Paedogenesis
Guides
Apterona helicoidella
snailcase bagworm
A bagworm moth native to Europe that constructs a distinctive helical, snail-like case. The species was accidentally introduced to North America in the 1940s and has since established populations across multiple U.S. regions. Adults are reduced or absent in females, which retain a larval form and remain within their cases.
Cecidomyiidae
gall midges, gall gnats
Cecidomyiidae is a family of minute flies comprising over 6,650 described species, with estimates suggesting global diversity may exceed one million species. The family is characterized by larvae that typically feed within plant tissues, inducing abnormal growths called galls. Adults are delicate, 0.5–8 mm in length, with notably long antennae and hairy wings—unusual among Diptera. Some species exhibit paedogenesis, where larvae reproduce without maturing. The family includes major agricultural pests such as the Hessian fly and soybean gall midge, as well as species used in biological control.
Heteropeza
Heteropeza is a genus of gall midges and wood midges (family Cecidomyiidae) comprising approximately six described species. The genus is notable for its unusual paedogenetic life cycle, in which immature larvae reproduce parthenogenetically without metamorphosis to the adult stage. Heteropeza pygmaea, the best-studied species, has been observed in association with shiitake mushrooms (Lentinula edodes) and exhibits unique chromosomal biology including chromosome elimination during early embryonic development.
Heteropeza pygmaea
A minute gall midge (family Cecidomyiidae) described from Europe in 1846. The species has been studied extensively for its unusual cytogenetics and developmental biology, particularly its paedogenetic reproduction and dramatic chromosome elimination during early embryogenesis. Germ-line cells contain approximately 58 chromosomes, but somatic nuclei retain only 10 chromosomes through programmed elimination of E-chromosomes during cleavage.
Miastor
Miastor is a genus of gall midges and wood midges in the family Cecidomyiidae, comprising approximately seven described species. The genus is notable for exhibiting paedogenesis, a rare reproductive strategy in which larvae reproduce parthenogenetically without metamorphosing into adults. Multiple asexual generations can occur before adults eventually develop. Larvae have been recorded in diverse habitats including fungal fruiting bodies, dung, tree bark, and decaying plant matter.
Micromalthidae
Telephone-pole Beetles
Micromalthidae is an ancient, relictual family of beetles in the suborder Archostemata, represented today by a single extant species, Micromalthus debilis. The family has a fossil record extending to the Late Permian (approximately 260 million years ago), making it one of the oldest surviving beetle lineages. Members are characterized by highly unusual reproductive biology, including paedogenesis (reproduction by larvae) and parthenogenesis. The family shows extreme morphological reduction in adults, particularly males, with larvae serving as the primary feeding and persistent life stage.
Micromalthus
telephone-pole beetle
Micromalthus is a monotypic genus of beetles containing the single living species Micromalthus debilis, commonly known as the telephone-pole beetle. It represents the sole extant member of the family Micromalthidae, making it a "living fossil" with all other relatives extinct. The genus has been the subject of considerable taxonomic controversy, historically placed in various families including Lymexylidae and Telegeusidae before its current classification in Archostemata. Its reproductive biology is extraordinarily complex, involving multiple developmental pathways and forms of parthenogenesis.
Micromalthus debilis
Telephone-pole Beetle
Micromalthus debilis is a small beetle native to eastern North America and the sole living representative of the family Micromalthidae, often considered a 'living fossil'. The species exhibits one of the most unusual reproductive strategies in Coleoptera: obligate paedogenesis, where reproduction occurs exclusively through parthenogenetic female larvae without production of fertile adults. Adults are vestigial, sterile, and rarely encountered in nature; they can be artificially induced through heat treatment but cannot reproduce. The species is associated with decaying wood and fungal near-red-rot habitats.
Mycophila
wood midges
Mycophila is a genus of cecidomyiid midges established by Ephraim Porter Felt in 1911, comprising seven described species. Species within this genus are associated with fungal substrates, with some documented as pests of cultivated mushrooms. The genus exhibits diverse reproductive strategies including paedogenesis and parthenogenesis. At least three species have been recorded from China, with additional species known from North America and Europe.
Mycophila speyeri
Mycophila speyeri is a mushroom-infesting cecid fly in the family Cecidomyiidae, first described by Barnes in 1926. It reproduces primarily through larval paedogenesis, a form of asexual reproduction in which larvae produce daughter larvae directly. Sexual reproduction and adult flies are rarely observed in commercial mushroom growing operations. The species has been documented as a significant pest of cultivated mushrooms in Pennsylvania and has been reported from China and several European countries including Denmark, Norway, Sweden, and Japan.
Onychopoda
Onychopoda is a specialized order of predatory branchiopod crustaceans within the superorder Cladocera, distinguished by having only four pairs of legs (compared to five or six in related orders) and segmented raptorial appendages used for grasping prey. The order comprises three families (Cercopagididae, Podonidae, Polyphemidae), ten genera, and approximately 33 described species. Most species are endemic to the Ponto-Caspian basin, though some occur in freshwater and marine habitats worldwide. Onychopoda exhibits one of the most distinctive morphological and ecological radiations among cladocerans, having evolved predation as a novel feeding strategy and colonized habitats across a broad salinity range.