Parthenogenesis
Guides
Naryciinae
Naryciinae is a subfamily of bagworm moths (Psychidae) characterized by monandrous females that mate only once. Females are immobile and wingless, while males are short-lived, non-feeding, and capable of multiple copulations. Several species exhibit parthenogenetic reproduction, including *Dahlica fennicella* and *D. triquetrella*. The subfamily serves as host for a diverse parasitoid wasp complex in northern European populations.
Naupactini
broad-nosed weevils
Naupactini is a diverse tribe of broad-nosed weevils (subfamily Entiminae) with highest genus and species diversity in South America. Members range from 3.5 to 35 mm and exhibit diverse coloration including iridescent scales. The tribe is notable for frequent flightlessness and parthenogenesis in habitats with sparse vegetation, with parthenogenesis linked to Wolbachia bacterial infection. Several species are agricultural pests, particularly on Fabaceae.
Naupactus
White-fringed Weevils
Naupactus is a large genus of weevils in the family Curculionidae, commonly known as white-fringed weevils. The genus comprises exclusively Neotropical species, several of which have been introduced to other regions and become significant agricultural pests. Members of this genus are characterized by reduced humeri and lack of metathoracic wings, traits formerly used to separate them into the genus Graphognathus before taxonomic revision. Some species exhibit parthenogenetic reproduction, and flightless adults are common.
Naupactus leucoloma
white-fringed weevil, white-fringed beetle
Naupactus leucoloma is a broad-nosed weevil native to South America that has become a globally distributed agricultural pest. Adults are flightless, parthenogenetic females outside their native range, with males occurring only rarely in Argentina, Uruguay, and southern Brazil. The species is notable for its extreme polyphagy, having been documented feeding on over 385 plant species. Larval root-feeding causes substantially more economic damage than adult folivory.
Nauphoeta
speckled cockroach, lobster cockroach, cinereous cockroach
Nauphoeta is a monotypic genus of cockroaches in the family Blaberidae, containing the single species Nauphoeta cinerea. The genus is notable for its well-studied social behavior, including male territoriality and dominance hierarchies. Nauphoeta cinerea has become a widely used laboratory model organism for behavioral, physiological, and toxicological research, and has achieved a circumtropical distribution through human-mediated dispersal.
Neocloeon
Neocloeon is a genus of mayflies in the family Baetidae. The species Neocloeon triangulifer has emerged as an important laboratory model organism for aquatic ecotoxicology and physiological studies due to its sensitivity to environmental stressors and ability to complete its life cycle in controlled conditions. The genus is distinguished by parthenogenetic reproduction in at least some populations, a trait that facilitates laboratory culture. Species in this genus inhabit freshwater streams and serve as bioindicators for water quality assessment.
Neodiprion abietis
balsam fir sawfly
Neodiprion abietis, the balsam fir sawfly, is a conifer-feeding sawfly native to North America. Larvae are gregarious defoliators that feed preferentially on balsam fir (Abies balsamea) needles, with outbreaks capable of causing significant tree mortality in eastern Canadian forests. The species exhibits sexual dimorphism in development, with females typically undergoing six instars over 35 days and males five instars over 30 days. Population dynamics are strongly regulated by a host-specific nucleopolyhedrovirus (NeabNPV), which has been developed as a registered biological insecticide (Abietiv™) for outbreak management.
Neodiprion pratti
Virginia pine sawfly, jack pine sawfly
Neodiprion pratti is a conifer sawfly native to North America with documented populations in Canada and the eastern United States. The species exhibits complex host-associated population structure, with distinct populations adapted to specific pine hosts including Virginia pine (Pinus virginiana), jack pine (Pinus banksiana), sand pine (Pinus clausa), slash pine (Pinus elliottii), and longleaf pine (Pinus palustris). Populations show significant variation in life history, with northern forms typically univoltine and a distinctive West Florida population exhibiting winter-active phenology with adults emerging in October-November.
Neohydatothrips
soybean thrips (N. variabilis), marigold thrips (N. samayunkur)
Neohydatothrips is the most species-rich genus in the Thripidae subfamily Sericothripinae, with approximately 120 described species. Members are phytophagous thrips that feed and breed on leaves and flowers of diverse host plants. Several species are economically significant agricultural pests and plant virus vectors, including N. variabilis (soybean thrips), which transmits soybean vein necrosis orthotospovirus. The genus has a global distribution with approximately 70% of species occurring in the New World.
