Platycranus bicolor Douglas & Scott 1868

Platycranus bicolor (Douglas & Scott, 1868)

Figures 13–15, 59, 81, 92, 133–137, 151, 164, 178–181, 196

Litosoma bicolor Douglas & Scott, 1868: 267 [n.sp.]

Hypsitylus bicolor Reuter, 1883: 342 [descr.]

Pachylops bicolor Carvalho, 1958: 120 [cat.]; Wagner, 1974: 170 [descr.]; Schuh, 1995: 174 [cat.] Platycranus bicolor Carapezza, 1997: 76; Carapezza & Kerzhner, 1998: 146

Diagnosis. Distinguished by the following combination of characters: variable from uniformly pale to darkened along midline coloration (Figs. 13–15), relatively small first antennal segment, 0.3–0.4 × as long as width of head, narrow vertex, male 1.88–2.13 ×, female 2.4–2.8 × as wide as eye, right paramere weakly tapering, apical process with oval tip (Figs. 133–137). Most similar to P. re m a n e i in the body proportions, measurements and color-pattern, and widely simpatric with that species in France and Spain, but differs in the presence of black simple setae on head and pronotum and comparatively short pulvillus.

Description. Male. Small, 3.9–4.4. COLORATION. Variable from uniformly greenish yellow to more or less darkened along midline (Figs. 13–14). Head: yellow to pale brown; first antennal segment yellow, second entirely yellow or with darkened distal part, third and fourth segments brown. Thorax: pronotum, exposed part of mesonotum and scutellum greenish yellow to entirely brown; scuto-scutellar suture brown; thoracic pleura yellow. Hemelytron: greenish yellow, sometimes with more or less wide brown stripe along inner margin; membrane more or less darkened. Legs: yellow, apical part of third segment dark brown. Abdomen: yellow, sometimes partly brown dorsally. SURFACE AND VESTITURE. Mesial stiff setae on first antennal segment present; antenna with brown simple setae. STRUCTURE. Head: vertex 1.88–2.13 × as wide as eye; first antennal segment 0.30–0.35 × as long as width of head; second antennal segment 1.33–1.45 × as long as width of head and 1.02–1.17 × as long as width of pronotum. Thorax: pronotum with straight or slightly concave lateral and posterior margins, and straight anterior margin, 1.95–2.26 × as wide as long and 1.24–1.3 × as wide as head. Hemelytron: cuneus twice as long as wide. Legs: third tarsal segment nearly equal in length to first and second combined; pulvillus relatively short, not reaching midpoint of claw (Fig. 196). GENITALIA. Genital capsule as in Fig. 81; left paramere as in Fig. 92; right paramere weakly tapering (Figs. 132–136); aedeagus as in Fig. 151.

FIGURES 89–96. Left parameres: 89–91— P. metriorrhynchus; 92— P. b i c o l o r; 93–96— P. re m a ne i, 93— Slovenia, 94— Ukraine, 95— Spain, 96— Turkey.

Female. Small, 3.4–3.9. COLORATION. Always uniformly pale (Fig. 15). SURFACE AND VESTITURE. As in male. STRUCTURE. As in male except larger interocular distance, vertex 2.40–2.83 × as wide as eye; first antennal segment 0.27–0.32 × as long as width of head; second antennal segment 1.18–1.32 × as long as width of head and 1.0–1.07 × as long as width of pronotum; pronotum 2.11–2.33 × as wide as long and 1.17–1.26 × as wide as head. GENITALIA: Interramal lobes more or less elongated, with flat apex (Figs. 178–181); sclerotized rings of dorsal labiate plate as in Fig. 164.

Distribution. Widespread in western Europe, north to southern United Kingdom, west to Atlantic coast of Spain and Portugal, south to Portugal and southern France, east to northern Italy (Fig. 59).

parameres: 97— P. re m a ne i (France); 98— P.; 99— P. genistae; 100— P. p i c t u s; 101— P.

wagneri; aedeagus, P. e r b e r i: 102—lateral view; 103—ventral view; arrow indicates the secondary gonopore.

Host associations. According to Douglas & Scott (1868), the host plant of P. b i c o l o r in the United Kingdom is Ulex europaeus L. Ribes (1982) collected P. b i c o l o r from Genista scorpius (L.) de Candolle and Cytisus scoparius (L.) Link (= Sarothamnus scoparius (L.) W.D.J.Koch) in Spain. Ehanno (1960) also indicated Cytisus scoparius and Ulex europaeus as hosts of the species in France.

Discussion. The species was originally described by Douglas & Scott (1868) as Litosoma bicolor from Esher (Great Britain). Later, Douglas & Scott (1875) synonymized the species with Capsus chloropterus Kirschbaum, 1856. Reuter (1877) stated that L. bicolor is not conspecific with C. chloropterus, and may be a synonym of Pachylops chloropterus Fieber, but did not explain this conclusion. He transferred L. bicolor to the genus Hypsitylus Fieber and used the earlier name Pachylops as a junior synonym. Kirkaldy (1906) did not accept the name Hypsitylus and put it in synonymy under Pachylops. Thus until the end of the 20th century the species was mentioned in literature by both generic names. Carapezza (1997) investigated the structure of male genitalia in Pachylops (= Hypsitylus) species and found them to be clearly different from drawings in Wagner & Weber (1964) and Wagner (1974). He found out that parameres and aedeagus of P. b i c o l o r are most similar to those of Platycranus species and transferred the species to Platycranus. For more detailed information see Carapezza & Kerzhner (1998).

