Laboratoire Venins et Activités Biologiques, EA 4357, Institut National Universitaire Jean-Francois Champollion, Université Fédérale de Toulouse-Midi Pyrénées, Albi, France.
Laboratoire Evolution et Diversité Biologique, UMR5174, CNRS-Université Toulouse III-IRD, F-31062, Université Paul Sabatier, Toulouse, France.
Parasitol Res. 2019 Oct;118(10):2935-2943. doi: 10.1007/s00436-019-06435-2. Epub 2019 Sep 5.
Varroa destructor, an acarian parasite of the Western honey bee Apis mellifera L., is a serious threat to colonies and beekeeping worldwide. The parasite lifecycle occurs in close synchrony with its host development. The females have to discriminate between different developmental stages of the host and trigger an appropriate behavioral response. Many studies have focused on these behavioral aspects, whether it is the choice of a precise host stage or the reproduction of female mites. Behavioral tests often require laboratory settings that are very different from the mite's environment. Our first experiment was designed to study the impact of the surface of test arena on the mite behavior. We found that plastic from Petri dishes commonly used as test arenas disturbs the female mites and can cause death. We searched for a substrate that does not harm mites and found that gelatin-coated plastic Petri dishes responded to these expectations. We then investigated the host choice behavior of phoretic mites confronted with larval stages of the bee on gelatin-coated arenas to watch if the well-documented orientation towards 5th instar larva was observable in our conditions. Pupal stages were included in the host choice experiments, initially to act as neutral stimuli. As white-eyed pupae were revealed attractive to the mite, several pupal stages were then included in a series of host choice bioassays. These additional experiments tend to show that the positive response to the white-eyed pupa stage depends on cues only delivered by living pupae. Further investigation on the nature and impact of these cues are needed as they could shed light on key signals involved in the parasite lifecycle.
瓦螨（Varroa destructor），西方蜜蜂（Apis mellifera L.）的一种节肢动物寄生虫，是全世界蜂群和养蜂业的严重威胁。寄生虫的生命周期与宿主的发育密切同步。雌性必须区分宿主的不同发育阶段，并触发适当的行为反应。许多研究都集中在这些行为方面，无论是选择精确的宿主阶段还是雌性螨虫的繁殖。行为测试通常需要非常不同于螨虫环境的实验室设置。我们的第一个实验旨在研究测试场地表面对螨虫行为的影响。我们发现，用作测试场地的 Petri 盘的塑料会干扰雌性螨虫并导致其死亡。我们寻找一种不会伤害螨虫的基质，发现涂有明胶的塑料 Petri 盘符合这些期望。然后，我们在涂有明胶的场地上研究了寄生螨虫对蜜蜂幼虫阶段的宿主选择行为，以观察在我们的条件下是否可以观察到针对第 5 龄幼虫的良好记录的定向行为。蛹期最初被纳入宿主选择实验中作为中性刺激。由于白眼睛的蛹对螨虫具有吸引力，因此随后将几个蛹期纳入一系列宿主选择生物测定中。这些额外的实验表明，对白眼蛹期的积极反应仅取决于活体蛹提供的线索。需要进一步研究这些线索的性质和影响，因为它们可能揭示寄生虫生命周期中涉及的关键信号。
