mite Chaetodactylus krombeini phoretic on the orchard mason bee, Osmia lignaria
Fig. 1. Phoretic deutonymphs of the mite Chaetodactylus krombeini dispersing on the orchard mason bee, Osmia lignaria, Michigan Click here to enlarge

Bee Mites : Acari : Acariformes : Sarcoptiformes : Chaetodactylidae
 

Genus Chaetodactylus Rondani, 1866

Trichodactylus Dufour, 1839: 276 (type species Trichodactylus osmiae Dufour, 1839 by monotypy) (nom. preocc. Latreille, 1828 in Decapoda).
Chaetodactylus Rondani, 1866: 183 (nom. n. pro Trichodactylus Dufour, 1839).
Chaetodactylus (Chaetodactylus): Fain, 1981: 1.
Saproglyphus (non Berlese, 1890): Hirashima, 1957: 200.
Trichotarsus Canestrini, 1888: 7 (nom. n. pro Trichodactylus "Dugès", part.).
Trichotarsus group C Oudemans, 1903: 147.
Chaetodactylus (Spinodactylus) Fain, 1981: 2 (type species Chaetodactylus claviger Oudemans, 1928, by original designation).
Tricholarsus Vitzthum, 1912: 292 (lapsus).
[See Klimov and OConnor (2008) for complete synonymy]

Type species Trichodactylus osmiae Dufour, 1839 by monotypy.

Diagnosis (unique characters only). Phoretic deutonymph. Gnathosomal solenidion present and setae on free palpi absent and free palpi present (unique combination of character states). Immobile deutonymph present. Adults. Cupules im ventral. Male. Progenital sclerites completely fused forming large unpaired sclerite (Fig. 3). Lateral processes (horns) of dorsal supporting sclerite with secondary processes (Fig. 4). Distinct anterio-dorsal protuberance on tarsi I-IV present (Fig. 5). Heteromorphic males absent. Larva. Claparède's organ shaft more or less cylindrical, constricted apically; dome spherical.
Biology and host associations. Species of this genus are associated with Megachilidae, tribes Lithurgini (Lithurgus, Trichothurgus, Microthurge), Osmiini (Osmia (Fig. 1), Hoplitis, Chelostoma), Anthidiini (Rhodanthidium, Anthidium), and Megachilini (Megachile), and with Apidae, tribes Emphorini (Melitoma, Diadasia, Ptilothrix, Ancyloscelis), and Tapinotaspidini (Chalepogenus). Most species occur on Lithurgus and Osmia, while only one species is associated with each of the remaining host genera.
Immobile heteromorphic deutonymph of Chaetodactylus micheneri (Chaetodactylidae)
Fig. 2. Immobile heteromorphic deutonymph of Chaetodactylus micheneri. Click here to enlarge
The mites usually kill young bee larvae and feed on provisioned pollen and nectar. In nests with partitions (Osmia), bees that develop in the innermost cells chew their way out of the nest, and phoretic deutonymphs from the opened cells may attach to them. The mites in the innermost cell would possibly die because of their inability to break through the partition. In nests without partitions (Lithurgus), some young bees possibly complete development and transform to adults that disperse the mites.
The presence of the inert non-phoretic deutonymph along with the phoretic deutonymph is the most conspicuous feature in the life-cycle of this genus. This is a highly regressive, cyst-like morph with legs and most setae greatly reduced (Fig. 2). It is capable of surviving in old bee nests and infesting new hosts that reuse these nests or nest material. Inert deutonymphs are very important for the mite survival when mites are trapped in innermost cells of an infested nest or all bee larvae are killed and therefore cannot transfer mites to a new nest as adults.
Biology has been studied for Chaetodactylus osmiae (Chmielewski 1993, Fain 1966, Lith 1957, Popovici-Baznosanu 1913), Ch. birulai (Lith 1957), and Ch. krombeini (Krombein 1962, 1967).
Distribution (Show map). Chaetodactylus is associated with megachilid bees on a worldwide basis (except Antarctica), while species associated with apid bees are only found in the Neotropical region. Chaetodactylus is associated with Hoplitis species in the Nearctic region, but not in the Old World where this host bee genus also occurs. Similarly, no records are known for Chaetodactylus associated with North American Chelostoma and Megachile, while the mites do occur on these hosts in the western Palaearctic. The close similarity of species of the osmiae-lineage and Ch. anthidii associated with Rhodanthidium sticticum suggests a recent host shift from Osmia and subsequent vicariance in the Palaearctic region. No Chaetodactylus are positively known from New World Anthidiini, although we were able to find one on Anthidium spp. in Chile. The distribution patterns of Ch. krombeini + Ch. claviger and Ch. claudus + Ch. osmiae, sister species living in the Nearctic and southwestern Palaearctic regions, respectively, indicate their recent vicariance. The ludwigi-dalyi lineage has a broad distribution in the Australian, Oriental, Afrotropical, Neotropical, and south Palaearctic regions, which may imply intercontinental dispersal events or an ancient Gondwanan origin of this early derivative lineage.

