Phytobia ( Diptera : Agromyzidae ) from Brazil : new species , new record and a key to the Neotropical species

Phytobia Lioy, 1864 flies occur in all continents. There are four recorded species of these flies in Brazil, but recent expeditions at unexplored areas in the country have revealed that the genus is far more diverse than previously known. Based on material collected in the states of Mato Grosso, Mato Grosso do Sul, and Rondônia (as part of the SISBIOTA Diptera Project), we describe fourteen new species of Phytobia. Additionally, we redescribe P. kallima (Frost), previously recorded only from Panama, and provide a key to the 32 resulting Neotropical species. All descriptions include details and illustrations of the male and female terminalia. The speciemens are deposited in the collections of Museu de Zoologia, Universidade de São Paulo (São Paulo, Brazil) and Museu Nacional, Universidade Federal do Rio de Janeiro (Rio de Janeiro, Brazil).

Phytobia species have a unique feeding behavior among the Agromyzidae.Their larvae feed on young xylem, a plesiomorphic feature within the family (Nowakowski 1962).All mining larvae of Phytobia are found in stems and branches, next to the cambium of deciduous trees.However, contrary to previous beliefs (Spencer 1973), they do not feed directly on cambium cells: they feed on young, undifferentiated cells right after these cells detach from the cambium; the meristematic cells remain untouched (Wallner andGregory 1979, Ylioja et al. 1998).This feeding habit, the large size of some species, the worldwide distribution of the genus, and the occurrence of species with plesiomorphic characters, dicot plants such as Rosaceae (which are present in fossils from the Eocene period), suggest that Phytobia is a very old genus (Spencer 1990).At least two extant conifer genera serve as hosts for these flies, Callitris Vent. in Australia, and the fossil Juniperoxylon silesiacum (Prill) Kräusel (both Cupressaceae) (Süss 1979).
Phytobia flies are economically relevant because they damage several trees that are important to humans (e.g., cricket bat, cheese box, and inlay industry).The larval marks, called "pith flecks", may decrease the commercial value of wood (Dempewolf 2004).In North America, Phytobia flies occur in Acer L. (Sapindaceae), Betula L. (Betulaceae), Amelanchier Medik., Crataegus L., and Prunus L. (Rosaceae), whereas in Europe they feed on Betula and Alnus Mill.(Betulaceae), Crataegus, Sorbus L., and Malus Mill.(Rosaceae), Populus (L.) and Salix L. (Salicaceae) (Spencer 1981).Spencer (1973) mentioned five species that attack the twigs and trunks of Betulaceae, Salicaceae, and Rosaceae in Europe and North America.In the most recent host list (Benavent-Corai et al. 2005) the hosts of only eleven described species of Phytobia from the Palearctic and Nearctic regions are indicated.
Although the host plants of all Neotropical Phytobia are yet to be documented, it is believed that their larvae are xylem feeders (Spencer 1966, Spencer and Stegmaier Jr 1973, Zlobin 2008).For instance, the larval galleries in the cambium of Wedelia calycina (L.) (Asteraceae) from Petit-Bourg in Guadeloupe have been attributed to Phytobia sp., although no adults have been reared from these plants (Étienne and Martinez 2003).
The identification of Phytobia can be difficult, since some species have characters of the Agromyzinae while others have characters of the Phytomyzinae.Using the key of Boucher (2010), for example, different Phytobia species will key out to either one of the subfamilies.Although the genus is similar to Agromyza Fallén in the shape of the Sc vein, both genera can be easily segregated based on the the absence of the stridulatory mechanism, which is present in all Agromyza species (males and females), (Spencer and Steyskal 1986).Some Phytobia species are included in groups, e.g. the Phytobia unica group, which includes species with Sc joining R 1 before reaching C and the distal margin of R 1 usually expanded near the junction, as in the Agromyzinae (Boucher 2010).Scheffer et al. (2007) did a molecular analysis of the Agromyzidae in which they included three north temperate species of Phytobia.In their data, there was no support for the basal position of Phytobia.The authors also noted that representatives of tropical species should be included in further analyses to help clarify the phylogenetic position of the genus.According to Zlobin (2008), the monophyly of Neotropical Phytobia is still not confirmed and needs future studies.
