Aztecatopse huertai,

Amorim, Dalton de Souza & Brown, Brian V., 2020, Urban Scatopsidae (Diptera) of Los Angeles, California, United States, Insect Systematics and Diversity 4 (1), No. 1, pp. 1-41: 17-21

publication ID 10.1093/isd/ixaa001

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Aztecatopse huertai


Aztecatopse huertai  sp.nov.

( Figs. 4View Figs, 18View Figs, and 52–56)

(Zoobank LSID: )

Diagnosis. Labella quite elongate—differently from A. diabolica (Duda)  . Spiracular sclerite with wide anterior, ventral and posterior margins, with regular dorsoanterior extension—similar to the

condition in A. diabolica  . R 5 rather long, wing length 4.45 times R 1 - R 5 length (4.9 in A. diabolica  , 7.2 in A. amorimi Huerta and Haenni  , 7.4 in A. neotropica  , 7.1 in A. foliosa  and 8.0 in A. spinosa  ). Distal

fourth of CuA slightly curved towards base. Female sternite 7 with

a wide, triangular extension of posterior margin folded underneath

the sternite distally. Mid-posterior margin of female sternite 8 with

1–2 long setae on a short protuberance on each side (similar to

A. diabolica  ).

Material Examined. Holotype: ♀, United States, California, Los Angeles Co., Los Angeles, Los Feliz , 34.116°N 118.279°W, Malaise trap, 29 March–14 April 2014, BioSCAN site 6, Coll. Jeff, Aaron and Jacob Koch, BioSCAN sample 15939 ( LACM) (on slide)GoogleMaps  . Paratypes: 1 ♀, same data, Larchmont , 34.077°N 118.32°W, Malaise trap, 29 March–5 April 2014, BioSCAN site 18, Coll. KT Wiegman, BioSCAN sample 15968 (on slide) ( MZUSP)GoogleMaps  ; 1 ♀, same data, Exposition Park , 34.018°N 118.289°W, 55 m, Malaise trap, 2–9 May 2014, BioSCAN site 1, Coll. Lisa Gonzalez and Dean Pentcheff, BioSCAN 15915 (on slide) ( LACM)GoogleMaps  ; 1 ♀, United States, California, Los Angeles Co., Los Angeles, Silverlake , 34.093°N 118.274°W, Malaise trap, 28 December 2013 – 4 January 2014, BioSCAN site 5, Coll.Walter Renwick,BioSCAN sample 15419 ( LACM)GoogleMaps  ; 1 ♀, United States, California, Los Angeles Co., Los Angeles, Los Feliz , 34.113°N – 118.292°W, 174.7 m BioSCAN Site 20, 30 May–6 June 2014, BioSCAN sample 16102 ( LACM)GoogleMaps  ; 1 ♀, United States, California, Los Angeles Co., Los Angeles, Silverlake , 34.093°N 118.274°W, 166.1 m, Coll. Walter Renwick, BioSCAN Site 5, 31 May–7 June 2014, BioSCAN sample 16113 ( LACM)GoogleMaps  ; 2 ♀♀, United States, California, Los Angeles Co., Los Angeles, Silverlake , 34.093°N 118.274°W, 166.1 m, Coll. Walter Renwick, BioSCAN Site 5, 28 June– 5 July 2014, BioSCAN sample 16268 ( LACM)GoogleMaps  .

Description. Male. Unknown.

Female ( Fig. 4View Figs). Body length, 2.50–2.82 mm. General body color dark brown, with lighter areas on thorax, dark ochre brown abdomen. Head ( Fig. 52View Figs). Dark brown, slightly higher than long. Antenna slightly longer than head height, scape and pedicel slightly longer than first flagellomere; eight flagellomeres, first flagellomere subquadrate, following flagellomeres about twice as wide as long, each with a single whorl of setae, last flagellomere club-shaped, about the length of previous two flagellomeres, with three whorls of setae; palpi large, reniform, slightly pointed apically; labella slender, slightly shorter than palpus, but much longer than wide. Thorax ( Fig. 53View Figs). Scutum slightly longer than wide, covered with rather dense setation, a well-marked row of 11 supra-alar setae, scutellum with a row of 12 elongate marginal setae. Anterior spiracular sclerite setose, a well-marked antero-dorsal pointed projection, spiracle rather large, about as long as high; 13 anepisternals along antero-dorsal margin, 8 mesepimerals, no meral setae, 5 subspiraculars. Wing ( Fig. 54View Figs). Wing length, 1.78–2.00 mm, width, 0.80–0.96 mm. Membrane with dense microtrichia, no macrotrichia on membrane except along margin. Humeral present, Sc very pale but distinguishable. R 5 reaching C slightly beyond mid of wing, more distal than level of medial fork. Wing length (WL)/h-R 1 length, 3.85; WL/R 1 -R 5 length, 4.45; h-R 5 length/WL, 0.49. M fork about 2.5 stem length, fork gradually widening towards margin. CuA 2 with a clear fold towards posterior margin on basal third and a gentle additional curve on distal fourth. Haltere brown, with four setae on the stem. Legs. Brown, tarsi light brown; comb of setae on posteroapical part of hind tibia well-developed; first tarsomere of posterior leg longer than second. Abdomen ( Fig. 18View Figs). Dark ochre brown. Tergites 1–3 with reduced pilosity, only with a row along posterior margin. Tergite 2 with well-defined pretergite. Sternite 1 unsclerotized, sternites 2 to 7 regularly sclerotized, densely setose. Tergite 7 rectangular, posterior margin not emarginate medially; sternite 7 with posterior margin with medial lunate emargination, rounded inner fold longer medially, extending along almost entire posterior margin. Terminalia ( Figs. 55 and 56View Figs). Tergite 8 + 9 entire, long, bearing pair of basal sub-median spiracles, more projected latero-distally; sternite 8 with a pair of medial projections distally, densely setose, two setae at each side on posterior margin lateral to medial distal projections; tergite 10 divided, setose, with a pair of lateral flaps externally; genital furca weakly sclerotized, not pointed on anterior end; spermatheca ovalrounded.

