Acaridae

Stored Products Mites, Mold Mites, Grain Mites

Genus Guides

is a of mites in the order Sarcoptiformes, commonly known as stored products mites or mold mites. The family includes over 400 across multiple , with distributions. Many species are inhabiting both natural environments (soil, litter, animal nests, decomposing plant material) and artificial environments (human dwellings, granaries, greenhouses). Several genera contain significant agricultural and stored product pests, including *Acarus*, *Tyrophagus*, and **, which cause economic damage to crops, bulbs, and stored foodstuffs.

Boletoglyphus by (c) Matteo Marcandella, some rights reserved (CC BY), uploaded by Matteo Marcandella. Used under a CC-BY license.

Tyrophagus by (c) Temdor, some rights reserved (CC BY). Used under a CC-BY license.

Tyrophagus by no rights reserved, uploaded by Randal. Used under a CC0 license.

Pronunciation

How to pronounce Acaridae: /əˈkɛrəˌdeɪ/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

are distinguished from related by features including the presence of a phoretic deutonymph stage in many —a non-feeding nymph specialized for by riding on larger animals. are typically small, soft-bodied mites with reduced . The family can be differentiated from other Astigmata families by chaetotaxy patterns and genital structure, though precise identification requires microscopic examination. are distinguished by leg chaetotaxy, palp structure, and body setation patterns.

Images

Habitat

Natural include soil, leaf litter, animal nests, and decomposing plant material. Artificial habitats include human dwellings, granaries, greenhouses, plant nurseries, stored food facilities, and plant tissue culture laboratories. Some lineages are specialized: *Acarus* inhabit nests of warm-blooded animals; *Tyrophagus formicetorum* and relatives occur exclusively in nests; *Histiogaster* species live subcortically beneath bark.

Distribution

. with worldwide distributions include *Acarus*, *Sancassania*, and *Tyrophagus*. Documented occurrences include Europe (Denmark, Norway, Sweden, England and Wales), Asia (India, China, Iran, Turkey), Africa (South Africa, Algeria), North America (United States, Vermont, Mexico), South America, Australia, New Zealand, and Cuba.

Seasonality

vary by . In agricultural settings, * robini* reaches peak in bulbs during May and June. Stored product pests thrive year-round in suitable conditions, with explosions possible in humid environments.

Diet

Many are feeders on decomposing organic material, fungi, and . Some are facultatively phytophagous, feeding on living plant material including bulbs, roots, and ornamental plants. Specialized diets include: fungi (subcortical *Histiogaster* species); dead beetles and mushrooms (certain *Sancassania* species); and specific associations with nests or nests.

Host Associations

Allium cepa - pestonion bulbs, major crop damage
Allium sativum - pestgarlic bulbs
Lilium - pestbulb crops
Hyacinthus - pestbulb crops
Formicidae - commensal*Tyrophagus formicetorum* lineage exclusively in nests
Scarabaeidae - phoretic*Sancassania* ride phoretically on live beetles, feed on dead beetles
Apoidea - commensalcertain *Sancassania* associated with bees
Rodentia - commensal*Acarus* inhabit rodent nests
Aves - commensal*Acarus* inhabit bird nests

Life Cycle

includes , larva, , tritonymph, and stages. Many possess a phoretic deutonymph—a non-feeding stage that rides on larger animals. *Tyrophagus putrescentiae* completes development in approximately 8.75 days (egg: ~4.5 days; larva: ~1.5 days; protonymph: ~1.3 days; tritonymph: ~1.3 days) under laboratory conditions. time is approximately 29.5 days with of 0.11 individuals per female per day. Some *Tyrophagus* species lack the deutonymph stage entirely, dispersing as feeding stages instead.

Behavior

is a key : deutonymphs attach to larger animals to reach new . Hyperphoresy (riding an animal that is itself riding a third animal) has been documented, with acarid deutonymphs on Uropodidae mites on beetles. Non-phoretic disperse by active movement or air currents. Stored product pests aggregate in humid conditions on damp materials.

Ecological Role

Decomposers in natural , contributing to nutrient cycling through consumption of fungi and decaying organic matter. In agricultural and storage ecosystems, many become pests causing significant economic damage. Some species fungi and bacteria in plant tissue culture laboratories. Certain lineages have evolved specialized commensal or parasitic relationships with insects and vertebrates.

Human Relevance

Major pests of stored products: **, *A. farris*, *Tyrophagus putrescentiae*, *T. longior*, and *Tyrolichus casei* infest grains, flour, dried fruit, milk products, hams, cheeses, straw, animal hides, and animal feed. ** and *T. longior* damage living plants, particularly bulb crops and ornamentals. Can cause dermatitis in humans through piercing attempts to feed or via contact allergens. Contaminants in plant tissue culture laboratories.

Similar Taxa

GlycyphagidaeAlso Astigmata mites with similar and phoretic deutonymphs; distinguished by body and chaetotaxy patterns
HistiostomatidaeAstigmata with phoretic deutonymphs; differ in feeding apparatus structure and preferences
Pyroglyphidae; overlap in human-associated but differ in and specific habitat preferences

More Details

Taxonomic Note

The belongs to the superfamily Acaroidea within the suborder Astigmata. The title of one source incorrectly places Phytoseiidae and Tetranychidae within Acaridae; these are separate families in different superfamilies.

Economic Impact

Stored product acarids thrive in humid conditions; management requires humidity control and proper storage practices. * robini* can sustain vitality at 35°C, contributing to its persistence in storage and greenhouse environments.

Phoretic Specialization

The deutonymph stage represents a distinct strategy for . Its presence or absence varies among and even lineages, reflecting different ecological strategies.