P. b i c o l o r can be relatively easily separated from all other species of the subgenus Genistocapsus except the largely sympatric P. re m a n e i. Males of the latter are distinguished by the relative width of vertex, color pattern, and relatively thin, apically tapering process of the right paramere (see diagnosis of P. re m a n e i). Females of both species possess similar pale coloration and largely overlapping variability in body proportions and genital structures, and apparently could not be separated without association with males. The only more or less reliable character is the length of pulvillus.

Material. Lectotype: locality label missing [UNITED KINGDOM: England: Esher, Douglas], 1Ƥ (AMNH _PBI 00340441) (BMNH).

Other Specimens Examined: FRANCE: Aquitaine: Gironde Co.: Arcachon, La Teste, southern France, 44.65 ° N 1.16666 ° W, 22 Aug 1956, E. Wagner, 13 (AMNH _PBI 00336222), 3Ƥ (AMNH _PBI 00336223- AMNH _PBI 00336225) (ZSM). Pyrenees Atlantiques Co.: Guethary, 43.42667 ° N 1.44111 ° W, 1927, G.C. Champion, 33 (AMNH _PBI 00340473- AMNH _PBI 00340475) (BMNH). Nord-Pas de Calais: Pas-de-Calais Co.: St. Omer, 50.74611 ° N 2.26167 ° E, no date provided, L. Lethierry, 13 (AMNH _PBI 00340476), 1Ƥ (AMNH _PBI 00340476) (BMNH). SPAIN: Catalonia: Martinet (Cerdanya), 42.36666 ° N 1.7 ° E, 27 Jun 1964, J. Ribes, 13 (AMNH _PBI 00336221), 1Ƥ (AMNH _PBI 00336221) (JR). Galicia: Ois (Coruna), 43.23333 ° N 8.11666 ° W, 20 Aug 1969, Ribes, 13 (AMNH _PBI 00336220), 1Ƥ (AMNH _PBI 00336220) (JR). Portela da Arbore (Lugo), 43 ° N 7.5 ° W, 13 Aug 1985, Ribes, 13 (AMNH _PBI 00336261) (JR). UNITED KINGDOM: England: Dorset Co.: Holt, 50.834 ° N 1.96 ° W, 16 Aug 1935, P.H., 13 (AMNH _PBI 00337197), 1Ƥ (AMNH _PBI 00337198) (BMNH). Essex Co.: Danbury, 51.715 ° N 0.582 ° E, 12 Aug 1953, A.M. Massee, 13 (AMNH _PBI 00340479), 1Ƥ (AMNH _PBI 00340478) (BMNH). Hampshire Co.: New Forest, 50.86667 ° N 1.56667 ° W, Aug 1911, E. A. Butler, 13 (AMNH _PBI 00337193) (BMNH); 28 Aug 1935, P.H., 5Ƥ (AMNH _PBI 0 0 337196, AMNH _PBI 00337197), 23 (AMNH _PBI 00337198) (BMNH). Hereford Co.: Breinton, 52.0 6 ° N 2.78 ° W, Aug 1913, E. A. Butler, 13 (AMNH _PBI 00337191) (BMNH). Kent Co.: East Malling, 51.29032 ° N 0.47077 ° E, 0 1 Aug 1953, A.M. Massee, 1Ƥ (AMNH _PBI 00340472) (BMNH). London Co.: Esher, 51.35 ° N 0.36667 ° W, 31 m, no date provided, Power coll., 93 (AMNH _PBI 00340459- AMNH _PBI 0 0 340466, AMNH _PBI 00337194), 8Ƥ (AMNH _PBI 00340467- AMNH _PBI 0 0 340471, AMNH _PBI 00340456- AMNH _PBI 00340458) (BMNH). Norfolk Co.: Dersingham, 52.846 ° N 0.502 ° E, 10 Aug 1980, A. Carapezza, 1Ƥ (AMNH _PBI 00314074) (ZISP); 15 Aug 1983, A. Carapezza, 13 (AMNH _PBI 00314083) (ZISP). Ditchingham, 52.46676 ° N 1.44351 ° E, no date provided, Power coll., 1Ƥ (AMNH _PBI 00337195) (BMNH). Staffordshire Co.: Wyre Forest, 52.385 ° N 2.36861 ° W, 0 8 Aug 1953, A.M. Massee, 13 (AMNH _PBI 00340477) (BMNH). Surrey Co.: Egham, 51.4289 ° N 0.5479 ° W, 14 Sep 1854, G.E. Woodroffe coll., 13 (AMNH _PBI 00340454), 1Ƥ (AMNH _PBI 00340455) (BMNH). Locality label missing, 13 (AMNH _PBI 00337192) (BMNH).