This paper describes fourteen new species of Phytobia and presents the redescription of P. kallima (Frost), newly recorded from Brazil.An illustrated key to 32 valid Neotropical species is provided.

MATERIAL AND METHODS
Specimens were collected in three Brazilian states: Mato Grosso, Mato Grosso do Sul, and Rondônia, where expeditions were made during 2011 and 2013, as part of the "SISBIOTA Diptera Project", a project that aimed to access the Diptera fauna of hitherto unexplored areas of Brazil.The material was captured using entomological nets and Malaise traps and was preserved in 98% alcohol.All specimens were mounted on entomological pins and deposited in the collections of Museu de Zoologia, Universidade de São Paulo (MZUSP) and Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ).
Male and female terminalia were macerated in KOH 10% for 48 hours and then placed in concave slides with glycerin for dissection.The drawings were made under an optical microscope using a camera lucida.Digital images of the species were made using a Leica MZ16 stereomicroscope and the AutoMontage software (Syncroscopy, version 5.03.0061).The terminology follows Cumming and Wood (2009) and Boucher (2010).
A key was elaborated to segregate the 32 species recorded from the Neotropical region and includes information on their geographical distribution, illustrations of the male terminalia for the new species, and illustrations and diagnoses available in the literature (for the previously described species).Additional characters are added within brackets.The types of the species from Brazil are deposited in the MZUSP collection, and were examined for the preparation of the key and for comparisons with the new species.Only the terminali of the adult male of P. xanthophora were analyzed, since all other parts have been lost.

TAXONOMY
All Phytobia species studied share the following characters: interfrontal hairs absent; eye bare; oc long, strong, parallel, and forward directed; ivt long and strong; ovt strong and outward directed; one row of strong peristomals; pp present; 1 prs; 1 ia; 1 sa; 2 pal; 1 pprn; posthumeral absent; 2 long and strong pairs of scutellar setae, 1 sub-basal, 1 apical; katepisternum with medium and thin setae and 1 long and strong posterior seta; Sc joining R 1 before reaching C and distal margin of R 1 straigth at junction; C extending to M; fore femur with strong row of pd setae; fore tibia with 1 ventral apical seta; mid and hind femora without differentiated setae; mid tibia with 1 ventral apical seta; hind tibia with an apical ventral seta.
Head.Frons slightly visible above eye margin in lateral profile; 2 reclinate ors and 2 inclinate ori, similar in size; orbital setulae slightly reclinate in one row; facial keel differenciated, extending to bases of antennae, slightly widening below; eye height/para-facialia+gena: 5; ocellar triangle short, ending before second ors; lunule high, about 20% of frons length; clypeus rounded; epistoma height 0.06 mm; first flagellomere rounded and finely pubescent; arista long, almost same vertical height of eye, finely pubescent; vibrissa long and strong, measuring half of aristal length.
Thorax.Acr in eight irregular rows; prsc absent; 1+3 dc, first presutural broken, second and third long, last one a little stronger; 2 npl, posterior one shorter.Wings.Wing tip nearer to R 4+5 than to M; R 4+5 and M slightly recurved; C sections 2-4 in proportion: 0.58: 0.23: 0.17; ultimate section of CuA 1 0.8 length of basal section; r-m basal to midpoint of dm.Legs.Fore tibia without pd, mid tibia with 3 pd on middle third.

Distribution. Rondônia (Brazil).
Etymology.The specific epithet refers to the Amazonian Rain Forest biome, where the species was found.
Thorax.Acr in seven irregular rows; prsc absent; 1+3 dc, third longer and stronger than others; 2 npl, similar in size.Wings.Wing tip between R 4+5 and M; R 4+5 and M straight; C sections 2-4 in proportion: 0.61: 0.22: 0.16; ultimate section of CuA 1 0.55 length of basal section; r-m distal to midpoint of dm.
