Description of a new genus and new species of New World Phlebotominae (Diptera, Psychodidae)

 

 

Eunice Aparecida Bianchi Galati^I; José Dilermando Andrade-Filho^II; Antônio Carlos Lima da Silva^III; Alda Lima Falcão^II

^IFaculdade de Saúde Pública, Universidade de São Paulo. Av. Dr. Arnaldo, 715, 01246-904 São Paulo-SP, Brazil. E-mail: egalati@usp.br
^IILaboratório de Leishmanioses, Centro de Pesquisas René Rachou-Fiocruz. Av. Augusto de Lima 1715, 30190-002 Belo Horizonte-MG, Brazil. E-mail: Alda@cpqrr.fiocruz.br and jandrade@cpqrr.fiocruz.br
^IIINúcleo Entomologia do Piauí/NEPI/UFPI/SESAPI, Campus Ministro Petrônio Portela, Ininga SG -16. 64049-550 Teresina-PI, Brazil

 

 

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ABSTRACT

A new genus and new species of Phlebotominae, Edentomyia piauiensis (Diptera, Psychodidae) from a cave in Piauí State, Brazil, are described. This new genus belongs to Phlebotomini, but its inclusion in any subdivision of this tribe depends on further study.

Keywords: Edentomyia gen. nov.; Edentomyia piauiensis sp. nov.; Phlebotominae; Psychodidae; taxonomy.

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INTRODUÇÃO

According to the classification of GALATI (1995), Phlebotomini Rondani, 1840 is divided into several subtribes: Phlebotomina, Australophlebotomina Artemiev, 1991, Brumptomyiina Artemiev, 1991, Sergentomyiina Artemiev, 1991, Lutzomyiina Abonnenc & Léger, 1976 and Psychodopygina Galati, 1995. The subtribe Phlebotomina is restricted to the Old World. It represents the earliest ramification in the cladogram and the divergent branch, constituted by the ancestor of Australophlebotomina+, has as synapomorphy which unites this monophyletic group, the presence of horizontal teeth in the female cibarium. Hence, the cibarium of females without these teeth represents a plesiomorphy which, for American sandflies, has been described only for species of Hertigiina Abonnenc & Léger, 1976. However, the absence of the horizontal teeth in the cibarium was observed in male and female of a sandfly species captured in Piauí State, Brazil, besides several other plesiomorphic characteristics; thus, seems that these specimens belong to a new genus and new species which are here described.

 

MATERIAL AND METHODS

The specimens, after clarification by the method given by FORATTINI (1973) and mounted on microscope slides in NC medium (CERQUEIRA 1943) were measured with a Zeiss® eye-piece calibrated according to a standard Zeiss® scale and drawn with the help of an Olympus® drawing attachment. The measurements are given in micrometers, those in parentheses represent the average and standard deviations for the paratypes. The specimens were captured with automatic light CDC trap (SUDIA & CHAMBERLAIN 1962) from 6:00 p.m. to 6:00 a.m. in a cave. The terminology adopted for the morphological structures, in general, follows MCALPINE (1981), but some of these latter (ventrocervical sensillae, setae on the anterior edge of katepisternum and labial sutures), specifically studied in phlebotomines are described following GALATI (1995), who although presented them, not drown them, due to the limited size of that short communication. Thus they are here illustrated for the first time. The use of the sign + following a taxon signifies that it refers to the earlier branch of a monophyletic group constituted of three or more taxa, according to a suggestion of AMORIM (1982). The types are deposited in the entomological collection of the Centro de Pesquisa René Rachou, Fundação Oswaldo Cruz - Fiocruz, Belo Horizonte, Brazil (CPqRR), Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil (FSP) and Instituto Oswaldo Cruz- Fiocruz, Rio de Janeiro, Brazil (IOC).

Edentomyia gen. nov.

Type-species: Edentomyia piauiensis sp. nov.

