Hydrellia egeriae, Júnior, Francisco De Assis Rodrigues, Mathis, Wayne Nielsen & Hauser, Martin, 2015

Júnior, Francisco De Assis Rodrigues, Mathis, Wayne Nielsen & Hauser, Martin, 2015, Argentine Hydrellia Robineau-Desvoidy (Diptera, Ephydridae): new species and key to identification, Zootaxa 3957 (1), pp. 131-136: 133-136

publication ID

http://dx.doi.org/10.11646/zootaxa.3957.1.11

publication LSID

lsid:zoobank.org:pub:7167DF3D-459F-4918-BD0A-E1F2EE13A8E7

persistent identifier

http://treatment.plazi.org/id/03D487DD-3237-FF9F-FF55-FEAD27FCFB8D

treatment provided by

Plazi

scientific name

Hydrellia egeriae
status

sp. nov.

Hydrellia egeriae   sp. nov.

(Figs.: 1–3.3)

Cabrera Walsh et al. 2013: 133–147 (as Hydrellia   sp. 1 and 2) [ecology; host plant: Egeria densa Planchon   ( Hydrocharitaceae   )].

Diagnosis. Body length of male: 1.86–2.07 mm ( Fig. 1 View FIGURE 1. H ); Female: 1.70–2.09 mm; ocellar setae three times shorter than pseudopostocellar; face usually wholly golden microtomentose; dorsocentral setae 1 + 1; tarsi dark brown ( Fig. 1 View FIGURE 1. H ); ctenidial setae along anteroventral margin of forefemur minute; sternite 4 and 5 of male apparently divided (Figs. 2.1 and 2.2); lateral arms of sternite 5 covered with many long hair-like setulae on posterior margin and many spine-like setae concentrated on inner mid- posterior margin (Figs. 2.1 and 2.2); aedeagus, in lateral view, with a pointed, shallowly recurved process on dorsal margin (Fig. 2.4); surstylus larger than wide, posterior margin concave, narrow medially, with a small mid apical cleft, forming broad lateral arms, each lateral arm with a small concavity lateroapically (Fig. 2.7); sternite 8 setulose, convex on anterior margin, pointed on posterior margin, projecting under the cerci (Fig. 3.1).

Description. Head ( Fig. 1 View FIGURE 1. H ): frons broader than high; frontal vitta golden brown; fronto-orbital plate opaque brown to black; ocellar setae present, three times shorter than pseudopostocellar setae; both proclinate and lateroreclinate fronto-orbital setae present, with a third shorter setulae between both; antenna mostly dark brown to black, first flagellomere with grayish micropubescence ventrobasally; pedicel without prominent setae on dorsal margin, but with 2 ventral hair like setulae; face usually wholly golden microtomentose, sometimes silver, and in few cases golden microtomentose only medially and silvery along the row of facial setae; bearing 4–6 facial setae (usually 5); parafacial usually concolorous with face; face in lateral view nearly vertical, but with a small medial carina and shallow but distinct antennal grooves; lunule silver; gena, postgena and occiput silvery gray, genal groove dark brown to black; maxillary palpus yellow, spatulate, bearing two setulae; epistomal ratio: 1.56–1.58; mesofacial ratio: 2.03–2.06; vertex ratio: 5.20–5.30; eye-to-gena ratio: 2.84–3.72; head ratio: 1.29–1.33.

Thorax ( Fig. 1 View FIGURE 1. H ): well-developed dorsocentral setae 1 + 1; mesonotum densely dark brown microtomentose; pleurae silvery gray, except for brown microtomentose notopleura; 1 mesokatepisternal seta; 3 scutellar setae, mid pair weakly developed; 1 postpronotal seta. Wings ( Fig. 1 View FIGURE 1. H ): length 1.85–2.32 mm; hyaline with brown venation; knob of halter fluorescent yellow to whitish yellow, stem pale brown; costal sections indices: II/I: 1.74–1.84; III/ IV: 2.80–2.92; V/IV: 3.06–3.19; vein M ratio: 3.39–3.79. Legs ( Fig. 1 View FIGURE 1. H ): mostly silvery gray microtomentose, joints brown; posterior margin of mid and hind femur glossy brown; tibiae mostly brown; tarsi dark brown; ctenidial setae along anteroventral margin of forefemur minute.

