Correlation of heteromorphic life instars in terrestrial Parasitengona mites and its impact on taxonomy - the case of Leptus molochinus (C. L. Koch, 1837) and Leptus ignotus (Oudemans, 1903) (Acari: Trombidiformes: Prostigmata: Erythraeidae) Author Laydanowicz, Joanna Author Mąkol, Joanna text Journal of Natural History 2010 2010-02-23 44 11 - 12 669 697 http://dx.doi.org/10.1080/00222930903383560 journal article 10.1080/00222930903383560 1464-5262 5207355 Leptus molochinus (C. L. Koch, 1837 ) Rhyncholophus molochinus C. L. Koch, 1837 Leptus ignotus ( Oudemans, 1903 ) , syn. nov. For other synonyms see Southcott (1961 , 1992 ). Diagnosis Adult and deutonymph. Anterior sensillary area of crista metopica oval, elongated. Posterior sensillary area with posterior process. Dorsal idiosomal setae relatively short (<45), stout, with uniform acuminate setules outgoing from the main stem. Larva. One seta on palp femur and palp genu. Four intercoxalae at level of coxae IV. Tibia I (<120) with two solenidia (ϕ). ISD = 58–75; Ti III/AW ≤ 1.72; DSmax <70; L/W 0.87–1.12; Ti III 105–134. For other characters see diagnosis of the genus. Description Adult and deutonymph. ( Figures 1–6 ). For morphometric data see Table 1 . Colour in life brownish. Body oval in shape, slightly widened anteriorly ( Figure 1 ) and densely covered with uniform setae. Chelicerae narrow, dagger-like, retractable into idiosoma. Palps ( Figure 2 ) slender. Palp genu almost parallel-sided, palp tibia triangular in outline, palp tarsus slightly longer than wide and rounded terminally. Odontus simple, relatively short, hook-like. All segments of palps covered with sparsely distributed setae. All setae on palp trochanter and palp tibia, as well as those that cover the medial and lateral side of palp femur and palp genu, elongated, slender, covered with short, delicate setules. Setae placed at dorsal side of palp femur and palp genu more stout, similar to normal setae covering leg segments. Numerous setae with very short setules present on palp tarsus. Table 1. Morphometric data on adults and deutonymph of Leptus molochinus (C. L. Koch, 1837 ) .

Character	Females	Males	Deutonymph
LB	1605–2272 ( n =8, x =1945,	2248–2272 ( n =3, x =2256,	1086 ( n =1)
SD=244.8)	SD=14.2)
WB	988–1408 ( n =8, x =1223,	1260 ( n =1)	692 ( n =1)
SD=163.3)
LB/WB	1.50–1.67 ( n =8, x =1,59,	1.80 ( n =1)	1.57 ( n =1)
