Platytenes occultus Setliff and Larson, 2009

Setliff, Gregory P. & Larson, Peter A., 2009, The Indo-Australian weevil genus Platytenes Pascoe, 1870 (Coleoptera: Curculionidae: Cryptorhynchinae), Insecta Mundi 2009 (79), pp. 1-14 : 4-10

Platytenes occultus Setliff and Larson , new species

( Fig. 1 , 5–10 , 12 , 14, 16, 18 , 19–22, 25–31 )

Diagnosis. This new species is most easily separated from its only known congener, P. varius , by differences in the pronotal shape and the vestiture of the pronotum, elytra, and scutellum. Unlike its congener, P. occultus has a broad, parallel sided, subquadrate pronotum with the four fasciculate prominences at the apex of the disk closely approximate. All four prominences are well developed and form a tight cluster surrounding a distinct medial depression. The sides of the pronotum are marked with deep transverse sulci that are situated just behind the postocular lobes. On the pronotal disk, these sulci narrowly separate the apical pair of dorsal prominences from the basal pair on either side of the medial depression. The base of the pronotum also lacks a medial, oblong, white macula that nearly always occurs in P. varius . The scutellum has sparse, decumbent scales on the base and lateral margins and is never entirely glabrous. The produced portions of the elytra embracing the scutellum consistently bear white patches of scales that have not been observed in P. varius . The last two characters can be seen with little or no magnification. Finally, the basal flange on the outer margin of the hind tibia is reduced in this species whereas it is well developed in P. varius .

Description. Length 5.6–7.3 mm (mean = 6.5 mm), maximal width 2.9–3.7 mm (mean = 3.3 mm). Habitus. Body dorsoventrally depressed, nearly twice as long as wide; elytral humeri 1.3–1.5 (mean = 1.4) times as broad as basal width of pronotum, elytra tapering towards apex ( Fig. 5–7 ). Integument dark brown, apex of rostrum and antenna lighter reddish-brown, entirely covered in densely distributed appressed scales interspersed with longer suberect to erect scales except on glabrous prosternal canal and distal two-thirds of rostrum; scutellum glabrous along middle with sparsely distributed, decumbent scales on sides ( Fig. 12 ). Scales ranging from bright white and cream colored to ruddy-brown and black. Dorsal vestiture typically comprised of darker scales mottled with lighter scales, pattern of mottling highly variable among sympatric specimens, declivity to apices uniformly clothed in whitish scales ( Fig. 5–7 ). Vestiture on ventral portion of meso- and metasternites and abdominal ventrites composed of uniformly light colored scales ( Fig. 9 ). Hind femora with light scales on basal one-third to one-half, black scales on distal portion ( Fig. 8 ).

Head visible in dorsal view. Eyes situated laterally ( Fig. 10 ). Frons slightly narrower than basal width of rostrum, depressed between eyes, vertex more or less flat, densely set with erect scales. Rostrum narrow, weakly curved, slightly shorter than or equal to pronotal length, uniform small, shallow, lateral punctures to just before apex in males; female rostrum shinier, with very fine, nearly imperceptible lateral punctures only. Head and basal portion of rostrum densely squamate with appressed and erect scales, rostrum glabrous beyond antennal insertions in both sexes (see Fig. 10 for male). Scrobe short, margin directed ventrally towards bottom of eye, open behind. Antennae inserted subbasally on rostrum. Scape short, subequal in length to club, slightly longer than first 2 articles of funicle, not reaching eye; broadened apically. Funicular article 1 more robust and longer than article 3, article 2 twice as long as other articles; articles 3–4 each as broad as long, articles 5–7 broader than long. Club narrowly ovate.

Thorax. Pronotum 1.1–1.5 (mean = 1.2) times broader than long, parallel sided from base to apical one third with well developed dorsomedial prominence at apex supporting four closely approximate, fasciculate tubercles; area surrounded by tubercles deeply depressed; cervical region constricted in dorsal view, marked behind by deep transverse sulcus, delimiting postocular lobes on sides. Posterior pronotal margin sinuate, middle produced posterad ( Fig. 10 , 14 ). Prosternal canal and mesosternal receptacle deeply cavernous, glabrous; receptacle enclosed behind, posterior margin of receptacle in line with middle of mesocoxae. Pro- and mesocoxae closely approximate; distance between meso- and metacoxae much greater than diameter of mesocoxa ( Fig. 9 ). Thoracic pleura covered in dense squamae, obscuring individual sclerites and sutures. Mes- and metepisternal margins distinct, not concealed by elytra. Metepisternite broad, less than 2.5 times long as broad, with anterodorsal margin to middle strongly produced dorsad ( Fig. 8 , 16 ). Sclerolepidia not observed. Scutellum cordate, smooth, glabrous along middle, sparse decumbent scales on sides ( Fig. 12 ); strongly embraced by elytra laterally. Elytra 1.3–1.6 (mean = 1.4) times longer than broad. Elytral humeri produced, angulate; lateral margins tapering to elytral declivity in dorsal view ( Fig. 5–7 ), anapleural margin with semicircular recess accommodating enlarged metepisternite ( Fig. 8 , 16 ); disk nearly flat. Pro-, meso-, and metafemora short, broad, dentate, laterally compressed. Metafemora not reaching apex of elytra. Tibiae broad, shorter than femur, strongly compressed, weakly arcuate, with well developed uncus. Hind tibiae with weak flange on outer margin near base ( Fig. 18 ). Tarsomere 1 slightly longer than tarsomeres 2+3 combined.

