Pachyrhynchus phaleratus Waterhouse, 1841

Yoshitake, Hiraku, Bollino, Maurizio & Sandel, Franco, 2019, Pachyrhynchus elenae Rukmane, 2016, a new synonym of Pachyrhynchus phaleratus Waterhouse, 1841 (Coleoptera: Curculionidae: Entiminae), Zootaxa 4585 (1), pp. 197-200 : 197-198

Pachyrhynchus phaleratus Waterhouse, 1841

Pachyrhynchus phaleratus Waterhouse 1841: 24 (type locality: “the Philippine Islands ”; type depository: BMNH); 1842, 218; 1843, 320.— Schoenherr 1845: 385 (reprinting of the original description; “ P. Ins. Philippines.”).

Pachyrrhynchus phaleratus: Heller 1912: 309 (placed in “GRUPPE V”; in key), 321 (in diagnosis of Pachyrrhynchus stellio Heller, 1912).— Schultze, 1922: 578 (in diagnosis of Pachyrrhynchus halconensis Schultze, 1922), 593 (male aedeagal structures), pl. 3, fig. 13 (male aedeagus in dorsal and lateral views); 1923: 636 (placed in “Group I”; in key), 646 (redescription; “ CATANDUANES, Virac”), pl. 2, fig. 30 (lateral habitus, female), pl. 3, fig. 24 (male aedeagus in dorsal and lateral views), pl. 5, fig. 19 (dorsal habitus, female; “ Catanduanes, Virac”).— Dalla Torre et al. 1931: 35 (cataloged; “ Catanduanes ”).

Pachyrhynchus elenae Rukmane 2016: 82 (type locality: “Mindanao Isl., Cotabato, Mt. Apo”—mislabeled; type depository: DUBC), fig. 4A, B (dorsal and lateral habitus, male), 4E, F (male aedeagus in dorsal and lateral views). NEW SYNONYMY.

Type material examined. Male holotype of Pachyrhynchus phaleratus (BMNH). The holotype male of Pachyrhynchus

elenae (DUBC) was not examined, but the images of habitus and aedeagus published along with the original description

clearly support the above synonymy.

Specimens examined. PHILIPPINES: Luzon. Sierra Madre, Aurora: 3 males and 3 females, VI. 2010 ( CFS); 1

female, V. 2012 (NIAES). Dingalan , Aurora: 1 male and 3 females, VI. 2012 ( NIAES) ; 1 male, IX. 2012 ( CFS) ; 22 exs.,

III. 2013 ( MBLI); 2 males and 2 females , IV. 2013 ( CFS); 2 males , VII. 2013 ( CFS); 1 male and 1 female , III. 2014

(CFS); 3 males and 3 females, IX. 2014 ( CFS) ; 7 males and 3 females, 9–12. III. 2013, M. Maruyama et al. ( NIAES) ; 1

male and 1 female, III. 2015 ( CFS) ; 1 female, XI. 2015 ( NIAES) ; 1 male, III. 2016 ( CFS) ; 1 male and 1 female, IX. 2017

(CFS); 1 female, II. 2018 ( CFS) ; 3 males and 5 females, III. 2018 ( CFS) ; 1 male and 1 female, IV. 2018 ( CFS) .

Ditumabo, Aurora: 1 male, VI. 2018 (CFS). Labuyo, Aurora: 3 males and 1 female, I. 2009 (NIAES); 1 female, III. 2010

(NIAES); 3 females, VI. 2011 ( CFS) ; 6 males and 3 females, V. 2013 ( NIAES) . San Luis , Aurora: 22 exs., III. 2012 ( CFS

& MBLI). Barangay Dimanayat, San Luis , Aurora : 1 female, V. 2012 ( NIAES) ; 4 males and 1 female, XI. 2012

(NIAES). Sierra Madre , Quirino: 1 male, VI. 2013 ( CFS) ; 1 female, VI. 2013 ( CFS) . Disimugal, Nagtipunan , Quirino: 2 males, XI. 2014 ( CFS) . Kayapa , Nueva Vizcaya: 1 male, IX. 2011 ( CFS) . In addition, a series of specimens of both sexes from Virac, Catanduanes were examined at SMTD.