Legs.Fore tibia with 1 pd; mid tibia with 2 pd on middle third.
Etymology.The specific epithet refers to the type locality, Cacaulândia, where the holotype was collected.
Remarks.This new species has a singularly infuscated wing with a brown area above Sc and in cup cell.This pattern has not been seen in any other species of Phytobia.The wing of P. lanei Spencer, 1966 is conspicuously spotted and the wing of P. rabelloi Spencer, 1966 is fully infuscated.In addition, P. cacaulandia sp.nov.can also be distinguished from other species in the length of the wing, 2.9 mm (5.1 mm in P. lanei), number of dorsocentrals 1+3 (1+4 in P. rabelloi), the shape of the phallus, and the ejaculatory apodeme with lower blade broader than base.This species also has a distinct pd on fore tibia.
Thorax.Acr in eight irregular rows; prsc absent; 1+3 dc, presutural and first postsutural shorter than second and third; 2 npl, similar in size.Wings.Wing tip nearer R 4+5 than M; R 4+5 and M straight; C sections 2-4: 0.72:0.16:0.12;ultimate section of CuA 1 with same length of basal section; r-m distal to midpoint of dm.Legs.Fore tibia without pd; mid tibia with 2 pd on middle third.
Etymology.The specific epithet refers to the common characters showed by the species within the genus, except the male terminalia.
Remarks.This new species is morphologically similar to P. megapodema sp.nov. in the length of the body and wing and in the general color of the body, but it can be differentiated by the antennae entirely orange brown; surstylus with about 32 setae, distiphallus well sclerotized with two arms and short ejaculatory apodeme.
Color.Frons mat black; fronto-orbital plate shining black; upper shiny dark orbit touching ovt and ivt; ocellar triangle mat black; lunule silvery; face greyish-black; clypeus black subshining; gena brown; antenna and arista entirely brown; palpus brown; proboscis yellow; labellum yellow, with yellow setae; scutum weakly shining brown, light yellow laterally and before scutellum, black ia area of scutum not reaching scutellum and forming two distinct bands divided by narrow yellow stripe (Fig. 29); scutellum light yellow, with sub-basal lateral brown spot; postpronotum light yellow, with basal brownish spot; notopleuron and anepimeron light yellow; anepisternum light yellow, with small brown spot on basal half; katepimeron light yellow, katepisternum and meron brown; haltere entirely yellow; calypters light yellow, with margin and fringe brown; wing clear, light yellow at base; legs brown with all knees yellow; pulvilli light yellow; abdomen yellow, tergite 5 and tergite 6 with median brown stripe touching at limit of tergites; terminalia entirely brown.
Head.Frons slightly visible above eye margin in lateral profile; 2 reclinate ors and 2 inclinate inwards ori, first ori more inclinate than second ori and slightly thinner and shorter than others; orbital setulae slightly reclinate in one row; facial keel undifferenciated; eye height/parafacialia+gena: 6; ocellar triangle short, ending shortly after second ors; lunule a little high, about 16% of frons length; clypeus obtuse; epistoma height 0.02 mm; first flagellomere rounded and finely pubescent; arista long, same size vertical height of eye, finely pubescent; vibrissa short and thin, measuring about 1/3 of aristal length.
Thorax.Acr in six irregular rows; prsc absent; 1+3 dc, presutural thinner and shorter than others, second broken, third and fourth long and strong; 2 npl, similar in size.Wings.Wing tip nearer R 4+5 than to M; R 4+5 and M erect; C sections 2-4: 0.72:0.18:0.09;ultimate section of CuA 1 0.9 length of basal section; r-m basal to midpoint of dm.Legs.Fore tibia without pd; mid tibia with 2 pd on middle third.
Etymology.The specific epithet refers to the membranous and delicate phallus.
