Ferraz, Fernando F. F.

Monteiro, Ricardo F.

Vanin, Sérgio A.

English

Cadernos Espinosanos (E-Journal)

— \> Papéis Avulsos de Zoologia MUSEU DE ZOOLOGIA DA UNIVERSIDADE DE SÃO PAULO ISSN 0031-1049 Papéis Avulsos de Zool., S. Paulo 41(17): 247-257 31.VII.2000 ECOLOGICAL NOTES OF PACHOLENUS PELLICEUS BOHEMAN, 1836, A STEM GALL-FORMER, WITH DESCRIPTION OF FULLGROWN LARVA (CURCULIONIDAE, MOLYTINAE) Pacholenus pelliceus Boheman, 1836 was collected in restinga of Barra de Maricá, Maricá, Rio de Janeiro State, Brazil, and reported for the first time as a stem gall-former Galls were found on Gomidesia martiana Berg. and G. fenzliana Berg. (Myrtaceae). Some ecological aspects of weevils and galls are discussed. The full-grown larva is described and illustrated, based on reared specimens. Comparisons with other described larvae of Molytinae are made, corroborating the inclusion of Pacholenini within the Molytinae. Keywords: Curculionidae, gall-former, Gomidesia, Pacholenus, weevil larva. During gall studies conducted by the júnior authors, in restinga of Barra de Maricá, Rio de Janeiro State, Brazil, some weevils were reared from 1. Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Caixa Postal 11461, 05422-970 São Paulo, SP, Brasil. 2. Laboratório de Ecologia de Insetos, Departamento de Ecologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Caixa Postal 68020, 21941-590 Rio de Janeiro, RJ, Brasil. Recebido para publicação em 01 .X. 1998 c aceito em 03.VI. 1999. Sérgio A. Vanin1 Ricardo F. Monteiro2 Fernando F. F. Ferraz2 Abstract Introduction UCTI! n? ^iogií . üSP i íl . fji i O í F C A 248 Papéis Avulsos de Zoologia myrtaceous stem galls. The adults were sent for identifícation to the sênior author, who identified them as Pacholenuspelliceus Boheman, 1836. The Pacholenini were revised by Vanin & Reichardt (1976). Pacholenus Schoenherr, 1826 includes five species: three known from the Atlantic Forest along eastem coast of Brazil, and two from Central Brazil, but probably inhabiting gallery forests or forest enclaves (Vanin & Reichardt, 1976). Up to now, no biological Information was published for any of the five species oí Pacholenus, nor for the remaining species of the tribe. This discovery give us the opportunity to make the first report of the biology of a species of a Pacholenini. Some ecological aspects, the description of the full-grown larva, and comments on the taxonomic position of the Pacholenini are presented. Ecological aspects of the gall-former Pacholenus pelliceus Pacholenus pelliceus galls were observed and collected in restinga of Barra de Maricá, Rio de Janeiro State, Brazil, from July 1994 to July 1995. This stem gall (Fig. 1) is unicameral and presents an only larva. The gall is first apparent at the apex of a shoot but does not seem to hinder distai growth of the stems (Fig. 1). Larva of P. pelliceus develops and pupates into the gall chamber and the adult emerges through a hole near the base of the gall (Fig. 1). The adult of this weevil has a slender form and a brownish-yellow color, what makes it cryptic on the stem it emerges from. This gall was only found on Gomidesia martiana Berg. and G.fenzliana Berg. (Myrtaceae) in restinga of Barra de Maricá, the only two plant species on this genus in the area. Intensive inspections on ali of the 14 myrtaceous species were made during one year and casual observations were carried out for five years in the restinga vegetation but P. pelliceus was never found on another host plant. Gomidesia martiana is more abundant and exhibit a wider distribution than G. fenzliana in the area. The number of galls found in each of the host plants were similar, however, G. fenzliana showed a significantly higher frequency of attacked plants (%2= 4.55, P= 0.033). Pacholenus pelliceus galls were found ali year long but the highest abundance occurred during the winter and the lowest numbers were detected in summer (Fig. 2). During this hot and wet season the two host plant species flower, what may affect their vegetative growth lessening the resource for the galling insect. In spite of