Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, 980-8572, Japan.
Sci Rep. 2020 Mar 18;10(1):4931. doi: 10.1038/s41598-020-61935-x.
It is well known that Diptera and Lepidoptera can recognize tastes through their legs, which allows them to select suitable hosts. In Coleoptera, the largest insect order, however, the role of the legs in taste recognition to aid in host selection is unclear. In the present study, we investigated taste recognition through the legs of Chrysomelidae, Coleoptera. Through morphological observations, we found that all subfamilies of Chrysomelidae exhibit gustatory sensilla in the distal leg segment, i.e., the tarsus. In contrast, we did not find evidence of these sensilla in the species that we examined from four families of Coleoptera. We confirmed that different tastes, i.e., sweet, bitter, and leaf surface wax, were received through the tarsal sensilla of Chrysomelidae by recording the electrophysiological responses of the sensilla. Further, we found that Galerucella grisescens (Chrysomelidae) can respond to different tastes used in the electrophysiological tests using only their tarsi, whereas Henosepilachna vigintioctomaculata (Coccinellidae), lacking tarsal gustatory sensilla, did not exhibit similar responses. Our results suggest that although tarsal taste recognition is not common throughout Coleopteran species, it may be a common feature in Chrysomelidae, and tarsal gustation may play an important role in host selection in this family.
众所周知，双翅目和鳞翅目昆虫可以通过它们的腿来识别味道，这使它们能够选择合适的宿主。然而，在最大的昆虫目——鞘翅目目中，腿在味觉识别中帮助选择宿主的作用尚不清楚。在本研究中，我们研究了鞘翅目叶甲科昆虫通过腿部的味觉识别。通过形态学观察，我们发现叶甲科的所有亚科在腿部的末端，即跗节上都有味觉感受器。相比之下，我们在从鞘翅目四个科检查的物种中没有发现这些感受器的证据。我们通过记录感受器的电生理反应，确认了不同的味道，即甜味、苦味和叶表面蜡，是通过叶甲科的跗节感受器接收的。此外，我们发现，灰翅叶甲（叶甲科）仅用跗节就能对电生理测试中使用的不同味道做出反应，而没有跗节味觉感受器的二十八星瓢虫（瓢虫科）则没有表现出类似的反应。我们的结果表明，尽管跗节味觉识别在整个鞘翅目物种中并不常见，但它可能是叶甲科的一个共同特征，跗节味觉可能在该科的宿主选择中发挥重要作用。