Remarks.Phytobia delicata sp.nov. is morphologically similar to P. spinifera sp.nov. in external characters and coloration of the body, but can be differentiated by the rounded surstylus with about 11-19 setae and distiphallus membranous, sclerotized centrally.[MZUSP] (Fig. 2).
Color.Frons egg yellow in lower half and yellow with pollinose silver on upper half; fronto-orbital plate yellow; upper dark orbit touching ovt and yellowish in ivt; ocellar triangle brownish-black; lunule and face greyish-yellow; clypeus dark subshining; gena yellow; scape and pedicel dark brown, first flagellomere dark brown, orange anteriorly; arista brown; palpus yellow, with black and yellow setae apically; proboscis yellow; labellum yellow, with yellow setae; scutum brown, grey pollinose, light greyish-yellow before scutellum (Fig. 30); scutellum light greyish-yellow, with one brown spot laterally on basal middle; postpronotum and notopleuron light yellow; anepimeron and anepisternum brown anteriorly and yellow posteriorly; katepimeron light yellow, katepisternum dark brown, yellowish on upper part; meron dark brown with yellow transversal band upperly; haltere entirely yellow; calypters light yellow, with margin and fringe black; wing clear, yellow at base; legs dark brown, with fore knees yellow; pulvilli yellow; abdomen yellow, tergite 5 with brown median spot, tergite 6 with brown median stripe and brown lateral round spot; terminalia entirely brown.
Head.Frons not visible above eye margin in lateral profile; 2 reclinate ors and 2 inclinate inwards ori, ori slightly thinner and shorter than ors; orbital setulae thin and short, slightly reclinate in one row; facial keel undifferenciated; eye height/ parafacialia+gena: 5.5; ocellar triangle short, ending before second ors; lunule a little high, about 14% of frons length; clypeus rounded; epistoma height 0.01 mm; first flagellomere rounded and finely pubescent; arista long, slightly longer than vertical height of eye, finely pubescent; vibrissa short and strong, measuring about 1/3 of aristal length.
Etymology.The specific epithet refers to the egg-yellow frons of the species.
Remarks.This new species resembles P. pipinna (Sasakawa, 1992) from Peru in the yellow coloration of the body, but can be differentiated by the short wing and body length, scape and pedicel dark brown, frons conspicuously egg yolk yellow in lower half and yellow silver pollinose on upper half, one seta on postgonite, surstylus with about 11-18 setae, phallus shape, and the broad ejaculatory apodeme.
Color.Frons mat black; fronto-orbital plate shining black; upper dark orbit touching ovt and ivt; ocellar triangle mat black; lunule silvery; face brown with grey pollinose; clypeus black, sligltly shiny; gena dark brown; antenna and arista entirely brown; palpus brown; proboscis light brown; labellum light brown, with brown setae; scutum dark brown, weakly shining; scutellum dark brown; postpronotum, notopleuron, anepimeron, anepisternum, katepimeron, katepisternum, and meron dark brown; haltere entirely light yellow; calypters light yellow with margin and fringe brown; upper fourth of wing brown and with brown area from radial sector reaching transversal r-m and dm-cu veins; legs dark brown; pulvilli yellow; abdomen entirely dark brown.
Thorax.Acr in eight irregular rows; prsc present; 1+3 dc, increasing in size from presutural to third postsutural; 2 npl, similar in size.Wings.Wing tip between R 4+5 and M; R 4+5 and M slightly recurved; C sections 2-4: 0.68:0.15:0.15;ultimate section of CuA 1 0.44 length of basal section; r-m distal to midpoint of dm, close to limit of apical third.Legs.Fore tibia without pd; mid tibia with 2 pd on middle third.
Terminalia.Epandrium large and rounded with long setae; cercus short, slightly less than 1/3 height of epandrium and with long setae and one distinct at apex; surstylus oblong and large with about 23-32 setae; hypandrium U-shaped; phallapodeme about twice length of hypandrium; mesophallus tubular; distiphallus as in Figs 55 and 56; ejaculatory apodeme broad, at its broader part about 3.3 times wider than constricted area at base (Fig. 57).