Male. Head. Clypeus shorter than the eyes; interocular sutures not united with the interantenal suture; occipital bristles arranged in arrow-head formation; AIII with external ascoid implanted more apical than the internal one or both situated at the same level. AIV with simple and short ascoids, the distal prolongation not reaching the middle of the segment. AV with the papilla present or absent. AXIII without papilla. Palpal formula: 1.2.3.4.5. Palpomere III with Newstead's spines grouping in the basal third and presence of a preapical seta. Palpomere IV with more than five pairs of setae. Cibarium with long chamber, in which only rudimentary lateral teeth are present, absence of pigmented patch and posterior bulge, arch complete. Pharynx unarmed. Labrum-epipharynx short, measuring half of the head length; labial sutures forming a furca.

Cervix. Presence of ventrocervical sensillae.

Thorax. Presence of posalar, proepimeral, upper anepisternal bristles (these some times absent) and setae on the anterior edge of katepisternum; suture between katepimeron and metepisternum long.

Abdomen. Bristles covering the tergites arranged without forming transversal bands; presence of the tergal papillae on some tergites. Terminalia: gonostyle with five spines, two of them apical, the two external spines implanted on the apical 4^th and the internal one in the middle of structure; gonocoxite without basal tuft, only sparse setae implanted in the middle; of it; lateral lobe with rounded tip and as long as the gonocoxite; simple and digitiform paramere; conical and long aedeagus; genital filaments with simple tip.

Female. Clypeus shorter than the eyes; interocular sutures not united with the interantennal suture; occipital bristles arranged in arrow-head formation. AIII with external ascoid implanted more apical than the internal one. AIV with simple and short ascoids, the distal prolongation reaching the middle of the segment. AV with the papilla. AXIII without papilla. Palpal formula: 1.2.3.4.5. Palpomere III with Newstead's spines implanted together in the basal third and presence of one preapical seta. Palpomere IV with six pairs of setae. Cibarium with long chamber, in which only rudimental lateral teeth are present, absence of pigmented patch and posterior bulge, arch complete. Pharynx unarmed. Labrum-epipharynx short, measuring a little more than half the length of the head; labial sutures forming a furca. Maxilla: lacinia with the external teeth disposed in a longitudinal row. Hypopharynx with deep apicolateral teeth.

Cervix. Ventrocervical sensillae present.

Thorax. Characters as in the male.

Abdomen. Bristles covering the tergites arranged without forming transversal bands. Terminalia: tergite VIII without bristles. Spermathecae annulated, common duct short and the individual ducts ca. 3 x the body length.

Etymology. The name Edentomyia alludes to the absence of cibarial armature in both sexes.

Edentomyia piauiensis sp. nov.
(Figs. 1-20)

Holotype (male). Total body length 2710. General coloration pale.

Head (Fig. 1). Length ca. 1.16 x its width (1.16 ± 0.06; n = 18). Interocular suture not united with antennal suture. Ratio between lengths: clypeus/head: 0.39 (0.39 ± 0.015; n = 19); eye/head: 0.43 (0.42 ± 0.02; n = 20); labrum-epipharynx/head: 0.5 (0.5 ± 0.02; n = 19); labrum-epipharynx/AIII: 0.9 (0.84 ± 0.04; n = 4). Antennal formula AIII-AXV 2; AXVI 0 (Fig. 7). AIII with external ascoid implanted more apically than the internal one (in some paratypes, the internal and external ascoids are situated on the same level). Ascoids in AIV simple, without proximal prolongation and the distal one not reaching the middle of the segment (Fig. 5). AV (Fig. 6) without papilla (presence in four paratypes; n = 34). AXIII without papilla. Palpal formula: 1.2.3.4.5. Palpomere II without Newstead's spines. Palpomere III (Fig. 8) with Newstead's spines implanted in the basal third of the segment and one apical seta. Cibarium (Fig. 9) with long chamber, with only rudimental lateral teeth; lacking the pigmented patch and posterior bulge; complete arch. Pharynx without developed teeth. Labium (Fig. 3): sutures forming a labial furca. (See measurements in the Table 1.).

