Tetrabdella neotropica Hernandes & Feres

Hernandes, Fabio A. & Feres, Reinaldo J. F., 2006, Tetrabdella neotropica (Acari: Bdellidae), a new genus and species from Brazil, Zootaxa 1135, pp. 57-68 : 60-67

Tetrabdella neotropica Hernandes & Feres n. sp.

Adult

Females and males similar, except for the usual differences in internal genitalia. Dorsum. Propodosomal striae longitudinal/oblique, with a sparsely broken and lobed pattern medially in adults ( Figs.8 , 16 ); two pairs of eyes separated by 10 m and diagonal striae between them ( Fig. 16 ); dorsal setae strongly plumose ( Fig.8 ); Venter. Genital valves each with 8 club­shaped setae ( Fig.9 , 17 a), proximal pair slender; 24–26 aggenitals; 1 unpaired seta between coxa IV; anal opening ventro­terminal with four paired setae ( Fig. 10 ); genital tracheae well developed; Gnathosoma. Chelicera with longitudinal striae ( Fig. 7 ), two pairs of strong setae dorsally, fixed and movable digits scissorlike; venter of hypostome with two pairs of strong setae, two minute pairs of adoral setae distally and two small dorsal setae ( Fig.5 ); palp chaetotaxy: trochanter 0; basifemur 3; telofemur 1; genu 3; tibiotarsus 3 tactiles plus 2 long tactile end setae ( Fig.6 ). Legs. ( Figs.1–4 , measurements shown on Table 2 ). Broken striae on dorsal tarsi distally. Chaetotaxy ( Fig.17 ): coxa I 5–6 club­shaped ( Fig.17 a), 1 long slender ( Fig.17 b); coxa II, III and IV club­shaped ( Fig.17 a, number shown in Table 1 ); trochanters I and II 1 long slender ( Fig.17 b), trochanter III 1 club­shaped ( Fig.17 a), 1 swordlike ( Fig.17 c), trochanter IV 1 club­shaped ( Fig.17 a); basifemur I 3 short slender ( Fig.17 d), 1 fine dorsal ( Fig.17 c), basifemur II 3 short slender ( Fig.17 d), 1 pectinate dorsal ( Fig.17 e), basifemur III 2 swordlike ( Fig.17 c), 2–3 plumose ( Fig.17 f–g), basifemur IV 2 short slender (Fig.d), 1 swordlike ( Fig.17 c), 1 plumose ( Fig. 17 g); telofemur I 2 short slender ( Fig.17 d), 2 swordlike ( Fig.17 c), telofemur II 1 short slender ( Fig.17 d), 3–4 plumose ( Fig. 17 g), telofemur III 4 plumose ( Fig.17 f–g–h), telofemur IV 5 plumose ( Fig.17 f–h); genu I 1 tactile ( Fig.17 j), 1 short slender ( Fig.17 d), 2 swordlike ( Fig.17 c), 1 attenuate sensory () ( Fig. 17 i), genu II 1 tactile ( Fig.17 j), 1 swordlike ( Fig.17 c), 2 plumose ( Fig. 17 g), 1 attenuate sensory () ( Fig. 17 i), genu III 1 tactile ( Fig.17 j), 4 plumose ( Fig.17 f–g–h), 1 attenuate sensory () ( Fig. 17 i), genu IV 1 tactile ( Fig.17 j), 6 plumose ( Fig. 17 g); tibia I 1 attenuate sensory ()( Fig. 17 i), 1 peglike ( Fig.17 k), 9–10 tactile ( Fig.17 j), tibia II 9–11 tactile ( Fig.17 j), tibia III 1 attenuate sensory () ( Fig. 17 i), 9–10 tactiles ( Fig.17 j), tibia IV 10 tactile ( Fig.17 j); tarsus I 1 attenuate sensory () ( Fig. 17 i), 1 blunt sensory ()( Fig.17 l), 2 slender trichobothrium­like seta ( Fig. 17 m), 4 dorsoterminal ( Fig.17 n), 11–16 tactile ( Fig.17 j), 1 duplex setae in larvae ( Fig. 17 q), tarsus II 1 blunt sensory ()( Fig.17 l), 1 slender trichobothrium­like ( Fig. 17 m), 4 dorsoterminal ( Fig.17 n), 14–17 tactile ( Fig.17 j), tarsus III 1 trichobothrium ( Fig.17 o), 6 dorsoterminal, 1 long tactile ( Fig.17 p), 10–13 tactile ( Fig.17 j), tarsus IV 1 trichobothrium ( Fig.17 o), 1 long tactile ( Fig.17 p), 16–18 tactiles ( Fig.17 j), 4 dorsoterminal ( Fig.17 n).