Species included
  1. Chaetodactylus abditus Klimov and OConnor, 2004
  2. Chaetodactylus anthidii (Oudemans, 1911)
  3. Chaetodactylus antillarum Klimov and OConnor, 2008
  4. Chaetodactylus azteca Klimov and OConnor, 2008
  5. Chaetodactylus birulai Zachvatkin, 1941 (=Chaetodactylus poetae Samšiňák, 1973)
  6. Chaetodactylus chrysidis Fain and Baugnée, 1996 (=Chaetodactylus chrysidis aurulenticola Fain and Baugnée, 1996)
  7. Chaetodactylus claudus Klimov and OConnor, 2008
  8. Chaetodactylus claviger Oudemans, 1924
  9. Chaetodactylus dalyi (Fain, 1974)
  10. Chaetodactylus dementjevi Zachvatkin, 1941
  11. Chaetodactylus furunculus Klimov and OConnor, 2008
  12. Chaetodactylus gibbosi Klimov and OConnor, 2004
  13. Chaetodactylus hirashimai Kurosa, 1987
  14. Chaetodactylus hopliti Klimov and OConnor, 2008
  15. Chaetodactylus kouboy Klimov and OConnor, 2008
  16. Chaetodactylus krombeini Baker, 1962
  17. Chaetodactylus lassulus Klimov and OConnor, 2007
  18. Chaetodactylus lithurgi Klimov and OConnor, 2004
  19. Chaetodactylus ludwigi (Trouessart, 1904)
  20. Chaetodactylus melitomae Klimov and OConnor, 2007
  21. Chaetodactylus micheneri Klimov and OConnor, 2008
  22. Chaetodactylus nipponicus Kurosa, 1987
  23. Chaetodactylus osmiae (Dufour, 1839) (=Chaetodactylus mahunkai Samšiňák, 1973)
  24. Chaetodactylus reaumuri (Oudemans, 1905)
  25. Chaetodactylus rozeni Klimov and OConnor, 2008
  26. Chaetodactylus zachvatkini Klimov and OConnor, 2008

Key to species of the genus Chaetodactylus of the World
Phoretic heteromorphic deutonymphs

