Denticle rows on appendages of larvae in twelve species of Phytoseiidae (Parasitiformes: Mesostigmata)

The larval stages of phytoseiid mites (Acari: Phytoseiidae) are rarely considered in taxonomic descriptions. The presence of denticles on the palpi and legs is rarely documented in any developmental stages of mites of this family. To address this gap, the presence of denticles was evaluated on the appendages of larvae of the following twelve species: Amblydromalus limonicus (Garman and McGregor), Amblyseius herbicolus (Chant), Amblyseius orientalis Ehara, Amblyseius taiguensis Liu, Ma and Fan, Euseius utilis (Liang and Ke), Neoseiulus benjamini (Schicha), Neoseiulus californicus (McGregor), Neoseiulus setarius Ma, Meng and Fan, Neoseiulus womersleyi (Schicha), Neoseiulus zwoelferi (Dosse), Phytoseiulus persimilis Athias-Henriot and Phytoseius hongkongensis Swirski and Shechter. We identified and described the denticles on the palps, basis capitulum, and specific leg segments of these species, and hypothesized that the denticle rows might potentially be used for tearing open their own epidermis during hatching.