Phytoseioidea

Phytoseioidea can be distinguished from other Gamasina superfamilies by a combination of morphological characters, though specific diagnostic features vary among constituent families. Within the superfamily, families are differentiated by leg chaetotaxy patterns, particularly the presence or absence of specific setae on tarsi II–IV. For example, Africoseiulella is unique in lacking setae al3 and pl3 on tarsi II–IV and seta ad2 on tarsus IV, and in possessing a stout unbranched palp tarsus apotele with a large membranous flap fused to a sickle-shaped movable cheliceral digit. Blattisociidae exhibits an apical ventral process on the tarsus of legs II to IV. Some genera such as Opilioseius are characterized by strikingly long legs relative to body size.

Habitats vary considerably among families. Blattisociidae includes species inhabiting the lower surface of fungal hosts in lowland tropical rainforest. Some phytoseioid mites occur in agroecosystems, including date palm plantations. The superfamily as a whole occupies diverse terrestrial environments, though specific habitat preferences are family- or genus-dependent rather than uniform across Phytoseioidea.

Documented from multiple regions including: northern Iran (Africoseiulella hajiqanbari); Tunisia (Africoseiulella flechtmanni from low-growing vegetation); Egypt (Africoseiulella sedishazlensis); Costa Rica (Opilioseius grallator in lowland tropical rainforest); Saudi Arabia (treated in separate dedicated publication). The superfamily has a broad global distribution with representation in both temperate and tropical regions.

• Acheta domesticus (house cricket) - associationDocumented for Africoseiulella hajiqanbari sp. nov. in Iran; not generalizable to entire superfamily
• Coriolus fungi - habitatDocumented for Opilioseius grallator in Costa Rica; mites complete life histories on lower surface of fungal hosts

Some blattisociine mites undergo complete life histories on fungal hosts. Reproductive features include unusually large egg size relative to maternal female body size in some Blattisociidae. Developmental stages (adults and deutonymphs) have been documented for some species, but generalized life cycle patterns for the superfamily are not established.

Some blattisociine mites exhibit gregarious tendencies, coexisting with diverse assemblages of other mesostigmatic mites on shared fungal substrates. Certain genera display strikingly elongated legs, though the functional significance of this trait remains unstudied.

Members of Phytoseiidae within this superfamily are widely recognized as predators of pest mites and small arthropods, with substantial application in agricultural biological control. Other families likely contribute to decomposition food webs through associations with fungi, though specific ecological functions remain poorly documented for most taxa.

Phytoseiidae mites are economically significant as biological control agents against agricultural pests, particularly spider mites in greenhouse and field crops. The superfamily otherwise has limited direct human impact; some species occur in agroecosystems without documented economic role.

• Other Gamasina superfamiliesPhytoseioidea is distinguished within Gamasina by family-specific morphological characters; leg chaetotaxy patterns and palp structure provide primary differentiation from Ascoidea, Dermanyssoidea, and other superfamilies

• mites
• Mesostigmata
• predatory mites
• biological control
• acarology
• Gamasina

• BugGuide
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Mesostigmatic mites (Acari: Mesostigmata) of Saudi Arabia (excluding Phytoseioidea), new records and a key to the known species
• Africoseiulella Kreiter (Acari, Mesostigmata): description of a new species, taxonomic affinities within Phytoseioidea, establishment of a new family, and revised classification of Treatiinae Wainstein
• Revised diagnosis of the family Blattisociidae (Acari: Mesostigmata: Phytoseioidea), with a key to its genera and description of a new fungus- inhabiting genus from Costa Rica