Taxonomically-challenging
Guides
Anapus
A genus of plant bugs in the family Miridae. Species identification is challenging due to significant intraspecific polymorphism in coloration and body proportions. Male genitalia, particularly the aedeagus, provide reliable diagnostic characters for species delimitation. The genus is Palearctic in distribution.
Boletina
fungus gnats
Boletina is a species-rich genus of fungus gnats in the family Mycetophilidae, characterized by a mainly Holarctic distribution. The genus has historically been taxonomically challenging due to morphological similarities among species and paraphyletic relationships with related genera including Aglaomyia, Coelosia, and Gnoriste. Recent molecular phylogenetic studies and taxonomic revisions have clarified some relationships, though the genus remains under active investigation. Boletina species are particularly diverse in northern Europe, where ongoing research continues to reveal new species.
Gymnosoma
ladybird flies, bug-killer flies
Gymnosoma is a genus of tachinid flies (Diptera: Tachinidae) commonly known as ladybird flies or bug-killer flies. Species are small parasitoids, typically 5–6 mm, with distinctive rounded abdomens often colored red or orange with dark markings, resembling lady beetles. Larvae develop as internal parasitoids of true bugs (Hemiptera), particularly shieldbugs (Pentatomidae). The genus has been taxonomically challenging; genomic analysis suggests many Palearctic species may represent a single highly variable species rather than distinct taxa. Adults visit flowers for nectar.
Parancistrocerus bicornis
Parancistrocerus bicornis is a small mason wasp in the subfamily Eumeninae, described by Roberts in 1901. Like other members of the genus, it is a solitary, cavity-nesting wasp that provisions its nests with paralyzed caterpillars as food for its larvae. The species is part of a taxonomically challenging group where live specimens and even microscope examination often cannot reliably distinguish between closely related species such as Parancistrocerus and Stenodynerus.