How to determine if it is a dust mite? - briefly
Examine a sample under a microscope at 100‑400× magnification; dust mites appear as 0.2–0.3 mm translucent, oval bodies with eight legs and no eyes. Confirm identification by noting the dorsal shield and scaly setae on the legs.
How to determine if it is a dust mite? - in detail
Dust mites are microscopic arachnids, typically 0.2–0.3 mm in length. Their identification relies on several observable characteristics and laboratory techniques.
The organism’s body is oval, covered with a smooth, translucent cuticle. Six legs are present on the anterior half of the body; the posterior half lacks legs, a feature distinguishing mites from insects. The gnathosoma, located near the front, contains chelicerae adapted for feeding on skin scales and organic debris. Under a compound microscope at 100–400× magnification, these structures become visible.
Key steps for verification:
- Collect a sample from suspected sites (carpets, bedding, upholstered furniture) using a vacuum with a fine‑mesh filter or a tape lift. Transfer the collected material onto a microscope slide.
- Apply a clearing agent (e.g., lactophenol) to enhance transparency of the specimens.
- Examine the slide at appropriate magnification. Confirm the presence of an eight‑segmented body, the characteristic leg arrangement, and the absence of wings.
- Compare observed morphology with reference images or taxonomic keys specific to common domestic species such as Dermatophagoides pteronyssinus and Dermatophagoides farinae.
- For ambiguous cases, perform a DNA barcoding assay: extract genomic DNA, amplify the mitochondrial COI region, and match the sequence against a curated database.
Additional indicators support identification:
- Habitat preference for humid environments with relative humidity above 50 %.
- Concentration of specimens in areas with frequent human activity, where skin flakes provide food.
- Presence of allergenic proteins (Der p 1, Der f 1) detectable by enzyme‑linked immunosorbent assay (ELISA), confirming dust‑mite species.
Combining morphological examination with molecular confirmation yields reliable determination of dust‑mite presence.