Remarks.Phytobia kallima was described by Frost (1936) based only on external characters.Here we provide the first description of the male terminalia.It was previously known from Panama and differs from the other species by the conspicuously pictured wing and by the shape of the phallus, besides the broad ejaculatory apodeme.
Etymology.The specific epithet is in honor of Dr. Carlos Einicker Lamas (Museu de Zoologia, Universidade de São Paulo) in recognition of his great contribution to the Brazilian Diptera fauna knowledge.
Remarks.This new species resembles P. spinifera sp.nov.and P. delicata sp.nov. in the general coloration of the body and chaetotaxy, but can be distinguished from them by the yellow abdomen with a brown stripe on tergites 3-5 and tergite 6 almost entirely brown.It also differs by the presence of 3-4 short setae at apex of postgonite, surstylus with about 12 setae, and distiphallus rounded with two sclerotized areas centrally.
Color.Frons mat black, more brownish at base; fronto-orbital plate shining black; upper dark orbit touching ovt and ivt; ocellar triangle mat black; lunule silvery; face black with grey pollinose; clypeus mat black; gena dark brown; scape and pedicel brown; first flagellomere brown, light brown apically; arista and palpus brown; proboscis light brown; labellum light brown, with yellow setae; scutum dark brown, grey pollinose, light yellow before scutellum (Fig. 32); scutellum light yellow, with sub-basal lateral brown spot; postpronotum light yellow, brown on basal half; notopleuron light yellow; anepimeron brown; anepisternum dark brown, yellow posteriorly; katepimeron, katepisternum, and meron dark brown; haltere entirely yellow; calypters light yellow with margin and fringe black; wing clear, yellow at base; legs brown with all knees yellow; pulvilli yellow; abdomen yellow, tergites 3-6 with median brown stripe and two brown spots laterally; terminalia brown.
Thorax.Acr in nine irregular rows; prsc absent; 1+3 dc, presutural and first postsutural shorter than two others; 2 npl, similar in size.Wings.Wing tip between R 4+5 and M; R 4+5 and M slightly recurved; C sections 2-4 in proportions: 0.64:0.17:0.17;ultimate section of CuA 1 with same length of basal section; r-m distal to midpoint of dm.Legs.Fore tibia without pd; mid tibia with 2 pd on middle third.
Distribution.Rondônia, Mato Grosso, and Mato Grosso do Sul (Brazil).Remarks.This new species is morphologically similar to P. communis sp.nov. in body and wing length and in the general coloration, but it can be distinguished by the scape and pedicel brown, surstylus triangular with about 38 setae, distiphallus very complex, and very broad ejaculatory apodeme.[MZUSP] (Fig. 3).
Color.Frons mat black, greyish pollinose; fronto-orbital plate and ocellar triangle mat black; upper shiny dark orbit touching ovt and ivt; upper shinning dark orbit touching lunule and face silvery; clypeus mat black; gena greyish-black; scape and pedicel brown; first flagellomere orange brown; arista brown; palpus orange, with black setae apically; proboscis yellow; labellum yellow, with yellow setae; scutum and all pleurae uniformly brown, grey pollinose; haltere entirely light yellow; calypters light yellow, with margin and fringe brown; wing clear, yellow at base; legs dark brown; pulvilli yellow; abdomen entirely brown.
Etymology.The specific epithet refers to the great number of setae on surstylus.
Color.Frons, fronto-orbital plate and ocellar triangle mat black; upper dark orbit touching ovt and ivt; lunule silvery; face brown; clypeus black subshining; gena dark brown; scape and pedicel brown; first flagellomere brown, yellow apically; arista brown; palpus yellow; proboscis yellow; labellum yellow, with yellow setae; scutum brown with grey pollinose, light yellow before scutellum (Fig. 33); scutellum light yellow, brown laterally at basal two-thirds; postpronotum light yellow, with brown spot centrally; notopleuron light yellow; anepimeron dark brown, with upper and posterolateral margins yellow; anepisternum, katepimeron, katepisternum and meron dark brown; haltere entirely yellow; calypters light yellow, with margin and fringe black; wing clear, yellow at base; legs dark brown with fore knees yellow; pulvilli yellow; abdomen yellow, with dark brown spot centrally in all tergites, tergites 3-6 with dark brown spot on each side; terminalia dark brown.