1 Solenidion f IV longer than combined length of genu and tibia IV. Tarsal setae w, r, f, and e IV longer than tarsus IV and nearly uniform in length; all stiff ("non-bendable"). Suckers ad3 larger than inner unsclerotized area of suckers ad1+2. Associated with Melitoma (Apidae). Mexico: Chiapas, Oaxaca, Tabasco; Honduras: Yoro ...  Chaetodactylus melitomae Klimov and OConnor, 2007
- Solenidion f IV shorter than combined length of genu and tibia IV. At least one of tarsal setae w, r, f, and e IV shorter than tarsus IV, if all longer then they are non-uniform in length and width; long setae, if present, filiform ("bendable"). Suckers ad3 smaller or equal to inner unsclerotized area of suckers ad1+2. Associated with Megachilidae or rarely Apidae ... 2
2(1) Setae mG II and vF II shorter than combined length of femur, genu, and tibia II. Posterior apodeme II absent, if present than interrupted and less than half of distance separating base of leg II and apodemes III (3/4 of lateral edge of sternal shield in Ch. lassulus). Primarily associated with Lithurgus, one species with Megachile bombycina ... 17
- At least one setae, mG II or vF II, equal to or exceeding combined length of femur, genu, and tibia II. Posterior apodeme II well-developed, at least 1/2 length of distance separating base of leg II and apodemes III. Primarily associated with Osmia, Hoplitis, Chelostoma, and Rhodanthidium  ... 3
3(2) Tarsal setae e and f IV longer than length of tarsus IV. Primarily associated with Osmia, Hoplitis, Chelostoma, and Rhodanthidium. Holarctic ... 4
- Tarsal setae e and f IV microsetae, shorter than width of tarsus IV, or absent. Primarily associated with Osmia subgenera Cephalosmia, Diceratosmia, Helicosmia. Nearctic ... 15
4(3) Setae c2 situated outside prodorsal shield. Both tarsal setae e and f IV, or only e IV shorter or slightly longer than legs IV. Setae wa I-II not widened or only slightly widened at bases ... 5
- Setae c2 situated on prodorsal shield (in small specimens of Ch. chrysidis may be outside the shield). Both tarsal setae e and f IV longer than legs IV. Setae wa I-II usually distinctly widened at bases ... 11
5(4) Setae si not extending beyond posterior edge of prodorsal shield, shorter than se, situated anterior to transverse level of c2 and cp. Setae e and f IV subequal, both shorter or roughly equal to leg IV, in one species (Ch. reaumuri) setae e IV longer than legs IV and more than 2 times longer than f IV. Associated with Osmia or Anthidium. Holarctic ... 6
- Setae si extending beyond posterior edge of prodorsal shield and almost as long as se, situated almost on same transverse level with c2 and cp. Setae e IV longer than legs IV and more than 2 times longer than f IV. Setae e1 as long as d1. Associated with Chelostoma florisomne and Chelostoma rapunculi (Megachilidae), also found on its parasites, Sapyga quinquepunctata and S. clavicornis (Hymenoptera: Sapygidae). Russia: Kirovskaya Oblast'; Czech Republic; Netherlands ... Chaetodactylus birulai Zachvatkin, 1941 (=Ch. poetae Samšiňák, 1973)
6(5) Setae mG and usually cG I shorter or equal to combined length of genu and tibia I. Western Palaearctic ... 7
- Setae mG and cG I distinctly longer than combined length of genu and tibia I. Holarctic ... 8
7(6) Setae si distinctly shorter than 1/2 of distance between them. Setae d1 shorter or nearly equal to 1/2 of distance between them. Most of prodorsal shield usually with transverse linear pattern. Associated with Osmia tricornis (type host), O. niveata, O. cornuta, and O. latreillei. Italy (type locality), Spain, Tunisia ... Chaetodactylus zachvatkini Klimov and OConnor, 2008. (=Ch. osmiae sensu Zachvatkin, 1941 (part., non Dufour, 1839))
- Setae si nearly as long as 1/2 of distance between them. Setae d1 distinctly longer than 1/2 of distance between them. Most of prodorsal shield with scale-like pattern. Associated with Rhodanthidium sticticum. Tunisia (type locality), France ... Chaetodactylus anthidii (Oudemans, 1911)
8(6) Setae f IV about 3 times shorter than e IV; e IV much longer than leg IV. On "Osmia rufiventris Panzer"ii (type host), O. niveata, O. leucogastra, O. brevicornis, O. tricornis, also phoretic on cleptoparasite of Osmia: Stelis murina . Czech Republic (type locality), Germany, Italy, Spain, Turkey, Greece, Ukraine, Georgia, Tunisia ... Chaetodactylus reaumuri (Oudemans, 1905)
- Setae f and e IV subequal, both shorter than leg IV ... 9
9(8) Conoids ps2 less than 8 in diameter; anterior edges of their bases posterior to posterior edge of inner unsclerotized area of suckers ad1+2. Distance between cupules ih and bases of ps2 nearly equal to diameter of latter. Associated with Osmia ribifloris. USA: Texas, Utah ... Chaetodactylus claudus Klimov and OConnor, 2008
- Conoids ps2 exceeding 8 in diameter; anterior edges of their bases anterior to posterior edge of inner unsclerotized area of suckers ad1+2. Distance between cupules ih and bases of ps2 less than diameter of latter. PalaearcticPEE  ... 10
