Cantao ocellatus Thunberg 1784
Creators: name: Tsai, Jing-Fu
name: Rédei, Dávid
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Scutelleridae
Cantao
Cantao ocellatus

description: Cantao ocellatus (Thunberg, 1784)
Cimex ocellatus Thunberg, 1784: 60. Lectotype (McDonald 1988: 289) (ɗ): Japan or China; UZIU. Cantao pakistanensis Ahmad & Kamaluddin 1996: 116. Holotype (Ψ): Pakistan, Punjab; NHMUK. New synonymy. For a complete list of synonyms of C. ocellatus see Göllner-Scheiding (2006: 193).
C. borealis Distant, 1899 C. excellens Walker, 1867 sensu lato (Figs. 1–8, 28–31) (Figs. 19 –27, 32–35)
1. head shorter, lateral margin nearly straight (Figs. 28–29) head longer, lateral margin distinctly emarginate
anteriad to eye (Figs. 32–33)
Selected references of C. ocellatus. Sharp 1890: 411 (male genitalia); Distant 1902: 43 (redescription, habitus, figures, distribution, biology), Schouteden 1904a: 18 (catalogue, distribution); Kirkaldy 1909: 308 (catalogue, distribution, host plants); Singh-Pruthi 1925: 144 (male genitalia); Esaki 1932: 1562 (redescription, habitus); Yang 1934: 270 (diagnosis, figures, variability, distribution); Yang 1962: 27 (redescription, habitus, host plant, distribution); Kumar 1964: 60 (male genitalia); Ahmad & Mushtaq 1977: 28, 29, 31, 34, 35, 37, 38 (morphology, habitus, male and female genitalia); Hsiao & Zheng 1977: 60 (redescription, photo, figures, host plants, distribution); McDonald 1988: 288 (in key), 289 (redescription, figures, genitalia, distribution, host plants); Tomokuni 1993: 217 (redescription, colour photo, immatures); Yang & Chang 2000: 694 (male genitalia); Göllner-Scheiding 2006: 193 (catalogue, distribution).
Discussion. Cantao pakistanensis was described based on a single female from Pakistan (Ahmad & Kamaluddin 2006). According to the original description, the holotype is deposited in NHMUK; however, we were informed by a colleague from the respective institution that currently it cannot be found there (R. Hussain, pers. comm.). As it was noted by its authors, C. pakistanensis is very close to C. ocellatus, but several differences were listed as of diagnostic value. These characters were tested by examination of specimens of C. ocellatus from various localities all over the Oriental Region, and are discussed below one by one.
(1) Labium longer, reaching to middle of third sternite (shorter in C. ocellatus). — Among dozens of C. ocellatus examined by us, the labium most frequently extends to about the middle of the third sternite; in extreme cases it reaches only the base of the abdomen or approaches the posterior margin of the 4th sternite.
(2) Abdominal venter with median sulcus extending to 7th sternite (median sulcus restricted to base of abdomen in C. ocellatus). — The shallow median abdominal furrow shows quite strong intraspecific variability in C. ocellatus. In the male, it is generally indistinct or absent; in the female, it is more distinct, usually extending to the posterior margin of the 5th or 6th sternite.
(3) Anteocular region more than 1.25 times as long as remaining portion of head (“not quite” 1.25 times longer in C. ocellatus). — In 20 randomly selected specimens of C. ocellatus, the above ratio varied between 1.18–1.48 (n = 10, mean±SD as 1.35±0.10), and 1.12–1.52 (n = 10, mean±SD as 1.33±0.10) in males and females, respectively. The broad range of this calculated ratio is caused partly by methodological problems (the length of the postocular part of the body strongly depends on its relative position with the pronotum), but the shape and length of the head is otherwise quite variable in this species.
(4) Second antennal segment (= segment IIa) distinctly less than half of the length of the third (= segment IIb) (longer than half of the length of third in C. ocellatus). — In 20 randomly selected specimens of C. ocellatus, the above ratio varied between 0.38–0.52 (n = 10, mean±SD as 0.47±0.04), and 0.45–0.58 (n = 10, mean±SD as 0.50±0.03) in males and females, respectively.
(5) “First gonocoxae” (= 8th gonocoxites) apically broadly rounded, posterior margin truncate (apically narrowly rounded, posterior margins indented in C. ocellatus). — The illustration of Ahmad & Kamaluddin (1996: 118, fig. 1C) shows the typical condition of C. ocellatus. Quite obviously the authors did not compare their holotype to specimens of C. ocellatus but rather to the drawing presented by Ahmad & Mushtaq (1977: 29, fig. 103), where the concavity of the 8th gonocoxite is somewhat exaggerated.
(6) Spermathecal pump with more prominent distal and proximal flanges (less prominent in C. ocellatus). — See below under (7).
(7) Distal spermathecal duct more than 2 times as long as proximal duct (only slightly longer than proximal duct in C. ocellatus). — The spermatheca as figured by Ahmad & Kamaluddin (1996: 118, fig. 1D) is well within the variability of C. ocellatus. The differences in the size of the flanges and the lengths of the proximal and distal ducts are insignificant and clearly not of species level importance.
Since none of the diagnostic characters of C. pakistanensis presented by its authors are of species level importance; and, moreover, its original description and illustrations perfectly fits with C. ocellatus, C. pakistanensis is regarded as conspecific with the latter and it is placed in synonymy with C. ocellatus. It should be noted that the structure called as “2nd gonocoxae” (= 9th paratergites) in C. pakistanensis by Ahmad & Kamaluddin (1996) is apparently the median projection of the gonangulum. The 9th paratergites are missing in C. ocellatus.
description: Published as part of Tsai, Jing-Fu & Rédei, Dávid, 2010, Taxonomical notes on Oriental and Pacific jewel bugs (Hemiptera: Heteroptera: Scutelleridae), pp. 25-47 in Zootaxa 2572 on pages 30-32, DOI: 10.5281/zenodo.197410