Ricinus dalgleishi Nelson, 1972

Valan, Miroslav, Sychra, Oldrich & Literak, Ivan, 2016, Redescriptions and new host records of chewing lice of the genus Ricinus (Phthiraptera: Ricinidae) from the Neotropical Region, Zootaxa 4154 (2), pp. 179-189 : 180-182

Ricinus dalgleishi Nelson, 1972

( Figs 1–6 , 19 , Table 1)

Ricinus dalgleishi Nelson, 1972: 82 , plate 22, figs 1–5. Ricinus dalgleishi Nelson, 1972 ; Price et al. 2003: 247.

Type host. Geothlypis trichas (Linnaeus, 1766) —Common yellowthroat ( Passeriformes : Parulidae )

Type locality. State College , Mississippi, United States of America.

Diagnosis. This species belongs to the marginatus species-group ( Nelson 1972) by having lunar nodi, no ovoid sclerite evident, and mandibles without finger-like extension. By having 4 setae on the paramere apices, R. dalgleishi is distinguished from Ricinus marginatus ( Children, 1836) , Ricinus pallens ( Kellogg, 1899) , and Ricinus emersoni Nelson, 1972 , which have 3 setae. Further, it differs from Ricinus dendroicae Nelson, 1972 , Ricinus picturatus ( Carriker, 1902) and Ricinus frenatus ( Burmeister, 1838) in having setae a6, and from Ricinus flavicans Carriker, 1964 , Ricinus seiuri Nelson, 1972 and Ricinus polioptilus Carriker, 1964 in having temple apices hooked outside.

Description. Head subconical, with straight lateral margins. Frons narrowly convex; lateral margins convergent in the front and rounded; not continuous with head lateral margin. Temple apices acute, hooked outside. Occipital margin nearly straight. Eyes protruded. Transverse carina present; nearly straight. Lunar nodi present; tentorial nodi present; and lunar nodi nearly equal to tentorial. Mandibles monomorphic; blades long, thin and sharp needle-like; tips not notched; galea not evident; basal lobe without finger-like process. Maxillary plates sickle shaped (sausage-like); pigment pattern absent; palpi geniculate; not reaching the margin of head. Ovoid sclerite not evident. Gula with 2 pairs of setae; top of gular plate sclerite truncate; medial part with concavity; posterior projections present; directing posteriorly. Anterior margin of labium concave.

The cf series composed of 10 setae; df series present; f1 evidently longer than f2; a1 far shorter than m4; with two associated sensilla; a3 absent; a4 present; a6 present; m1–m3 equal; m2 off the marginal carinae; m4 evidently longer than pa. Labium with 13 pairs of setae. Mental setae positioned laterally to each other. Preantennal setae strongly spinose. Setae along the antennal lappets 12–13. Three pilose, subequal postocular setae.

Thorax. Prothorax hexagonal; anterior margin distinctly concave; lateral margins slightly notched; posterior margin concave. Posterolateral angles of prothorax slightly pointed. Prosternal sclerites thin, parallel, not joined. Anterior margin of sternal plate rounded, without lateral depression; posterior angles acute. L3 present; L6 present; L5 nearly equal to L4 and L6; L9 evidently shorter than L7 and L8; c4 present; c1 twice or more longer than c2; c2 pilose; c3 twice or more longer than c4; w series composed of 6 setae; anterior setae unequal. Long sternal setae situated medially on pterothorax 3; q series composed of 2 spines; q2 strongly spinose; q2 not shorter than w series; b1 evidently shorter than b2. Coxa I with 2 tactile setae; femur I with 2 tactile setae; femur II and III with present tactile setae.

Abbreviations: a, dorsal setae on temples; ant. n., antennal nodi; b, dorsal setae on posterior margin; c, 4 pairs of dorsal setae on pterothorax; d, dorsal setae on head; dps, dorsal pleural setae; L, lateral prothoracic setae; lun. n., lunar nodi; m, dorsoventral setae on marginal carinae; max. palp., maxillary palpi; max., maxillary setae; ment., mental setae; pa, paraantennal setae; pm, paramental setae; po, postocular setae; pr, dorsal prothoracic setae; preant., preantennal setae; prst. pl., prosternal plate; prst. s., prosternal plate setae; ps. s., postspiracular setae; q, ventral and submarginal setae on pterothorax; sc, sternal central setae; sen., sensilla; sl, sternal lateral setae; spir., spiracle; st. s., sternal setae; t, dorso-lateral setae on temples; tent. n., tentorial nodi; term. s., terminal setae of tergite IX; VI–VIII, tergites; vps , ventral pleural setae; w, series of lateral setae on pterothorax. Scale bars are in mm. Note: Complete anal fringes are drawn as in Nelson (1972).