Abdomen. Ventrites I+II connate, longer than ventrites III–V, ventrite V three times broader than long ( Fig. 9 ).

Male terminalia. Spiculum gastrale with apical arms weakly produced, more or less symmetrical; apodeme subequal in length to aedeagal apodemes ( Fig. 19 ). Tergite VIII subquadrate, slightly broader than long, posterior margin weakly truncate ( Fig. 20 ). Aedeagal body (= median lobe of authors) one-third as long as apodemes, somewhat curved at base, more or less straight to apex; apex broadly rounded; short paired sclerites at base of body; sclerite with broad lobe nearly touching lobe of opposite sclerite at middle ( Fig. 21–22 ). Tegmen with parameroid lobes well developed, apodeme shorter than width of tegminal ring ( Fig. 25–26 ). Tergite VII nearly twice as broad as long, posterior margin truncate to slightly emarginate, 14–17 large plectral tubercles arranged in 2 longitudinal rows on either side of midline, rows reaching posterior margin ( Fig. 27 ).

Female terminalia. Tergite VIII longer than broad, apex slightly broader than subapical region, strongly bent ventrad, apical margin simple, deeply bifurcate ( Fig. 28–29 ). Sternite VIII with apical plate spatulate; plate apically curved ventrad, set with short, stout setae; plate shorter, one-third as long as apodeme ( Fig. 30–31 ). Tergite VII broader than long, posterior margin rounded, with 20–24 large plectral tubercles arranged in 2 longitudinal rows on either side of midline, reaching posterior but not anterior margin ( Fig. 32 ). Hemisternites broader towards base; styli short, broader towards apex, hemisternites eight times longer than styli, with apical setae distinct ( Fig. 33 ). Spermatheca hook-shaped, apex of cornu truncate ( Fig. 34 ).

