The biology of the moss and leaf litter inhabiting flea beetles is poorly understood. In this study, a new species of moss-eating flea beetles Cangshanaltica fuanensis sp. nov. is described; the morphology of adult and immature stages is examined and illustrated. Its life history and biology are studied. The remarkable and unique biological features are revealed: (1) females deposit one large egg at a time, egg length equals 0.4–0.5 times the female body length, these are unusual in Chrysomelidae; (2) females have only two ovarioles on each side of the ovary, which has not been reported in other Chrysomelidae species; (3) females lay and hide each egg under a spoon-shaped moss leaf; (4) cannibalism of a second instar larva on an egg was observed. Both adults and larvae feed on moss and are polyphagous; their feces mainly consist of un-digested moss fragments; high humidity is essential for the survival of eggs and larvae and expedites the hatching. In addition, a modified fan-driven Berlese funnel is designed for faster extraction of moss inhabiting flea beetles. This device could also be used for collecting other ground-dwelling arthropods. Its working diagram is illustrated and described.

Stag beetles (Coleoptera, Scarabaeoidea, Lucanidae) have received extensive attention from researchers in behavioral ecology and evolutionary biology. There have been no previous quantitative analyses, particularly using a geometric morphometric approach based on a large sample of data, to shed light on the morphological diversity and evolution of Lucanidae. Thoracic adaptation and ecological differentiation are intimately related, and the pronotum bears important muscles and supports the locomotion of prothoracic legs. The elytron is an autapomorphy of the Coleoptera. To reconstruct and visualize the patterns of evolutionary diversification and phylogenetic history of shape change, an ancestral groundplan can be reconstructed by mapping geometric morphometric data onto a phylogenetic tree. In this study, the morphologies of the pronotum and elytron in 1303 stag beetles (Lucanidae), including approximately 99.2% of all globally described species, were examined, thus revealing several aspects of morphological diversity and evolution. First, on the basis of geometric morphometric analysis, we found significant morphological differences in the pronotum or elytron between any two Lucanidae subfamilies. And we subsequently reconstructed the ancestral groundplans of the two structures in stag beetles and compared them with those of extant species (through cladistic and geometric morphometric methods). The ancestral groundplan of Lucanidae was found to be most similar to extant Nicagini in both the pronotum and elytron, according to Mahalanobis distances. Furthermore, we analyzed species richness and morphological diversity of stag beetles and the relationships between them and found that the two parameters were not always correlated. Aesalinae was found to be the most diverse subfamily in both the pronotum and elytron, despite its poor species richness, and the diversity of the pronotum or elytron was not superior in Lucaninae, despite its high species richness. Our study provides insights into the morphological variations and evolutionary history of the pronotum and elytron in four subfamilies of stag beetles, and it illuminates the relationship between morphological diversity and species richness. Intriguingly, our analysis indicates that morphological diversity and species richness are not always correlated. These findings may stimulate further studies in this field.

Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) rely on a symbiosis with fungi for their nutrition. Symbiotic fungi are preserved and transported in specialized storage structures called mycangia. Although pivotal in the symbiosis, mycangia have been notoriously difficult to study, given their minute size and membranous structure. We compared the application of novel visualization methods for the study of mycangia, namely micro-computed tomography (micro-CT) and laser ablation tomography (LATscan) with traditional paraffin sectioning. Micro-CT scanning has shown the greatest promise in new organ discovery, while sectioning remains the only method with sufficient resolution for cellular visualization. All three common types of mycangia (oral, mesonotal, and pronotal) were successfully visualized and presented for different species of ambrosia beetles: Ambrosiodmus minor (Stebbing) 1909, Euplatypus compositus (Say) 1823, Premnobius cavipennis Eichhoff 1878, Scolytoplatypus raja Blandford 1893, Xylosandrus crassiusculus (Motschulsky) 1866 and X. amputatus (Blandford) 1894. A reconstruction of the mycangium and the surrounding musculature in X. amputatus is also presented. The advantages of micro-CT compared to the previously commonly used microtome sectioning include the easy visualization and recording of three-dimensional structures, their position in reference to other internal structures, the ability to distinguish natural aberrations from technical artifacts, and the unprecedented visualizations of the anatomic context of mycangia enabled by the integrated software.

The diversity and biology of the moss and leaf litter-inhabiting flea beetles are still poorly known. In this study, three new species of Benedictus are described from China: Benedictus fuanensis Ruan & Konstantinov, sp. nov., Benedictus quadrimaculatus Ruan & Konstantinov, sp. nov., and Benedictus wangi Ruan & Konstantinov, sp. nov. Comments on their biology are given. Benedictus quadrimaculatus has a highly unusual morphological feature not reported before in flea beetles: black spots on the abdominal tergites that are visible through the elytra. Traditional and modified ethanol traps were tested and proven useful for collecting leaf litter- and moss-inhabiting flea beetles. Based on our tests, eight traps could collect one specimen each day in the testing sites in Fujian Province; three traps could collect one specimen each day in the testing sites in Guangdong Province.

The species name Cangshanaltica fuanensis, previously published in Ruan et al. (2020), is invalid. In this paper, we described Cangshanaltica fuanensis sp. nov. from Fujian, China in order to fully meet the criteria for the publication of a new species according to the Amendment of the International Code of Zoological Nomenclature (2012).