Neoprociphilus aceris
woolly maple aphid, woolly alder aphid
Neoprociphilus aceris is a woolly aphid species in the family Aphididae, commonly known as the woolly maple aphid or woolly alder aphid. It exhibits a holocyclic life cycle with alternating sexual and parthenogenetic generations on alder trees (Alnus spp.). The species produces dense woolly wax secretions covering its body, forming conspicuous colonies on branches and twigs. It is a phloem-feeding specialist with documented host associations primarily with alder, though its common name suggests potential maple associations that require verification.
Neuroterus anthracinus
Oyster Gall Wasp
Neuroterus anthracinus is a gall wasp in the family Cynipidae that forms chemically induced leaf galls on oak trees. The species exhibits heterogony, alternating between sexual and agamic (parthenogenetic) generations that produce two distinct gall types: the oyster gall and the April-bud gall. This wasp has been widely distributed across Europe and has been introduced to North America.
Neuroterus niger
jumping gall wasp, black jumping gall wasp
Neuroterus niger is a species of gall wasp in the family Cynipidae that induces distinctive galls on oak leaves. This species exhibits an alternating sexual and asexual life cycle, with different generations producing different gall types. The asexual generation creates small, spherical galls that detach from leaves and fall to the ground, where the larva's movements cause the gall to jump—giving rise to the common name "jumping gall." The sexual generation produces inconspicuous leaf galls. The species has been documented across much of eastern and central North America.
Neuroterus quercusminutissimus
Neuroterus quercusminutissimus is a species of cynipid gall wasp in the genus Neuroterus. The species was described by Ashmead in 1885 and is associated with oak trees (Quercus species), as indicated by its specific epithet. Like other Neuroterus species, it induces the formation of galls on oak tissue. The genus Neuroterus contains approximately 50-60 species, many of which are known for their complex life cycles involving alternating generations that produce different gall types on oak leaves or other plant parts.
Neuroterus saltarius
Jumping Gall Wasp
Neuroterus saltarius is a species of gall wasp in the family Cynipidae, commonly known as the jumping gall wasp. It induces distinctive leaf galls on oak trees that detach from the plant and fall to the ground. The developing larva inside the fallen gall can cause the gall to jump when it moves, a unique behavioral trait that gives the species its common name. This species is part of the diverse Neuroterus genus, which contains many oak-associated gall wasps with complex life cycles.
Neuroterus saltatorius
Jumping Gall Wasp
Neuroterus saltatorius, commonly known as the jumping gall wasp, is a North American oak gall wasp in the family Cynipidae. The species is notable for producing small, round galls that detach from leaves and exhibit a distinctive jumping behavior caused by larval movements. It has a complex life cycle with alternating bisexual and parthenogenetic generations, each producing different gall types on oak hosts.
Nothridae
Nothridae is a family of oribatid mites comprising at least 3 genera and approximately 70 described species. The family includes the genera Nothrus (semi-cosmopolitan), Novonothrus (Gondwanan distribution), and Trichonothrus (previously known only from South Africa, now recorded from Australia). Members are primarily associated with moist forest habitats, particularly cool temperate rainforests. Australian Nothridae show relict Gondwanan biogeographical affinities, with high diversity of sexual species in temperate rainforests contrasting with thelytokous parthenogenetic species in the Northern Hemisphere.
Notomicrus
Notomicrus is a genus of small water beetles in the family Noteridae, first described by Sharp in 1882. Species occur in freshwater habitats across the New World, from North America through Central America to South America and the Caribbean. The genus includes at least 13 described species, with several recent descriptions from Guadeloupe and Suriname. Some species exhibit unusual reproductive traits, including suspected obligate parthenogenesis.
Oligotomidae
webspinners
Oligotomidae is a family of webspinners (order Embioptera) comprising approximately 6 genera and at least 40 described species. Members are characterized by silk-producing glands in the enlarged basal tarsomere of the forelegs, used to construct protective galleries. The family exhibits a predominantly Old World distribution with some introduced populations in the Americas. Notable genera include Oligotoma, Aposthonia, and Haploembia, with some species showing complex reproductive strategies including parthenogenesis.