Abdomen ( Fig. 1 View FIGURE 1. H ): brown microtomentose dorsally, concolorous with mesonotum; in lateral view silvery gray. Male terminalia: sternite 4 apparently divided or unsclerotized medially, as sternite 5, setulose and with spine-like setae on inner medial margin (Figs. 2.1 and 2.2); sternite 5 attached with anterior margin of hypandrium, apparently divided, anterior margin truncate, pointed anterolaterally, lateral arms covered with many long hair-like setulae on posterior margin and many spine-like setae concentrated on inner mid- posterior margin (Figs. 2.1 and 2.2); postsurstylus with an inner rounded membrane (Fig. 2.2); pregonite rod-like, except for the apical bifurcation, each lobe bearing an apical setulae (Fig. 2.2); epandrium broad, forming an inverted U (Fig. 2.1); phallapodeme in ventral view Y shaped, bifurcated on posterior margin (Fig. 2.5), in lateral view shallowly sinuous medially (Fig. 2.6); aedeagus in ventral view fusiform (Fig. 2.3), in lateral view with a pointed, shallowly recurved process on dorsal margin (Fig. 2.4); surstylus larger than wide, posterior margin concave, narrow medially, with a small mid apical cleft, forming broad lateral arms, each lateral arm with a small concavity lateroapically (Figs. 2.1 and 2.7); Female terminalia: sternite 6 rounded trapezoidal (Fig. 3.1); sternite 7 rounded quadrate (Fig. 3.1); sternite 8 setulose, convex on anterior margin, pointed on posterior margin, projecting under the cerci (Fig. 3.1); tergites subequal in length (Fig. 3.2); cerci ovoid (Fig. 3.2); hypoproct small, flap-like (Fig. 3.2); ventral receptacle with a cap cupuliform, as broad as large, with an extended process, J-shaped in lateral view (Fig. 3.3).

Material examined. Holotype male ( USNM): Argentina: 8 km SE Campana, Buenos Aires province (34 14 ’ 0 4 S, 58 52 ’ 32 W); USDA-ARS laboratory colony Albany, CA VII- 25-2013; J. Herr coll. Paratypes: labeled the same as holotype (7 males / 7 females in MNRJ and 8 males / 7 females in USNM); 10 males, 10 females CSCA, 1 male ( CSCA FTC: # 13 M 460) GenBank accession number (CO 1): KJ 703244 View Materials ); Hurlingham, Buenos Aires province (3435 ’ 14 S, 5838 ’ 27 W); USDA-ARS laboratory colony Albany, CA. VII- 25-2013; J. Herr coll. (8 males / 7 females in MNRJ and 7 males / 8 females in USNM); 1 female ( CSCA FTC: # 13 M 459), GenBank accession number (CO 1): KJ 703243 View Materials ).

Distribution. Neotropical: Argentina (Campana and Hurlingham).

Etymology. The specific epithet egeriae   refers to the host plant Egeria densa Planchon   , with which this species is associated and feeds during the larval stage.

Notes. Hydrellia egeriae   is very similar to H. schneiderae Rodrigues-Júnior, Mathis & Couri   and H. vulgaris Cresson   , but can be distinguished by the shape of sternite 5, aedeagus and the discrepancy of surstylus of male and sternite 8 of female.

DNA results. When comparing the two identical CO 1 sequences of Hydrellia egeriae   with sequences in the BOLD database, we could not find any close matches. The most similar results were Scatophagidae   with 89.37 % similarity. The first ephydrid ( Hydrellia griseola   ) had a 88.96 % similarity with our sequences. The results for a BLAST-search in GenBank were similar, with the closest matches being Muscidae   and Calliphoridae   with 89 % similarity. In general intraspecific variation is less than 2 % and between genera 7 %. Of course there are significant differences in certain taxonomic groups. The reason for this poor match is very likely the lack of Hydrellia   sequences in these databases – only a few species were available in these databases. Furthermore, comparing our CO 1 sequence with the two available Hydrellia   sequences on GenBank, H. tritici   (EU 493564.1) and H. pakistanae   (EU 493563.1), yielded a similarity of 83 % and 86 % respectively. The comparison between H. tritici   (EU 493564.1) and H. pakistanae   (EU 493563.1) yielded 87 % similarity. This could be an indication that the genus Hydrellia   includes very divergent species. The new species is from the Neotropics, while H. pakistanae   is from the Oriental region and H. tritici   from Australia. The aim of this paper is to characterize and name a new potential biocontrol agent and not to revise the genus Hydrellia   . Therefore the sequences of H. egeriae   are to aid identifications, especially of immature stages or females. The comparison with other Hydrellia   DNA indicates that there is need for further investigations into the phylogenetic relationships of Hydrellia   and that much more sequencing is needed before any taxonomic conclusions can be drawn.

USNM

Smithsonian Institution, National Museum of Natural History

MNRJ

Museu Nacional/Universidade Federal de Rio de Janeiro

CSCA

California State Collection of Arthropods

DNA

Department of Natural Resources, Environment, The Arts and Sport

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Ephydridae

Genus

Hydrellia