Alfalfa
Guides
Agromyza frontella
alfalfa blotch leafminer
Agromyza frontella, the alfalfa blotch leafminer, is a small dipteran leafminer in the family Agromyzidae. Native to Europe, it has become an established agricultural pest of alfalfa (Medicago sativa) in North America, particularly in Canada and the northern United States. Larvae feed between leaf surfaces, creating distinctive blotch-shaped mines. The species exhibits sexual dimorphism in daily activity patterns, with males most active during cooler morning and evening periods while females feed and oviposit throughout the day. It has been subject to classical biological control using the introduced parasitoid Dacnusa dryas.
Empoasca fabae
potato leafhopper
Empoasca fabae, commonly known as the potato leafhopper, is a small, lime-green leafhopper native to North America and a significant agricultural pest. It migrates northward annually from Gulf States to the Midwest and eastern United States, causing damage to over 200 plant species. The species feeds on plant sap and injects a toxin that causes 'hopperburn'—characteristic drying, curling, and rotting of plant tissues. Climate warming has been linked to earlier arrival dates (approximately 10 days earlier than in the 1950s) and more severe infestations in warmer years. It completes one to two generations per year in northern regions like Québec, with population peaks occurring in June-July.
Florilegus condignus
Worthy Longhorn
Florilegus condignus is a long-horned bee in the family Apidae, commonly known as the Worthy Longhorn. It is an uncommon species distributed across the Caribbean, Central America, and North America. The species is notable for its ecological importance as a pollinator of alfalfa and its association with wetland habitats containing pickerelweed.
Hypera brunnipennis
Egyptian alfalfa weevil
Hypera brunnipennis, commonly known as the Egyptian alfalfa weevil, is a true weevil in the family Curculionidae. It is a significant agricultural pest of alfalfa (Medicago sativa) in certain regions, particularly in parts of the Middle East and North Africa. The species has been subject to biological control research focusing on its natural enemies, including parasitoid wasps and predatory insects. Its scientific name is frequently misspelled as 'brunneipennis' in the literature.
Hypera postica
Alfalfa Weevil
Hypera postica, the alfalfa weevil, is a small curculionid beetle native to Europe and a major pest of alfalfa in North America following accidental introductions. Adults measure 4–5.5 mm and are brown with a dark mid-dorsal stripe; larvae are yellowish-green with a black head and white dorsal stripe, reaching about 1 cm before pupation. The species causes significant economic damage through larval skeletonization of alfalfa foliage, with yield reductions up to 15%. Multiple biological control agents, particularly parasitoid wasps in the genus Bathyplectes, have been introduced to manage populations.
Lygus punctatus
plant bug
Lygus punctatus is a species of plant bug in the family Miridae. It reaches a body length of approximately 6–7 mm. The species has a broad distribution across Europe, Northern Asia (excluding China), North America, and Southern Asia. Adults have been recorded in high abundance on alfalfa (Medicago sativa).
Megachile rotundata
Alfalfa Leafcutter Bee, Alfalfa Leaf-Cutter Bee, Leafcutter Bee
Megachile rotundata is a solitary leafcutting bee native to Europe and the Mediterranean region, now widely established as a managed pollinator across North America and other continents. It is the second most important commercial pollinator globally after the honey bee, specifically renowned for its efficiency in alfalfa pollination. Females construct individual nests in pre-existing cavities, lining cells with precisely cut circular leaf pieces. The species is non-aggressive, does not produce honey, and has been introduced deliberately and accidentally to multiple regions for agricultural pollination services.
Nabis roseipennis
sculpted damsel bug, damsel bug
Nabis roseipennis is a small predatory true bug in the family Nabidae, commonly known as the sculpted damsel bug. It is one of the most abundant damsel bugs in cotton and soybean agroecosystems across the southeastern United States. The species is univoltine, with adults active from mid-July through September, and functions as a generalist predator of various agricultural pests. It has been extensively studied for its role in biological control and its tritrophic interactions with resistant crop plants.