10(9) Posterior edge of bases of conoids ps2 posterior to center of inner unsclerotized areas of suckers ad1+2. Unsclerotized elements of pattern of prodorsal and hysterosomal shields lens-like. Associated with Osmia rufa (type host), O. tricornis, O. niveata, O. cornuta. France (type locality), Belgium, England, Spain, Germany, Hungary, Croatia, Romania (only verified records listed) ... Chaetodactylus osmiae (Dufour, 1839) (=Ch. mahunkai Samšiňák, 1973)
- Posterior edge of bases of conoids ps2 anterior to center of inner unsclerotized areas of suckers ad1+2. Unsclerotized elements of pattern of prodorsal and hysterosomal shields represented by short lines. On Osmia cornifrons (type host), O. excavata, O. pedicornis, O. taurus. Japan. ... Chaetodactylus nipponicus Kurosa, 1987
11(4) Coxal setae 1a not inflated at bases, situated on soft cuticle. Seta si not reaching posterior edge of prodorsal shield. Tarsus IV with only one ventro-medial seta (w IV). Anterior and posterior apodemes IV connected on outer edge of coxal field IV. Posterior apodemes IV without protruding medial end. Lateral angles of prodorsal shield attenuated. Associated with Osmia aurulenta, and its parasite, Chrysura trimaculata (Chrysididae) (type host). Belgium (type locality), Germany ... Chaetodactylus chrysidis Fain and Baugnée, 1996 (=Ch. chrysidis aurulenticola Fain and Baugnée, 1996)
- Coxal setae 1a inflated at bases (only slightly in Ch. hirashimai), situated on sclerite fused with anterior apodemes II. Tarsus IV with both ventro-medial setae (w and s IV) present. Seta si distinctly extending beyond posterior edge of prodorsal shield. Anterior and posterior apodemes IV disjunct on outer edge of coxal field IV. Posterior apodemes IV with protruding medial end. Lateral angles of prodorsal shield not attenuated. Holarctic ... 12
12(11) Sclerites surrounding alveoli of 4b and 3a represented by thin margins around bases of setae; sclerites of 3a not fused to anterior coxal apodemes IV. Coxal setae 3a and 4b only slightly widened at bases, almost filiform. Posterior end of sternal apodeme usually simple. Associated with Osmia and Hoplitis ... 13
- Sclerites surrounding alveoli of 4b and 3a large, irregularly shaped; sclerites surrounding alveoli of 3a fused to anterior coxal apodemes IV. Coxal setae 4b and 3a usually more distinctly widened at base. Posterior end of sternum usually distinctly bifurcated. Associated with Osmia ... 14
13(12) Setae 1a distinctly inflated at bases. Seta se reaching transverse level of c2. Associated primarily with Hoplitis spp. USA: Michigan, North Carolina, New York, Ohio, Tennessee, Idaho ... Chaetodactylus hopliti Klimov and OConnor, 2008
- Setae 1a only slightly widened at bases. Seta se not reaching transverse level of c2. Associated with Osmia excavata (type host), O. cornifrons, O. imaii, O. pedicornis. Japan ... Chaetodactylus hirashimai Kurosa, 1987
14(12) Posterior end of anterior coxal apodeme II without large sclerite. Setae h3 0.9-1.3 (1.1±0.1, n=10) times longer than h2. Associated primarily with Osmia lignaria. USA, Canada ... Chaetodactylus krombeini Baker, 1962
- Posterior end of anterior coxal apodeme II with large sclerite. Setae h3 1.2-2.0 (1.5±0.2, n=8) times longer than h2. Associated primarily with Osmia tricornis. Italy (type locality), France, Egypt ... Chaetodactylus claviger Oudemans, 1924
15(3) Setae d2 situated outside hysterosomal shield. Prodorsal setae si distinctly longer than 1/2 of distance between their bases. Seta h3 shorter than femur I. Posterior apodeme II, approximately 1/2 the length of lateral edge of sternal shield. Anterior and posterior apodemes IV not connected on outer edge of coxal field IV. Setae mG II more than 2 times shorter than vF II. Associated with Osmia (Diceratosmia) azteca. Mexico: Chiapas.... Chaetodactylus azteca Klimov and OConnor, 2008
- Setae d2 situated on hysterosomal shield. Prodorsal setae si shorter than 1/2 of distance between their bases. Seta h3 longer than femur II. Posterior apodeme II exceeding 3/4 the length of lateral edge of sternal shield. Anterior and posterior apodemes IV connected on outer edge of coxal field IV. Seta mG II longer than vF II ... 16
16(15) Setae h3 equal or exceeding combined length of femur, genu, and tibia I. Associated primarily with Osmia (Cephalosmia): O. subaustralis, O. montana, O. marginipennis, O. californica, and O. grinnelli. Northwestern, southwestern, and northeastern USA; western and subarctic Canada. Click here for identification of 3 partially overlapping morphs  ... Chaetodactylus micheneri Klimov and OConnor, 2008
- Setae h3 distinctly shorter than combined length of femur, genu, and tibia I. Associated with Osmia (Helicosmia) georgica. USA: North Carolina ... Chaetodactylus rozeni Klimov and OConnor, 2008
17(2) Hysterosomal setae d2 situated outside hysterosomal shield and setae c1 on anterior edge of this shield. Tarsal setae la I-II lanceolate (filiform in undescribed species from Neotropics). Tarsal seta w IV more than 1.5 times shorter than s IV; seta e IV more than 2 times shorter than f IV. Seta s III submedial. Afrotropical, Oriental, Australian, southeastern Palaearctic, Neotropical regions ... 18
