Population-genetics
Guides
Acanthophlebia
pronggill mayflies
Acanthophlebia is a genus of mayflies in the family Leptophlebiidae, currently represented by the species Acanthophlebia cruentata. That species is documented from streams across New Zealand’s North Island and has not been collected on the South Island. Research on its populations has found geographic structure in genetic variation across the North Island. Adult size also varies with elevation and genetic region, based on wing-length measurements.
Aphis aurantii
Black Citrus Aphid, Camellia Aphid
Aphis aurantii is an economically significant aphid species known as the Black Citrus Aphid or Camellia Aphid. It is a major pest in commercial tea plantations and gardens in China, where it causes substantial damage to Camellia sinensis. The species exhibits a broad host range across multiple plant families, with documented specialization on Ficus in sympatric populations suggesting ongoing host-associated divergence. Population genetic studies reveal high haplotype diversity across Chinese populations with evidence of recent expansion events and isolation-by-distance patterns.
Cryptolestes ferrugineus
rusty grain beetle, rust-red grain beetle
Cryptolestes ferrugineus, the rusty grain beetle, is a small lined flat bark beetle and major cosmopolitan pest of stored grain products. Native to Europe, it has achieved worldwide distribution through human commerce, infesting stored cereals, grain products, and dry plant materials. The species is characterized by rapid population growth, strong flight capability for dispersal between storage facilities, and cryptic behavior hiding in cracks and crevices. Its economic impact stems from direct feeding damage to grain germ and endosperm, contamination of products, and resistance to some insecticides.
Dicraeus
Dicraeus is a genus of small flies in the family Chloropidae, first described by Loew in 1873. Species within this genus exhibit specialized feeding habits, with some species feeding on bamboo flowers and others developing as seed predators in grasses. The genus shows notable host specificity, with oviposition behavior influenced by host plant morphology such as glume pubescence. Population genetic studies in Japanese species reveal contrasting patterns of genetic structure correlated with host plant flowering phenology.
Euphydryas anicia anicia
Anicia checkerspot, Variable checkerspot
Euphydryas anicia anicia is a subspecies of checkerspot butterfly in the family Nymphalidae. Populations studied at Cumberland Pass, Colorado (elevation 3700 m) numbered 50,000–100,000 individuals, the largest recorded in 19 years of Euphydryas population studies. Adults sequester iridoid glycosides from host plants including Castilleja and Besseya species. Movement distances between recapture events averaged less than 100 meters, though greater than most Euphydryas populations and comparable to more vagile E. chalcedona and E. editha populations.
Hypnoidus bicolor
Bicolour Click Beetle
Hypnoidus bicolor is a click beetle species (Elateridae) found throughout the Canadian Prairies and other parts of the Holarctic region. The species exists as a potential cryptic species complex, with two genetically distinct clades (>4.66% COX1 sequence divergence) identified in prairie populations. Larvae are soil-dwelling wireworms that can damage soybean and other crops, though they are smaller and less destructive than related pest species such as Limonius californicus and Hypnoidus abbreviatus. Population genetic studies indicate uneven gene flow among populations with low regional genetic structuring, and evidence of range expansion coinciding with intensive agricultural practices.
Kaylathalia
Kaylathalia is a genus of isotomid springtails known from the Antarctic species Kaylathalia klovstadi. The species has been recorded in Northern Victoria Land, continental Antarctica. The genus is notable for a taxonomic reassessment that combined morphological, ecological, and molecular evidence, and for population-genetic work on how Antarctic landscape features shape its genetic variation.
Leptoglossus clypealis
western leaf-footed bug
Leptoglossus clypealis, commonly known as the western leaf-footed bug, is a phytophagous true bug native to western North America. Adults measure 18–19 mm in length and are characterized by brown coloration with leaf-like expansions on the hind tibiae and a pale band across the wings. The species has been documented as a pest of agricultural crops, particularly almonds and pistachios, causing kernel damage and fruit drop. Its range has expanded eastward in recent decades, with genetic studies confirming populations in Texas represent native range extensions rather than recent introductions.