Immatures

There are 4 immature stages in Tetrabdella neotropica n. sp., which differ mainly on the numbers of genital and aggenital setae ( Figs. 11–13 , Table 4 ), number of leg setae ( Table 1 ), and adoral setae on hypostome ( Table 4 ). tritonymph: 4 pairs of genital setae on genital valves, the anterior pair slender; 9 pairs plus 2 unpaired aggenital setae between coxae IV; deutonymph: 1 pair of genital setae on genital valves; 5 pairs plus 1 unpaired aggenital between coxae IV; protonymph: no seta on genital valves; 3 pairs plus 1 unpaired aggenital seta between coxae IV; larva: neither genital valve, genital nor aggenital setae present. Dorsum and gnathosoma are similar to described for adult, except for the smaller size and propodosomal striae that are thinner and continuous in immatures (rather than sparsely broken like in adults). Larva bears only one pair of minute adoral setae at tip of hypostome (2 pairs in subsequent stages). Venter of hypostome bears two ventral pairs in all stages. Additional differences are shown in Table 4 .

Stage Leg coxa trochanter basifemur Telofemur genu tibia tarsus Diagnosis

This new species shares many similarities with Spinibdella mali Jorgensen (1967: 98) : longitudinal striae sparsely broken on central region of propodosoma, with irregular small lobes ( Fig. 16 ); 4 setae on palp femur and 5 setae on palp tarsus; central region of hysterosoma with transverse striae; lateral hysterosoma with longitudinal striae; two pair of eyes separated by diagonal striae. It can be distinguished by the latter by having trichobothria present on tarsi III and IV, 8 setae on each genital valve (rather than 6 as in S. mali ), and by the chaetotaxy of tarsi. Leg chaetotaxy, body dimensions and length of dorsal setae are shown on Tables 1 , 2 and 3 , respectivelly. The specimens present asymmetry in leg chaetotaxy (Table I).

*without rostrum; ** Palpal segments I–V: trochanter, basifemur, telofemur, genu and tibiotarsus, respectivelly.

Remarks

The specimens were found mostly at the base of rubber tree leaflets, inside a silken cocoon where they probably moult ( Hernandes & Feres 2006). A similar moulting behavior is reported for Spinibdella cronini ( Baker & Balock) and Biscirus thori Womersley in woodlands, forests and grasslands of Australia ( Wallace & Mahon 1972).

According to Hernandes & Feres (2006) T. neotropica occur in large number at the transition from the dry to the rainy season (October to January) in the northwestern region of the State of São Paulo, Brazil. In the laboratory, they were observed feeding on Tetranychus ogmophallos Ferreira & Flechtmann (Acari: Tetranychidae ), a pest of Arachis hypogaea L. (peanut) and A. pintoi Krapov & Gregory (ornamental plant).

Type material

Holotype male (n. 6174), Hevea brasiliensis , 18.XII.2002, Cedral (20o55’30’’S, 49o26’49’’W), São Paulo, Brazil. Paratypes: 5 males (19.II.2001, 27.III.2002, 20.XI.2002, 24.XI.2003), 2 females (26.VIII.2003, 24.XI.2003), 4 tritonymphs (20.XI.2002, 26.VIII.2003), 3 deutonymphs (19.VI.2001, 23.IV.2003, 31.X.2003), 3 protonymphs (19.VI.2001, 26.XI.2001, 20.XI.2002) and 3 larvae (19.II.2001, 19.XII.2001, 24.XI.2003), from same host and locality, 1 female from Poloni, São Paulo, Brazil (20o42’24”S, 49o58’16”W) (26.VI.2002), same host, deposited at DZSJRP (n.6175 to n.6193), and 1 paratype male, 19.II.2001, from the same host and locality as holotype, deposited at USDA, Beltsville, Maryland, USA.

Etymology

The generic designation refers to the four trichobothriae, on tarsi III and IV, unique character of the new genus; and the species neotropica , refers to the Neotropical region, where this species was collected.

Figures

FIGURE 16. dorsal propodosoma of adult Tetrabdella neotropica gen. n., sp. n., phase contrast photomicrograph.

FIGURE 17. Hypothetical leg of Tetrabdella neotropica gen. n., sp. n. showing type and position of leg setae (dark circles = dorsal, light circles = ventral, dark / light circles = dorsal and ventral). a: club – shaped; b: long slender; c: like sword; d: short slender; e: pectinate dorsal; f – g – h: plumose; i: attenuate sensory –; j: tactile; k: peglike; l: blunt sensory; m: slender trichobothrium­like; n: dorsoterminal; o: trichobothrium; p: long tactile; q: duplex seta.