- Both hysterosomal setae d2 and c1 situated either on hysterosomal shield or outside this shield. Tarsal setae la I-II filiform. Tarsal seta w and s IV subequal; setae e and f IV subequal or absent. Seta s III subterminal. Holarctic and Neotropical ... 19
18(17) Setae 4b not reaching transverse level of anterior coxal apodemes IV. Associated with Lithurgus atratus (type host), L. scabrosus. Micronesia (type locality), Indonesia, New Caledonia, French Polynesia, South India ... Chaetodactylus ludwigi (Trouessart, 1904)
- Setae 4b slightly extending beyond transverse level of anterior coxal apodemes IV. Associated with Lithurgus pullatus and L. aethiops, few specimens collected on Ceratina (Pithitis) turneri (type host). South Africa (type locality), Zimbabwe, Mozambique, Madagascar. ... Chaetodactylus dalyi Fain, 1974
19(17) Setae c1 and d2 situated outside hysterosomal shield. Tarsus I elongated and solenidion w1 and w3 distinctly separated, distance exceeds 3 diameters of alveolus of famulus ((). Legs IV 2.8-3.6 times shorter than idiosoma ... 20
- Setae c1 and d2 situated on edges of hysterosomal shield. Tarsus I not elongated and solenidion w1 and w3 close to each other, distance less than 3 diameters of alveolus of famulus ((). Relative length of legs IV variable ... 22
20(19) Prodorsal shield small, not extending anteriorly beyond se. Setae si situated outside prodorsal shield. Posterior apodemes II exceed half the length of lateral edges of sternal shield. Longitudinal striation between coxae III-IV present. Ventral side of claws I-III finely striated. Setae e and f IV vestigial or absent. Associated with Trichothurgus dubius, T. herbsti. Chile.... Chaetodactylus lassulus Klimov and OConnor, 2007
- Prodorsal shield larger, extends anterior of se. Setae si situated on prodorsal shield. Posterior apodemes II absent or shorter than 1/3 of lateral edges of sternal shield. Longitudinal striation between coxae III-IV absent. Ventral side of claws I-III smooth. Setae e and f IV longer than width of tarsus IV ... 21
21(20) Dorsal idiosomal setae relatively short: d2 not reaching anterior margin of hysterosomal shield and reaching e2, si and e1 shorter than half the distance between corresponding pairs. Alveolus of vi indistinct. Solenidion s I usually about 0.6 of genu I length. Proximal acetabular extensions IV connected. Solenidion s III present, short. Associated with Lithurgus listrotus. USA: California ... Chaetodactylus furunculus Klimov and OConnor, 2008
- Dorsal idiosomal setae longer: d2 extending beyond anterior margin of hysterosomal shield and reaching e2, si and e1 distinctly longer than half the distance between corresponding pairs. Alveolus of vi distinct. Solenidion s I nearly as long as genu I or longer. Proximal acetabular extensions IV disjunct. Solenidion s III absent. Associated with Lithurgus antilleorum. Jamaica, Dominican Republic ... Chaetodactylus antillarum Klimov and OConnor, 2008
22(19) Setae e and f IV longer than width of tarsus IV. Genual seta mG I extending beyond base of tarsus I. Legs IV 3.2-3.5 times shorter than idiosoma. Seta si more than 1.5 times shorter than d2 and e2. Associated with Megachile bombycina and M. ligniseca. Western Palaearctic ... Chaetodactylus dementjevi Zachvatkin, 1941
- Setae e and f IV shorter than width of tarsus IV. Genual seta mG I not extending beyond base of tarsus I. Legs IV 4.1-5.3 times shorter than idiosoma. Seta si less than 1.5 times shorter than d2 and e2. Associated with Lithurgus. Nearctic ... 23
23(22) Setae si, d2, and e2 represented by microsetae, shorter than 1/4 of prodorsal shield length. Setae of hysterosomal shield represented by microsetae. All idiosomal setae smooth. Apical tarsal setae e and f IV absent. On Lithurgus apicalis. USA: New Mexico ... Chaetodactylus kouboy Klimov and OConnor, 2008
- Setae si, d2, and e2 longer than 1/4 of prodorsal shield length. On hysterosomal shield, at least setae f2 are not microsetae. Idiosomal setae smooth or some long setae pectinate. Apical tarsal setae e and f IV present or absent. ... 24
24(23) Ratio of length of prodorsal shield/length of seta d1 4.7-7.3 (5.8±0.70). Associated with Lithurgus gibbosus. USA: Florida ... Chaetodactylus gibbosi Klimov and OConnor, 2004
- Ratio length of prodorsal shield/length of seta d1 2.4-4.4 (3.2±0.43) ... 25
25(24) CV 1 and 2 fall within lithurgi group. Ratio length of seta vF II/length of seta h2 1.2-2.6 (1.6±0.26). Associated with Lithurgus apicalis, L. littoralis, and L. gibbosus. USA: Texas, New Mexico, Arizona, Colorado, Idaho ... Chaetodactylus lithurgi Klimov and OConnor, 2004
- CV 1 and 2 fall within abditus group. Ratio vF II/h2 2.2-3.4 (2.7±0.31). Associated with Lithurgus planifrons and L. echinocacti. USA: Arizona; Mexico: Socorro Is. ... Chaetodactylus abditus Klimov and OConnor, 2004
Immobile heteromorphic deutonymphs

