We present a study of interactions in the highly competitive insect communities inhabiting the carrion of small mammals. Via manipulation in a fully quantitative design, we delayed community development by excluding insect colonization in mouse and rat carcasses for 3 days, to study the role of early competitively dominant colonizers [burying beetles (Nicrophorus spp.; Coleoptera: Silphidae) and blowfly larvae (Diptera: Calliphoridae)] in the course of heterotrophic succession on small cadavers. Earlier studies demonstrated that in the case of large mammalian carrion, exclusion of insects’ access to the carcass in the early stages of decomposition altered the successional trajectory and species assemblages. However, the effect of such manipulation in easy monopolizable small vertebrate carrion remained unknown. Our results demonstrate that delaying insect access to carrion significantly lowered blowfly larvae abundances, while it simultaneously had no effect on colonization and carrion burial by burying beetles. Higher abundances of blowfly larvae seem to deter necrophagous beetles, whereas they are not harmful to the larvae of flesh flies, at least in larger rat carcasses. Predatory beetle species preferred the lower abundances of blowfly larvae, presumably due to better accessibility of their prey. Our results therefore suggest that in the course of the entire season, larvae of blowflies are the dominant competitors in small carcasses, and significantly affect the assembly of other insect groups, whereas burying beetles may exhibit a more temporal pattern of dominance.

Integrative taxonomy of Diamesus Hope, 1840 (Coleoptera: Silphinae) is presented. Adults of D. bimaculatus Portevin, 1914 (endemic to Taiwan) and D. osculans (Vigors, 1825) (widely distributed from northern India to Australia) are redescribed, keyed and figured, including characters of the male and female genitalia of both species. Variation in elytral maculation in D. osculans is discussed and illustrated. The absence of diagnostic differences of D. osculans var. reductus Pic, 1917 from D. osculans is discussed, and the former name is confirmed as a junior subjective synonym of D. osculans. Types of all three names available were studied; a lectotype and paralectotypes are designated for the name D. osculans var. bimaculatus Portevin, 1914. Molecular phylogenetic analysis confirms the genus Diamesus is sister group to the genus Necrodes Leach, 1815, and D. osculans and D. bimaculatus are two, well supported clades. Detailed data on the distribution of D. bimaculatus and D. osculans are presented and mapped. Species distribution models for both species were created and interpreted. Diamesus osculans is reported for the first time from India: Uttarakhand, China: Anhui, Hainan, Hunan, Jiangxi, Shaanxi and Zhejiang Provinces, and Australia: Victoria; it is also recently confirmed from Taiwan, being sympatric in distribution there with D. bimaculatus. Available data on the ecology and seasonality of both species of Diamesus are also discussed.

The genus Ablattaria Reitter, 1884 (Coleoptera: Silphidae: Silphinae) is revised. Four taxa are recognized as valid species: Ablattaria arenaria (Kraatz, 1876), Ablattaria cribrata (Ménétries, 1832), Ablattaria laevigata (Fabricius, 1775) and Ablattaria subtriangula Reitter, 1905. Ablattaria laevigata var. meridionalis Ganglbauer, 1899 is newly treated as a junior subjective synonym of Ablattaria laevigata. Lectotypes are designated for Phosphuga arenaria Kraatz, 1876, Ablattaria arenaria var. punctigera Reitter, 1884, Ablattaria arenaria var. alleoni Portevin, 1926, Silpha cribrata Ménétries, 1832, Silpha laevigata Fabricius, 1775, Silpha gibba Brullé, 1832, Ablattaria gibba var. costulata Portevin, 1926, Ablattaria gibba var. distinguenda Portevin, 1926, Ablattaria gibba var. punctata Portevin, 1926 and Ablattaria subtriangula Reitter, 1905. The distribution of all taxa is mapped, based on material examined. Geometric morphometric methods were used to evaluate shape variability in Ablattaria. Results indicated sexual dimorphism in all species. Shape inconsistency was found between the sexes of all taxa when tested independently. The first two relative warp axes indicated 65.17% shape variation in males and 65.72% in females. Canonical variate analysis separated the taxa studied. There was minimal overlap between some groups in both sexes. Differences in body shape between populations of Ablattaria laevigata from Central Europe, Italy and Greece + Turkey were also examined. Relative warps implied 58.01% shape variability on both axes in males and 64.78% in females. CVA revealed noticeable overlaps between the groups, although the Italian population demonstrated a higher separation in both sexes.

Larval morphology of all three instars of Nicrophorus (Nicrophorus) nepalensis Hope, 1831 (Coleoptera: Silphidae: Nicrophorinae) is described and illustrated, based on reared larvae. The eastern Palaearctic and Oriental N. (N.) nepalensis is similar to the western Palaearctic N. (N.) humator (Gleditsch, 1767) in a number of larval characters. This is congruent with recent classification of the genus Nicrophorus Fabricius, 1775 by Sikes, who suggested a close phylogenetic affinity of the N. nepalensis species group (with 16 species) with the N. humator species group (2 species). The generic description of larvae of Nicrophorus Fabricius, 1775 is expanded, based on detailed SEM observation.

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