FIGURES 5 – 10. Tetrabdella neotropica gen. n., sp. n.: venter of hypostome (5), palp (6), chelicera (7), dorsum (8), genital (9) and anal region (10).

FIGURES 1 – 4. Tetrabdella neotropica gen. n., sp. n.: tibia and tarsus of adult (I to IV, respectively).

FIGURES 11 – 15. genital region of Tetrabdella neotropica gen. n., sp. n.: protonymph (11), deutonymph (12), tritonymph (13); female ovipositor (14) and male genitalia (15).

Tables

TABLE 2: Measurements of Tetrabdella neotropica n. gen., n. sp.

Stage	body length	idiosoma* width	leg I	leg II	Leg III	Leg IV	palp I**	palp II**	palp III**	palp Palp IV** V**
Female (3)	693– 759	550–616 319– 341	275– 286	297– 341	374– 396	396– 423	11– 14	82	19– 27	16–19 38– 43
Male (6)	649– 737	638–737 253– 352	264– 286	275– 319	319– 352	363– 396	11	73– 95	22– 27	16–19 38– 41
Tritonymph (4)	616– 638	627–649 275– 319	220– 253	253– 275	297– 319	330– 352	8	60– 68	22– 27	16 35– 38
Deutonymph (3)	517– 577	506–627 231– 264	187– 220	209– 220	264– 275	264– 286	8	63– 68	14– 16	14 33– 35
Protonymph (3)	363– 473	374–462 165– 231	154– 187	165– 198	198– 242	187– 231	8	46– 54	14– 19	11–14 24– 27
Larva (3)	335– 368	330–363 165– 187	132– 154	154	176– 187	–	8	43– 46	8–11	8–11 22– 24

TABLE 1: Leg chaetotaxy of Tetrabdella neotropica n. gen., n. sp., showing variations on some individuals.

Adult I 6–7 1	4	4–5	5 11–12 19–24
II 3–5 1	4–5	4–6	4–5 9–11 20–23
III 4–5 2	4–5	4	6 10–11 18–21
IV 3–4 1	3–4	4–5	6–8 10 18–20
Tritonymph I 6–5 1	3	2	5 8 19
II 4–3 1	3	3	5 7 18
III 4–5 1	3–4	4	5 7 15–17
IV 2–3 1	2	4	5 6 14–16
Deutonymph I 4 1	2	2	5 7 16
II 3 1	2	3	4–5 6 15
III 3–4 2	1	3	4–5 6 14
IV 2 1	1	3	4 4 12–13
Protonymph I 4 1	2	2	5 6–7 16
II 2 1	2	3–4	5 6 15
III 3 1	1	3	5 6 13
IV 0 0	0	­	0 1 7
Larva I 2 0	4	­	5 7 14
II 1 0	5	­	5 6 13
III 2 0	4	­	5 5 11

TABLE 4: Characters for recognizing life­history stages of Tetrabdella neotropica n. gen., n. sp.

	Number of legs (pairs)	Number of genital setae	Duplex seta on tarsus I	Number of adoral setae on hypostome	Trichobothria on tarsi III and IV	Femora divided
Larva	3	0	yes	1 pair	1, 0	no
Protonymph	4	0	no	2 pairs	1, 1	basi + telofemora, except leg 4
Deutonymph	4	1	no	2 pairs	1, 1	basi + telofemora
Tritonymph	4	4	no	2 pairs	1, 1	basi + telofemora
Adul	4	8	no	2 pairs	1, 1	basi + telofemora

TABLE 3: Measurements of dorsal setae of Tetrabdella neotropica n. gen., n. sp.

stage	vi	ve	sci	sce	C1	c2	d1	e1	f1	f2	h1	h2
Female (3)	49– 54	33– 38	27– 30	44– 52	23– 24	27– 35	26– 27	24– 27	24– 27	24– 28	27– 30	27– 31
Male (6)	49– 54	33– 38	22– 30	46– 54	22– 27	30– 33	22– 27	22– 27	22– 27	22– 30	24– 33	27– 35
Tritonymph (4)	49– 52	27– 33	19– 22	43– 46	22– 22	22– 27	22– 22	19– 22	19– 22	22– 24	22– 24	27– 27
Deutonymph (3)	38– 46	19– 24	19– 24	38– 46	16– 19	19– 22	16– 19	16– 16	16– 16	22– 22	22– 22	22– 22
Protonymph (3)	35– 41	16– 16	14– 16	27– 41	14– 16	16– 19	14– 16	14– 14	14– 16	16– 19	19– 22	24– 24
Larva (3)	33– 38	16– 16	14– 14	33– 35	13– 16	14– 16	16– 19	14– 19	16– 22	19– 22	24– 27	24– 27