SD=0.063)
PaTr (L)	65–72 ( n =8, x =69, SD=2.2)	65–72 ( n =8, x =69, SD=2.3)	60 ( n =1)
PaTr (W)	57–72 ( n =8, x =65, SD=4.9)	52–65 ( n =8, x =60, SD=4.4)	60 ( n =1)
PaFe (L)	175–242 ( n =8, x =222,	175–212 ( n =8, x =194,	137 ( n =1)
SD=21.0)	SD=10.3)
PaFe (W)	107–140 ( n =8, x =121,	100–130 ( n =8, x =116,	97 ( n =1)
SD=10.8)	SD=10.6)
PaGe (L)	132–175 ( n =8, x =159,	132–165 ( n =8, x =143,	110 ( n =1)
SD=15.0)	SD=11.7)
PaGe (W)	67–82 ( n =8, x =75, SD=5.1)	62–87 ( n =8, x =74, SD=7.6)	70 ( n =1)
PaTi (L)	62–82 ( n =8, x =76, SD=6.8)	65–82 ( n =8, x =73, SD=5.1)	55 ( n =1)
PaTi (W)	52–62 ( n =8, x =58, SD=4.2)	52–62 ( n =8, x =57, SD=3.0)	50 ( n =1)
PaTiCl (L)	22–27 ( n =8, x =26, SD=1.9)	20–25 ( n =7, x =22, SD=2.2)	22 ( n =1)
PaTa (L)	30–50 ( n =8, x =44, SD=6.1)	35–45 ( n =7, x =41, SD=4.0)	37 ( n =1)
PaTa (W)	27–32 ( n =8, x =29, SD=1.9)	25–30 ( n =8, x =28, SD=1.9)	20 ( n =1)
CML	545–660 ( n =8, x =608,	455–605 ( n =7, x =552,	390 ( n =1)
SD=43.6)	SD=50.8)
ASAL	105–132 ( n =8, x =117,	77–112 ( n =7, x =97, SD=11.6)	77 ( n =1)
SD=10.6)
ASAW	50–65 ( n =8, x =57, SD=6.0)	47–57 ( n =7, x =52, SD=3.4)	42 ( n =1)
ASens	78–90 ( n =8, x =83, SD=4.1)	73–87 ( n =6, x =80, SD=6.4)	63 ( n =1)
SBa	19–27 ( n =8, x =22, SD=2.7)	17–25 ( n =7, x =21, SD=2.4)	18 ( n =1)
AM	47–62 ( n =8, x =55, SD=6.1)	40–56 ( n =7, x =48, SD=5.7)	50 ( n =1)
PSAL	67–95 ( n =8, x =79, SD=9.0)	67–80 ( n =8, x =76, SD=4.0)	60 ( n =1)
PSAW	47–67 ( n =8, x =55, SD=6.6)	45–57 ( n =8, x =52, SD=4.8)	43 ( n =1)
pPr	37–42 ( n =3, x =40, SD=2.5)	40–57 ( n =4, x =51, SD=7.7)	37 ( n =1)
PSens	112–137 ( n =8, x =126,	95–120 ( n =7, x =112, SD=8.5)	98 ( n =1)
SD=9.1)
SBp	20–30 ( n =8, x =25, SD=3.3)	20–27 ( n =8, x =24, SD=3.0)	20 ( n =1)
O	22–35 ( n =7, x =31, SD=5.4)	27–42 ( n =7, x =36, SD=5.5)	25 ( n =1)
O-O	310–465 ( n =8, x =399,	300–490 ( n =6, x =410,	215 ( n =1)
SD=53.5)	SD=68.5)
OAS	150–200 ( n =8, x =176,	110–195 ( n =6, x =160,	105 ( n =1)
SD=24.6)	SD=29.5)
ISD	450–565 ( n =8, x =521,	380–525 ( n =7, x =472,	325 ( n =1)
SD=39.76)	SD=47.5)
pDS min	22–28 ( n =8, x =26, SD=2.4)	20–23 ( n =8, x =22, SD=1.1)	24 ( n =1)
pDS max	31–40 ( n =8, x =36, SD=2.7)	31–41 ( n =8, x =36, SD=2.9)	39 ( n =1)
pVS min	24–37 ( n =8, x =29, SD=4.4)	22–26 ( n =8, x =24, SD=1.3)	30 ( n =1)
pVS max	38–49 ( n =8, x =43, SD=3.7)	34–44 ( n =8, x =38, SD=3.7)	38 ( n =1)

( Continued ) Table 1. (Continued).