the high frequency of parasitoids in restinga gall species (Monteiro et ai, 1994) only two parasitoid wasps, of the same species of Eupelmidae (Hymenoptera), were obtained from near a hundred oíP. pelliceus galls reared in the laboratory. Vol. 41(17), 2000 249 After adult emergence some galls were colonized by ant species which nest inside the gall chamber. Description of the full-grown larva Pacholenus pelliceus Boheman, 1836 (Figs.3-16) Description (terminology according to Anderson, 1991 and May, 1993). Full-grown larva (Fig. 3). Length: 13.8 mm; maximum width: 3.1 mm; head width: 1.3 mm. Body evenly curved, with about same width from metathorax to abdominal segment VII, with ali lobes prominent, color cream yellow except pronotum lightly pigmented yellowish brown. Cuticle smooth or microasperate in transverse linear series (100X). Setae yellowish; major thoracic setae about 4-5 times as long as minor setae. Head (Fig. 4) yellowish brown with 4 pale longitudinal stripes, 2 paramedian dorsal and 2 lateral; labrum, mandibles and epistoma darker. Stemmata absent. Antenna exposed (Fig. 5), with conical accessory appendage about 2 times as long as wide, and 5 smaller processes. Epicranial suture distinct, approximately 0.6 times as long as head capsule. Frontal suture complete. Endocarina weak but distinct. Frons with 5 pairs of frontal epicranial setae (fes) and 2 pairs of sensilla, one dorsal to fes2 and other between fes3 and fes4; fsl, fs2 and fs3 small, fs4 and fs5 larger and subequal. Dorsal epicranium with 5 pairs of dorsal epicranial setae (des), 4 pairs of very minute posterior epicranial setae (pes) and 3 pairs of sensilla, first lateral to pes, second near desl, and third lateral to des5; des3 situated on epicranium, not within frontal suture or on frons. Lateral epicranium with 2 lateral epicranial setae (les). Ventral epicranium with 2 ventral epicranial setae (ves). Clypeus transversal (Fig. 7), anterior margins straight, with 2 pairs of clypeal setae (cls) and 1 pair of sensilla, each placed between clsl and cls2. Labrum transversal (Fig. 7), anterior margin rounded, with 3 pairs of labral setae (Ims), Imsl largest, lms2 and lms3 subequal. Epipharynx (Fig. 8) with 3 anterolateral setae (ais) on each side, 6 anteromedian setae (ams), 2 pairs of median spines, and 2 groups of sensory spots, each group a cluster of 3 pores; labral tormae elongated, curved near middle and divergent posteriorly. Mandibles symmetrical, stout (Fig. 6), apically bidentate (teeth somewhat eroded in older specimen examined and illustrated), and with a small triangular tooth on mesal region; bearing 2 mandibular setae, aligned 250 Papéis Avulsos de Zoologia longitudinally, and a sensillum. Maxilla (Figs.9-10): maxillary palpus 2- segmented, proximal segment with 1 short lateral seta and 2 sensilla; distai segment slightly shorter than precedent, with apical cluster of minute papillae but without setae or sensilla; stipes with 4 setae and 2 sensilla on ventral surface; mala with 5 ventral (Fig. 9) and 8 dorsal setae (Fig. 10). Labium (Fig. 9): labial palpi 2-segmented; segments subequal in length, each bearing a sensillum; premental sclerite strongly narrowing posteriorly; prementum with 3 pairs of setae and 2 pairs of sensilla, one pair behind and other between proximal segments of palpi; postmentum with 3 pairs of setae. Thorax (Fig. 3). Pronotum with 9 setae on each side, 2 of which longer. Thoracic spiracle (Fig. 13) bicameral, peritreme subcircular, air tubes annulated, dorsad; spiracle encircled by a raised, lightly pigmented sclerotized ridge; thoracic spiracle larger than abdominal ones. Prodorsum of meso- and metathorax with 1 seta. Postdorsum of meso- and metathorax with 4 setae. Alar area of meso- and metathorax with 1 seta. Spiracular area of mesothorax with 1 long seta and 4 smaller setae; spiracular area of metathorax with 3 long setae. Thoracopods (Figs. 11 -12); mediostemal lobe (ml) with 1 seta on pro-, meso- and metathorax; ventropedal lobe (vpl) with 2 setae on prothorax and 1 seta on meso- and metathorax; pedal lobe (pl) with 5 