Oobius
Oobius is a genus of parasitic non-stinging wasps in the family Encyrtidae (Hymenoptera: Chalcidoidea). Species are specialized egg parasitoids of wood-boring beetles, particularly in the family Buprestidae (jewel beetles) and Cerambycidae (longhorn beetles). The genus has gained significant attention due to the use of O. agrili as a biological control agent against the invasive emerald ash borer (Agrilus planipennis) in North America. Oobius species are small, morphologically cryptic wasps that are often distinguished by subtle differences in antennal structure and tarsomere count. Several species exhibit parthenogenetic reproduction and undergo diapause to synchronize their life cycles with host availability.
Oobius agrili
Oob
Oobius agrili is a tiny, solitary egg parasitoid wasp in the family Encyrtidae, native to Northeast Asia. It is the only egg parasitoid released for biological control of the invasive emerald ash borer (Agrilus planipennis) in North America, where it has been introduced in over 31 US states. The species is parthenogenic, produces multiple generations annually, and achieves partial phenological synchrony with its host's egg-laying period. Individual females can parasitize more than 60 host eggs, with field parasitism rates reaching 60% in optimal conditions.
Oonopidae
Goblin spiders
Oonopidae, commonly known as goblin spiders, is a diverse family of minute spiders comprising approximately 2,000 described species across 115 genera worldwide, with total species diversity estimated at 2,000–2,500. These spiders are characterized by their tiny size (typically 1–3 mm), reduced eye number (usually six, though some species have four, two, or are completely eyeless), and frequently exhibit unusual morphological modifications in males. The family shows remarkable morphological diversity including hardened abdominal plates (scuta), modified mouthparts, sternal pouches, and elaborate pedipalp structures. Goblin spiders are predominantly ground-dwelling, inhabiting leaf litter, soil, and rock crevices, with some lineages adapted to canopy habitats, caves, or termite nests. The family has an extensive fossil record in amber deposits dating back over 100 million years, with Orchestina already widespread by the end of the Cretaceous.
Otiorhynchini
Otiorhynchini is a tribe of true weevils within the subfamily Entiminae, family Curculionidae. The tribe was established by Schönherr in 1826 and contains approximately 24 extant genera, including the large and economically significant genus Otiorhynchus. Members of this tribe are part of the broad-nosed weevil group, characterized by their relatively short, broad rostrums compared to other weevil lineages. The tribe includes both extant and fossil genera, with two extinct genera known from the fossil record.
Otiorhynchus
root weevils, vine weevils
Otiorhynchus is a large genus of flightless weevils containing over 1,500 species distributed across more than 110 subgenera. The genus is native to the Palearctic region, though sixteen species have become established in North America as introduced pests. Several species, notably the black vine weevil (O. sulcatus) and strawberry root weevil (O. ovatus), are economically significant agricultural pests. The genus exhibits unusual reproductive diversity, with many species containing both diploid bisexual and polyploid parthenogenetic populations.
Otiorhynchus sulcatus
black vine weevil, vine weevil, strawberry weevil, cyclamen weevil
Otiorhynchus sulcatus is a parthenogenetic weevil native to the Palearctic region that has become a globally significant horticultural pest. Adults are flightless, nocturnal, and feed on foliage, producing characteristic notching damage along leaf margins. Larvae develop belowground, feeding on roots, corms, and rhizomes, causing severe plant damage or death. The species reproduces exclusively through thelytokous parthenogenesis; males are absent from all populations. Adults exhibit strong visual and thigmotactic preferences for refuge selection, favoring dark colors (black, blue), tall silhouettes, and basal entrance openings.
Parisotoma
Parisotoma is a genus of elongate-bodied springtails in the family Isotomidae, comprising approximately 11 described species. The genus is notable for containing Parisotoma notabilis, one of the most abundant and widely studied springtails in temperate regions of the northern hemisphere. This species complex exhibits extensive cryptic genetic diversity, with at least six distinct lineages that show differential distribution patterns and habitat associations. Parisotoma species are eurytopic soil microarthropods used in biological monitoring and ecological research.
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.
