Alder
Guides
Acalitus brevitarsus
Alder erineum mite
Acalitus brevitarsus is an eriophyid mite that induces distinctive galls on alder species (Alnus). The mite lives and feeds within erineum—dense mats of hair-like structures—on the lower leaf surface, causing pale, domed swellings on the upper surface. It overwinters in old cones and bark crevices during autumn. The species is known from Europe, ranging from Spain to Russia.
Acleris caliginosana
Acleris caliginosana is a tortricid moth species native to North America. It has been recorded across a broad geographic range spanning Canada and the United States. The species is associated with deciduous trees in the genera Alnus and Betula.
Alniphagus
Alniphagus is a genus of crenulate bark beetles in the family Curculionidae, comprising approximately eight described species. The genus is notable for containing hardwood-killing bark beetles, particularly Alniphagus aspericollis (the alder bark beetle), which is capable of killing live alder trees—a rarity among bark beetles, as most tree-killing species in this group specialize on conifers. Species in this genus breed in the subcortical tissues of alder trees (genus Alnus) and have been documented from western North America, Africa, and Eurasia.
Altica ambiens
Alder Flea Beetle
Altica ambiens, commonly known as the alder flea beetle, is a species of flea beetle in the family Chrysomelidae. It is found in North America. The species was described by John Lawrence LeConte in 1859. Two subspecies are recognized: Altica ambiens alni and the nominate Altica ambiens ambiens.
Calligrapha alni
Russet Alder Leaf Beetle
Calligrapha alni, the russet alder leaf beetle, is a leaf beetle in the family Chrysomelidae found in North America. The common name indicates an association with alder (Alnus spp.), though specific host plant details are limited in available sources. Like other members of the genus Calligrapha, it likely exhibits high host specificity, a trait characteristic of this northeastern North American genus.
Chrysomela interrupta
alder leaf beetle
Chrysomela interrupta, the alder leaf beetle, is a leaf beetle in the family Chrysomelidae found in North America. It is one of several species in the genus Chrysomela associated with woody host plants. The species is documented in entomological records and citizen science observations, though detailed biological studies appear limited in the accessible literature.
Corythucha heidemanni
alder lace bug
Corythucha heidemanni, commonly known as the alder lace bug, is a species of lace bug in the family Tingidae. It is native to North America and has been documented across Canada and the United States. Like other lace bugs, it is a small, sap-sucking true bug with distinctive lacy wings. The species is associated with alder trees (Alnus spp.), though specific ecological details remain limited in published literature.
Corythucha pergandei
Alder Lace Bug
Corythucha pergandei, commonly known as the alder lace bug, is a species of true bug in the family Tingidae. It is native to and distributed throughout North America, with records from both Canada and the United States. Like other lace bugs, it is a sap-feeding insect that typically inhabits the undersides of leaves. The species is associated with alder (Alnus) as its primary host plant, from which it derives its common name. As with other members of the genus Corythucha, it likely causes characteristic white stippling damage on foliage through its piercing-sucking mouthparts.
Cyclophora pendulinaria
sweetfern geometer moth, pearly-grey wave
A small geometrid moth with wingspan 17–26 mm, found across much of North America from Newfoundland to the Yukon and south to Georgia. Adults are active from spring through fall, with larvae feeding on sweetfern (Comptonia) and alder (Alnus) leaves. The species inhabits moist to mesic forests.
Enargia decolor
Pale Enargia, Aspen Twoleaf Tier Moth
A noctuid moth with boreal-transcontinental distribution across North America, primarily associated with trembling aspen and related poplar species. Adults are active in late summer, with larvae capable of reaching outbreak densities that cause extensive defoliation of host stands. The species shows a disjunct western distribution pattern that may represent cryptic diversity.
Eriocampa
woolly sawflies
Eriocampa is a small Holarctic genus of sawflies in the family Tenthredinidae comprising approximately five to ten described extant species. The genus is characterized by larvae that produce conspicuous white waxy secretions, giving them a woolly appearance that likely serves as a defense against predators and parasitoids. Several species are economically significant as defoliators of woody plants, including Eriocampa juglandis (butternut woollyworm) on walnut and hickory, and Eriocampa ovata (woolly alder sawfly) on alder. The genus has a debated taxonomic history, with various classifications placing it in different subfamilies within Tenthredinidae.
