Palaearctic-native
Guides
Cassida rubiginosa
Thistle Tortoise Beetle
Cassida rubiginosa, commonly known as the thistle tortoise beetle, is a leaf beetle in the subfamily Cassidinae native to Europe and Asia that has been introduced to North America, New Zealand, and other regions as a biological control agent for invasive thistles. The beetle derives its common name from the tortoise-like appearance of adults, whose elytra and pronotum form a shield-like covering over the body. Both adults and larvae feed on thistle foliage, with larvae possessing a distinctive defensive structure—a forked caudal appendage used to carry accumulated feces and exuviae as a mobile 'fecal shield' that deters predators. The species has demonstrated effectiveness in reducing thistle biomass and seed production, though its host range extends beyond the primary target to other Cardueae species.
Olesicampe
Olesicampe is a genus of ichneumonid wasps containing at least 130 described species. Species in this genus are parasitoids of sawfly larvae (Hymenoptera: Symphyta), with documented associations to hosts in the genera Pristiphora and Cephalcia. Several species have been introduced as classical biological control agents against larch sawfly and mountain ash sawfly pests in North America, where they have established successfully and achieved significant host population suppression. The genus is native to the Palaearctic region.
Onthophagus nuchicornis
Small black-and-brown Dung Beetle
Onthophagus nuchicornis is a Palearctic dung beetle introduced to North America in the 1840s, now established across Canada and the northern United States. The species exhibits generalist coprophagy, successfully reproducing using dung from both domestic livestock and indigenous mammals including bobcat, moose, red fox, and raccoon. It possesses an obligatory cold reproductive diapause restricting it to a single generation per year. In the United Kingdom, it is listed as Vulnerable, while in North America it is abundant and has been employed as a model organism for ecotoxicological studies of ivermectin effects on dung burial behavior.
dung-beetleintroduced-speciescoprophagediapauseecotoxicology-modelpasture-ecosystemsexual-dimorphismivermectin-effectsgeneralist-feederPalaearctic-nativeNearctic-introducedsingle-generation-per-yearbrood-balltunneling-behaviorcompetition-with-native-speciesCLIMEX-bioclimatic-modelnutrient-cyclingsoil-aerationcattle-pasture-managementVulnerable-(UK)Psammodius basalis
Psammodius basalis is a small aphodiine dung beetle in the family Scarabaeidae. The species is native to the Palaearctic region and has been introduced to North America, where it is established in Maryland. As a member of the subfamily Aphodiinae, it belongs to a group commonly known as small dung beetles or aphodiines that are associated with decomposing organic matter. The genus Psammodius is distinguished by adaptations to sandy habitats.
Sciaphilus asperatus
Scaly strawberry weevil, Strawberry root weevil
A wingless, parthenogenetic weevil with a broad Palaearctic distribution, recently introduced to North America. Adults feed on leaves of diverse plants, producing distinctive notched edges, while larvae develop underground on roots. The species exhibits high reproductive output and can form locally abundant populations.
Silvanus unidentatus
Silvanus unidentatus is a small bark-dwelling beetle in the family Silvanidae, measuring 2.3–2.8 mm. Native to the Palaearctic region across 33 countries plus Korea, it has been introduced to North America and Chile. The species inhabits the space beneath tightly attached bark of dead broadleaved trees, where both larvae and adults develop. It has been the subject of genome sequencing research, yielding a chromosome-level assembly of 187.15 Mb.
Teuchestes fossor
gravedigger dung beetle
Teuchestes fossor is a coprophagous dung beetle native to the Palaearctic region that has become widespread in North America following accidental introduction during European settlement. Both adults and larvae feed on herbivore dung, with adults consuming liquid fractions and larvae consuming fibrous material. The species is readily collected from livestock dung and supports key ecosystem services in cattle systems. It is one of the most frequently observed dung beetles in its range, with over 600 citizen science records.
Tipula oleracea
marsh crane fly, common crane fly
Tipula oleracea is a crane fly species native to the Palaearctic region that has been introduced to parts of the Nearctic and Neotropics. Adults are typically greyish with wings 18–28 mm long, and are active in two flight periods: early summer (April–June, peaking May–June) and late summer (August–October). The species is notable for its larval 'leatherjackets' which can reach densities of up to 400 per square meter in agricultural soils, causing damage to crops such as cabbage by feeding on roots and, at night, above-ground plant parts.