1 Legs I-II more than 2 times longer than their bases, some articles distinct. Attachment organ situated on distinct posterior projection ... Ch. ludwigi
- Legs I-II less than 2 times longer than their bases, without distinct articulation. Posterior body rounded  ... 2
2(1) Anterior apodemes IV developed as well as apodemes I-II. Hysterosoma with distinct border situated outside legs II-IV ... Chaetodactylus krombeini
- Anterior apodemes IV not developed. Border outside legs I-II absent ... 3
3(2) Legs III-IV longer than their bases ... Chaetodactylus micheneri
- Legs III-IV shorter than their bases ... Chaetodactylus osmiae and Ch. claudus

Females

1 Central part of dorsal opisthosoma more or less uniformly covered with small (1.5-2.0) mammillae (2.0-4.0 in Ch. claudus); at least some mammillae conical or subconical, with attenuated, darker tips. Adanal setae ad3 extending well beyond ih. (-) Setae c3 almost reaching or extending beyond trochanters IV. Position of setae ps3 relatively 4a variable. Sclerotized lining of outer end of inseminatory canal shorter than 0.4 length of inseminatory canal. Setae gT I-II smooth, filiform; hT I-II only slightly barbed, almost smooth
... 4
 
- Central part of dorsal opisthosoma covered with fleshy tubercles (2.0-3.5), usually with rounded, transparent tips. Adanal setae ad3 extending at most only slightly beyond ih. Setae ps3 posterior to 4a level. Other charcters variable
... 2
 