Character	Females	Males	Deutonymph
GOP	340–420 ( n =8, x =385, SD=28.8)	255–355 ( n =7, x =309, SD=41.8)	62 ( n =1)
AOP Cx I	77–102 ( n =7, x =92, SD=8.6) 207–265 ( n =8, x =231, SD=17.8)	77–90 ( n =8, x =83, SD=4.7) 215–240 ( n =8, x =229, SD=9.5)	67 ( n =1) 160 ( n =1)
Tr I	115–142 ( n =8, x =131, SD=10.1)	117–145 ( n =8, x =132, SD=9.0)	102 ( n =1)
bFe I	200–297 ( n =8, x =260, SD=28.6)	225–282 ( n =8, x =251, SD=16.8)	185 ( n =1)
tFe I	205–325 ( n =8, x =283, SD=37.1)	237–285 ( n =8, x =262, SD=17.4)	182 ( n =1)
Ge I	250–357 ( n =8, x =312, SD=32.3)	262–335 ( n =7, x =296, SD=22.5)	225 ( n =1)
Ti I	267–370 ( n =8, x =341, SD=31.7)	305–350 ( n =6, x =320, SD=17.0)	242 ( n =1)
Ta I (L)	305–405 ( n =8, x =371, SD=37.0)	370–415 ( n =6, x =393, SD=21.1)	230 ( n =1)
Ta I (W)	142–167 ( n =8, x =157, SD=9.9)	185–215 ( n =6, x =200, SD=11.8)	120 ( n =1)
Ta I (L/W)	1.85–2.81 ( n =8, x =2.37, SD=0.289)	1.83–2.24 ( n =6, x =1.97, SD=0.148)	1.92 ( n =1)
Leg I	1575–2132 ( n =8, x =1930, SD=171.2)	1797–2015 ( n =6, x =1885, SD=84.4)	1326 ( n =1)
Cx II	275–342 ( n =8, x =312, SD=24.8)	300–340 ( n =8, x =316, SD=14.7)	190 ( n =1)
Tr II	107–142 ( n =8, x =127, SD=13.7)	100–135 ( n =8, x =116, SD=13.0)	97 ( n =1)
bFe II	95–152 ( n =8, x =139, SD=18.6)	125–152 ( n =8, x =134, SD=8.7)	100 ( n =1)
tFe II	160–215 ( n =8, x =184, SD=17.3)	140–192 ( n =8, x =172, SD=15.6)	112 ( n =1)
Ge II	210–305 ( n =8, x =238, SD=28.9)	195–225 ( n =8, x =212, SD=11.2)	150 ( n =1)
Ti II	222–287 ( n =8, x =247, SD=18.6)	212–245 ( n =8, x =226, SD=10.2)	165 ( n =1)
Ta II	150–205 ( n =8, x =189, SD=18.8)	162–190 ( n =8, x =176, SD=8.2)	127 ( n =1)
Leg II	1220–1642 ( n =8, x =1437, SD=120.1)	1262–1425 ( n =8, x =1352, SD=53.6)	941 ( n =1)
Cx III	230–300 ( n =8, x =254, SD=22.6)	212–255 ( n =8, x =228, SD=13.8)	180 ( n =1)
Tr III	100–135 ( n =8, x =118, SD=10.3)	102–127 ( n =8, x =113, SD=10.8)	92 ( n =1)
bFe III	155–167 ( n =8, x =146, SD=16.0)	127–150 ( n =7, x =140, SD=7.0)	95 ( n =1)
tFe III	162–227 ( n =8, x =200, SD=20.9)	162–212 ( n =7, x =182, SD=16.5)	140 ( n =1)

Table 1.

Character	Females	Males	Deutonymph
Ge III	215–330 ( n =8, x =273, SD=37.6)	225–255 ( n =7, x =238, SD=12.1)	175 ( n =1)
Ti III	217–312 ( n =8, x =278, SD=28.2)	250–295 ( n =7, x =267, SD=17.8)	200 ( n =1)
Ta III	142–215 ( n =8, x =188, SD=22.7)	170–200 ( n =7, x =183, SD=10.1)	125 ( n =1)
Leg III	1190–1657 ( n =8, x =1458, SD=144.0)	1275–1440 ( n =7, x =1352, SD=52.4)	1007 ( n =1)
Cx IV	375–515 ( n =8, x =454, SD=53.4)	430–500 ( n =7, x =446, SD=25.3)	315 ( n =1)
Tr IV	132–180 ( n =8, x =155, SD=14.7)	137–182 ( n =8, x =153, SD=15.8)	112 ( n =1)
bFe IV	180–255 ( n =8, x =236, SD=24.4)	205–255 ( n =7, x =225, SD=15.0)	145 ( n =1)
tFe IV	232–332 ( n =8, x =302, SD=30.7)	265–315 ( n =7, x =285, SD=18.9)	192 ( n =1)
Ge IV	335–430 ( n =8, x =402, SD=32.5)	330–395 ( n =7, x =376, SD=22.7)	250 ( n =1)
Ti IV	332–430 ( n =8, x =406, SD=31.7)	365–395 ( n =7, x =381, SD=12.9)	250 ( n =1)
Ta IV	195–270 ( n =8, x =238, SD=25.5)	217–255 ( n =7, x =231, SD=14.8)	157 ( n =1)
Leg IV	1787–2410 ( n =8, x =2194, SD=196.4)	1997–2275 ( n =6, x =2088, SD=100.3)	1421 ( n =1)
IP	5772–7842 ( n =8, x =7018, SD=620.8)	4697–7155 ( n =6, x =6330, SD=846.2)	4695 ( n =1)

