Mesostigmata

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Taxonomy

updated 2025

Diagnostic characters

• Fixed chela with membranous lobe replacing pilus dentilis
• Movable chela with ventral mucro near base
• Epigynial shield usually rounded posteriorly
• Anal shield usually bearing circum-anal setae only
• Spermatheca of laelapid-type but often obscure and always lacking well sclerotized cervix
• Dorsal shield entire; podonotal region holotrichous or nearly so, seta z3 present; opisthonotal region with 18–22 pairs of setae, including most of the posterior marginal (R) setae.
• Female usually with metasternal plates 
• Corniculi stout, sometimes bifid or toothed

More about Proctolaelaps on Bee Mite ID

Similar taxa

Except for Mycolaelaps, no other Melicharinae have dorsal shields that capture most of the R-series, but the Proctolaelaps hystrix group captures only R1–4 (R5–7 in soft cuticle) and is similar to Mucroseius, but lacks the distal cheliceral process. Also, species of Proctogastrolaelaps have a separate ventral shield; species of Rhinoseius, Tropicoseius, and Xanthippe has incised dorsal shields; species of Mucroseius have macrosetae on telotarsus IV and a distal process on the fixed digit; species of Melichares lack metasternal plates. Species of Neojordensia and Orthadenella capture the R -setae, but have a ventrianal shield.

Similar taxa not in the Lucid key (see below): Orolaelaps De Leon (=Proctolaelaps)

Key to the genera of Melicharinae

1. Idiosoma narrow, dorsal shield greater than twice as long as wide; leg setation strongly neotenous, genua I–II–III–IV with 12–7–6–7 setae, tibiae with 11–7–6–6 setae; female lacking metasternal plates and with ventri-anal shield bearing 1–3 pairs of ventral setae in addition to circumanal setae.............................. Mycolaelaps
   - Idiosoma broader, legs not strongly neotenous, metasternal plates present or absent, only anal shield or separate anal and ventral shields.............................. 2

2. Female with separate ventral shield bearing 4 pairs of setae between genital and anal shields; posterior connection of peritrematal shield to exopodal plate beside coxa IV broad (subequal to width of stigma); corniculi slender, acute; rows of deutosternal denticles narrow, in deep trough; epistome convex, smooth; movable chela of female unidentate.............................. Proctogastrolaelaps
   - Ventral area not sclerotized, only small anal shield with 3 circumanal setae present.............................. 3

3. Fixed chela of female and nymphs with pointed or rounded flange-like projection distally; leg IV with 1 or 2 erect macrosetae on telotarsus (pd2, +/- ad2); 3rd pair of sternal pores absent.............................. Mucroseius
   - Fixed chela without distal flange-like projection; leg IV usually without macrosetae; 3rd pair of sternal pores usually present.............................. 4

4. Dorsal shield of adults with pair of deep midlateral incisions, lacking setae z3 on podonotal region; movable chela with 0 or 1 tooth; female without metasternal plates.............................. 6
   - Dorsal shield of adults entire, usually with setae z3 on podonotal region; movable chela with 3 teeth; with or without metasternal plates.............................. 5

5. Adults with 7–13 pairs of marginal (r–R) setae on soft lateral cuticle (rarely fewer if some r–R setae lacking); female with 14–15 pairs of setae on opisthonotal region of dorsal shield and lacking metasternal plates (except in Orolaelaps).............................. Melichares
   - Adults with 1–4 pairs of posterior marginal (R) setae on soft ventro-lateral cuticle, all others on edge of dorsal shield; female with 18–22 pairs of setae on opisthonotal region of dorsal shield; female usually with metasternal plates.............................. Proctolaelaps

6. Movable chela unidentate; female with 1st pair of sternal setae on soft cuticle in front of sternal shield; male with separate ventral & anal shields; male leg II with tarsal seta pv1 unmodified.............................. Xanthippe
   - Movable chela edentate; female with first pair of sternal setae on sternal shield; male usually with consolidated ventrianal shield; male leg II with apical tarsal seta pv–1 slightly to conspicuously thickened.............................. 7