Eriocampa ovata
alder sawfly, woolly alder sawfly
Eriocampa ovata is a sawfly in the family Tenthredinidae, native to Europe and introduced to North America. Females reproduce primarily by parthenogenesis; males are unknown in North America and rare in Europe. The species is notable for its distinctive woolly larvae that feed on alder leaves.
Euceraphis gillettei
American Alder Aphid
Euceraphis gillettei, commonly known as the American Alder Aphid, is a North American aphid species in the family Aphididae. It belongs to the genus Euceraphis, which comprises aphids associated with alder trees (Alnus spp.). The species was described by Davidson in 1915 and is distinguished from its congener Euceraphis punctipennis primarily by geographic distribution and host preferences.
Eupristocerus
Eupristocerus is a monotypic genus of jewel beetles (family Buprestidae) containing the single species Eupristocerus cogitans. The genus is classified within the tribe Coraebini, a group of buprestids characterized by their association with woody host plants. Eupristocerus cogitans is notable as the only coraebine buprestid known from North America north of Mexico.
Eupristocerus cogitans
Alder Gall Buprestid
Eupristocerus cogitans is a jewel beetle (family Buprestidae) and the only North American representative of the coraebine buprestids. It is commonly known as the Alder Gall Buprestid due to its larval association with alder trees (Alnus spp.). The species has been recorded from eastern Canada and the northeastern United States.
Fenusa dohrnii
European alder leafminer
Fenusa dohrnii is a sawfly species in the family Tenthredinidae, commonly known as the European alder leafminer. The species is native to Europe and has been introduced to North America, with records from Canada. As a leafminer, its larvae feed internally within leaf tissue, creating distinctive mines on alder leaves.
Hemichroa crocea
striped alder sawfly, banded alder sawfly
Hemichroa crocea is a sawfly species in the family Tenthredinidae, commonly known as the striped alder sawfly or banded alder sawfly. The species is likely native to Europe and has been introduced to North America, where it is actively expanding its range. It is notable for having two generations per year and for the gregarious feeding behavior of its larval stage on alder foliage.
Heterarthrus
Heterarthrus is a genus of sawflies in the family Tenthredinidae. Species occur in Eurasia and North America. The genus includes leafmining species that feed on trees in the family Betulaceae. Heterarthrus vagans, a Palaearctic species, has been introduced to southwestern British Columbia, Canada, where it mines leaves of native red alder.
Isochnus flagellum
Isochnus flagellum is a small weevil in the family Curculionidae, tribe Rhamphini. The species was originally described as Orchestes flagellum by Erichson in 1902. It is known from high-latitude regions of North America including Alaska, Yukon Territory, and Northwest Territories. As a member of the genus Isochnus, it belongs to a group of leaf-mining weevils associated with birch and alder foliage.
Phyllonorycter incanella
Phyllonorycter incanella is a micro-moth in the family Gracillariidae, known from scattered locations in western and eastern North America. Adults have a wingspan of approximately 9 mm. The species is a leaf miner, with larvae feeding on alder species.
Prociphilus tessellatus
Woolly Alder Aphid, Maple Blight Aphid
Prociphilus tessellatus, commonly known as the woolly alder aphid, is a species of aphid in the family Aphididae. It is notable for producing dense white, waxy filaments that cover its body, giving it a distinctive woolly or cloud-like appearance. The species has been observed forming colonies on alder (Alnus) species, including European alder (Alnus glutinosa). It serves as prey for various predators, including the Asian lady beetle (Harmonia axyridis). The waxy secretions are believed to provide protection against predators and environmental conditions.
Pterocallis
Alder Aphids
Pterocallis is a genus of aphids in the family Aphididae, tribe Pterocallidini. Species in this genus are associated with alder trees (Alnus spp.) as their primary hosts. The genus occurs across Europe, Northern America, and New Zealand. The most studied species, Pterocallis alni, feeds on common alder (Alnus glutinosa) and exhibits temperature-driven population dynamics.
Saperda obliqua
Alder Borer
Saperda obliqua is a longhorn beetle in the family Cerambycidae, described by Thomas Say in 1826. It is commonly known as the Alder Borer due to its association with alder trees (Alnus spp.). The species occurs in Canada and the United States, with its southwestern distributional limit in Missouri.
Stigmella undescribed-species-on-alnus
An undescribed species of pygmy moth in the genus Stigmella, recognized by its association with alder (Alnus) as a host plant. The species has been documented as a leafminer on alder but has not yet received a formal scientific name. As a member of the Nepticulidae, it is part of a diverse family of minute moths whose larvae create distinctive mines in leaves.