Crista metopica ( Figure 3 ) elongated. Anterior sensillary area oval, with two sensillary setae (ASens) placed slightly behind the mid level of sensillary area and covered with setules along the entire stem. Rod of crista narrow, parallel-sided. Posterior sensillary area drop-like in shape, with two sensillary setae (PSens) moved to the posterior margin of sensillary area. PSens longer than ASens and covered with slightly shorter setules. Posterior process of crista weakly marked, shorter than posterior sensillary area of crista. Eyes ( Figure 3 ) sessile, each composed of single circular lens, placed laterally to the rod of crista metopica, at the level of anterior part of crista, close to half its length. Dorsal opisthosomal setae ( Figures 5 , 6A ) uniform in shape, slightly longer at aspidosoma. Setae oval in outline, stout, densely covered with setules outgoing from the main stem. Setules relatively thick at base, then acuminate. Ventral setae similar to those placed on idiosoma dorsum, also uniform but more slender and with more delicate setules. Genital opening ( Figure 4 ) surrounded by centrovalves and epivalves. Centrovalval setae delicate, covered with setules, which are more densely distributed in proximal part of the stem. Epivalval setae similar in length to centrovalval ones but stouter and with setules covering the entire stem. In females, two pairs of genital acetabulae, sometimes both pairs shifted to one side of genital opening. Anal opening ( Figure 4 ) surrounded by paired valves. Medial valves membraneous, with a row of delicate, sparsely setulose setae arising along the medial margin of each valve. Lateral valves sclerotised, with several setae, which are stouter than those covering the medial valves and arise along the lateral margin of each sclerite. Figure 1. Leptus molochinus (C. L. Koch, 1837 ) , adult, female. Habitus. Figure 2. Leptus molochinus (C. L. Koch, 1837 ) , adult, female. Palp, lateral aspect. Figure 3. Leptus molochinus (C. L. Koch, 1837 ) , adult, female. Crista metopica and eyes (chaetotaxy beyond crista metopica omitted). Figure 4. Leptus molochinus (C. L. Koch, 1837 ) , adult, female. Genital and anal region (chaetotaxy beyond genital sclerites omitted, genital acetabulae superimposed on each other). Figure 5. Leptus molochinus (C. L. Koch, 1837 ) , adult, female. Dorsal opisthosomal setae, lateral view. Legs IV slightly longer than legs I. Legs II and III the shortest ( Figure 1 ). Leg segments covered with setae of different type : normal, densely setulose setae ( Figure 6B ) present on all leg segments, confined on tarsi to dorsal part of the segment; more slender and more sparsely setulose setae ( Figure 6C ) present also on coxae; normal, brush-like setae ( Figure 6F ) aggregated along the ventral side of tarsi [setae covering tarsi gradually pass from the robust ones ( Figure 6B ), which are located dorsally, into brush-like setae ( Figure 6F ), which dominate along the ventral part of the segment]; few setae, covered with very short setules ( Figure 6D ), sparsely distributed on all segments, beyond trochanters; few setae of the same type , however slightly thicker and longer ( Figure 6E ) located ventrally at termination of tibiae II–IV; setae of “eupathidium type ” ( Figure 6G ) (spinalae according to Southcott (1961) arise along the dorsal side of all telofemora, genua, tibiae and on tarsus I; c . 