Thorax.Acr in six irregular rows; prsc absent; 1+3 dc, increasing in length from presutural; 2 npl, similar in size.Wings.Wing tip between R 4+5 and M; R 4+5 and M erect; C sections 2-4 in proportion: 0.58: 0.25: 0.16; ultimate section of CuA 1 1.14 length of basal section; r-m distal to midpoint of dm.Legs.Fore tibia without pd; mid tibia with 1 pd on middle third.
Etymology.The specific epithet is in honor of Dr. Silvio Nihei (Universidade de São Paulo) in recognition of his great contribution to our knowledge of the Neotropical Diptera.
Thorax.Acr in eight irregular rows; prsc present; 1+3 dc, presutural and first postsutural with same size, smaller than second and third, this longer than anterior one; 2 npl, anterior one shorter than posterior one.Wings.Wing tip nearer to R 4+5 than to M; R 4+5 and M erect; C sections 2-4: 0.60:0.20:0.20;ultimate section of vein CuA 1 1.1 the length of basal section; r-m distal to midpoint of dm.Legs.Fore tibia without pd; mid tibia with 3 pd on the middle third.
Etymology.The specific epithet is derived from the Latin words planus (flat) and palpis (palpus), referring to the flattened palpus of the species.
Remarks.This new species is morphologically similar to P. kallima in the dark coloration of the body, but it can be distinguished by the hyaline wing, palpus flattened, postgonite with two setae, surstylus with about 13-20 setae, and a distinct tulip-shaped distiphallus.
Color.Frons mat black; fronto-orbital plate and ocellar triangle weakly shining black; upper shining dark orbit touching ovt and ivt; lunule silvery; face greyish-black; clypeus black subshining; gena dark brown; antenna and arista entirely brown; palpus brown; proboscis brownish-yellow; labellum brownish-yellow, with light setae; scutum shining black, with yellow area before scutellum, black intra-alar area of scutum almost reaching scutellum and forming one short band divided by narrow yellow stripe (Fig. 34 central brownish spot; notopleuron and anepimeron light yellow; anepisternum light yellow, brown in lower part; katepimeron, katepisternum and meron brown; haltere entirely yellow; calypters light brown, yellow at base and with margin and fringe brown; wing infuscate, darker on apical longitudinal third and on dm-cu crossvein; legs brown with fore knees brownish-yellow; pulvilli yellow; abdomen yellow on tergites 1+2 and tergite 3, tergite 4 with central black stripe, tergites 5, 6 and terminalia entirely black.
Thorax.Acr in seven irregular rows; prsc absent; 1+3 dc, increasing in size from presutural; 2 npl, similar in size.Wings.Wing tip between R 4+5 and M; R 4+5 and M slightly recurved; C sections 2-4: 0.69:0.15:0.15;ultimate section of CuA 1 0.58 length of basal section; r-m distal to midpoint of dm, close to limit of apical third.Legs.Fore tibia without pd; mid tibia with 2 pd on middle third.
Etymology.The specific epithet refers to the pear-shaped distiphallus.
Remarks.Phytobia pyri sp.nov. is similar to P. monsonensis Sasakawa, 1992, from Peru, in the general coloration of the body, chaetotaxy and the length of the phallapodeme (2.5 mm) in relation to the length of the hypandrium.However, the new species can be differentiated by the length of the body and wing, lunule silver, mid tibiae with two posterodorsal setae on middle third, surstylus with 6-11 setae and the phallus shape with distiphallus membranous and pear-shaped in dorsal view.
