Vowell Tomie, Manley Megan E, Ho Jordie R, Watanabe Shizu, Melzer Michael J
Agrosecurity Laboratory, Department of Plant and Environmental Protection Sciences, College of Tropical Agriculture and Human Resources, University of Hawai'i, Honolulu, HI, United States.
Front Insect Sci. 2023 May 24;3:1157769. doi: 10.3389/finsc.2023.1157769. eCollection 2023.
(Coleoptera: Scarabaeidae) is an invasive pest of palms in the Pacific Region, including Hawaii, for which limited management options are available. O. rhinoceros larvae develop in materials rich in organic materials such as green waste and animal manure. Biosolid waste within Hawaii's infestation zone, however, was determined to inhospitable to . To determine if the elevated metal salts present in the biosolid waste was responsible for this observation, life stages were acutely and chronically exposed to several metal salts at increasing concentrations to determine the impact of these salts on survival, development, and oviposition behavior. Acute (7 days) exposure to mulch rehydrated in solutions of CaCl, KCl, MgCl, or NaCl increasing in concentration from 0 to 0.7 M resulted in increased mortality, with concentrations > 0.5 M generally being 100% lethal to both first and second-instar larvae. A similar trend in survival was observed in subsequent experiments using a horticultural grade of Epsom salt (MgSO) at 1×, 2×, and 5× the recommended application rate. Chronic exposure (eggs reared on mulch through pupation) to Epsom salt at these same rates resulted in significantly delayed instar development and reduced adult biometrics at both 1× and 2× levels. Similar to the acute exposure, eggs exposed to 5× levels did not hatch, or the first instar died soon after emergence. In choice experiments, gravid females showed no oviposition preference for media hydrated with water or 2× Epsom salt but did avoid ovipositing in mulch rehydrated in 5× Epsom salt. These trials demonstrate a potentially novel approach to managing pest populations of .
（鞘翅目：金龟科）是太平洋地区包括夏威夷在内的棕榈树入侵害虫，针对该害虫的管理选择有限。犀牛奥氏金龟幼虫在富含有机物质的材料中发育，如绿色垃圾和动物粪便。然而，夏威夷疫区的生物固体废弃物被认定不适宜犀牛奥氏金龟生存。为确定生物固体废弃物中存在的金属盐含量升高是否是导致这一现象的原因，将犀牛奥氏金龟的不同生命阶段急性和慢性暴露于浓度不断增加的几种金属盐中，以确定这些盐对其生存、发育和产卵行为的影响。将覆盖物在浓度从0至0.7 M递增的氯化钙、氯化钾、氯化镁或氯化钠溶液中再水化后进行急性（7天）暴露，结果导致死亡率增加，浓度>0.5 M时通常对一龄和二龄幼虫均有100%的致死率。在随后使用园艺级泻盐（硫酸镁）以推荐施用量的1倍、2倍和5倍进行的实验中，观察到了类似的生存趋势。以相同比例对泻盐进行慢性暴露（卵在覆盖物上饲养直至化蛹），在1倍和2倍水平时均导致龄期发育显著延迟和成虫生物特征减小。与急性暴露类似，暴露于5倍水平的卵未孵化，或一龄幼虫在孵化后不久死亡。在选择实验中，怀孕雌虫对用水或2倍泻盐水化的介质没有产卵偏好，但确实避免在5倍泻盐水化的覆盖物中产卵。这些试验证明了一种潜在的新颖方法来管理犀牛奥氏金龟的害虫种群。