Pelecinidae
pelecinid wasps
Pelecinidae is a family of parasitic wasps in the superfamily Proctotrupoidea, containing only one living genus, Pelecinus, with three extant species restricted to the Americas. The family was highly diverse during the Cretaceous, with fossils from 43 species in a dozen genera found across North America, Europe, and Asia dating back to the early Cretaceous (121–124 mya). Today, the family is represented by a single genus with three species: Pelecinus polyturator (widespread from southern Canada through South America), P. thoracicus (Mexico), and P. dichrous (South America). All species are parasitoids of scarab beetle larvae.
Pemphigus
Poplar Leaf-stem Gall Aphids
Pemphigus is a genus of gall-forming aphids in the family Aphididae, commonly known as poplar leaf-stem gall aphids. Species in this genus are specialized herbivores that induce distinctive galls on poplar (Populus) and related host plants. The genus is notable for its complex life cycles involving alternation between primary woody hosts and secondary herbaceous hosts, with some species remaining entirely on roots of secondary hosts. Pemphigus species are frequently confused with other root-feeding aphids in agricultural and horticultural contexts.
Pemphigus spyrothecae
Poplar Spiral Gall Aphid
Pemphigus spyrothecae is a gall-forming aphid that induces distinctive spiral-shaped galls on leaf petioles of Populus nigra. The species exhibits eusocial behavior with a sterile soldier caste comprising first-instar nymphs with thickened hind legs that defend the colony against predators. Colony defense includes fortress defense, gall repair, and maintenance of colony hygiene. The aphid has a holocyclic life cycle with four generations: fundatrix, apterous virginoparae, alate sexuparae, and sexual males and females. Genetic relatedness within galls is high due to clonal reproduction, with clonal mixing averaging 0.68-10.4% across populations.
Periphyllus lyropictus
Norway Maple Aphid
Periphyllus lyropictus is a specialist aphid species feeding exclusively on Norway maple (Acer platanoides). It possesses a distinctive di-symbiotic bacterial system involving Buchnera aphidicola and Serratia symbiotica as co-obligate nutritional endosymbionts. The S. symbiotica strain in this species exhibits a highly invasive phenotype with bacterial motility due to complete flagellum expression, contrasting with the strictly compartmentalized symbiont arrangement found in related aphid species. The two symbionts metabolically complement each other for biosynthesis of essential amino acids and B vitamins.
Petrobia
brown wheat mite, oxalis mite
Petrobia is a genus of spider mites in the family Tetranychidae, containing 34 described species. The genus includes several economically important agricultural pests, notably P. latens (brown wheat mite) and P. harti (oxalis mite). Species are distinguished by morphological features including elongated first leg pairs, pad-like claws with hooked empodia, and distinctive prodorsal setae arrangements. The genus is divided into three subgenera: Mesotetranychus, Petrobia, and Tetranychina, differentiated primarily by peritreme structure and dorsal setae characteristics.
Phalangiidae
Phalangiid Harvestmen, Harvestmen
A family of harvestmen (Opiliones: Eupnoi) containing approximately 380 described species. The family includes the widespread and well-studied Phalangium opilio, one of the most recognizable harvestmen in temperate regions. Members are characterized by long, slender legs and a fused body lacking the narrow waist seen in spiders. The family has a primarily Holarctic distribution with some representation in Africa and other regions.
Phasmatidae
stick insects, walking sticks
Phasmatidae is a family of stick insects characterized by extreme elongation of the body and limbs to resemble twigs or branches. Members range from small species to the largest insects known, with Phobaeticus chani reaching 567 mm total length. The family exhibits remarkable crypsis through body form, coloration, and behavior, including swaying movements that mimic branches in wind. Many species possess defensive chemical glands when camouflage fails. The family has undergone significant taxonomic revision, with six subfamilies recognized in Phasmatidae sensu stricto.
Phasmida
stick insects, walking sticks, stick-bugs, phasmids, ghost insects, leaf insects
Phasmida is an order of insects comprising approximately 3,000 valid species worldwide, grouped into 523 genera and 13 families. Members are renowned for extreme cryptic morphology resembling sticks, twigs, or leaves, with elongated bodies and appendages that match host vegetation in color and texture. The order exhibits remarkable size variation, from small species to the longest insects known, with some exceeding 18 inches in length. The group was formerly classified within Orthoptera but now constitutes its own order based on distinct morphological and molecular characteristics. The name derives from Greek 'phasma' (apparition, ghost), referencing their uncanny resemblance to inanimate plant parts.