setae on pro-, meso- and metathorax. Abdômen (Fig. 3) with 8 pairs of bicameral spiracles (Figs.14-15), peritreme subcircular, tubes annulated, caudad; abdominal spiracles of segments I to V subequal, VI to VIII gradually increasing in size, VIII largest and situated on dorsum; ali spiracles encircled by a raised, pigmented sclerotized ridge, lightly in spiracles I to V, deeply in spiracles VI to VIII. Abdominal segments I to VII each with 3 dorsal folds; folds not distinct on segments VIII and IX. Setation on abdominal segments I to VI similar (setae described on one side of body only): prodorsum with 1 seta; postdorsum with 5 setae (pds), pds3 and pds5 larger. Spiracular area with 1 seta on segments I to VII; epipleural area with 2 setae (1 long, 1 short); pleural area and eustemum with 2 setae each; stemellum distinct, with 1 seta. Abdominal segment VII with 4 pds and VIII with 3 pds. Abdominal segment IX bearing 6 setae, of which 2 dorsal of unequal length. Anus terminal, 4-lobed. Alimentary canal (Fig. 16) with proventriculus intemally 8-ridged; cardiac mycetomes absent; anterior ventriculus smooth; posterior ventriculus 2-coiled, with about 12 finger-like ceca, more or less aligned on either side of lower coil; Malpighian tubules rather thick, arranged 3+3. Material examined. Brazil. Rio de Janeiro. Maricá, 28. VII. 1992, Monteiro, R.F. col., host plant: Gomidesia fenzliana (1 immature larva); same data but 30.IV. 1994 (1 full-grown larva, dissected and mounted on slides; 2 immature Vol. 41(17), 2000 251 larvae, one ofwhich dissected); same locality andhost, 23.X.1996, Ferraz, F.F.F col. (1 immature larva). Ali specimens deposited in the Museu de Zoologia, Universidade de São Paulo, São Paulo. Remarks This is the flrst larva described of the tribe Pacholenini. Vanin & Reichardt (1976) revised the genus Pacholenus Schoenherr, 1826 and assigned it, along with Pileophorus Schoenherr, 1843, Antilophus Kuschel, 1952 and Lenopachus Vanin & Reichardt, 1976, to the tribe Pacholenini, within the Hylobiinae. Wibmer & 0'Brien (1986) fused the Hylobiinae, the Cholinae and a few additional taxa into an expanded Molytinae, and maintained the Pacholenini as a distinct tribe of that subfamily. Kuschel (1995) proposed a reclassification of families and subfamilies of Curculionoidea, based on a phylogenetic analysis. He considered the Curculionidae as formed by 6 subfamilies only, Brachycerinae, Curculioninae, Rhynchophorinae, Cossoninae, Scolytinae, and Platypodinae, the first two comprising most of the "subfamilies" of previous classifications. As a result, the "older" subfamilies and tribes, if maintained, must have their ranks lowered. However, as yet no phylogenetic work has been done at lower leveis, a prerequisite for nomenclatural or status changes. May (1993) presented an overview of the larvae of superfamily Curculionoidea, based chiefly on specimens from New Zealand. The systematic arrangement followed KuscheTs scheme of 6 families and 21 subfamilies (Kuschel, 1995). The tribe Molytini, (= Molytinae, sensu Wibmer & CBrien, 1986), included within Curculioninae by Kuschel (1995), was represented in May's study by 5 species pertaining to 5 genera. According to May (1993), Molytini share with Curculionini the following characters: 1- cuticle microasperate in transverse linear series; 2- frontal setae 1,2 and 3 usually minute or absent; 3- antennae conical, exposed; 4- mandibular setae aligned longitudinally; 5- labral tormae subparallel or bowed; 6- abdominal segment VIII with 3 postdorsal setae; 7- abdominal VIII spiracle on dorsum. May (1994) considered the Molytinae to the subfamilial rank and studied 6 species representing 4 genera. The author proposed 4 features "dominant" in Molytinae, but which also apply to Curculioninae and some Cossoninae: 1- dorsal epicranial seta 3 (des3) situated on epicranium, not within frontal suture or on frons; 2- mandibular setae longitudinal (equal to characteristic 4 of May, 1993); 3- abdominal segment IX having 2 or 3 dorsal setae, usually of unequal length; 4- frontal setae 4 and 5 (fs4 and