Species-rich-genus
Guides
Agra
elegant canopy beetles
Agra is a genus of ground beetles (Carabidae) commonly known as elegant canopy beetles. The genus contains over 500 described species, with more than 1000 additional specimens in collections awaiting formal description. Members of this genus belong to the subfamily Lebiinae and tribe Lebiini, and are characterized by their association with forest canopy habitats.
Arrenurus
water mites
Arrenurus is the largest genus of water mites, comprising approximately 950 species with cosmopolitan distribution in lentic freshwater habitats. Adults are heavily sclerotized, predatory, and exhibit marked sexual dimorphism—males possess diagnostic caudal modifications used in mating, while female taxonomy remains problematic. The life cycle includes seven stages: egg, inactive prelarva, parasitic larva, protonymph, deutonymph, tritonymph, and adult. Larvae are ectoparasites of aquatic insects, particularly Odonata (dragonflies and damselflies), but also Diptera and Coleoptera, utilizing hosts for both nutrition and phoretic dispersal.
Dissomphalus
Dissomphalus is the most species-rich genus in the family Bethylidae (Hymenoptera), with over 600 valid species globally. The genus exhibits exceptional diversity in the Neotropical region, where the majority of species occur, though it has a cosmopolitan distribution including the Oriental region and southwestern Pacific islands. Species delimitation relies heavily on male genitalia characters and metasomal tergal process structures, with species-groups defined primarily by these morphological features. Taxonomic revisions have revealed high levels of undescribed diversity, particularly in underexplored regions such as Panama, Thailand, and the Fiji-Solomon Islands archipelago.
Dusona
Dusona is a large genus of parasitoid wasps in the family Ichneumonidae, subfamily Campopleginae, with 442 described species. It is the most species-rich genus in its subfamily and has a cosmopolitan distribution. Members are morphologically distinctive within Campopleginae and primarily parasitize Lepidopteran larvae.
Strongylium
darkling beetles
Strongylium is a large genus of darkling beetles (Tenebrionidae: Stenochiinae) containing more than 1,400 described species, making it one of the most species-rich genera in both the family and subfamily. The genus exhibits a broad tropical and subtropical distribution across the Old and New Worlds, with particularly high diversity in the Neotropics (over 300 species). Species-level identification is challenging due to the genus's size and morphological diversity, often requiring specialist knowledge or detailed examination.
Tenthredo
Common Sawflies
Tenthredo is a large genus of sawflies comprising over 700 species with Holarctic distribution. Adults exhibit wasp-mimicry with long antennae and lack the narrow petiole ('wasp waist') characteristic of true wasps. Larvae are herbivorous and feed on diverse host plants, with most species showing host specificity. Adults are predatory or omnivorous, feeding on smaller insects as well as pollen and nectar at flowers. The genus is notable for its complex wing venation and soft-bodied, delicate adults.
Zelotes
ground spider
Zelotes is a large genus of ground spiders in the family Gnaphosidae, with approximately 400 described species distributed worldwide. These small to medium-sized spiders (5-10 mm) are typically dark reddish brown to nearly black in color. They are characterized by distinctive eye arrangements and frequently display a pale patch on the inner surface of the first femur. The genus was first described by J. Gistel in 1848 and represents one of the most species-rich genera within the ground spider family.