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Larvae of some leaf beetles carry masses of feces covering parts or all of the body, which is called a “fecal shield”. In general, the shield is thought to be a defense structure against natural enemies. However, some studies have suggested that defense effectiveness varies depending on the natural enemy. In this study, we used a fecal retention leaf beetle Ophrida xanthospilota (Coleoptera: Chrysomelidae), and 2 local generalist predators (an ant, Camponotus japonicus (Hymenoptera: Formicidae) and a stinkbug, Arma custos [Hemiptera: Pentatomidae]) as a system to test the hypothesis that the fecal shield of O. xanthospilota plays different roles in predation behavior of different predators and can provide multiple chemical communication signals in predator–prey interactions. Prey bioassays showed that the fecal shield of O. xanthospilota larvae repelled the ant C. japonicus while attracting the stinkbug A. custos. The results also strongly demonstrated that hexane extracts of the fecal shield significantly repelled C. japonicus, while dichloromethane (DCM) extracts did not inhibit ant predation. Interestingly, DCM extracts attracted A. custos, but hexane extracts did not. Therefore, we suggest that the fecal shield is a double-edged sword for the larvae of O. xanthospilota. Our results also indicated that the risk–benefit tradeoff of an insect should be estimated at a community level involving multiple enemies (predators and parasites) and herbivores, rather than in a single prey–predator pair.

Colour polymorphism offers rich opportunities for studying the eco-evolutionary mechanisms that drive the adaptations of local populations to heterogeneous and changing environments. We explored the colour morph diversity and composition in a Chrysomela lapponica leaf beetle across its entire distribution range to test the hypothesis that environmental and climatic variables shape spatio-temporal variation in the phenotypic structure of a polymorphic species. We obtained information on 13 617 specimens of this beetle from museums, private collections and websites. These specimens (collected from 1830-2020) originated from 959 localities spanning 33 degrees latitude, 178 degrees longitude and 4200 m altitude. We classified the beetles into five colour morphs and searched for environmental factors that could explain the variation in the level of polymorphism (quantified by the Shannon diversity index) and in the relative frequencies of individual colour morphs. The highest level of polymorphism was found at high latitudes and altitudes. The colour morphs differed in their climatic requirements; their composition was independent of the geographic distance that separated populations but changed with collection year, longitude, mean July temperature and between-year temperature fluctuations. The proportion of melanic beetles, in line with the thermal melanism hypothesis, increased with increasing latitude and altitude and decreased with increasing climate seasonality; it also declined during the past century, but only at high latitudes and altitudes where recent climate warming was especially strong. The observed patterns suggest that colour polymorphism is especially advantageous for populations inhabiting unpredictable environments, presumably due to the different climatic requirements of coexisting colour morphs. This article is protected by copyright. All rights reserved.

A new genus of Languriinae, Tomolanguria Huang, gen. nov. is erected for a single species, Languria aculeata Gorham, 1887 from Mexico. It is similar to the Neotropical genus Languria Latreille, 1802. The differential diagnosis of this new genus is based on the structural features of the elytral apices and slight impressions present on each elytron. Languria aculeata is designated as the type species of the new genus. This species is redescribed and illustrated (all the three specimens examined are shown in the dorsal, ventral, and lateral views). Finally, a mimic relationship between this new genus and genus Paederus Fabricius, 1775 (Staphylinidae) is discussed.

Extensive studies have shown that cuticular hydrocarbons (CHCs) are among the major cues that allow many insects to identify interspecific and intraspecific variation between individuals. CHCs often have mutually nonexclusive functions that can provide multiple types of signals, while their role in predator–prey interactions has received little attention. Here, we used a predatory stink bug, Zicrona caerulea (Hemiptera: Pentatomidae), and one of its favorite flea beetle prey, Altica viridicyanea (Coleoptera: Chrysomelidae), to test the hypothesis that CHCs of prey are important chemical cues for a predator. Two-choice bioassays using dead beetles and glass dummies clearly indicated that the CHC profile of A. viridicyanea is the pivotal cue in prey identification for Z. caerulea. The results also suggested that the role of acoustic and visual cues can be ignored in prey recognition at close range.

A worldwide review of the genus Callilanguria is presented. Three new species are described: C. weiweii Huang & Yang, sp. nov. from Sabah, Malaysia; C. helleri Huang & Yang, sp. nov. from Panay, the Philippines; and C. nigripes Huang & Yang, sp. nov. from Samar Island, the Philippines. Callilanguria scrupulosa Heller, 1918 is transferred to the genus Doubledaya. The other species are C. eximia Fowler, 1885; C. gorhami Villiers, 1945; C. asymmetrica Heller, 1900; C. ruficeps Achard, 1923; C. milloti Villiers, 1945; C. stenosoma (Harold, 1879); C. flaviventris Fowler, 1886; C. wallacii Crotch, 1876; and C. luzonica Crotch, 1876. In total, twelve species are recognized in the genus Callilanguria, and a key to the described species of the genus is provided.