fs5) subequal. The larva of Pacholenus pelliceus shares ali features reported by May 252 Papéis Avulsos de Zoologia V*-^ -T 1 v £- Ir 1 cm rC V ^di^ípio M Fig. 1. Branch of Gomidesiafenzliana Bcrg. (Myrtaceae) with 2 stem galls of Pacholenuspelliceus. Note the cmergcnce hole of the wecvil at the base of the galls. Vol. 41(17), 2000 253 Bnv inp CD 5 CD .55 unp ÁeiAi CD CD Jdv jbiai q0d UBp oan aon PO d0Q ônw lnP IO o LO o IO o LO o CO CO CN CN S||e6 jo jaquinfg 254 Papéis Avulsos de Zoologia vT r— 1 1 mm o 2 \ > pes desi e des 2 desa des4 C 05 mm z fsT lesl ts2 fs3 vesl IH f$4 Ies2 desS^| ves2 rs 5 r/ VA ^ eis 1 cls2 Ims3 Ims2 ' Imsl ais Figs. 3-8. Pacholenus pelliceus, mature larva from Maricá, RJ. 3, habitus, lateral; 4, hcad, dorsa (dcs, dorsal cpicranial seta; fs, frontal seta; les, lateral epicranial seta; pes, posterior cpicrania setae; ves, ventral cpicranial seta); 5, right antenna; 6, right mandible, dorsal; 7, labrum, clypcuí and epistoma (cls, clypeal seta; Ims, labral seta); 8, epipharyngeal lining (ais, anterolateral setae ams, anteromedian setae). Figs. 6-8 to same scale. Vol. 41(17), 2000 255 O /C2 =5) CD o -o 03 6 e 2 J3 JH T3 C oj 13 Í3 c D > * Oj 6 JS bí) s o cfa 03 è: o3 a 03 e «o S .O -C; Ci, o -s: «o a O, bO £ 256 Papéis Avulsos de Zoologia vpl pl 11 o m I % ç—- vpl pi 12 0.2 mm 14 m 15 r —i 2 mm W 16 Figs. 11-16. Pacholenuspelliceus, mature larva from Maricá, RJ. 11, thoracopod I (ml, mcdiostcmal lobe; pl, pedal lobe; vpl, ventropedal lobe); 12, thoracopod II; 13, prothoracic spiracle; 14, abdominal spiracle IV; 15, abdominal spiracle VIII; 16, alimentary canal. Vol. 41(17), 2000 257 (1993; 1994) for the Molytinae, indicated above by bold typing, and corroborate the placement of the Pacholenini (sensu Vanin & Reichardt, 1976) within the Molytinae (sensu Wibmer & 0'Brien, 1986). However, the relationships within the Molytinae remain uncertain, and the proposition of a phylogenetic hypothesis depends on further analysis, including representativos of the different subgroups. Acknowledgments We are indebted to Dr. Mário C. C. de Pinna (Departamento de Zoologia, Universidade de São Paulo) for his comments and suggestions on the manuscript. Finantial support and schoolarship came from Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, FAPERJ. References Anderson, D.M. 1991. Curculionidae (broad sense) (Curculionoidea), p. 594-616, in: J.F. Lawrcnc (coord). Order Coleoptera (chapter 34) p. 144-658. In: F.W. Stehr (ed.) Immature Insects. Kendall/Hunt Publ. Co., Dubuque. Vol. 2, xvi + 975p. Kuschel, G. 1995. A phylogenetic classification of Curculionoidea to familics and subfamilies. Memoir Entomol. Soe. Wash. 14: 5-33. May, B.M. 1993. Fauna ofNew Zealand, 28. Larvae of Curculionoidea (Insecta: Coleoptera): a Systematic Overview. Manaaki Whenua Press, Lincoln, New Zealand, 226 p. May, B.M. 1994. An introduetion to the immature stages ofAustralian Curculionoidea, p. 365-721. In: E.C. Zimmcrman. Australian Weevils (Coleoptera: Curculionoidea). CSIRO, East Melboumc. Vol. 2, 721 p. Monteiro, R.F., F.F.F. Ferraz, V.C. Maia & M.A.P. de Azevedo. 1994. Galhas entomógenas cm restingas: uma abordagem preliminar. Atas do III Simpósio de Ecossistemas da Costa Brasileira, vol. III (ACIESP, 87): 210-220. Vanin, S.A. & H. Reichardt. 1976. Revision of the gcncra of Pacholenini, a ncotropical tribe of Hylobiinac (Coleoptera, Curculionidae). Papéis Avulsos Zool., S. Paulo 29 (19): 155-176. Wibmer, G.J. & C.W. 0'Bricn. 1986. Annotated checklist of the weevils (Curculionidae sçnsu lato) of South America (Coleoptera; Curculionoidea). Mem. Amer. Ent. Inst. 39: 1-563. Publicado com o auxílio financeiro da Fundação de Amparo a Pesquisa no Estado de São Paulo, FAPESP. 

Ecological notes of Pacholenus Pelliceus Boheman, 1836, a stem gall-former, with description of fullgrown larva (Curculionidae, Molytinae)

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Ecological notes of Pacholenus Pelliceus Boheman, 1836, a stem gall-former, with description of fullgrown larva (Curculionidae, Molytinae)

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