Cervix. Ventrocervical sensillae present.

Thorax. Presence of 3, 5 proepimeral bristles (paratypes: 2-6; n = 22). One upper anepisternal bristle (0-3; n = 22). One posalar bristle (1-2; n = 22). Paratergital bristles absent (1 in two paratypes). Setae on the anterior katepisternum edge present. Suture between katepimeron and metepisternum well defined and long. Wing as in Fig. 15. (See measurements in the Table 1).

Abdomen. 1700 long (1664 ± 169; n = 20). Tergites III-VII with tergal papillae. Terminalia (Fig. 18): gonostyle length 133 (133 ± 7; n = 20) with five well developed spines, two apical; the upper external inserted subapically; the lower external on the 4th apical; the internal in the middle of the structure. Gonocoxite length 250 (250 ± 14; n = 20) maximum width 45 (46 ± 5; n = 20), with 9-10 isolated bristles (7-14; n = 34). Paramere simple, dorsal margin length 170 (165 ± 11; n = 20), the ventral margin length 178 (185 ± 11; n = 20) with setae implanted beyond the middle. Lateral lobe length 228 (220 ± 22; n = 20); width, measured in the middle of the structure, 25 (25 ± 2; n = 20). Aedeagus (Fig. 19): conical, dorsal margin length 135 (128 ± 9; n = 20), ventral margin length 85 (77 ± 8; n = 20). Genital pump length 125 (118 ± 6; n = 20); piston length 100 (92 ± 5 n = 20); chamber length 18 (19 ± 2; n = 20). Genital filaments length 380 (356 ± 28 n = 20) or 3.04 times length of genital pump; tip of genital filaments simple (Fig. 19).

Allotype. Total body length 2920 (2820 ± 230; n = 9). General coloration pale.

Head (Fig. 2). Length 1.09 x its width (1.08 ± 0.04; n = 9). Interocular sutures not united with the antennal suture. Ratio between lengths: clypeus/head: 0.33 (0.36 ± 0.01; n = 9); eye/head: 0.45 (0.45 ± 0.04; n = 9); labrum-epipharynx/head: 0.53 (0.54 ± 0.01; n = 9); labrum-epipharynx/AIII: 0.9 (0.96 ± 0.04; n = 3). Antennal formula AIII-AXV 2; AXVI 0 (observed in two paratypes). AIII with external ascoid implanted more apical than the internal one. Ascoids in AIV without proximal prolongation; apical one reaches middle segment (Fig. 10). AV with papilla (Fig. 11). AXIII damaged in the allotype, but without papillae in two paratypes. Palpal formula: 1.2.3.4.5. Palpomere II without Newstead's spines. Palpomere III (Fig. 12), with Newstead's spines in the basal third of the segment and one apical seta. Cibarium (Fig. 13) with long chamber having no anterior or posterior teeth, only lateral teeth; pigmented patch and posterior bulge absent; arch complete (Fig. 14 - paratype). Pharynx without developed teeth. Labium (Fig. 4) with sutures forming the labial furca. Maxilla: lacinia with 6 external teeth (5-8; n = 10) disposed in longitudinal row with 17, 20 internal teeth (17-21; n = 10). Hypopharynx with ca. 20 deep apicolateral teeth. (See measurements in the Table 1).

Cervix. Ventrocervical sensillae present.

Thorax (Fig. 17). Presence of 3 proepimeral bristles (paratypes: 1-3; n = 9). Five and seven upper anepisternal bristles (3-7; n = 9). Two posalar bristles (1-2; n = 9). Paratergital bristles absent (1, in three paratypes). Setae on the anterior katepisternum edge present. Suture between katepimeron and metepisternum well defined and long. Wing as in Fig. 16. (See measurements in the Table 1.).