Liparus
Liparus is a genus of weevils in the beetle family Curculionidae. Its genus account places the listed species in Europe, while detailed evidence available here concerns particular species rather than the genus as a whole. One studied member, Liparus glabrirostris, illustrates how populations in separate mountain ranges can differ genetically even when researchers found no confirming morphological differences.
Maruca vitrata
legume pod borer, maruca pod borer, bean pod borer, soybean pod borer, mung moth, spotted pod borer
Maruca vitrata is a pantropical moth and major agricultural pest of leguminous crops, particularly affecting cowpea, pigeon pea, mung bean, and soybean. Larvae feed on flower buds, flowers, and young pods, causing yield losses of 20–80% in susceptible cowpea varieties. The species has low genetic differentiation across its range due to high gene flow, with populations in India showing evidence of recent demographic expansion. It serves as host for several parasitoid wasps (Braconidae, Ichneumonidae) and flies (Tachinidae) that provide biological control.
Mecaphesa
crab spiders
Mecaphesa is a genus of crab spiders in the family Thomisidae, first described by Eugène Simon in 1900. The genus contains approximately 49 species distributed across North America, Central America, the Caribbean, South America, and Hawaii. Species exhibit cryptic coloration for ambush predation on flowers.
Metepeira ventura
labyrinth spider
Metepeira ventura is an orb-weaving spider in the family Araneidae, found in the United States and Mexico. Like other members of its genus, it constructs a characteristic web consisting of a small orb web connected to a thimble-like retreat surrounded by a tangled network of lines. A California population has been studied for genetic diversity and its relationship to reproductive fitness.
Ochthebius
minute moss beetles
Ochthebius is a large genus of minute moss beetles in the family Hydraenidae, comprising at least 460 described species. These tiny beetles are predominantly associated with aquatic and semi-aquatic habitats, particularly supratidal rockpools, coastal marshes, and freshwater spray zones. Many species exhibit narrow habitat preferences and restricted distributions, with numerous endemic taxa. The genus shows significant diversity in the Mediterranean region, Africa, and other parts of the world, and includes several cryptic species complexes.
Parisotoma notabilis
elongate-bodied springtail
Parisotoma notabilis is a cosmopolitan, eurytopic springtail in the family Isotomidae and one of the most abundant Collembola species in temperate regions of the northern hemisphere. Despite morphological uniformity, the species comprises six distinct genetic lineages (L0, L1, L2, L3, L4-Saltzwedel, L4-Hebert) with divergence levels approaching species boundaries. It is predominantly parthenogenetic, with males rarely occurring, which facilitates rapid colonization of disturbed habitats. The species is widely used as a model organism for studying soil microarthropod population genetics and serves as a bioindicator for environmental monitoring.
Phacaspis
Phacaspis is a genus of long-legged flies (Dolichopodidae) with four accepted species. The genus is associated with tropical marine shores, especially mudflats at mangrove fronts. A study of P. mitis in southern Thailand found substantial geographic genetic structure, making this small shore fly notable as a subject of population-history research.
Pityogenes
bark beetles
Pityogenes is a genus of bark beetles in the family Curculionidae, comprising over 30 described species distributed across the Northern Hemisphere. Species in this genus are primarily associated with coniferous trees, with P. chalcographus being the most extensively studied due to its economic significance as a pest of Norway spruce. The genus exhibits typical scolytine characteristics including aggregation pheromone communication and specialized host-finding behaviors. Some species demonstrate notable geographic variation in morphology and genetics, suggesting population differentiation across their ranges.
Platycorynus
Platycorynus is a genus of leaf beetles in the family Chrysomelidae and subfamily Eumolpinae. Records and taxonomic accounts place the genus in Africa and Asia. Its best-studied example here is P. peregrinus: a Thai population-genetics study found strong variation among populations and substantial mitochondrial haplotype diversity. That species is also discussed as an agricultural pest, although those findings should not be generalized to every Platycorynus.