Abdomen. Lateral margin of abdomen nearly straight. Segment IX nearly equal to VIII. Pleural nodi on segment IX present, relatively wide, margins smooth; lateral part of abdominal pleurites lightly pigmented.

Second ventral pleurite with 3 setae; II vps 1–3 large spinose; III vps 1–2 small spinose; III vps 3 small spine; IV vps 1 large spine; IV vps 2 long pilose; IV vps 3 large spine; V vps 1 small spine; V vps 3 small pilose; VI vps 1,3 small pilose; VII vps 1,3 small pilose; VIII vps 1 small pilose; VIII vps 3 moderately long pilose. Two pairs of setae on tergite VIII. Sternolateral setae equal to sternocentral on II–VI sternites. Vulva with 4 setae. Abdominal segment IX with 2 long terminal setae.

Male genitalia. Symmetrical, basal plate narrow anteriorly and lateral margin slightly concave. Parameres triangular, with blunt endings. Mesosomal plate pigmented, lightly pointed and without medial extension. Four setae on the distal tips of the parameres.

Dimensions. Female (n = 8). Head length 0.66–0.67; width 0.59–0.60; head index 110–113. Labrum width 0.28–0.29. Prothoracic length 0.31–0.32. width 0.52–0.53, ratio 0.59–0.60. Distance between prosternal setae 0.063–0.072. Abdominal width 0.82–0.85. Total length 3.20–3.35. Ratio of total length and abdomen width 3.90– 3.94.

Male (n = 6). Head length 0.60–0.62; head width 0.54–0.55; head index 111–113. Labrum width 0.24–0.25. Prothoracic length 0.29–0.31, width 0.46–0.47, ratio 0.63–0.66. Distance between prosternal setae 0.058–0.065. Abdominal width 0.73–0.74. Total length 2.95–3.00. Ratio of total length and abdomen width 4.04–4.05. Length of male genitalia 0.41–0.43. Width of mesosomal plate 0.160–0.168.

Material examined. Paratypes. Ex Geothlypis trichas : 2♀, Pearlington , Mississippi, U.S.A., 3 Jun. 1910, G.G. Rohwer, slide Bish-29874 (Lot 40-14138) ; 1♀, Damarest , New Jersey, U.S.A., 20 May 1926, B.S. Bowdish ; 5♀, Elmhurst , New York, U.S.A., 9 May 1932, M.V. Beals, slide Bish-19646 ; 2♀, Groton , Massachusetts, U.S.A., 21 May 1933, W.P. Wharton, slide Bish-21187 ; 1♀, New London , North Carolina, U.S.A., 4 Apr. 1945, R.C. Simpson. [Note: all these paratypes are held in the USNM].

Non types. Ex Helmitheros vermivorum (Gmelin, 1789) —Worm-eating warbler ( Passeriformes : Parulidae ): 2♂, 2♀, Utila Island, Islas de la Bahía , Honduras (16°06' N, 86°54' W), 23 Aug. 2014, I. Literak, slides UT22a–b [also 3♂, 2♀, 6N in alcohol] ; 1♀, same collecting data as previous sample, 26 Aug. 2014, slide UT65; 1♂, 1♀, 2N, Marshall’s Pen, Mandeville , Jamaica, Feb. 1981, R. Dalgleish, slide 814 ( USNM) ; 2♀ same collecting data as previous sample, 24–30 Dec. 1982 (USNM).

Remarks. Ricinus dalgleishi was described by Nelson (1972) from females only. Our comparison of female paratypes of this species against females from Helmitheros vermivorum has shown that those from H. vermivorum are only slightly smaller, but without significant morphological differences. Therefore, we regard samples from both hosts as belonging to the same species.

Considering that we have examined adult lice of both sexes and nymphs from two host individuals of H. vermivorum collected in two different localities, and that these specimens share the same morphological and morphometric characteristics, we confirm H. vermivorum as a natural and regular host for R. dalgleishi and establish it as new host-parasite association. Also, we record and describe the male of R. dalgleishi for the first time.

Figures

FIGURES 1 – 6. Ricinus dalgleishi. 1, dorso-ventral views of head. 2, dorso-ventral views of abdomen. 3, male genitalia. 4, mandibles. 5, labium. 6, ventro-dorsal views of thorax.

FIGURES 19 – 21. Females: 19, Ricinus dalgleishi. 20, Ricinus sp. ex Corythopis delalandi. 21, Ricinus vireoensis.