7. Tibiae III and IV with 9 and 10 setae respectively (pl2 present); dorsal shield with setae s6; female with hyaline anterior margin of epigynial shield rounded, and with genital setae on lateral edges of this shield; male tarsus II with seta pv–1 knob- or spine-like, and tarsus III with 1–3 setae (always av2) knob-like; male spermatodactyl directed anteriorly.............................. Tropicoseius
   - Tibiae III and IV with 8 and 9 setae respectively (pl2 absent); dorsal shield lacking setae s6; female with hyaline anterior margin of epigynial shield usually truncated or emarginated, and with genital setae on soft cuticle flanking this shield; male tarsus II with seta pv1 but slightly thickened, and tarsus III without modified setae; male spermatodactyl directed posteroventrally.............................. Rhinoseius

Ecology and distribution

About 100 species of Proctolaelaps have been described from numerous habitats and associations. Some species are flower mites phoretic on hummingbirds, butterflies or honey opossums. Others are common inhabitants in beetle galleries, ant colonies, bumblebee nests, stored products, insect cultures, rotting fruit, and soil. Adults are found on a variety of insects and at least one species is a parasite of cockroaches.

References

• Colwell 1995Colwell 1995:
  Colwell RK. 1995. Effects of nectar consumption by the hummingbird flower mite Proctolaelaps kirmsei on nectar availability in Hamelia patens. Biotropica 27: 206–217.
• Egan and Hunter 1975Egan and Hunter 1975:
  Egan ME, Hunter PE. 1975. Redescription of a cockroach mite, Proctolaelaps nauphoetae, with notes on its biology. Annals of the Entomological Society of America 68: 361–4.
• Egan and Moss 1969Egan and Moss 1969:
  Egan ME, Moss WW. 1969. The life cycle and behavior of a cockroach mite, Proctolaelaps nauphoetae (Acari: Mesostigmata: Ascidae). Notulae Naturae 420: 1–9.
• Evans and Till 1979Evans and Till 1979:
  Evans EO, Till WM. 1979. Mesostigmatic mites of Britain and Ireland (Chelicerata: Acari-Parasitiformes): An introduction to their external morphology and classification. Transactions of the Zoological Society of London 35 (2): 145–270.
• Halliday et al. 1998Halliday et al. 1998:
  Halliday RB, Walter DE, Lindquist EE. 1998. Revision of the Australian Ascidae (Acarina: Mesostigmata). Invertebrate Taxonomy 12: 1–54.
• Karg 1993Karg 1993:
  Karg W. 1993. Acari (Acarina), Milben Parasitiformes (Anactinochaeta) Cohors Gamasina Leach, Raubmilben. Die Tierwelt Deutschlands 59: 1–523.
• Krantz 1986Krantz 1986:
  Krantz GW. 1986. A manual of acarology [2nd ed., emended 1986]. Oregon State University Book Stores, Corvallis.
• Krantz and Ainscough 1990Krantz and Ainscough 1990:
  Krantz GW, Ainscough B. 1990. Mesostigmata. pp. 583–665. In: Dindal DL, ed. Soil biology guide. John Wiley & Sons, Brisbane.
• Lindquist 1971Lindquist 1971:
  Lindquist EE.  1971. New species of Ascidae (Acarina : Mesostigmata) associated with forest insect pests. Can. Entomol. 103: 919–42
• Lindquist and Evans 1965Lindquist and Evans 1965:
  Lindquist EE, Evans GO. 1965. Taxonomic concepts in the Ascidae, with a modified setal nomenclature for the idiosoma of the Gamasina (Acarina: Mesostigmata). Memoirs of the Entomological Society of Canada 47: 1–64
• Lindquist and Hunter 1965Lindquist and Hunter 1965:
  Lindquist EE, Hunter PE. 1965. Some mites of the genus Proctolaelaps Berlese (Acarina: Blattisociidae) associated with forest insect pests. The Canadian Entomologist 97: 16–32.
• McGraw and Farrier 1969McGraw and Farrier 1969:
  McGraw JR, Farrier MH. 1969. Of the superfamily Parasitoidea (Acarina: Mesostigmata) associated with Dendroctonus and Ips (Coleoptera: Scolytidae). North Carolina Agricultural Experiment Station Technical Bulletin No. 192, 162 pp.