Abdomen length 1900 (1854 ± 164; n = 9). Terminalia: tergite VIII without bristles. Spermathecae (Fig. 20) length 33 (36 ± 5; n = 9) and maximum width 12 (10 ± 1; n = 9) with 8 (7-11; n = 7) segments; individual duct length 137 (134 ± 12; n = 9), maximum width 5 (4 ± 1; n = 9); common duct length 23 (32 ± 7; n = 9) and maximum width 10 (8 ± 2; n = 9). Cercus simple, 158 long (169 ± 8; n = 9).

Material examined. Holotype male. BRAZIL, Piauí State, Picos county, Cristovinho district, Cristovinho's cave, 30/31.X.2000. A. C. L. Silva col. (CPqRR). Allotype and paratypes: same data of holotype: 20 males and 3 females (CPqRR); 15 males, 3 females (FSP); 5 males, 2 females (IOC). 28 males, 14 females, 2/3.XI.1999, A. C. L. Silva col. (CPqRR).

Remarks. The type locality: Cristovinho's cave which is about 4 km north from the town of Picos (North: 9 217 019.26 UTM, East: 227 485.23 UTM), in the eastern region of Piauí State, has a main entrance 20 m wide x 15 m high and is inhabited by bats.

Other localities of Piauí State where specimens of this new species have been captured: Piracuraca county (North: 9 565 364.63 UTM, West: 199 137.79 UTM)- Parque Nacional de Sete Cidades; Castelo do Piauí county (North: 9 411 345.82 UTM, East: 217 093.42 UTM) - Pedra do Castelo; São Raimundo Nonato county (North: 9 002 659.31 UTM, East: 752 918.63 UTM )- Parque Nacional da Serra da Capivara (in cave).

 

TAXONOMIC DISCUSSION

According to GALATI (1995) the tribe Phlebotomini is distinguished from the Hertigiini by the apomorphies: the presence of proepimeral bristles; bristles covering the tergites arranged without forming transversal bands; cerci shorter than lateral lobes and absence of intra-abdominal rods. In the Phlebotomini, Australophebotomina, Brumptomyiina, Sergentomyiina, Lutzomyiina and Psychodopygina form a monophyletic group supported by a single synapomorphy represented by the presence of horizontal (anterior and/or posterior) teeth in the cibarial armature. The synapomorphies that distinguish the four latter subtribes of Australophlebotomina are represented by the presence of upper anepisternal bristles and tergite IX lacking a single sclerite at its base, i. e. completely modified in two lateral lobes

However, in Edentomyia piauiensis sp. nov. the presence of upper anepisternal setae and cibarium without anterior and posterior teeth raise some questions concerning its classification: 1) Does the absence of these bristles in Phlebotomina and Australophlebotomina signify the loss of these structures? Or, in fact, did they appear only in the ancestor of the subtribe Bumptomyiina+, as considered in GALATI'S (1995) classification? 2) Did the arrangement of horizontal teeth in the Australophlebotomina's cibarium arise independently of the Brumptomyiina+? Or did it occur as a single event, as considered in this classification? If this last event did in fact take place, it seems reasonable to suppose that the first alternative to question 1 also occurred, i. e. the upper anepisternal bristles arose in the ancestor of Phlebotomina+ and were lost in Phlebotomina and Australophlebotomina.

As a second supposition, the absence of teeth in the cibarium of this new taxon may be a loss, hence an apomorphy, as suggested by HENNIG (1972) for Warileya, Hertigia and Phlebotomus. He also suggested that the loss of mandibles among males and the concomitant atrophy of the cibarium supported this view. However, it may be concluded from an examination of the male cibarium that the atrophy did in fact occur, but maintained some similarity to that of the females, i. e. with only horizontal, vertical and lateral vestigial teeth. Further, the presence of lateral teeth alone in the sandfly Chinius, with many plesiomorphies, and in Sycoracinae, another subfamily of Psychodidae, with mouthparts of females adapted for sucking blood, at least in some genera (YOUNG, 1979), is an argument that favours the later appearance of horizontal teeth as an apomorphic state of the character. RISPAIL & LÉGER (1998) argue that the development of the simple cibarial armature into a later well-developed one, may suggest an adaptive character.