Head.Frons slightly visible above eye margin in lateral profile; 2 reclinate ors and 2 inclinate inwads ori, similar in size; orbital setulae erect in one row; facial keel undifferentiated; eye height/gena+parafacialia: 5; ocellar triangle short, ending before second ors; lunule high, about 20% of frons length; clypeus rounded; epistoma height 0.03 mm; first flagellomere rounded and finely pubescent; arista long, with same measure of vertical height of eye, minutely pubescent; vibrissa long and strong, measuring almost half of aristal length.
Terminalia.Epandrium rounded, wider than heigh, with long setae; cercus long, about 2/3 height of epandrium and with long setae and distinct seta at apex; surstylus rounded with about 10 setae; hypandrium U-shaped with small projection on apex; phallapodeme about twice length of hypandrium; mesophallus simple and thin; distiphallus sclerotized with two medium arms (Figs 84,85); ejaculatory apodeme broad, at its broader part about 3.4 times wider than constricted area at base (Fig. 86).
Etymology.The specific epithet refers to the simple shape of the phallus.
Remarks.Phytobia simpla sp.nov. is morphologically similar to P. multisetosa sp.nov. in the length of the wing and color of the scutum, brown grey pollinose.It can be distinguished by the frons mat black, with basal half brown close to lunule, surstylus rounded with about 10 setae and distiphallus sclerotized with two medium arms.
Phytobia spinifera sp.nov.black, slightly shiny; gena brown; antenna and arista entirely blackish-brown; palpus brown; proboscis light yellow; labellum light yellow, with yellow setae; scutum weakly shining black, strongly yellow laterally and before scutellum, black intra-alar area of scutum not reaching scutellum and forming two distinct bands divided by narrow yellow stripe (Fig. 35); scutellum strongly yellow; postpronotum strongly yellow, with central brownish spot; notopleuron and anepimeron strongly yellow; anepisternum strongly yellow, brown on basal half; katepimeron yellow; katepisternum and meron brown; haltere entirely yellow; calypters whitish-yellow, with margin and fringe brown; wing clear; legs brown with fore knees brownish-yellow; pulvilli light yellow; abdomen yellow, T5 and T6 with median brown spot; terminalia entirely brown.
Head.Frons not visible above eye margin in lateral profile; 2 reclinate ors and 2 inclinate inwards ori, similar in size; orbital setulae slightly reclinate in one row; facial keel undifferentiated; eye margins little divergent towards vertex;  at its broader part about 4.0 times wider than constricted area at base (Fig. 89).
Etymology.The specific epithet refers to the presence of two spines on the distiphallus.
Remarks.This new species is close to P. delicata sp.nov.
in external characteristics and coloration of the body, but it can be distinguished by the male terminalia with a basal seta on postgonite, surstylus with about 11-13 setae and two strong spines, and distiphallus bulb-shaped with one apical spine on each side.Description.Male.Body length 2.75 mm; wing length 2.5 mm (Fig. 25). Female.Unknown.
Thorax.Acr in nine irregular rows; prsc present; 0+2 dc, first smaller than last one; 2 npl, similar in size.Wings.Wing tip between R 4+5 and M; R 4+5 and M erect; C sections 2-4 in proportion: 0.58:0.23:0.17;ultimate section of vein CuA 1 0.75 length of basal section; r-m past middle point of dm.Legs.Fore tibia without pd; mid tibia with 2 pd on middle third.
Etymology.The specific epithet refers to the spinous membrane around the phallus.
Remarks.This species is morphologically close to P. unica Spencer (in Spencer and Stegmaier Jr 1973), known from Jamaica, due to the presence of only 2 dc and general coloration of the head, but it can be distinguished by the presence of the two posterodorsal setae on mid tibiae, the prescutellar present, and the male terminalia with distiphallus bifid with a surrounding membrane bearing many spines.Frons black [epandrium densely setulose; surstylus with about 37 spines, including 6-7 minute ones; cercus with dense setae; hypandrium about 4/5 length of phallapodeme (Fig. 96); phallus about 1.2 times as along as phallapodeme, distiphallus as two long tubules, basiphallus short but rather well-developed, ventral process membranous (Fig.