Bt-resistance
Guides
Chloridea
Chloridea is a genus of owlet moths in the family Noctuidae, subfamily Heliothinae. The genus was reinstated as valid in 2013 based on molecular and morphological research, having previously been considered a synonym of Heliothis. It contains at least three described species, including the agriculturally significant Chloridea virescens (tobacco budworm moth). The taxonomic status of Chloridea remains contested, with some sources continuing to treat it as a synonym of Heliothis.
Chloridea virescens
Tobacco Budworm Moth, Tobacco Budworm
Chloridea virescens, the tobacco budworm moth, is a noctuid moth native to the Americas and a major agricultural pest. The species was transferred from genus Heliothis to Chloridea in 2013 based on genetic and morphological evidence. Adults are brownish with green tinge and distinctive wing banding. Larvae feed on buds, blossoms, and fruit of diverse host plants, causing significant crop damage. The species has developed rapid resistance to multiple insecticide classes, making management challenging.
agricultural-pestnoctuidaetobacco-pestcotton-pestinsecticide-resistanceBt-resistanceNorth-AmericaSouth-Americacomplete-metamorphosisparasitoid-hostpheromone-communicationhost-plant-preferencematernal-effecttemperature-dependent-developmentsoil-pupationdiapausecannibalismlarval-defense-behaviorintegrated-pest-managementsterile-insect-techniquetransgenic-crop-targetHeliothisChlorideaLepidopteraowlet-mothbudwormbollworm-complexCrocidosema
Crocidosema is a genus of tortrix moths in the family Tortricidae, tribe Eucosmini, subfamily Olethreutinae. The genus contains approximately 29 described species, distributed primarily in the Southern Hemisphere with particular abundance in the Neotropics. Some species occur in other regions, including the Hawaiian Islands. The genus includes both agricultural pests and species used in biological control.
Diabrotica virgifera
Western corn rootworm, Mexican corn rootworm
Diabrotica virgifera is a species of leaf beetle in the family Chrysomelidae, comprising two subspecies: D. v. virgifera (western corn rootworm) and D. v. zeae (Mexican corn rootworm). Both subspecies are significant agricultural pests of maize (Zea mays), with larvae feeding on corn roots and adults feeding on silks, pollen, and leaves. The species has been responsible for substantial economic damage to corn production, with estimates of $1 billion annually in yield losses and control costs in North America. The western corn rootworm has shown remarkable adaptive capacity, having evolved resistance to multiple management strategies including crop rotation and Bt toxins.
Diabrotica virgifera zeae
Mexican corn rootworm
Diabrotica virgifera zeae, the Mexican corn rootworm, is a subspecies of the western corn rootworm complex and a significant agricultural pest of corn (Zea mays) in Mexico and parts of the southern United States. Larvae feed on corn roots, causing damage that can lead to reduced yield, stunting, and plant lodging. Unlike the western corn rootworm subspecies (D. v. virgifera), the Mexican corn rootworm has been documented to damage corn following sorghum rotation in parts of South Central Texas, though this remains rare. Adults feed on corn silks, pollen, and leaves. The species has one generation per year, with eggs laid in soil during summer and fall, hatching the following spring when corn roots become available.
Helicoverpa
Heliothine moths, bollworms, earworms
Helicoverpa is a genus of noctuid moths established by David F. Hardwick in 1965. Several species rank among the world's most destructive agricultural pests, particularly H. armigera (cotton bollworm), H. zea (corn earworm/cotton bollworm), and H. punctigera. These species exhibit long-distance migration capabilities, with H. armigera recently expanding from the Old World into the Americas and threatening to establish in the continental United States. The genus is notable for rapid evolution of insecticide resistance, including documented introgression of resistance genes between sibling species H. zea and invasive H. armigera.
