How to differentiate male and female ticks? - briefly
«Male» ticks have a scutum that covers the whole dorsal surface, whereas «female» ticks display a reduced scutum with a larger, rounded abdomen. Males also show smaller, elongated mouthparts and a visible genital aperture near the posterior, while females possess larger mouthparts and lack an external genital opening.
How to differentiate male and female ticks? - in detail
Ticks are arachnids whose sex can be identified by external morphology and, when necessary, by internal or molecular characteristics. Accurate identification supports ecological studies, disease‑vector research, and control programs.
External features distinguish males from females in most hard‑tick species. Key characteristics include:
- Size: females are generally larger, especially after engorgement, while males remain relatively small and remain flat.
- Scutum: females possess a partially covered dorsal shield; the scutum occupies only the anterior portion, leaving the posterior dorsum uncovered for blood storage. Males have a fully covering scutum that extends across the entire dorsal surface.
- Ventral plates: females display a conspicuous genital opening located ventrally near the posterior margin, often appearing as a small slit. Males have a pair of gonopores situated laterally on the ventral side, each associated with a short, sclerotized structure.
- Leg length: male legs, particularly the first pair, are proportionally longer, aiding in mate searching; female legs are shorter and more robust.
- Scent glands: in many species, females possess larger anal glands, visible as swollen structures near the anus, whereas males have reduced or absent glands.
Microscopic examination of these traits requires a stereomicroscope with at least 20–40× magnification. Specimens should be positioned dorsal side up, and measurements recorded with an ocular micrometer to confirm size differences.
When morphological criteria are ambiguous—such as in nymphal stages or heavily engorged females—additional techniques are available:
- Dissection of the genital aperture reveals internal reproductive organs; females contain a single oviduct, while males possess paired testes.
- Molecular assays targeting sex‑specific genes (e.g., doublesex or transformer) provide definitive identification. Polymerase chain reaction (PCR) protocols amplify short DNA fragments unique to each sex, allowing rapid screening of large sample sets.
- Immunohistochemical staining with antibodies against sex‑specific proteins can differentiate sexes in histological sections.
Consistent application of these diagnostic criteria enables reliable sex determination across tick species, facilitating precise data collection for epidemiological and ecological investigations.