2(1) Some tubercles of central part of dorsal opisthosoma larger (2.5-3.0), partially fusing together. On peripheral part, tubercles arranged in transverse rows ultimately forming distinct linear pattern. Transverse linear pattern extending ventrally covering almost all ventral opisthosoma. Tibial setae gT I-II barbed, distinctly widened. Sclerotized lining of outer end of inseminatory canal longer than 0.4 length of inseminatory canal (Fig.). (-) c3 extending beyond trochanters IV. ps3 slightly posterior to 4a level. Inseminatory canal trumpet-shaped, about 2 times longer than its width at spermatheca (Fig.). Setae gT I-II distinctly barbed, spiniform. Copulatory tube very short, trapezoidal ... Chaetodactylus reaumuri
- Tubercles of central part of dorsal opisthosoma smaller (2.0-3.0), usually not partially fusing together and not forming distinct linear pattern on peripheral part of dorsal and on most part of ventral opisthosoma. Tibial setae gT I-II smooth, filiform; hT I-II only slightly barbed. Sclerotized lining of outer end of inseminatory canal shorter than 0.4 length of inseminatory canal. Copulatory tube absent
... 3
 
3(2) Inseminatory canal less than 3 times longer than its width at spermatheca (Fig.). Setae c3 not reaching trochanters IV ... Chaetodactylus zachvatkini
- Inseminatory canal more than 5 times longer than its width at spermatheca (Fig.). Setae c3 reaching trochanters IV but not extending beyond their posterior level ... Chaetodactylus micheneri
4(1) Inseminatory canal more than 2 times longer than its width at spermatheca (Fig.). Setae ps3 usually anterior to 4a level. Copulatory tube absent
... 6
 
- Inseminatory canal less than 2 times longer than its width at spermatheca. Short copulatory tube present... 5
5(4) Inseminatory canal about 1.1-1.2 times longer than its width at spermatheca. Dorsal opisthosomal mammillae 1.0-2.0 (-) Setae ps3 posterior to 4a level ... Chaetodactylus osmiae
- Inseminatory canal about 1.7 times longer than its width at spermatheca. Dorsal opisthosomal mammillae 2.0-4.0 ... Chaetodactylus claudus
6(4) Outer sclerotized ridge surrounding supracoxal gland opening distinctly longer than tibia II ... Chaetodactylus krombeini
- Outer sclerotized ridge surrounding supracoxal gland opening only as long as tibia II ... Chaetodactylus hopliti

Males

1 Backward bend of aedeagus posterior to dorsal supporting sclerite. Transverse processes of dorsal supporting sclerite spirally twisted, band-like (Fig.). Genital valves with posterior bifurcated flaps (Fig.). Setae d1 not extending beyond e1. (-) Setae c3 reaching trochanters IV but not extending beyond them. Central part of dorsal opisthosoma with mammillae or tubercles, diameter approximately 1.5. Basal widening of aedeagus not reaching level of ps3, distance between them exceeding length of basal widening. Medial sclerite of genital capsule not reaching posterior level of dorsal supporting sclerite. Anterior end of genital capsule without distinct projection. Aedeagus distinctly extending beyond genital capsule. Setae gT and hT I-II smooth. Ratio of pretarsal sucker width/tarsus III width 0.34-0.35. ... Chaetodactylus micheneri
- Backward bend of aedeagus at level of dorsal supporting sclerite. Transverse processes of dorsal supporting sclerite not twisted, and not band-like (dorsal supporting sclerite shaped like a vertebra in superior or inferior view) flaps (Fig.). Genital valves without posterior bifurcated flaps flaps (Fig.). Setae d1 extending beyond e1
... 2
 
2(1) Medial sclerite of genital capsule extending beyond posterior level of dorsal supporting sclerite (Fig.). Anterior end of genital capsule with distinct projection (Fig.). Anterior processes of dorsal supporting sclerite more than 2 times wider than posterior ones, forming anterior concavity that exceeds 1.6 of basal "body" (Fig.). (-) Setae d1 not extending beyond h1 (slightly extending beyond e1). Setae c3 reaching trochanters IV but not extending beyond them. Basal widening of aedeagus almost reaching level of ps3. Aedeagus distinctly extending beyond genital capsule. Setae gT I-II smooth and hT I-II barbed. Ratio of pretarsal sucker width/tarsus III width 0.41-0.44 ... Chaetodactylus reaumuri
- Medial sclerite of genital capsule not reaching posterior level of dorsal supporting sclerite (Fig.). Anterior end of genital capsule without distinct projection (Fig.). Anterior processes of dorsal supporting sclerite usually less than 2 times wider than posterior ones; anterior concavity not exceeding 1.6 of basal "body" (Fig.)
... 3
 