Distribution. United States, southern California.

Etymology. This species is named after Heron Huerta, Mexican dipterologist who has greatly increased the knowledge on the diversity of the Scatopsidae  in Mexico, as well as of different Bibionomorpha families.

Remarks. The genus Aztecatopse  was described quite recently ( Haenni and Huerta 2014) based on Scatopse diabolica Duda ( Duda 1928b)  from Mexico.Four additional species from Mexico were later added to the genus by Huerta and Haenni (2014). Scatopse diabolica  was placed in Neorhegmoclemina  by Cook (1967; as a subgenus of Rhegmoclemina  ), within the Rhegmoclematini  , and later transferred to the Swammerdamellini  genus Quateiella  by Amorim (2009). The redescription of Scatopse diabolica  allowed recognizing that the species belongs in an independent taxon of generic rank within the Scatopsinae  . Haenni and Huerta (2014) discussed the similarities of Aztecatopse  with Pharsoreichertella  , Reichertella, Pararhexoza  , and Quateiella  to conclude: “on the basis of the points enumerated above and pending a general reconsideration of the Scatopsini and Swammerdamellini  , Aztecatopse  is for the time being placed within the Scatopsini because the new genus appears to be more closely related to Reichertella  and Pharsoreichertella  .”

A relevant point in this context is that Colobostematini  is closer to the Swammerdamellini  than the Scatopsini ( Amorim 1982, 1994). This means that the placement of the genus either in the Scatopsini or in the Swammerdamellini  corresponds to quite divergent hypotheses. The shape of the spiracular sclerite in Aztecatopse  , as mentioned by Haenni and Huerta (2014), is similar to that of Pharsoreichertella  and of the Scatopsini, but the wing venation, the size and shape of the maxillary palpus, the shape of the basal sclerotization of the labella, the shape of the postmentum, features of the thoracic pleura, the size, shape, and degree of sclerotization of abdominal sternites 1–4, and the shape of the male sternite 9 and tergite 9 ( Amorim 2007) in Aztecatopse  suggests, however, a closer relationship of the genus to the Swammerdamellini—the position assumed here. It could be the case, indeed, that Pharsoreichertella  as well could be a Swammerdamellini  . This issue needs to be addressed in a wider phylogenetic analysis of the Scatopsinae  .

Although the male of Aztecatopse huertai  sp.nov. is still not known, it diverges from the remaining species of the genus (all of which are known only from Mexico) in aspects relevant enough to establish it as a separate species. Haenni and Huerta (2014) and Huerta and Haenni (2014) documented the variation in the shape of the spiracular sclerite in the species of the genus. The condition in the species described here is different from the other species, being wider at the posterior end and wider on its ventral half, in this sense, similar to A. diabolica  . C is longer in A. huertai  than in all other species of the genus—the only species with a similar extension of C is A. diabolica  , but it is still shorter than in A. huertai  . CuA is slightly bent close to apex in A. huertai  , similar to the condition in A. amorimi  and in A. foliosa  , but different from A. neotropica  , A. spinosa  and A. diabolica  . Aztecatopse diabolica  has a clearly short labella, while the labella in A. huertai  is clearly longer. Only the female of A. diabolica  is known. The setae along the posterior margin of sternite 9 in A. diabolica  ( Haenni and Huerta 2014, fig. 12) is quite similar to that in A. huertai  , as well as the shape of sternite and tergite 8. The distal margins of the genital furca (sometimes referred to as ‘labium’) in A. huertai  are extended into a pair of lateral flaps, also seen in A. diabolica  .

In Mexico, Haenni and Huerta (2014) described the habitat of A. diabolica  as arid environments dominated by Agavaceae  and Cactaceae  . We collected females of Aztecatopse  in garbage bins in San Luis Obispo, California, about 300 Km north of Los Angeles, that fit A. huertai  , sp.nov., but were not included here as paratypes.

This species is not particularly abundant in the project, with only nine females collected in Phase I samples. The species shows—although still based on few specimens—a peak of emergence in midspring (April–May), with a second smaller, mid-autumn emergence peak in October. Our collection in San Luis Obispo was in late June. All collecting sites for this species are in the northern range of the city, at Bioscan sites 1, 5, 6, 18, and 20. It is worth noting that one female was collected at the trap set at the Nature Garden, in the Los Angeles Natural History Museum. There are no records for Aztecatopse  so far in the BOLDSystems ( index.php/Public_SearchTerms?query= Holoplagia  [tax]).


Natural History Museum of Los Angeles County


Museu de Zoologia da Universidade de Sao Paulo