Emerging-pest
Guides
Cedusa vulgaris
blue Derbid planthopper
Cedusa vulgaris is a planthopper in the family Derbidae, commonly known as the blue Derbid planthopper. First described by Fitch in 1851, this species is native to North America but has been recently documented as an emerging pest in Indian grape vineyards since May 2024. Adults feed on phloem sap of grape plants through piercing-sucking mouthparts. The species belongs to a group of planthoppers often characterized by distinctive coloration and association with woody host plants.
Chaetocnema minuta
Chaetocnema minuta is a Nearctic flea beetle in the subfamily Alticinae. Historically associated with grasses, it has been recently documented causing economic damage to turfgrass in the southwestern United States, including perennial ryegrass and hybrid bermudagrass. The species is among the smallest flea beetles in North America, with adults measuring approximately 1–1.6 mm in length.
Curculio obtusus
Hazelnut Weevil
Curculio obtusus, commonly known as the hazelnut weevil, is a species of true weevil in the family Curculionidae. It is native to eastern North America and is one of four globally recognized hazelnut-feeding weevil species in the genus Curculio. The species is considered the most understudied of the hazelnut-feeding Curculio species, as commercial hazelnut production was historically not possible in its geographic range until the development of cold-hardy and disease-resistant hybrid hazelnut plants. It is expected to pose increasing economic concerns as hybrid hazelnut production expands in the United States.
Euschistus variolarius
one-spotted stink bug, onespotted stink bug
Euschistus variolarius, commonly known as the one-spotted stink bug, is a Nearctic species of shield bug in the family Pentatomidae. It is a phytophagous insect that feeds primarily on seeds and developing fruits of various plants, including legumes, grasses, and agricultural crops such as soybean and alfalfa. The species produces one generation per year in northern parts of its range, with adults overwintering in ground debris and emerging in spring to reproduce. While historically considered a minor pest, it has become increasingly recognized as an emerging pest in Midwestern soybean and corn production.
Leptodictya plana
Grass Lacebug
Leptodictya plana is a grass-feeding lace bug (Hemiptera: Tingidae) first described in 1913. It has been documented as an emerging pest on ornamental grasses in the southern United States, with Pennisetum species showing particular susceptibility to feeding damage and serving as oviposition hosts. The species remains seldom collected despite its economic relevance to horticulture.
Macrosaccus morrisella
hog peanut moth, soybean tentiform leafminer
Macrosaccus morrisella is a small leaf-mining moth in the family Gracillariidae, native to North America. Historically associated with native legumes including American hogpeanut and slickseed fuzzybean, it has recently expanded its host range to include soybean, with first reports from Quebec in 2016 and Minnesota in 2021. The species is notable for its hypermetamorphic larvae that produce distinctive serpentine-to-blotch-to-tentiform leaf mines, and its emergence as a potential agricultural pest of a major commodity crop.
Nepytia janetae
Nepytia janetae is a geometrid moth species that has transitioned from an innocuous, poorly studied insect to a significant forest pest in the southwestern United States. Since 1996, four major outbreaks have caused extensive defoliation and mortality of conifer trees across tens of thousands of acres in Arizona and New Mexico mountain ranges. The species exhibits an unusual life history as a univoltine, autumn- and winter-feeding looper at high elevations where temperatures regularly approach or fall below 0°F. Outbreaks appear associated with reduced snowpack, though the precise climatic mechanisms remain unclear.
Nepytia janetae
Janeta's looper moth
Nepytia janetae is a geometrid moth in the family Geometridae native to southwestern United States mountain ranges. Prior to 1996, it was an inconspicuous species with little ecological impact. Since 1996, four major outbreaks have caused extensive defoliation of conifer forests across Arizona and New Mexico, killing tens of thousands of acres of trees. The species exhibits an unusual winter-feeding larval stage, active when minimum temperatures approach or drop below 0°F. Outbreak termination occurs primarily through parasitism, viral infection, larval starvation, and occasionally heavy rain during egg deposition.
Pagiocerus frontalis
Pagiocerus frontalis is an invasive bark beetle in the family Curculionidae, subfamily Scolytinae, native to Central and South America. First detected in Africa in December 2018 in Arusha, Tanzania, it has emerged as a significant pest of stored maize and avocado seeds. The beetle bores into grains, producing powdery frass and exit holes, and can perforate woven polypropylene storage bags. Laboratory studies in Tanzania demonstrated substantial damage across 27 maize varieties, with grain damage ranging from 42.5% to 92.5%. Its invasion pattern and damage potential resemble those of the larger grain borer (Prostephanus truncatus), which caused severe losses following its introduction to Africa.
Pentastiridius
Pentastiridius is a genus of planthoppers in the family Cixiidae with nearly cosmopolitan distribution. The genus includes at least three described species, with P. leporinus emerging as a significant agricultural pest in central Europe. This species vectors two bacterial pathogens causing syndrome "basses richesses" in sugar beet and related diseases in potato and carrot. Originally associated with reed grass (Phragmites australis), P. leporinus has undergone rapid host range expansion to become polyphagous on crops.
Polyphagotarsonemus latus
Broad Mite, Yellow Tea Mite, Citrus Silver Mite
Polyphagotarsonemus latus, commonly known as the broad mite, is a microscopic tarsonemid mite with a cosmopolitan distribution and an exceptionally broad host range spanning over 60 plant families. First described from mango in a Washington, D.C. greenhouse in 1904, it has become a significant agricultural pest affecting crops including cotton, soybean, peppers, strawberries, blackberries, citrus, tea, coffee, and increasingly, cannabis and hemp. The mite feeds on young, tender plant tissues, causing characteristic damage including leaf stunting, twisting, and distortion that resembles auxin herbicide injury. It thrives in greenhouse environments and tropical to subtropical climates, with development occurring between 10–36°C at high humidity. Management relies on acaricides and biological control using predatory mites such as Amblyseius swirskii, Neoseiulus californicus, and A. orientalis.
Resseliella
Resseliella is a genus of gall midges in the family Cecidomyiidae containing at least 50 described species. The genus includes economically significant agricultural pests, notably R. maxima (soybean gall midge) which threatens soybean production in the north-central United States, as well as R. citrifrugis, a major citrus pest in China, and R. theobaldi (raspberry cane midge), an important pest of cultivated red raspberry in Europe. Some species exhibit mutualistic relationships with plants, such as R. kadsurae which pollinates Kadsura longipedunculata in China.
Suleima helianthana
sunflower bud moth
Suleima helianthana, commonly known as the sunflower bud moth, is a tortricid moth species native to central North America. The species is a specialist pest of sunflowers (Helianthus spp.), with larvae that tunnel into stalks and buds. Two generations occur annually. While historically documented on cultivated and wild sunflowers, the species was first recorded on Jerusalem artichoke (Helianthus tuberosus) in California's San Joaquin Valley in 2024, representing an emerging pest situation for small-farm producers.