate of P. bickleyi reduced consistently but slightly with increasing prey densities, but in absolute values, rates were always much higher than determined for N. baraki. The excessively high killing capacity of P. bickleyi, probably related to its high feeding requirement, may be detrimental in terms of stability. In fact, such high requirement for food suggests that P. bickleyi might not have a strong relation with the coconut mite and that the latter may not be its main food source under natural conditions. It is concluded that body sizes of both predators and the exceedingly high feeding requirement of P. bickleyi may limit their performance as control agents of the coconut mite.
在巴西东北部与椰子红蜘蛛 Aceria guerreronis Keifer 相关联的地方发现了几种捕食性螨虫。然而，后者仍然对该地区的椰子造成损害。本工作的目的是比较 Neoseiulus（植绥螨科）和 Proctolaelaps（革螨科）在巴西东北部沿海伯南布哥州的正常椰子和畸形椰子上的出现频率，并根据它们可能对椰子红蜘蛛的控制能力的限制来分析它们，评估它们对害虫栖息微生境的可能限制以及它们对害虫密度增加的功能和生殖反应。N. baraki（Athias-Henriot）主要出现在正常椰子上，而 P. bickleyi（Bram）主要出现在畸形椰子上。对椰子红蜘蛛占据的微生境入口的测量结果表明，这种不同的捕食者优势模式可能与捕食者的大小有关，尽管不能忽视其他环境因素。随着实验密度逐渐增加到每个果实 1200 只椰子红蜘蛛，N. baraki 的捕食率逐渐升高，这接近在巴西东北部确定的平均数量，之后略有下降。P. bickleyi 的捕食率随着猎物密度的增加而持续但略有下降，但绝对值始终远高于确定的 N. baraki。P. bickleyi 过高的捕杀能力，可能与其高的摄食需求有关，可能对稳定性不利。事实上，如此高的食物需求表明，P. bickleyi 可能与椰子红蜘蛛没有很强的关系，而且在自然条件下，椰子红蜘蛛可能不是其主要食物来源。结论是，两种捕食者的体型和 P. bickleyi 过高的摄食需求可能限制了它们作为椰子红蜘蛛控制剂的表现。
