Digamasellidae

Mohammadi, Leila & Hajizadeh, Jalil, 2024, Review of the family Digamasellidae (Acari: Mesostigmata) in Iran with three new records and a key to species, Persian Journal of Acarology 13 (3), pp. 375-393 : 385-387

Key to species of Digamasellidae recorded in Iran (adult females)

This key considers all of the species previously reported from the country, except for the species described as Dendrolaelaps acriluteus Athias-Henriot, 1961 and referred by Nemati et al. (2012) as Multidendrolaelaps acriluteus (Athias-Henriot, 1961) . In the available publications, this species is described based only on the deutonymph, and hence it is not included the subsequent key, based only on adult females.

1. Palptrochanter with bulbous ventral protuberance; corniculi weakly formed; hypostomal setae h1 and h2 more or less transversely aligned.............. Bulbolaelaps Faraji & Zare & Rahmani ......... ..................................................................... Bulbolaelaps bossei Faraji & Zare & Rahmani, 2021

– Palptrochanter without ventral protuberance; corniculi well sclerotised and mainly horn-like; hypostomal seta h1 is positioned far anterior to seta h2 ............................................................... 2

2. Seta Zv1 on ventrianal shield; anal opening conspicuously enlarged, longer than 1/5 the length of the ventrianal shield … Digamasellus Berlese .............. Digamasellus punctum ( Berlese, 1904)

– Seta Zv1 on unsclerotised integument next to anterior margin of ventrianal shield; anal opening not enlarged, shorter than 1/5 the length of the ventrianal shield ................................................ 3

3. Posterior margin of idiosoma bilobed. Dendrolaelaspis Lindquist ............................................. 4

– Posterior margin of idiosoma rounded ......................................................................................... 7

4. Ventrianal shieldadjacent to genital shield and with 6 pairs of setae (Jv1, Jv2, Jv3, Zv2, Zv3, Jv5); setae J4 short and serrate ....................................... Dendrolaelaspis angulosus ( Willmann, 1936)

– Ventrianal shieldlocated at a distance from genital shield and with 5 pairs of setae (Jv1, Jv2, Jv3, Zv2, Zv3); setae J4 with different lengths and shapes .................................................................. 5

5. Ventrianal shield wide triangular, with indentation at level of Zv1 ................................................ .............................................................................. Dendrolaelaspis longisetosus Shcherbak, 1977

– Ventrianal shield heart-shaped, without indentation at level of Zv1 ............................................. 6

6. Setae J2 and S1 club-shaped; posterior end of idiosoma strongly bilobed; lateral margin of the ventrianal shield well rounded .............. Dendrolaelaspis lobatus (Scherbak & Chelebiev, 1977)

– Setae J2 and S1 needle-shaped; posterior end of idiosoma not strongly bilobed; lateral margin of ventrianal shield less rounded .............................. Dendrolaelaspis lindquisti ( Shcherbak, 1978)

7. Movable cheliceral digit with at least five teeth ( Fig. 12 ) ............................................................ 8

– Movable cheliceral digit with 1–4 teeth ...................................................................................... 10

8. Spermatheca opening at base of coxa IV ............................................... Insectolaelaps Shcherbak .................................................................................... Insectolaelaps quadrisetus ( Berlese, 1920)

– Spermatheca opening at base of coxa III …........... Multidendrolaelaps Hirschmann ................. 9

9. Peritremes long, reaching beyond insertion of setae s1 ................................................................... ......................................................................... Multidendrolaelaps multidentatu s ( Leitner, 1949)

– Peritremes reduced, reaching only to insertion level of st2 or between st3 / st4 ............................... .................................................................... Multidendrolaelaps euepistomus ( Hirschmann, 1960)

10. Movable cheliceral digit with one, two or four teeth; anterior margin of the opisthonotal shield usually with median notch .................................... Dendrolaelaps Halbert ................................ 14

– Movable cheliceral digit with three teeth; anterior margin of the opisthonotal shield without median notch .............................................................................................................................. 11

11. With seven rows of deutosternal denticles; setae r4 and r5 on unsclerotized integument ............. ........................................................ Dendroseius Karg ............................................................. 12

– With six rows of deutosternal denticles; setae r4 and r5 on podonotal shield ................................ .................................................... Oligodentatus Shcherbak ....................................................... 13

12. Ventrianal shield nearly triangular, with posterior margin convex, peritreme extending anteriorly to middle level of coxa III ........... Dendroseius amoliensis Faraji, Sakenin-Chelav & Karg, 2006

– Ventrianal shield subrectangular, with posterior margin only moderately curved, peritreme relatively long, anteriorly to level coxae II ............ Dendroseius volgaris Ma, Ho & Wang, 2014

13. Ventrianal shield rectangular, peritremes short, extending anteriorly to level between coxae III and II ................................................... Oligodentatus tridentatus Shcherbak & Bregetova, 1980

– Ventrianal shield rounded triangular; peritremes long, extending anteriorly to posterior part of coxa I ............................................................................ Oligodentatus shcherbakae Barilo, 1989

14. Epistome prongs further apart than usual (distance between middle and lateral prongs equal or more than length of middle prong) .............................. Dendrolaelaps presepum ( Berlese, 1918)

– Epistome tips not further apart than usual .................................................................................. 15

15. Insemination opening in transverse gap between basifemur and telofemur III .......................... 16

– Insemination opening in middle of femur III or on border between femur and genu III ............ 18