Phenacoccus solani
Solanum Mealybug
Phenacoccus solani, commonly known as the solanum mealybug, is a parthenogenetic mealybug species in the family Pseudococcidae. It reproduces via thelytokous parthenogenesis, with females producing viable offspring without males. The species has a broad host range including plants in Solanaceae, Amaryllidaceae, and Compositae families, and is recognized as a pest of tomato, cotton, and ornamental plants. Historically confused with P. defectus due to morphological similarity, molecular and morphometric analyses confirmed these as conspecific in 2016, with P. defectus synonymized under P. solani. The species has a cosmopolitan distribution spanning the Nearctic, Mediterranean basin, Asia, South America, Africa, Australia, and Pacific islands.
Phyllonorycter emberizaepenella
Large Midget
A small leaf-mining moth in the family Gracillariidae with a wingspan of 9–10 mm. It reproduces exclusively by thelytokous parthenogenesis, with no males known to exist. Females nevertheless display diurnal calling behavior and produce sex pheromone compounds, despite the absence of mate attraction. The species is widespread across Europe and has been introduced to North America.
Phylloxera
phylloxeras
Phylloxera is a genus of tiny, soft-bodied, sap-sucking insects in the family Phylloxeridae, closely related to aphids. The genus includes economically significant agricultural pests, most notably the grape phylloxera (Daktulosphaira vitifoliae), which devastated European vineyards in the late 19th century and remains a major threat to viticulture worldwide. Phylloxera species induce characteristic galls on host plants through chemical secretions that manipulate plant tissue development. The genus exhibits complex life cycles involving multiple morphological forms, including winged and wingless parthenogenetic generations and a brief sexual generation.
Phylloxera caryaeavellana
hickory phylloxeran, hickory phylloxera
Phylloxera caryaeavellana is a small, gall-forming insect in the family Phylloxeridae that infests hickory trees (Carya species). The species causes distinctive swollen, globular galls to form on leaves, petioles, and leaf veins during spring growth. It is closely related to aphids and shares their piercing-sucking mouthpart morphology. The insect has a complex life cycle involving multiple generations and winged dispersal forms. Unlike the economically devastating grape phylloxera (Daktulosphaira vitifoliae), this species is primarily a curiosity rather than a significant agricultural pest, causing minimal lasting damage to healthy host trees.
Phylloxera caryaeglobuli
hickory phylloxeran, hickory phylloxera
Phylloxera caryaeglobuli is a small, soft-bodied, gall-forming insect closely related to aphids. It induces distinctive globular galls on hickory leaves and petioles, particularly on mockernut hickory. The species has a complex life cycle involving parthenogenetic reproduction within galls and winged dispersal stages. It overwinters as eggs deposited on bark or near old galls.
Phylloxera caryaescissa
pecan leaf phylloxera, hickory phylloxeran
Phylloxera caryaescissa is a tiny, soft-bodied insect closely related to aphids that forms galls on hickory and pecan leaves. The species survives winter as eggs in bark crevices, with nymphs emerging during spring bud break to feed on new growth. Unlike the more destructive pecan phylloxera (Phylloxera devastatrix), this species attacks leaf tissue only and does not damage shoots or nuts. Extensive infestations may cause some defoliation but typically do not significantly reduce yield.
Phylloxera chippokesiensis
Phylloxera chippokesiensis is a gall-forming insect in the family Phylloxeridae, closely related to aphids. Like other phylloxerans, it induces abnormal plant growths (galls) on host tissues through chemical secretions that redirect plant development. The species is named for Chippokes Plantation in Virginia, indicating an association with specific geographic or host plant contexts. As with congeners, it likely has a complex life cycle involving parthenogenetic reproduction within galls and seasonal transitions between winged and wingless forms.