3–4 vestigialae ( Figure 6H ), narrowed apically, located distally on tibia I, few solenidia ( Figure 6I ) scattered between spinalae on tarsus I; famulus ( Figure 6J ), rounded apically, present on terminal part of tarsus I. Larva ( Figures 7–15 ). For morphometric data see Table 2 . Gnathosoma ( Figures 7–9 , 11 , 12 ): chelicera composed of basal segment and movable claw. Dorsal side of gnathosoma ( Figure 8 ) with a pair of setiform adoral setae ( cs ) placed anteriorly and a pair of club-shaped supracoxal setae ( elcp ) located posterolaterally. Ventrally on gnathosoma ( Figure 9 ) a pair of very short (ca. 3) spine-like setae ( as ) and a pair of subcapitular (tritorostral) setae ( bs ), covered with few short setules. Pedipalp formula: 0-B-B-BBN-NNBBB wz . Palp femur and palp genu ( Figures 8 , 9 ) with one setulose seta. Palp tibia ( Figures 8 , 9 ) with two barbed setae and one smooth spinelike seta, the latter located close to the odontus base. Odontus simple. Palp tarsus ( Figures 7 , 12 ) with five normal setae, of which three are covered with distinct setules and the remaining two are smooth, one solenidion ( w ) located in proximal part of the segment and one prominent distal eupathidium ( z ). Figure 6. Leptus molochinus (C. L. Koch, 1837 ) , adult, female. Setae: (A) dorsal opisthosomal seta; (B–J) normal and specialised setae on legs: (B–F) normal setae; (G) spinala; (H) vestigiala; (I) solenidion; (J) famulus. Dorsal side of idiosoma: scutum ( Figure 8 ) triangular in outline, the widest anteriorly, rounded at corners, with two pairs of non-sensillary setae (AL and PL) and two pairs of trichobothria (ASens and PSens). Setae AL slightly shorter than PL, both thickened and covered with setules along the entire stem. ASens shorter than PSens, both with setules covering the distal half of the stem. Single eyes on circular sclerites located at the level of posterior part of scutum. The remaining part of idiosoma with cuticle folded in lines. Dorsal setae situated on small platelets and covered with setules evenly distributed along the entire stem. The number of setae in f D formula, except for those located on scutum, varies between 56 and 69 ( n = 5). Table 2. Morphometric data on larvae of Leptus molochinus (C. L. Koch, 1837 ) .

Character	New data		SOUTHCOTT
(1992)*
Larvae obtained	Larvae collected in the field	Larvae
by experimental rearing	collected
in the field
LB	392–530 ( n =27, x =454,	–	415–845 ( n =2)
SD=36.2)
LW	269–372 ( n =26, x =321,	–	270–590 ( n =2)
SD=29.2)
PaTr	22–32 ( n =14, x =28,	23–32 ( n =12, x =28, SD=2.5)	–
SD=2.9)
PaFe	38–46 ( n =14, x =42, SD=2.3)	40–47 ( n =12, x =43, SD=2.0)	–
PaGe	49–57 ( n =14, x =54, SD=2.3)	50–59 ( n =12, x =54, SD=2.5)	–
PaTi	15–19 ( n =14, x =17, SD=1.3)	15–20 ( n =12, x =18, SD=1.4)	–
PaTa	17–20 ( n =14, x =18, SD=0.9)	16–22 ( n =12, x =19, SD=1.7)	–
Odo	21–25 ( n =14, x =23, SD=1.3)	22–25 ( n =12, x =23, SD=0.8)	–
L	88–111 ( n =28, x =97, SD=4.4)	95–107 ( n =10, x =101,	91–109 ( n =13)
SD=4.3)
W	94–112 ( n =28, x =102,	98–109 ( n =11, x =103,	92–107 ( n =14)
SD=4.1)	SD=3.5)
ASens	41–50 ( n =28, x =44, SD=2.5)	38–49 ( n =10, x =43, SD=3.6)	36–48 ( n =12)
SBa	9–13 ( n =28, x =11, SD=1.1)	10–14 ( n =12, x =12, SD=1.0)	10–14 ( n =14)
PSens	57–78 ( n =28, x =70, SD=5.5)	60–76 ( n =8, x =69, SD=6.4)	55–73 ( n =15)