16. Ventrianal shield quadrate with five pairs of setae (Jv1, Jv2, Jv3, Zv2, Zv3); setae Jv3 long, twice longer than Jv1 ...................................................................... Dendrolaelaps latior ( Leitner, 1949)

– Ventrianal shield not quadrate and with five pairs of setae (Jv1, Jv2, Jv3, Zv2, Jv5); Jv3 short, less than twice the length of Jv1 ......................................................................................................... 17

17. Ventrianal shield pear-shaped or rectangular, wider at posterior than at anterior edge; spermatheca long and tubular with a bubble-like end .......................................................................................... ............................................................................... Dendrolaelaps punctatulus Hirschmann, 1960

– Ventrianal shield trapezoid, slightly wider at posterior than at anterior edge; spermatheca long and tubular, divided into a thicker proximal part and thinner distal part ........................................ ......................................................................................... Dendrolaelaps saprophilus Huhta, 1982

18. Insemination apparatus spiral ..................................................................................................... 19

– Insemination apparatus straight or slightly curved ..................................................................... 28

19. Insemination apparatus wound several times in a spiral (3 to 7 times); dorsal shield partly with granulation fields and indentations in region between z3 and z4 ..................................................... .................................................................................... Dendrolaelaps zwoelferi Hirschmann, 1960

– Insemination apparatus usually not very twisted (1 to 3 times, but in some species not twisted); dorsal shield usually without granulation fields and indentations in region between z3 and z4 .. 20

20. Ventrianal shield usually with two pairs of setae (Jv2, Jv3); spermatheca short and angular; posterior end of opisthonotal shield with four separate circular pores ............................................ ............................................................... Dendrolaelaps isochetus Shcherback & Bregetova, 1980

– Ventrianal shield with more than two pairs of setae, spermatheca not so short and angular; posterior end of opisthonotal shield without such circular pores ................................................ 21

21. Ventrianal shield with three pairs of setae (Jv2, Jv3, Zv2) ........................................................ 22

– Ventrianal shield with more than three pairs of setae ................................................................ 25

22. Seta Zv2 inserted on ventrianal shield, away from the margin .................................................. 23

– Seta Zv2 inserted on edge of the ventrianal shield ..................................................................... 24

23. Ventrianal shield rectangular, with straight edges; spermatheca spiral, without swollen end; setae Z3 as long as Z5 ........................................................... Dendrolaelaps foveolatus ( Leitner, 1949)

– Ventrianal shield quadrate with curved edges; spermatheca spiral, with swollen and bag-shaped end; setae Z3 shorter than Z5 .............................. Dendrolaelaps markewitschi Shcherbak, 1980

24. Ventrianal shield with wavy margins; spermatheca short, spiral with one twist ............................ ......................................................................................... Dendrolaelaps brevipilis ( Leitner, 1949)

– Ventrianal shield with straight margins; spermatheca long, spiral with three twists ...................... ...................................................... Dendrolaelaps brevipiloides Hirschmann & Wiśniewski, 1982

25. Ventrianal shield with four pairs of setae (Jv2, Jv3, Zv2, Jv5) .................................................. 26

– Ventrianal shield with more than four pairs of setae ................................................................. 27

26. Ventrianal shield quadrate; spermatheca in form of a long and trumpet-like tube, located in middle of femur III; peritreme extending to insertion level of setae z2 ...................................................... ............................................... Dendrolaelaps stammeriformis Hirschmann & Wiśniewski, 1982

– Ventrianal shield rectangular; spermatheca tubular, extending from trochanter to middle of femur III and two-branched in trochanter; peritreme extending anteriorly to level between setae s1 and z1 .................................................................................. Dendrolaelaps paradoxa Shcherbak, 1982

27. Ventrianal shield rectangular, with five pairs of setae (Jv2, Jv3, Zv2, Zv3, Jv5); spermatheca in form of a short tube in femur III ............................ Dendrolaelaps willmanni Hirschmann, 1960

– Ventrianal shield rectangular-oval, with six pairs of setae (Jv1, Jv2, Jv3, Zv2, Zv3, Jv5); spermatheca spiral with two twists, extending from middle of femur III to trochanter III ............ ............................................................................................. Dendrolaelaps arenarius Karg, 1971

28. Ventrianal shield rectangular, with two pairs of setae (Jv2, Jv3) ................................................... ................................................................................... Dendrolaelaps longiusculus ( Leitner, 1949)

– Ventrianal shield with more than two pairs of setae .................................................................. 29

29. Ventrianal shield quadrate, with rounded lateral edge, with four pairs of setae (Jv1, Jv2, Jv3, Zv2); spermatheca in form of a straight and wide tube in femur III, with a small funnel at border of genu ..................................................................................... Dendrolaelaps populi Hirschmann, 1960

– Ventrianal shield rectangular with wavy lateral edges, with five pairs of setae (Jv1, Jv2, Jv3, Zv2, Zv3); spermatheca it is not clearly discernible, sperm induction pore short and rounded, located in distal rim of femur III ................ Dendrolaelaps lignicolus Mohammadi and Hajizadeh, 2023

Figures

Figures 12–15. Oligodentatus tridentatus Shcherbak & Bregetova (female) – 12. Coxa–tibia of leg I; 13. Coxa–tibia of leg II; 14. Coxa–tibia of leg III; 15. Coxa–tibia of leg IV.