Other aspects of the cibarium of Edentomyia piauiensis sp. nov. such as the complete arch, the absence of the pigmented patch and posterior bulge, as occurs in Hertigiina, Phlebotomina and in Bruchomyiinae, the sister-group of Phlebotominae, indicate that the absence of the cibarial armature is a plesiomorphy.

Taking the cibarium of the Edentomyia piauiensis sp. nov. as being the plesiomorphic state and that the upper anepisternal bristles arose in the ancestor of Brumptomyiina+, then the placing of this new taxon in GALATI'S (1995) cladogram, would precede the position of this subtribe. In this case, the presence of horizontal teeth in the cibarium of Australophlebotomina would represent a convergence, implying that the monophyletic branch formed by this subtribe and Brumptomyiina+ would be, in fact, a polyphyletic group and hence undesirable in phylogenetic classification.

If the development of the horizontal teeth was a single event, it is then possible that the upper anepisternal bristles arose in the ancestor of Phlebotomina+ and were lost independently in this subtribe and in Australophlebotomina. The small number of these bristles in Edentomyia piauiensis sp. nov., sometimes absent in the males, reinforces this point of view.

As a third hypothesis, it may be thought that the upper anepisternal bristles arose early in Diptera and were maintained in a polymorphic condition in several families, including the Psychodidae. In this family these bristles are present at least in some genera of all Neotropical subfamilies: Bruchomyiinae, Phlebotominae, Psychodinae, Sycoracinae and Trichomyiinae. Hence, this polymorphic condition would have occurred prior to the division of the ancestral species of Bruchomyiinae and Phlebotominae and cladogenetic events occurred which split this species into two or more, without the fixation of this mutation either in the ancestor, or in its descendant species. The ancestral species of Hertigiini and that of Australophlebotomina lost this apomorphic allele, but in the ancestor of Phlebotomina+ retained the polymorphic condition, which was also preserved in Phlebotomina and Sergentomyiina. Thus the latters' descendants may or not present these bristles. On the other hand, Brumptomyiina and the ancestor of Lutzomyiina and Psychodopygina preserved the apomorphic state only, with the elimination of the plesiomorphic allele. So the presence of these bristles in Edentomyia piauiensis sp. nov., in some groups of Sergentomyiina, Brumptomyiina, Lutzomyiina and Psychodopygina may be considered a synapousy, according to the concept introduced by AMORIM et al. (1993).

Edentomyia piauiensis sp. nov. also presents several other characteristics in common with Phlebotomina (or the genus Phlebotomus, according to various authors), but many of these are plesiomorphies: palpal formula 1.2.3.4.5, Newstead's spines grouped in the basal half of the palpomere III, presence of ventrocervical sensillae, posalar bristles and setae on the anterior edge of the katepisternum, long suture between katepimeron and metepisternum, gonostyle with five spines, two of them in apical position; simple paramere and conical aedeagus. However, they share a few synapomorphies, such as the arrow-head formation of the occipital bristles, absence of ascoids on AXVI and spermathecae with annuli.

This new taxon, apart from the question of the cibarial armature, may be distinguished from the American subtribes Brumptomyiina, Sergentomyiina, Lutzomyiina and Psychodopygina by the following character. It differs from the Psychodopygina in the presence of posalar bristles, ventrocervical sensillae and palpal formula. From the Sergentomyiina, by having papilla on flagellomere III (AV), mainly in the females. In this subtribe, the new taxon seems to be similar to Deanemyia Galati, 1995, but only because of their plesiomorphies, such as the palpal formula, the presence of posalar bristles and setae on the anterior edge of the katepisternum and the long suture between the katepimeron and the metepisternum. However, it is easily distinguished from Deanemyia species by the labial sutures, which are not joined in these latter (Fig. 21). The plesiomorphies mentioned have also been found in the species of the genus Oligodontomyia Galati, 1995 (Brumptomyiina) (GALATI, 1995). In relation to the other genus of this subtribe, Brumptomyia, E. piauiensis sp. nov. is easily distinguished by the aspect of the ascoids in both sexes and by the terminalia of the males.