Pseudatomoscelis
Pseudatomoscelis is a genus of plant bugs in the family Miridae, established by Poppius in 1911. The genus contains at least four described species, with P. seriatus (cotton fleahopper) being the most economically significant due to its status as a major pest of cotton in the southern United States. Species in this genus are associated with diverse host plants, including both agricultural crops and native wild plants.
Saltonia incerta
Rare sheet-web-weaving spider, sole representative of monotypic genus Saltonia. Restricted to salt crusts of intermittent or dry lakes, streams, and rivers in desert southwestern North America. Previously presumed extinct following 1905 flooding of type locality at Salton Sea, but rediscovered in 1990s at multiple sites. Genetic analyses reveal significant population structure with two major clades (New Mexico versus California-northern Baja California) and minimal gene flow among isolated populations in fragmented desert salt flat habitats.
Scaptomyza graminum
Scaptomyza graminum is a small fly in the family Drosophilidae, originally described from Europe in 1823. The species has been used as a laboratory model for genetic studies, particularly for population genetics and chromosomal research. Wild specimens have been collected from grassy areas, though most biological knowledge derives from laboratory-maintained cultures. Under laboratory conditions at 25°C, development from egg to adult takes approximately 14 days. The species exhibits relatively sluggish behavior compared to Drosophila melanogaster, with reduced flight activity and ease of handling for experimental crosses.
Thyrinteina arnobia
eucalyptus brown looper, brown looper caterpillar
Thyrinteina arnobia is a geometrid moth native to the Americas and a major pest of Eucalyptus plantations in Brazil. The species occurs throughout South America and parts of Central and North America, where it feeds primarily on Myrtaceae, with Eucalyptus serving as a vulnerable host in commercial plantations. Larval infestations can reduce annual Eucalyptus biomass production by up to 40%, making it the primary defoliator of subtropical and tropical Brazilian eucalyptus farms. Population genetic studies indicate low genetic diversity in Brazil with three regional mitochondrial haplogroups, suggesting outbreaks arise from local populations rather than long-distance dispersal.
Trogloneta
spurred orb-weavers
Trogloneta is a genus of minute spurred orb-weavers in the family Mysmenidae, described by Eugène Louis Simon in 1922. The genus currently comprises twelve described species distributed across Europe, East Asia, and the Americas. These spiders are among the smallest known spiders, with some species measuring less than 2 mm in body length. Several species exhibit cave-adapted characteristics and restricted distributions, with some Chinese species showing extreme population genetic divergence due to geographic isolation in karst cave systems.
Tumidagena
Tumidagena is a genus of small, flightless delphacid planthoppers comprising at least three described species. The best-studied species, T. minuta, is a specialist herbivore of the salt marsh grass Spartina patens in eastern North America. Despite being predominantly flightless (>99% of adults), populations exhibit high gene flow and weak genetic differentiation over distances exceeding 400 km, suggesting mechanisms other than adult flight maintain connectivity.
Venturia
scab fungi
Venturia is a genus of ascomycete fungi in the family Venturiaceae, comprising approximately 58 species of plant pathogens that cause scab diseases on economically important Rosaceae crops. The genus includes notable species such as V. inaequalis (apple scab), V. pirina (pear scab), V. aucupariae (sorbus scab), and V. asperata (apple pathogen). These fungi are characterized by their ability to infect leaves, fruits, and twigs, producing characteristic black lesions that reduce crop quality and yield. Genome sequencing has revealed significant transposable element content and population structure variation across host-associated lineages.
Zarhipis
glowworm beetles
Zarhipis is a genus of glowworm beetles in the family Phengodidae, containing three recognized species restricted to western North America. Members of this genus exhibit sexual dimorphism, with females being larviform and bioluminescent while males are winged and non-luminous. The genus has been subject to population genetic studies, particularly for Zarhipis integripennis, revealing significant geographic structure and sex-biased dispersal patterns.