Phylloxera conica
hickory phylloxeran, hickory phylloxera
Phylloxera conica is a gall-forming insect closely related to aphids that induces distinctive globular galls on hickory leaves and petioles. The insect overwinters as eggs on bark or near old galls, with nymphs emerging during bud break to feed on new growth. Their feeding stimulates abnormal plant cell development, creating hollow galls that provide shelter and food. The species has a complex life cycle involving multiple generations, with winged forms eventually dispersing to lay overwintering eggs. Heavy infestations can reduce tree vigor and nut production in hickory trees.
Phylloxera crypta
Phylloxera crypta is a gall-forming insect closely related to aphids, known to induce distinctive galls on hickory trees (Carya species). Like other phylloxerans, this species manipulates plant tissue development through chemical secretions during feeding, creating protective structures that house developing nymphs. The species exhibits a complex life cycle involving multiple generations and both sexual and parthenogenetic reproduction phases.
Phylloxera subelliptica
Phylloxera subelliptica is a gall-forming insect in the family Phylloxeridae, closely related to aphids. Like other phylloxerans, this species induces abnormal plant growths (galls) on host plants through chemical secretions that manipulate plant tissue development. The species was described by Shimer in 1869. Phylloxerans typically have complex life cycles involving multiple generations and both sexual and parthenogenetic reproduction.
Phylloxera wiedenmanni
Phylloxera wiedenmanni is a gall-forming phylloxeran that induces galls on hickory trees. As a member of the family Phylloxeridae, it is closely related to aphids and shares their piercing-sucking mouthpart morphology. The species overwinters as eggs deposited on bark or near old galls, with nymphs emerging during bud break to feed on new leaf tissue. Its feeding stimulates the formation of globular galls on leaves and petioles, within which the insect completes development. The species exhibits complex life history traits including parthenogenetic reproduction within galls and winged dispersal forms.
Phylloxeridae
phylloxerans, phylloxerids
Phylloxeridae is a small family of plant-parasitic hemipterans comprising approximately 75 described species across 11 genera and two subfamilies (Phylloxerininae and Phylloxerinae). These minute insects are closely related to aphids and adelgids, with which they share the superfamily Phylloxeroidea. They are specialized gall-formers on deciduous trees and perennial fruit crops, with complex life cycles involving cyclical parthenogenesis and host alternation between primary woody hosts and secondary herbaceous hosts. The family includes the economically devastating grape phylloxera (Daktulosphaira vitifoliae), responsible for the 19th-century European vineyard crisis.
Phylloxerina
Phylloxerina is a genus of phylloxerids—small, sap-sucking true bugs in the family Phylloxeridae. These insects are closely related to aphids and are known for inducing distinctive leaf galls on host plants. The genus includes species such as Phylloxerina nyssae, which forms crescent-shaped galls on black tupelo (Nyssa sylvatica). Phylloxerids are morphologically unusual among Sternorrhyncha, with wax-covered bodies and complex life cycles involving both gall-dwelling and bark-dwelling generations. The genus is native to northern North America.
Phytomyza plantaginis
Plantain leafminer
Phytomyza plantaginis is a leaf-mining fly in the family Agromyzidae. It is notable as the second documented case of parthenogenetic reproduction (thelytoky) in its family. Populations in Australia exhibit variation in sex ratio, with some areas having only females and others maintaining bisexual populations with female-biased ratios. The species is associated with Plantago host plants.
Platythyrea
Platythyrea is a genus of predatory ants in the subfamily Ponerinae and the sole member of the tribe Platythyreini. Workers range from 4–20 mm in size. The genus exhibits remarkable reproductive diversity: most species have gamergates (reproductive female workers), though P. conradti has ergatoid queens instead. Some species with gamergates also produce alate queens. The genus has a worldwide distribution in tropical and subtropical regions.
Platythyrea punctata
Common Silvery Hunter Ant
Platythyrea punctata is a neotropical ant species distinguished by its remarkable reproductive flexibility. Most populations reproduce through thelytokous parthenogenesis, where unmated workers produce female offspring from unfertilized eggs, resulting in colonies with clonal genetic structure. The species also exhibits facultative sexual reproduction, with occasional queens, gamergates (mated reproductive workers), and males appearing in some populations. This combination of alternative reproductive tactics is unique among ants and has made the species a model for studying social evolution, division of labor, and the transition between sexual and asexual reproduction.