The new taxon differs from Lutzomyiina by the palpal formula and presence of posalar setae. Among the genera of this subtribe, E. piauiensis sp. nov. is closest to Lutzomyia, mainly to some species of the subgenus Lutzomyia, but can be distinguished from them by the absence of setae on the anterior edge of the katepisternum in the latter.

Consequently, Edentomyia piauiensis sp. nov. belongs to Phlebotomini, but for its insertion in one or other subtribe or as a new subtribe, further phylogenetic studies are necessary.

The association of the sexes was based on the capture of males and females in the same places and on the agreement of genital and extra-genital characteristics.

Etymology. The species name, Edentomyia piauiensis, refers to Piauí State, Brazil.

Acknowledgements. To the Fiocruz and Fundação Nacional da Saúde by the financial support for this work. We would like to express our appreciation to the anonymous reviewers of the manuscript.

 

REFERENCES

AMORIM, D. S. 1982. Classificação por seqüenciação: uma proposta para denominação dos ramos retardados. Revista Brasileira de Zoologia 1: 1-9.        [ Links ]

AMORIM, D. S.; M. E. ARAÚJO & A. M. SOLE. 1993. Origin of evolutionary novelties and the elimination of plesiomorphic alleles: some comments on limitations of the concept of synapomorphy. Revista Brasileira de Genética 16 (1): 245-252.        [ Links ]

CERQUEIRA, N. C. 1943. Novo meio para a montagem de pequenos insetos em lâminas. Memórias do Instituto Oswaldo Cruz 39:37-41.        [ Links ]

FORATTINI, O. P. 1973. Entomologia Médica. IV. Psychodidae. Phlebotominae. Leishmanioses. Bartonelose. São Paulo, Ed. Edgard Blücher Ltda. 658p.        [ Links ]

GALATI, E. A. B. 1995. Phylogenetic systematics of Phlebotominae (Diptera, Psychodidae) with emphasis on American groups. Boletín de la Dirección de Malariología y Saneamiento Ambiental 35(Supl. 1): 133-142.        [ Links ]

HENNIG, W. 1972. Insektenfossilien aus der unteren Kreide. IV. Psychodidae (Phlebotominae), mit einer kritischen Übersicht über das phylogenetische System der Familie und die bisher beschriebenen Fossilien (Diptera). Sttutgärter Beitrage zur Naturkende 241: 1-69.        [ Links ]

MCALPINE, J. F. 1981. Morphology and terminology - Adults. In: J. F. MCALPINE; B. V. PETERSON; G. E. SHEWELL; H. J. TESKEY; J. R. VOCKEROTH & D. M. WOOD (eds.). Manual of Nearctic Diptera. Ottawa, Research Branch Agriculture Canada, Monography 27,Vol. 1, p. 9-63.        [ Links ]

RISPAIL, P. & N. LÉGER. 1998. Numerical taxonomy of Old World Phlebotominae (Diptera: Psychodidae). 1. Consideration of morphological characters in the genus Phlebotomus Rondani & Berté 1840. Memórias do Instituto Oswaldo Cruz 93: 773-85.        [ Links ]

SUDIA, W. D. & R. W. CHAMBERLAIN. 1962. Battery operated light trap, an improved model. Mosquito News 22: 126-29.        [ Links ]

YOUNG, D. G. 1979. A review of the bloodsucking psychodid flies of Colombia (Diptera: Phlebotominae and Sycoracinae). Technical Bulletin 806, Agriculture Experimental Station, University of Florida, 226p.        [ Links ]

 

 

Received in 01.III.2002
Accepted in 20.XI.2002