3(2) Basal widening of aedeagus almost reaching or extending beyond level of ps3, longer than distance between ps3. Setae d1 extending beyond posterior end of body. Central part of dorsal opisthosoma with distinct conical mammillae, diameter about 0.9. (-) Setae c3 extending beyond trochanters IV. Aedeagus distinctly extending beyond genital capsule (Fig.). Setae hT I-II barbed
... 6
 
- Basal widening of aedeagus not reaching level of ps3, shorter than distance between ps3. Setae d1 not extending beyond posterior end of body. Central part of dorsal opisthosoma with tubercles or somehow conical mammillae, diameter 1.5-2.2. Aedeagus not or slightly extending genital capsule (Fig.), or distinctly extending and reaching ps3 level (Ch. claudus)
... 4
 
4(3) Setae c3 not reaching trochanters IV. Setae hT I-II smooth. (-) Central part of dorsal opisthosoma with mammillae or tubercles, diameter 2.2. Ratio of pretarsal sucker width/tarsus III width 0.30-0.34 ... Chaetodactylus zachvatkini
- Setae c3 reaching trochanters IV or extending beyond them. Setae hT I-II barbed
... 5
 
5(4) Aedeagus slightly extending beyond genital capsule, not reaching level of setae ps3 (Fig.). Central part of dorsal opisthosoma with mammillae or tubercles, diameter 1.5. Ratio of pretarsal sucker width/tarsus III width 0.41-0.43 ... Chaetodactylus osmiae
- Aedeagus distinctly extending beyond genital capsule, almost reaching level of setae ps3. Central part of dorsal opisthosoma with mammillae or tubercles, diameter about 2.0. Ratio of pretarsal sucker width/tarsus III width about 0.25 ... Chaetodactylus claudus
6(3) Distance d1-d1 (from outer edges) 46-56 (51±3, n=11) (1). Sclerotized area surrounding posterior supracoxal gland opening 36-45 (40±3, n=11) (2). (1)/(2) 1.1-1.4 (1.3±0.1, n=11) ... Chaetodactylus krombeini
- Distance d1-d1 (from outer edges) 54-67 (63±6, n=4) (1). Sclerotized area surrounding posterior supracoxal gland opening 34-36 (35±1, n=4) (2). (1)/(2) 1.6-1.9 (1.8±0.1, n=4) ... Chaetodactylus hopliti

References

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Chmielewski, W. 1993. Biologia Chaetodactylus osmiae (Duf., 1866) (Acarida, Chaetodactylidae - pylkozernego rozkruszka foretycznie zwiazanego z pszczolami samotnymi (Apoidea). Pszczelnicze Zeszyty Naukowe.37: 133-143.
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Fain, A. 1966. Notes sur la biologie des acariens du genre Chaetodactylus et en particulier de C. osmiae, parasite des abeilles solitaires Osmia rufa et O. cornuta en Belgique (Sarcoptiformes: Chaetodactylidae). Bulletin et Annales de la Societe Royale d'Entomologie de Belgique.102: 249-261.
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Krombein, K. V. 1967. Trap-nesting wasps and bees: life histories, nests, and associates. Washington, D.C: Smithsonian press. 570 pp.
Lith, J. P. v. 1957. On the behaviour of Chaetodactylus mites (Acar., Tyr.) in the nests of Osmia rufa L. and Chelostoma florisomne (L.) (Apidae, Megachilidae). Entomologische Berichten.17: 197-198.
Oudemans, A. C. 1903. Notes on Acari: Fifth Series. Tijdschrift voor Entomologie.45: 123-150.
Popovici-Baznosanu, A. 1913. Etude biologique sur l'acarien Trichotarsus osmiae Duf. Archives de Zoologie Expérimentale et Générale, Paris.52: 32-41.
Rondani, C. 1866. Alcune Parole: sull'Acaro dell'Ape osservato dal Signor Duchemin. Giornale di agricolture, industrie e commercio del Regno d'Italie.3: 182-183.
Vitzthum, H. 1912. Ueber einige auf Apiden lebende Milben. Zeitschrift für Wissenschaftliche Insektenbiologie.8: 289-293.




 

 

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Created: Mar 23, 2009
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