Material examined. The type material comes from two collections. The holotype and 60 paratypes came from the BPBM and 5 paratypes came from the USNM. The BPBM has graciously allowed us to distribute 14 paratypes to the following collections: 2 ANIC, 2 BMNH, 1 CASC, 1 CMNC, 1 CWOB, 2 GPSC, 1 MNHN, 1 MSNG, 2 SMTD, and 1 UMSP. All paratypes that are not labeled otherwise are deposited in BPBM. Holotype: male: “SOLOMON IS., Guadalcanal: Poha R., 1– 50m., Oct. 6, 1957 / J. L. Gressitt, Collector” ( BPBM). Paratypes: PAPUA NEW GUINEA: Bougainville Island: 1 male, “Bougainville I. 24 VI ’44, A. B. Gurney” ( USNM); 1 male, “Bougainville I. 5–15.VII ’44, A. B. Gurney” ( USNM); 2 females, “Bougainville I. VII 15. IX ’44, A. B. Gurney” ( USNM); 1 male, “Bougainville, Torpanos 200m, 6km. W. Tinputz/ 22–29.II.1968 / Abid Beg Mirza, Collector, Bishop”; 1 female, “Bougainville: NE, Mutahi. 700m, 18km S.E. Tinputz/ 1–7.III.1968 / Tawi, Collector, Bishop”; 1 male, “Solomon Is., Bougainville, Kukugai Vill., 150m, X.1960 / W. W. Brandt, Collector, Bishop” ( UMSP); 1 male, “Solomon Is., Bougainville, Kukugai Vill., 150m, XII.1960 / W. W. Brandt, Collector, Bishop”; SOLOMON ISLANDS: Choiseul Island: 1 female, “Solomon Is., Choiseul I., Malangona, 30m., 7.III.1964 / P. Shanahan, Collector, Bishop”; Fauro Island: 1 female, “Solomon Is., Fauro I., Toumoa, Village, 10m., 12.4.1964 / P. Shanahan, Collector, Bishop/ Malaise Trap, Bishop”; Guadalcanal Island: 1 female, “Solomon Is.: Guadalcanal I., Honiara, 0– 100m., XII.1976 / J. L. Gressitt, Collector, Bishop Museum”; 1 female, “SOLOMON IS: Guadalcanal I, Honiara, 0–200m, ii.1987, N. L. H. Krauss, Coll., BISHOP Museum” ( USNM); 1 female, “SOLOMON IS: Guadalcanal I, Honiara, 0–200m, III.1987, N. L. H. Krauss, Coll., BISHOP Museum”; 1 male, “SOLOMON IS: Guadalcanal I: Honiara, 0–100m, iii.1986, N. L. H Krauss, Bishop Museum”; 2 females, “SOLOMON IS: Guadalcanal I, Honiara, 0–100m, ii.1986, N. L. H. Krauss; 1 male, “Solomon Is: Guadalcanal I: Honiara, 0– 205m., X.10.1980/ palm/ J. L. Gressitt, Bishop Museum” ( CMNC); 1 male, “Solomon Is: Guadalcanal I: Honiara, 0– 205m., X.10.1980/ palm/ J. L. Gressitt, Bishop Museum” ( MSNG); 1 female, “SOLOMON IS.: Guadalcanal: Sahuluatea, 200–400m, I.1973 / N. H. L. Krauss, Collector, Bishop” ( MNHN); 1 male, 1 female, “Solomon Is., Guadalcanal, Behind Tenamba, 2– 15m., 10 7 ’57/ palm/ J. L. Gressitt, Collector, Bishop Museum” ( GPSC); 1 male, 1female “SOLOMON IS., Guadalcanal, Betikama R., IX. 1960 / W.W. Brandt, Collector, Bishop” ( ANIC); 1 female, “SOLOMON IS., Guadalcanal, Betikama R., IX. 1960 / W.W. Brandt, Collector, Bishop”; 2 males, “SOLOMON IS., Guadalcanal, Betikama R., VIII. 1960 / W. W. Brandt, Collector, Bishop”; 1 female, “SOLOMON IS., Guadalcanal: Poha R., 1– 50m., Oct.6, 1957 / J. L. Gressitt, Collector”; 1 male, “Solomon Is., Guadalcanal: Suta, 500–1200m., VI 27 1956 / J. L. Gressitt, Collector”; 2 females, “Solomon Is., Guadalcanal: Tenaru, R., 30– 60m., 25.VI.’64/ J. L. Gressitt, Collector, Bishop Museum”; 1 female, “[text illegible]anga River (Mth.), Guadalcanal, Sept. 27, 1944, H. E. Milliron “; 1 male, “Tenaru River, Guadalcanal, Nov. 13, 1944, H. E. Milliron/ H. E. Milliron, Collection”; 1 male, “Wrights Creek, Guadalcanal, July 11, 1944, H. E. Milliron/ H. E. Milliron, Collection”; 1 female, “Guadalcanar I. [sic], XI 9 44 Sol. Is./ Mataninkau, R./ J. Laffoon, Coll.”; 1 female, “Kiwi Creek, Guadalcanal, July 15, 1944, H. E. Milliron/ H. E. Milliron, Collection”; 1 female, “Kiwi Creek, Guadalcanal, Dec. 2, 1944, H. E. Milliron/ H. E. Milliron, Collection”; Kolombangara Island: 1 female, “Solomon Is., Kolombangara, Pepele, 0–30m, 6.2.1964 / P. Shanahan, Collector, Bishop”; Malaita Island: 1 female, “Solomon Is., Malaita: 3km N. Auki, 30m, 2.VI.1964 / J. A. Sedlacek, Malaise Trap, Bishop” ( CASC); 2 males, “Solomon Is., Malaita: Kwalo, 600–700m, 29.IX.’57/ J. L. Gressitt, Collector”; 1 female, “Solomon Is., Malaita: Tangtalau-Kwalo, 200– 350m., 9-30-1957 / J. L. Gressitt, Collector”; 1 male, “Solomon Is., Malaita: Tangtalau, 200m., IX 26 ’57/ palm/ 74/ J. L.Gressit, Collector” ( CASC); Gizo Island: 1 male, 1 female, “Solomon Is., New Georgia Group, Gizo I., 90m., 27.VI.1964 / J. & M. Sedlacek, Collectors, Bishop”; New Georgia Island: 2 females, “SOLOMON IS.: Guadalcanal I. [sic], Munda, 15-30m, 14–15.VII.1959 / J. L. Gressitt, Collector, Bishop Museum”; 1 male, “Solomon Is.: New Georgia Group, N. Georgia I. Munda, 1– 30m., VII 15 1959 / ginger/ J. L. Gressitt, Collector” ( BMNH); 1 female, “Solomon Is: New Georgia I: Munda, 0–150m, XI.1976 / N. H. L. Krauss, Collector, Bishop” ( BMNH); San Cristobal Islands: 1 female, “Solomon Islands: San Cristobal, Wairahu River, 100–400m, 9–15.V.64/ J. Sedlacek, Collector, Bishop”; Ugi Island: 3 males, 3 females, “Pawa, Ugi, Solomon Isl., W. M. Mann” [one female with “ Platytenes n. sp., Det. by E. C. Zimmerman”]; 1 male, 1 female, “Ugi, British, Solomon Isl., W. M. Mann/ Betel Palm/ W. M. Mann, coll., 1954” ( USNM); Vella Lavella Island: 1 female, “Vella Lavella, [illegible], P. Shanahan”; 1 male, “Vella Lavella, Kpw 10m, [text illegible] 1963, P. Shanahan”; 2 females, “Solomon Is., Vella Lavella, Kow, 30m., 28.XI.1963 / P. Shanahan, Collector, Bishop Museum/ Malaise Trap”; 1 male, 1 female, “Solomon Is., Vella Lavella, Ulo Crater, 10m, 17.XII.1963 / P. Shanahan, Malaise Trap, Bishop Mus.” ( SMTD); 2 females, “Solomon Is., Vella Lavella, Ulo Crater, 10m, VIII.1963 / Malaise Trap [one with “ Platytenes (valid!)? varius Pascoe , det. R. T. Thompson, 1993”].