SBp	11–17 ( n =28, x =14, SD=1.7)	12–17 ( n =12, x =14, SD=1.7)	14–18 ( n =14)
AL	45–54 ( n =28, x =48, SD=2.5)	42–55 ( n =12, x =50, SD=4.2)	40–53 ( n =15)
AW	71–86 ( n =28, x =80, SD=3.5)	73–81 ( n =11, x =77, SD=2.8)	72–81 ( n =14)
PL	58–73 ( n =28, x =67, SD=3.6)	61–76 ( n =12, x =68, SD=4.2)	57–71 ( n =15)
PW	81–100 ( n =28, x =92, SD=4.5)	84–97 ( n =11, x =91, SD=3.7)	84–98 ( n =14)
ISD	58–75 ( n =28, x =66, SD=3.4)	62–75 ( n =12, x =67, SD=4.2)	58–69 ( n =16)
DS max	50–67 ( n =14, x =59, SD=4.4)	57–65 ( n =9, x =62, SD=2.8)	48–62 ( n =18)
St I	32–40 ( n =11, x =37, SD=2.9)	36–37 ( n =2, x =36, SD=0.7)	24–36 ( n =15)
St II	32–42 ( n =11, x =39, SD=2.8)	38 ( n =2, x =38, SD=0)	29–43 ( n =15)
Co I	65–74 ( n =11, x =69, SD=2.7)	61–74 ( n =12, x =66, SD=4.4)	55–68 ( n =15)
Co II	27–32 ( n =10, x =30, SD=1.8)	25–31 ( n =10, x =28, SD=1.9)	22–31 ( n =16)
Co III	34–42 ( n =9, x =39, SD=2.5)	32–41 ( n =12, x =36, SD=2.7)	30–39 ( n =17)
Cx I	50–71 ( n =28, x =62, SD=4.6)	53–70 ( n =12, x =63, SD=4.2)	–
Tr I	35–45 ( n =28, x =38, SD=2.7)	35–46 ( n =12, x =39, SD=2.9)	–
bFe I	50–65 ( n =28, x =58, SD=3.3)	50–66 ( n =12, x =59, SD=3.9)	–
tFe I	45–57 ( n =28, x =52, SD=2.8)	52–57 ( n =12, x =54, SD=1.8)	–
Ge I	70–87 ( n =28, x =77, SD=4.1)	77–90 ( n =12, x =83, SD=5.0)	75–90 ( n =18)
Ti I	91–107 ( n =28, x =98, SD=3.6)	90–106 ( n =12, x =98,	85–106 ( n =17)
SD=5.0)
Ta I (L)	100–120 ( n =28, x =110,	100–116 ( n =11, x =108,	90–109 ( n =17)
SD=4.2)	SD=5.5)
Ta I (W)	27–35 ( n =28, x =32, SD=2.3)	22–37 ( n =11, x =30, SD=4.8)	22–32 ( n =17)
Leg I	463–517 ( n =28, x =495,	469–538 ( n =11, x =504,	500 ( n =1)
SD=13.8)	SD=22.4)

Table 2.

Character	New data		SOUTHCOTT
(1992)*
Larvae obtained	Larvae collected in the field	Larvae
by experimental rearing	collected
in the field
Cx II	77–90 ( n =28, x =84, SD=3.2)	75–90 ( n =12, x =85, SD=4.6)	–
Tr II	35–42 ( n =28, x =38, SD=2.4)	38–42 ( n =12, x =40, SD=0.9)	–
bFe II	47–62 ( n =28, x =54, SD=3.1)	50–60 ( n =12, x =55, SD =3.2)	–
tFe II	47–61 ( n =28, x =52, SD=3.2)	52–60 ( n =12, x =55, SD =2.9)	–
Ge II	65–85 ( n =28, x =73, SD=4.8)	70–82 ( n =12, x =77, SD=3.8)	70–79 ( n =16)
Ti II	82–103 ( n =28, x =93, SD=4.5)	91–105 ( n =10, x =95,	86–103 ( n =15)
SD=4.9)
Ta II (L)	94–109 ( n =28, x =102,	94–111 ( n =9, x =99, SD=5.4)	82–97 ( n =16)
SD=4.4)
Ta II (W)	24–33 ( n =28, x =30, SD=2.1)	22–34 ( n =9, x =27, SD=4.2)	22–28 ( n =17)
Leg II	459–533 ( n =28, x =497,	480–538 ( n =9, x =505,	505 ( n =1)
SD=16.9)	SD=17.9)
Cx III	70–84 ( n =28, x =76, SD=3.1)	72–89 ( n =12, x =79, SD=5.2)	–
Tr III	38–47 ( n =28, x =42, SD=2.2)	38–48 ( n =12, x =42, SD =2.8)	–
bFe III	53–71 ( n =28, x =61, SD=4.2)	55–68 ( n =12, x =61, SD =3.1)	–
tFe III	59–69 ( n =28, x =63, SD=2.8)	58–68 ( n =12, x =64, SD=2.7)	–
Ge III	75–91 ( n =28, x =81, SD=4.3)	80–89 ( n =12, x =83, SD=3.1)	74–91
( n =16)
Ti III	105–134 ( n =28, x =121,	115–130 ( n =12, x =122,	107–133
SD=6.2)	SD=5.7)	( n =16)
Ta III (L)	94–116 ( n =28, x =106,	94–111 ( n =11, x =104,	80–105
SD=4.8)	SD=5.3)	( n =16)
Ta III (W)	20–29 ( n =28, x =25, SD=2.3)	20–30 ( n =11, x =25, SD=3.9)	21–27
( n =16)
Leg III	509–591 ( n =27, x =549,	530–593 ( n =11, x =553,	550 ( n =1)
SD=18.8)	SD=20.8)
IP	1432–1640 ( n =28, x =1541,	1491–1654 ( n =9, x =1555,	1555 ( n =1)
SD=46.1)	SD=58.8)
