Elm
Guides
Aceria campestricola
Elm Leaf Gall Mite
Aceria campestricola is a gall-forming eriophyid mite that induces small pouch-like galls on elm leaves. First described in 1865, this microscopic arachnid overwinters in bark crevices before emerging in spring to attack new foliage. The species exhibits complex taxonomic history with related forms previously described under separate names based on gall morphology.
Acronicta rubricoma
Hackberry Dagger, ruddy dagger moth
Acronicta rubricoma, commonly known as the Hackberry Dagger or ruddy dagger moth, is a noctuid moth found in eastern and central North America. The species has a wingspan of 38–44 mm. Adults are active from April to October with two generations per year. The larvae feed on elm, hackberry, and sumac.
Aproceros
Aproceros is a genus of sawflies in the family Argidae, comprising ten recognized species native to eastern Asia. The genus gained international attention following the introduction of Aproceros leucopoda (elm zigzag sawfly) to Europe around 2003 and subsequently to North America in 2020. This invasive species has demonstrated rapid range expansion and significant defoliation capacity on elm trees (Ulmus spp.). Most Aproceros species remain restricted to their native East Asian ranges, with limited biological information available for the genus beyond A. leucopoda.
Arge scapularis
elm argid sawfly
Arge scapularis, commonly known as the elm argid sawfly, is a sawfly species in the family Argidae found across North America. It is a specialist herbivore that commonly infests elm trees (Ulmus spp.). The species name 'scapularis' refers to distinctive shoulder blade-like structures on the insect's thorax. As a member of the suborder Symphyta, it lacks the narrow 'wasp waist' characteristic of many other Hymenoptera.
Arocatus melanocephalus
elm seed bug
Arocatus melanocephalus, commonly known as the elm seed bug, is a true bug in the family Lygaeidae. Native to Europe, it has been introduced to North America in the 2000s and has become a notable nuisance pest in urban areas. The species is distinguished by its dark red body, black head, and characteristic M-shaped spot on the pronotum. Adults produce a strong, unpleasant odor reminiscent of bitter almonds from metathoracic scent glands. Unlike many Lygaeinae species, it has limited ability to store cardenolides.
Cameraria ulmella
Elm Leafminer
A minute leaf-mining moth in the family Gracillariidae, measuring 6.5–7 mm in wingspan. The species produces distinctive flat mines on the upper leaf surfaces of oak and elm trees. It exhibits bivoltine development with distinct seasonal broods that differ in overwintering strategy.
Ceratomia amyntor
Elm Sphinx, Four-horned Sphinx
Ceratomia amyntor is a North American hawkmoth with a wingspan of 8.2–11.5 cm. Larvae feed primarily on elm but also use birch, basswood, and cherry. The species is notable for its four head horns—additional to the caudal horn typical of sphingids—giving rise to the common name "four-horned sphinx." Adults are gray-brown with wavy forewing markings and a small white dot characteristic of the genus. The species has one generation in northern regions and up to five broods in the southern United States.
Colopha
Colopha is a genus of gall-forming aphids in the family Aphididae, first described by Monell in 1877. Species in this genus induce distinctive galls on host plants, most notably the elm cockscomb gall on American elm. The genus exhibits complex life cycles involving host alternation between woody plants and grasses, with both bisexual and unisexual reproductive strategies documented across species.
Colopha ulmicola
Elm Cockscomb Gall Aphid
Colopha ulmicola is an aphid species that induces distinctive cockscomb-shaped galls on American elm leaves. It has a complex life cycle involving alternation between elm hosts and grass roots, with parthenogenetic reproduction within galls and sexual reproduction producing winged migrants that return to elm in autumn. The species is notable for its dramatic seasonal aerial migrations and its ability to manipulate plant development through chemical secretions.
