Perera Nisansala N, Barrow Russell A, Weston Paul A, Rolland Vivien, Hands Philip, Gurusinghe Saliya, Weston Leslie A, Gurr Geoff M
Gulbali Institute of Agriculture, Water and Environment, Charles Sturt University, Wagga Wagga, NSW 2678, Australia.
School of Agriculture, Environment and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia.
Insects. 2023 Jul 12;14(7):627. doi: 10.3390/insects14070627.
Locating sporadically distributed food resources and mate finding are strongly aided by volatile cues for most insects, including dung beetles. However, there is limited information on the olfactory ecology of dung beetles. We conducted a scanning electron microscopy study on the morphology and distribution of the antennal sensilla of three introduced dung beetle species in Australia: (Coleoptera: Geotrupidae), and (Coleoptera: Scarabaeidae). Three main morphological types of antennal sensilla were identified: sensilla trichodea (ST), sensilla basiconica (SB) and sensilla chaetica (SCh). Distinct variations of SB distribution were observed in and and on different lamellar surfaces in both sexes of all three species. Sexual dimorphism in antennal sensilla distribution or their abundance was not evident. To complement the morphological characterisation of sensilla, electroantennography (EAG) was carried out to construct EAG response profiles of the three species to selected dung volatiles. An initial study revealed that antennae of all species were sensitive to a mix of phenol, skatole, indole, -cresol, butanone and butyric acid, common components of livestock dung headspace. In addition to these six compounds, dimethyl sulfide, dimethyl disulfide, eucalyptol and toluene were tested for antennal activity. All compounds evoked measurable EAG responses, confirming antennal sensitivity. exhibited significant responses to all the compounds compared to the control, whereas and only responded to a subset of compounds. A comparison of relative EAG amplitudes revealed highly significant responses to -cresol in and to skatole in . displayed differential responses to all the compounds. Pooled EAG data suggest highly significant differences in responses among the three species and among compounds. Our findings suggest that a blend of volatiles may offer potential for the trapping of dung beetles, thereby avoiding the use of dung baits that are inconvenient, inconsistent and may pose a threat to farm biosecurity.
对于包括蜣螂在内的大多数昆虫而言，挥发性线索对其寻找零星分布的食物资源和寻找配偶有很大帮助。然而，关于蜣螂嗅觉生态学的信息有限。我们对澳大利亚引进的三种蜣螂物种（鞘翅目：粪金龟科）、（鞘翅目：金龟科）触角感器的形态和分布进行了扫描电子显微镜研究。确定了触角感器的三种主要形态类型：毛形感器（ST）、锥形感器（SB）和刺形感器（SCh）。在和以及所有三个物种两性的不同板层表面观察到SB分布的明显差异。触角感器分布或其数量上的两性异形并不明显。为补充感器的形态特征描述，进行了触角电位（EAG）测定，以构建这三个物种对选定粪便挥发物的EAG反应图谱。初步研究表明，所有物种的触角对苯酚、粪臭素、吲哚、对甲酚、丁酮和丁酸（家畜粪便顶空的常见成分）的混合物敏感。除了这六种化合物外，还测试了二甲基硫醚、二甲基二硫醚、桉叶油素和甲苯的触角活性。所有化合物都引起了可测量的EAG反应，证实了触角的敏感性。与对照相比，对所有化合物都表现出显著反应，而和只对一部分化合物有反应。相对EAG振幅的比较显示，对甲酚有高度显著反应，对粪臭素有高度显著反应。对所有化合物表现出不同的反应。汇总的EAG数据表明，这三个物种之间以及化合物之间的反应存在高度显著差异。我们的研究结果表明，挥发性混合物可能为诱捕蜣螂提供潜力，从而避免使用不方便、不一致且可能对农场生物安全构成威胁的粪便诱饵。