Distribution. ( Fig. 1 ). Widely distributed throughout the Solomon Islands (including Bougainville). The type series includes specimens from every large island and major island group in the Solomon archipelago with the exception of Santa Isabel Island. We suspect that further collections on that island will recover specimens of P. occultus as well.

Figures

Figure 1. Distribution of Platytenes species. Squares = Platytenes varius; circles = Platytenes occultus. Localities are from the literature and material examined in the present study. The specific location for P. varius in northern Queensland, Australia could not be verified.

Figure 2–7. Platytenes species, dorsal habitus. 2) Platytenes varius, male (Jayapura, West Papua, Indonesia). 3) Same, female (Ambon Island, Indonesia). 4) Same, male (Finschhafen, Papua New Guinea). 5) Platytenes occultus, holotype, male (Guadalcanal, Solomon Islands). 6) Same, paratype, female (Guadalcanal, Solomon Islands). 7) Same, paratype, female (Ugi, Solomon Islands).

Figure 8–11. Platytenes species. 8–9) Platytenes occultus, holotype, male habitus. 8) Lateral view. 9) Ventral view. 10–11) Detail of male pronotum, lateral view. 10) Platytenes occultus, paratype. 11) Platytenes varius.

Figure 12–13. Platytenes species, scutellum, dorsal view. 12) Platytenes occultus. 13) Platytenes varius.

Figure 14–18. Platytenes species. 14–15) Dorsal outline of pronotum, broken lines indicate position of fasciculate prominences and raised medial area. 14) Platytenes occultus. 15) Platytenes varius. 16) Platytenes occultus, meso- and metapleura, lateral view, broken line indicates bent portion of mesepimeron; key: c2–c3. meso- and metacoxae, ely. left elytron, epm2. mesepimeron, eps2. mesepisternum, eps3. metepisternum, r. lateral wall of mesosternal receptacle, s2–s3. lateral portion of meso- and metasternites. 17–18) Left hind femur and tibia, anterior (outer) view. 17) Platytenes varius, arrow indicates flange. 18) Platytenes occultus. Scale bar = 1 mm.

Figure 19–34. Platytenes species. 19–22, 25–27) Platytenes occultus, male terminalia. 19) Spiculum gastrale, ventral view. 20) Tergite VIII and sternite VIII, ventral view. 21) Aedeagus (tegmen removed), lateral view. 22) Aedeagus, dorsal view. 25) Tegmen, ventral view. 26) Tegmen, lateral view. 27) Tergite VII, dorsal view. 23–24) Platytenes varius, aedeagus (tegmen removed). 23) Lateral view. 24) Dorsal view. 28–34) Female terminalia. 28) Tergite VIII, dorsal view. 29) Tergite VIII, lateral view. 30) Sternite VIII, ventral view. 31) Sternite VIII, lateral view. 32) Tergite VII, dorsal view. 33) Hemisternites, dorsal view. 34) Spermatheca. Scale bar = 0.5 mm.