Eriosoma americanum
Woolly Elm Aphid
Eriosoma americanum, commonly known as the woolly elm aphid, is a North American aphid species that alternates between two host plants: American elm (Ulmus americana) and Saskatoon (Amelanchier alnifolia). The species produces distinctive woolly or cottony wax secretions that give it its common name. Heavy infestations on American elm cause leaf curling and produce visible dark patches and cottony masses. Like other aphids, it excretes honeydew while feeding on plant sap.
Janetiella ulmii
Janetiella ulmii is a gall midge species in the family Cecidomyiidae, first described by Beutenmüller in 1907. The species is associated with elm trees (Ulmus), as indicated by its specific epithet. Gall midges in this genus are known for inducing plant galls, though specific details about the gall morphology and biology of J. ulmii remain poorly documented in available literature.
Magdalis armicollis
Red Elm Bark Weevil
Magdalis armicollis is a bark weevil in the family Curculionidae, commonly known as the red elm bark weevil. The species is strongly associated with elm trees (Ulmus), with larvae developing within wood and adults feeding on foliage. It occurs across eastern and central North America. The common name refers to its association with red elm (Ulmus rubra).
Orchestes mixtus
Orchestes mixtus is a weevil species in the family Curculionidae, first described by Blatchley and Leng in 1916. The species is recorded from multiple Canadian provinces including Alberta, British Columbia, Manitoba, New Brunswick, and Nova Scotia. As a member of the genus Orchestes, it belongs to a group of small weevils commonly known as elm leaf weevils or flea weevils, many of which are associated with elm trees.
Phyllonorycter argentinotella
Golden Elm Leafminer
Phyllonorycter argentinotella is a micro-moth in the family Gracillariidae, commonly known as the Golden Elm Leafminer. It is a leaf-mining species whose larvae feed on elm leaves (Ulmus species), creating characteristic blotch mines. The species occurs in eastern North America, from Québec south through the northeastern and midwestern United States. Adults are small, with a wingspan of 6.5–8 mm.
Phyllonorycter occitanica
Phyllonorycter occitanica is a micro-moth in the family Gracillariidae, known from Texas, United States. The larvae are leaf miners that feed on elm species (Ulmus), specifically Ulmus fulva and Ulmus rubra. Like other members of its genus, it produces characteristic blotch mines on the leaves of its host plants. The species was described by Frey and Boll in 1876.
Tautoneura
Tautoneura is a genus of leafhoppers in the family Cicadellidae, subfamily Typhlocybinae, tribe Erythroneurini, established by Anufriev in 1969. The genus is native to the eastern Palearctic and Indo-Malay region, with T. polymitusa being the first species recorded in Europe, where it has established adventive populations. Species in this genus are small, slender insects associated with trees in the family Ulmaceae.
Tetraneura nigriabdominalis
Tetraneura nigriabdominalis is a holocyclic, heteroecious gall-forming aphid native to East Asia that has expanded its range globally and is now established in Europe and North America. The species alternates between primary hosts (elm trees, genus Ulmus) and secondary hosts (roots of grasses in the family Poaceae, including maize). On elms, fundatrices induce characteristic galls on leaves, with development rates and fecundity strongly influenced by spring temperatures. The species has been documented as a potential agricultural pest due to its association with cultivated maize.
Tinocallis ulmiparvifoliae
elm aphid
Tinocallis ulmiparvifoliae is a small aphid species in the family Aphididae, originally described by Matsumura in 1919. It belongs to the genus Tinocallis, a group of eight species primarily associated with Ulmaceae (elm family). The species is a specialist herbivore feeding on elm foliage. It has been recorded from Europe (Spain, Italy, Great Britain) and the United States.
Trachys minutus
elm leaf miner
Trachys minutus is a small jewel beetle (Buprestidae) measuring 3–3.5 mm in length. It is native to Europe and the eastern Palearctic region and has been introduced to North America, where it is established in Massachusetts. The species is notable for its leaf-mining larvae, which feed on the mesophyll of elm leaves. Females oviposit directly on leaf surfaces, and the resulting larvae create characteristic blotch mines. Two subspecies are recognized: T. m. minutus and T. m. salicis.