Invasive-species-associate
Guides
Agonopterix alstroemeriana
Poison hemlock moth, Hemlock moth, Defoliating hemlock moth
Agonopterix alstroemeriana, commonly known as the poison hemlock moth, is a small moth in the family Depressariidae. Native to the Palearctic region, it was accidentally introduced to North America in 1973 and has since established across the contiguous United States. The species is a specialist herbivore exclusively associated with Conium maculatum (poison hemlock), a highly toxic plant containing piperidine alkaloids. Its larval feeding can cause significant defoliation of host plants.
Ctenocallis setosa
Ctenocallis setosa is a small aphid species native to Europe, adventive in North America, and recently detected in Japan (2017–2018, 2023–2024) as the first record for Asia. It is tightly associated with Cytisus scoparius (scotch broom), a naturalized invasive shrub. The species exhibits a monoecious holocyclic life cycle with sexual morphs produced in fall for overwintering eggs and no summer host alternation.
Phytomyza sempervirentis
English Holly Leafminer
Phytomyza sempervirentis is a leaf-mining fly in the family Agromyzidae. The species was described in 2018 and is associated with Ilex species, including English holly (Ilex aquifolium). Larvae create serpentine mines within holly leaves, feeding between the upper and lower epidermis. Adults are small black flies that emerge in spring to coincide with the production of tender new leaves.
Sarcophaga aldrichi
Friendly Fly, Large Flesh Fly
Sarcophaga aldrichi is a parasitoid flesh fly commonly known as the friendly fly or large flesh fly. It is a specialized parasitoid of the forest tent caterpillar (Malacosoma disstria), depositing live larvae into host cocoons where they consume the pupating caterpillars. The species exhibits distinctive delayed population dynamics, with outbreaks occurring one year after peak host caterpillar abundance. Adults are frequently encountered in large numbers during outbreak years, sometimes becoming a nuisance to humans despite being harmless.