Distribution. Philippines (“ Philippine Islands ”; Luzon: Aurora, Quirino, and Catanduanes Island). Although the precise type locality was not specified ( Waterhouse 1841, 1842, 1843), it is known that Hugh Cuming, during his journey to the Philippines, did not visit Catanduanes nor the provinces of Aurora or Quirino ( Broderip, 1840), while he visited the neighboring province of Nueva Ecija ( Dance, 1980), possibly the actual collecting locality of the holotype of Pachyrhynchus phaleratus . In addition, we studied a single male labeled “ Nueva Vizcaya ”, from where we have not obtained further specimens, for which we exclude the presence of the species in this province at the moment, considering how easy it is for traded or commercially sold specimens to be mislabeled.

Comments. Rukmane (2016, p. 83) provided dorsal and lateral images of the habitus ( Fig. 4A, B ) and of the male aedeagus ( Fig. 4E, F ) of the holotype and noted morphological differences between Pachyrhynchus elenae and P. phaleratus as follows: “ Pachyrhynchus elenae sp. n. is similar in general appearance to P. phaleratus Waterhouse, 1841 ( Fig. 4C, D ). The new species is easily distinguished from P. phaleratus by the shape of aedeagus, which is longer and less curved lateraly [sic!] and by the bigger number of longitudinal lines on each elytron ( Fig. 4G, H ). Pronotum of P. elenae sp. n. widest before the midian [sic!] part (pronotum of P. phaleratus widest in the middle).” Based on a long series of specimens of P. phaleratus , it is obvious that markings and body shape are variable ( Figs. 1–12 ). Individuals with the ‘ elenae -like’ pattern were collected only from Dingalan and San Luis (Aurora), while those with typical markings occur in a wide area from Quirino to the north to Catanduanes to the south. However, both localities of the ‘ elenae -like’ form overlap with those of the typical form and there are a number of intermediate specimens between the two forms even in the same population. In addition, the prothorax is more or less strongly expanded from the constricted base to its widest point usually situated before the middle, but sometimes precisely so at the middle. With regard to differences in the male genital structures, it is quite clear that the shape of the aedeagus of the holotype of P. elenae collapsed probably due to an excessive treatment with KOH solution and subsequent drying, whereas that of the figured P. phaleratus retained its original form ( Rukmane 2016: p. 83, Fig. 4G, H ), a fact that makes a comparison meaningless. Our observations of male genitalia of both forms shows that there are no significant differences to delimit a species boundary, not only in the shape of aedeagus but also in the endophallic structures ( Figs. 13–18 ). This demonstrates beyond doubt that P. elenae is conspecific with P. phaleratus . As far as we know, P. phaleratus occurs only in Luzon and its adjacent islands. Mount Apo, the type locality of P. elenae , is one of the most famous localities for insect trading in the Philippines. The holotype of P. elenae , whose collector is unidentified, was most probably mislabeled during the commercial distribution process.

Figures

FIGURES 1–12. Dorsal habitus images of Pachyrhynchus phaleratus Waterhouse, 1843 from Aurora province, Luzon, the Philippines. 1–3. Males from Labuyo. 4–6. Males from San Luis. 7. A female from Dingalan. 8. A female from Sierra Madre. 9, 10. Females from Labuyo. 11, 12. Females from San Luis.

FIGURES 13–18. Endophallic structures of Pachyrhynchus phaleratus Waterhouse, 1843.13–15, The typical form (Dingalan, Aurora, Luzon). 16–18, The ‘elenae’ form (San Luis, Aurora, Luzon). 13, 16, Dorsal view. 14, 17, Lateral view. 15, 18, Ventral view.