L/W	0.87–1.02 ( n =28, x =0.96,	0.91–1.02 ( n =10, x =0.98,	0.94–1.12
SD=0.035)	SD=0.035)	( n =12)
AW/AL	1.48–1.83 ( n =28, x =1.65,	1.38–1.76 ( n =11, x =1.56,	1.53–1.83
SD=0.090)	SD=0.124)	( n =12)
AW/ISD	1.08–1.29 ( n =28, x =1.21,	1.01–1.27 ( n =11, x =1.15,	1.07–1.28
SD=0.053)	SD=0.069)	( n =14)
AL/PL	0.64–0.83 ( n =28, x =0.72,	0.69–0.80 ( n =12, x =0.73,	0.63–0.82
SD=0.039)	SD=0.038)	( n =14)
PW/AW	1.07–1.23 ( n =12, x =1.15,	1.13–1.22 ( n =11, x =1.18,	1.13–1.21
SD=0.031)	SD=0.032)	( n =14)
Ti I/AW	1.14–1.32 ( n =28, x =1.22,	1.17–1.39 ( n =11, x =1.28,	1.16–1.36
SD=0.048)	SD=0.067)	( n =14)
Ti I/Ge I	1.14–1.47 ( n =28, x =1.26,	1.13–1.28 ( n =12, x =1.18,	1.05–1.29
SD=0.069)	SD=0.043)	( n =17)

( Continued ) Table 2. (Continued).

Character	New data		SOUTHCOTT
(1992)*
Larvae obtained	Larvae collected in the field	Larvae
by experimental rearing	collected
in the field
Ti II/PW	0.92–1.17 ( n =28, x =1.02,	0.98–1.15 ( n =9, x =1.06,	1.00–1.31
SD=0.059)	SD=0.064)	( n =13)
Ti II/Ge II	1.11–1.40 ( n =28, x =1.27,	1.13–1.37 ( n =10, x =1.25,	1.16–1.34
SD=0.062)	SD=0.065)	( n =15)
Ti III/AW	1.35–1.60 ( n =28, x =1.51,	1.47–1.71 ( n =11, x =1.59,	1.47–1.72
SD=0.069)	SD=0.080)	( n =14)
Ti III/Ge III	1.39–1.62 ( n =28, x =1.49,	1.38–1.60 ( n =12, x =1.46,	1.35–1.58
SD=0.064)	SD=0.077)	( n =16)
Ti III/Ti I	1.14–1.34 ( n =28, x =1.24,	1.16–1.30 ( n =12, x =1.24,	1.15–1.36
SD=0.049)	SD=0.041)	( n =16)

Note: *Data provided for the series of specimens representing L. ignotus ignotus sensu Southcott (1992) , the range of metric characters extended for verified data of the holotype and of two specimens of L. zbelutkaicus Haitlinger, 1987 , synonymised by Southcott (1992) with L. ignotus ignotus . Ventral side of idiosoma ( Figure 9 ): ventral setae (including coxalae and intercoxalae) similar to those covering the idiosoma dorsum but slightly narrower at termination. The number of setae in f V formula, except for coxalae and intercoxalae I, II, III varies between 28 and 37 ( n = 5), which makes the total number of setae in f D and f V formula 93–100. Coxal setation formula: 1-1-1. Setae 1b, 2b, 3b located on coxae I, II, III respectively; 1b in centrolateral position, 2b in posterolateral position and 3b shifted to anterior margin of coxal plate. Setae 1a, 2a, 3a 1 –a 2 placed between coxal plates I, II, III, respectively; 1a, at the level of symmetry axis of coxa I; 2a, slightly moved to the level of anterior part of coxa II; 3a 1 , before the level of coxa III; and 3a 2 , at the level of symmetry axis of coxa III. Legs ( Figures 10 , 13–15 ): leg segmentation formula: 7-7-7. For leg chaetotaxy see Table 3 . Normal setae on legs covered with setules. Setae on trochanters stouter than those covering the remaining leg segments. Solenidia present on genu I, tibia I and tarsus I, tibia II ( Figure 13 ) and tarsus II and also on tibia III. Tarsal solenidia stouter than the others. Vestigialae present on genu I, tibia I and on genu II ( Figure 13 ). Famulus on tarsus I located anteriorly to solenidion. Subterminal eupathidia present on tarsi I–III. All tarsi terminated with two claws and claw-like empodium ( Figures 10 , 14 , 15 ). Anterior claw stout, with short hairy setules covering threequarters of its length, proximally. Posterior claw feather-like. Claws without terminal