Nomia melanderi
alkali bee, Alkali Nomia
Nomia melanderi, commonly known as the alkali bee, is a solitary ground-nesting bee native to the western United States. It is the world's only intensively managed ground-nesting bee, commercially cultivated for alfalfa pollination. The species nests in dense aggregations in moist, alkaline soils and exhibits traits that preceded insect sociality, including defense of offspring against pathogens and predators.
Nomophila nearctica
Lucerne Moth, Clover Nomophila, False Webworm, Celery Stalkworm, American Celery Webworm
Nomophila nearctica is a crambid moth with broad distribution across North America and southward into the Neotropics. Adults are active from spring through late autumn. The species is notable for its narrow, elongated wing profile and association with low-growing herbaceous vegetation. Larvae feed on a range of plants including grasses, legumes, and celery, making it occasionally significant in agricultural contexts.
Plebejus icarioides pembina
Plebejus icarioides pembina is a subspecies of butterfly in the family Lycaenidae, historically classified within the genus Plebejus. It is currently recognized as a synonym of Cupido pembina according to GBIF taxonomy. The subspecies was described by W.H. Edwards in 1862. It represents a disjunct population of the Melissa blue complex, with the type locality in North Dakota. The species to which it belongs has been studied for its colonization of alfalfa and associated ecological interactions across the Great Basin region.
Sitona cylindricollis
sweetclover weevil
Sitona cylindricollis, the sweetclover weevil, is a broad-nosed weevil in the family Curculionidae. It is a documented agricultural pest of sweet clover (Melilotus officinalis) and alfalfa/lucerne (Medicago sativa). Adults feed on above-ground foliage, causing defoliation damage that is most severe during late summer critical periods. Larvae feed on root nodules and root tissue underground. The species exhibits temperature- and light-dependent dispersal flight behavior, with peak flight activity occurring in morning hours when ambient temperatures reach threshold levels.
Sitona hispidulus
Clover Root Curculio, Clover Weevil
Sitona hispidulus, the clover root curculio, is a weevil species native to Europe that has been introduced to Asia and North America. The larval stage is the most damaging, feeding cryptically underground on root nodules and taproots of legumes, particularly alfalfa and clovers. Adults feed on foliage with minimal damage. The species has been overlooked as a pest for decades but causes chronic issues including reduced stand establishment, shortened stand life, and increased winterkill in forage systems. Population levels are limited by availability of root nodules for early instars and taproot biomass for later instars.
Sitona lineellus
alfalfa curculio
Sitona lineellus, commonly known as the alfalfa curculio, is a broad-nosed weevil in the family Curculionidae. The species is found in North America, with distribution records from Canada (Alberta, British Columbia) and the United States. It is associated with alfalfa and legume crops, though specific ecological details remain limited in published literature. Two subspecies are recognized: S. l. crinitoides and S. l. samniticus.
Spissistilus
Three-cornered alfalfa hopper (for S. festinus)
Spissistilus is a genus of treehoppers (family Membracidae) native to North and Central America and the West Indies. The genus was erected by John S. Caldwell in 1949, with Membracis festina (now Spissistilus festinus) as the type species. The genus contains eight recognized species, with S. festinus being the most economically significant due to its status as a major agricultural pest.
Therioaphis
Therioaphis is a genus of aphids in the family Aphididae comprising more than 20 described species. The genus includes significant agricultural pests, notably the spotted alfalfa aphid (Therioaphis maculata, also treated as T. trifolii forma maculata) and the yellow clover aphid (Therioaphis trifolii), which infest alfalfa, clovers, and related legumes. These species have been extensively studied for biological control, host plant resistance, and their role as vectors of plant pathogens including alfalfa mosaic virus.
Therioaphis trifolii
yellow clover aphid, spotted alfalfa aphid
Therioaphis trifolii is a phloem-feeding aphid and major agricultural pest of alfalfa (Medicago sativa) and clover species (Trifolium spp.). The species exhibits significant intraspecific variation, with distinct biotypes showing host-specific adaptations: the spotted alfalfa aphid (SAA) primarily colonizes Medicago species, while the spotted clover aphid (SCA) specializes on Trifolium. Native to the western Palaearctic, it has established globally including Australia, North America, and parts of Asia. The species manipulates host plant defense pathways through salivary secretions, activating salicylic acid signaling while suppressing jasmonic acid responses to improve host suitability.