Nicaltica new genus and new species (N. selvanegra Konstantinov, Chamorro-Lacayo and Savini) from moss habitat in Nicaragua are described and illustrated. Nicaltica is compared to Kiskeya Konstantinov and Chamorro-Lacayo, Monotalla Bechyné, and Normaltica Konstantinov.

Beetles in the genus Acmaeodera were collected in southeastern Alberta, Canada. These did not fit the descriptions of the species reported to occur. Comparisons of structural characters and geographic ranges of species of several Acmaeodera species, A. diffusa Barr, A. idahoensis Barr, A. pulchella (Herbst), A. mixta LeConte, and A. immaculata Horn revealed that only A. immaculata is represented in Alberta, which represents a new record for Canada.

Pseudotriphyllus defoei new species represents the first North American species record of this predominantly Eurasian mycetophagid genus. The species is known from two specimens recovered from a single Berlese sample in the Great Smoky Mountains National Park, Tennessee (type locality, Albright Grove Loop Trail). It differs from other described Pseudotriphyllus by setal pattern, color, development of the pronotal lateral carina, size of the male prosternal fovea, and details of the aedeagus. The genus may be distinguished from all other North American mycetophagid genera by the presence of a median prosternal fovea on males and the width of the last antennal segment, which is narrower than the penultimate antennomere.

Two new species of Dytiscidae are reported from Hainan Island, China: Neptosternus yanbini Bian and Ji, new species and Microdytes wewalkai Bian and Ji, new species. Neptosternus yanbini is similar to N. pocsi Satô, 1972 in the color pattern of the elytra, but can be easily distinguished by the different shape of median lobe of aedeagus. Microdytes wewalkai is similar to M. jaechi Wewalka, but can be distinguished from it by its smaller size, darker body color, slimmer median lobe in lateral view, and is without two longitudinal rows of stronger punctures on the elytral disk.

Oxymorostes riedeli new genus and species is described from the Indonesian part of New Guinea. This new taxon is characterized by a number of unique characters: the presence of a deep excavation in the hypomeron and the unusually modified humeral area of the elytra. Its closest relationships seem to be within the newly defined “Perignamptus genus group”, characterized by mouthparts morphology, including the presence of a large pore on the mandibular surface. This group gathers at least the Oriental/Australasian genera Madrasostes Paulian, Perignamptus Harold, and Macrophilharmostes Paulian as well as a few species currently placed in other genera.

Glycobius speciosus (Say) was at one time found throughout the range of its larval host tree, sugar maple (Acer saccharum) but is currently missing from part of this range. The apparent lack of G. speciosus across much of Midwestern U.S.A. was validated. The characteristic and long-lasting scars left by G. speciosus make the determination of an absence of this species quite reliable. The presence and extent of the extirpation was established using museum records, extensive roadside surveys of host trees, and intensive surveys of hardwood forest patches. Glycobius speciosus is currently not found in an area that includes much of north and central Indiana and north and central Ohio. This area has experienced higher levels of forest loss and fragmentation than adjacent regions where evidence of the beetle remains common and obvious.

Hemipyxis yui Lee and Staines, new species, is described and its allied species, H. quadrimaculata (Jacoby, 1892), is redescribed. Male and female reproductive systems are illustrated in detail.

We use carbon and nitrogen isotope data to elucidate the diets of larval and adult Brychius hungerfordi Spangler in streams in Northern Lower Michigan. Diet analysis suggests that feeding behavior during the larval life stage is different from that of the adult. Larvae appear to prefer the alga Dichotomosiphon tuberosus (Braun) Ernst. Adults appear to be generalists, feeding on Dichotomosiphon, Cladophora Kuetzing and Chara Linnaeus as well as the epiphytic diatom Cocconeis Ehrenberg. Dichotomosiphon, although widespread, is not common. Its presence may be an important factor in determining the distribution of the Federally endangered beetle.

The formerly monotypic genus Blaiseus, known from Vietnam, is redescribed and nine new species are described and illustrated: B. fujianus new species (P.R. China), B. daklakensis new species (Vietnam), B. laoensis new species (Laos), B. malayensis new species (Malaysia), B. nothoafricanus new species (South Africa), B. zamoranoensis new species (Honduras), B. guatemalensis new species (Guatemala), and B. chiapasensis new species and B. mexicanus new species from Mexico. Morphological character states of the protibia, hind wing and aedeagus not previously observed in Elateridae are described and illustrated. A female specimen of Blaiseus (B. zamoranoensis) is first described here and displays a fossorial morphology type with reduced wings and eyes. Blaiseus is hypothesized to be at least 20 million years old based on its known geographic distribution and apparent female flightlessness.

The bess beetle, Odontotaenius disjunctus (Illiger), is a large subsocial beetle that inhabits decaying logs in which adults build tunnel systems and raise their larvae. Adults are territorial and both males and females protect tunnels from intruders. Though the behavior of many passalid beetle species, including O. disjunctus, has been studied, adult behavior toward conspecifics has not been thoroughly documented and many interactive behaviors have yet to be defined. We describe behaviors exhibited during laboratory interactions between non-cohabitating O. disjunctus adults. Twenty-four O. disjunctus were each tested in two experimental trials, once as a resident and once as an intruder, and in one control trial. We observed 18 behavior patterns and monitored them during trials. There were significant differences between control and experimental trials in some aggression behaviors, and in the total frequency of aggression, but no significant differences in submission, investigation, and neutral behaviors. Our data expand the behavioral repertoire for this species. Adults may use the described mild aggression behaviors in a territorial context, but we found no significant difference in total frequency of mild aggression between residents and intruders.