Mythimna unipuncta
true armyworm moth, white-speck moth, common armyworm, rice armyworm
Mythimna unipuncta is a migratory noctuid moth found across North America, South America, Europe, Africa, and Asia. Larvae feed on grasses and cereal crops, causing significant agricultural damage during outbreaks. Adults are nocturnal and nectivorous, feeding on flower nectar and ripe or decaying fruit. The species exhibits seasonal migration, traveling north in spring and south in fall to optimize mating conditions. Larvae display characteristic armyworm behavior, moving en masse between fields when food sources are depleted.
Plutella xylostella
diamondback moth, cabbage moth
Plutella xylostella is a globally distributed moth species and one of the most economically significant agricultural pests worldwide. The small grayish-brown moth derives its common name from the cream-colored band that forms a diamond pattern along its back. Its larvae feed exclusively on cruciferous plants, causing extensive damage to cabbage, broccoli, cauliflower, canola, and other Brassica crops. The species has evolved resistance to nearly every class of insecticide, including Bacillus thuringiensis toxins, making it exceptionally difficult to control. Annual global management costs are estimated at $4–5 billion.
Rachiplusia
sunflower looper (R. nu)
Rachiplusia is a genus of moths in the family Noctuidae, subfamily Plusiinae, containing at least four species distributed across the Americas. The most economically significant species is Rachiplusia nu, known as the sunflower looper or "oruga medidora del girasol," which has emerged as a major pest of soybean and sunflower in South America. Larvae of this genus are characterized by the looping locomotion typical of Plusiinae, resulting from having only three pairs of prolegs. The genus was revised taxonomically by Barbut in 2008, clarifying species boundaries and distributions.
Spodoptera
Armyworm Moths
Spodoptera is a genus of noctuid moths comprising approximately 30 species distributed across six continents. The larvae are commonly known as armyworms and include some of the most destructive agricultural pests worldwide. Several species, including the fall armyworm (S. frugiperda), beet armyworm (S. exigua), and cotton leafworm (S. littoralis), cause significant economic damage to crops. The genus is characterized by specific morphological traits that distinguish it from related noctuid genera.
Spodoptera eridania
Southern Armyworm Moth, Southern Armyworm
Spodoptera eridania is a highly polyphagous noctuid moth whose larvae are significant agricultural pests in tropical and subtropical regions of the Western Hemisphere. The species has emerged as one of the most important armyworm pests of soybean in Brazil and Argentina, particularly in cotton-growing regions, while remaining a sporadic pest in the southern United States. Larvae feed gregariously when young, skeletonizing leaves, and become solitary as they mature, often boring into fruit. The species has been introduced to West Africa (Nigeria and Cameroon).
Spodoptera frugiperda
Fall Armyworm, Fall Armyworm Moth
Spodoptera frugiperda, commonly known as the fall armyworm, is a migratory moth species native to the Americas that has become a devastating invasive pest across Africa and Asia. The larvae are polyphagous, feeding on more than 80 plant species including maize, sorghum, cotton, and soybean. Economic damage from this species has been severe, with estimated losses of $2.5–6.3 billion annually in affected African countries. The species cannot overwinter in temperate regions, reinvading northern areas annually through long-distance migration.
Striacosta
western bean cutworm (for sole species S. albicosta)
Striacosta is a monotypic genus of moths in the family Noctuidae, established by Lafontaine in 2004. The sole species, Striacosta albicosta (western bean cutworm), is an agricultural pest native to North America. The species underwent significant range expansion from the western Great Plains to eastern North America beginning in 1999. Larvae are serious pests of corn and dry bean crops, with documented resistance to Cry1F Bt protein.
Striacosta albicosta
Western Bean Cutworm, Western Bean Cutworm Moth
Striacosta albicosta, the western bean cutworm, is a noctuid moth and sole member of its genus. Historically restricted to the western Great Plains of the United States, it has undergone substantial eastward range expansion since 2000, now occurring throughout the U.S. Corn Belt and into Canada and Mexico. It is a significant agricultural pest of corn and dry beans, with larvae feeding on reproductive structures and causing yield losses up to 40% in corn. The species has developed resistance to Cry1F Bt protein, complicating management in transgenic crops.