hooks. Empodium with very short setules, evenly distributed along the whole shaft. The cuticle covering tarsi arranged in transverse folds ( Figure 14 ), especially distinct in distal part of the segments (character visible with both light and scanning electron microscopes). Figure 7. Leptus molochinus (C. L. Koch, 1837 ) , larva. Details of palp tarsus. Type material Neotype . Female ( PL – H/941) collected in Wroclaw (south-west Poland ), on the Odra R . shore ( 51º05′43′′ N , 17º05′37′′ E ), 3 June 2005 , by J. Laydanowicz , deposited at Biocentrum Grindel und Zoologisches Museum , Hamburg ( ZIMH ), Germany . Additionally, three larvae of L. molochinus , obtained from female selected as neotype , deposited in ZIMH . The remaining material is in the author’s collection ( Institute of Biology , Department of Invertebrate Systematics and Ecology , Wroclaw University of Environmental and Life Sciences ) . Distribution Europe. Biology Besides the members of Leptus , preliminarily assigned to two distinct species, another 10 species of Parasitengona terrestria were recorded sympatrically from the study plot ( Laydanowicz and Mąkol 2008 ). Altogether, 62 adults of L. molochinus ( 29 females , nine males , 24 adults of undetermined sex), four postlarval specimens not assigned to the stage, one protonymph and 17 larvae , preliminarily assigned to “ L. ignotus ”, were collected in the field. Adults were observed in the field from the end of May until the beginning of July, with the highest abundance in June ( 58 specimens , including 26 females , eight males , 24 adults of undetermined sex). The only deutonymph emerged under laboratory conditions from a protonymph that was collected in the field in March. Larvae of “ L . ignotus ” were collected in the field from mid-August for about 5 weeks. Field-collected females deposited eggs under laboratory conditions. The time between collecting of the female and oviposition varied between 3 and 21 days ( n = 29, mean = 9.1). The emergence of larvae during the laboratory experiment was observed from the beginning of July until the beginning of August. The number of larvae that emerged from eggs deposited by one female varied between 3 and 138 ( n = 29, mean = 41.7) and the time that elapsed between oviposition and appearance of larvae ranged from 23 to 32 days ( n = 10, mean = 26.6). Figure 8. Leptus molochinus (C. L. Koch, 1837 ) , larva. Dorsal side of the body (legs omitted beyond trochanters). Figure 9. Leptus molochinus (C. L. Koch, 1837 ) , larva. Ventral side of the body (legs omitted beyond trochanters). Figure 10. Leptus molochinus (C. L. Koch, 1837 ) , larva. (A) Leg I; (B) leg II; (C) leg III. Of the total number of field-collected larvae, 11 specimens were collected together with hosts. Specification of host taxa is given in Table 4 . In most cases one parasite was observed on a particular host, except for two cases in which two specimens were found on Opiliones and Acari . Attachment site on the host varied and no site preference was observed. Similarly, no change of the chosen attachment site was observed during the parasitic phase. The larvae detached from the host easily, usually as a result of mechanical irritation, which in case of insufficiently engorged specimens made further development into a protonymph impossible.