Phylloicus bidigitatus, Prather , 2003

PRATHER, AYSHA L., 2003, Revision of the Neotropical caddisfly genus Phylloicus (Trichoptera: Calamoceratidae), Zootaxa 275 (1), pp. 1-214 : 34-35

publication ID 10.11646/zootaxa.275.1.1

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Phylloicus bidigitatus

new species

Phylloicus bidigitatus   , new species

Fig. 27 View FIGURE 27

This species has long, paired, digitate posteroventral processes of tergum X ( Fig. 27A, B View FIGURE 27 ), which are distinctive. Phylloicus bidigitatus   is only known from one badly rubbed specimen from Rio de Janeiro state. This specimen may in fact be conspecific with P. obliquus   , of which I was able to identify only a single male specimen from Santa Catarina. Thus, I was not able to assess variation within the species. The shape of tergum X ( Fig. 27A, B View FIGURE 27 ) is different enough between the two specimens to suggest they are different species, but only additional specimens can resolve this question.

Adult. Forewing length 10.1 mm, n = 1.

Head chestnut brown. Maxillary palps golden brown. Antenna twice forewing length; dark brown, with narrow patches of pale sensilla on anteromesal surface of each flagellomere. Dorsal pterothorax chestnut brown; ventrolateral thorax golden brown. Legs golden brown. Tibial spur formula 2,4,4. Forewing flat; chestnut brown; with single transverse band; distal band ivory, beginning at anterior wing margin, at least 1/2 width of wing, narrow, less than 10 setae wide. Hind wing basal brush present in male, golden brown.

Male. Preterminalic abdominal terga with anteromesal notch. Corematic structures absent, terga III­V unmodified, without membranous lobes or sclerotized processes. Sternum VII with short, acute anteromesal process. Sternum VIII similar to anterior sterna, sternum IX not elongate. Tergum IX with mesal ridge extending 2/3 length of segment; posterior margin smoothly rounded ( Fig. 27B View FIGURE 27 ); lateral ridge present; dorsal pleural setae approximately 10, ventral pleural setae absent ( Fig. 27A View FIGURE 27 ); sternum IX with paired mesolateral ridges; sternum IX ( Fig. 27C View FIGURE 27 ). Preanal appendage shorter than tergum X, but greater than 2/3 length, of uniform diameter throughout length, setae long, but not filamentous or longer than appendage ( Fig. 27A, B View FIGURE 27 ). Tergum X without basal lobes; basodorsal process absent; basolateral processes absent; apex, in lateral view, rounded, in dorsal view, notched, notch deep and round; covered with short setae dorsally, with paired digitate posterior processes ( Fig. 27A, B View FIGURE 27 ). Harpago sharply tapered; peglike setae few, apical ( Fig. 27A, C View FIGURE 27 ). Phallic endotheca with paired apicolateral lobes, apicolateral lobes large and with digitate apical lobe; phallotremal sclerites average size, longest dimension less than diameter of phallobase; dorsal sclerite ovoid, in dorsal view horseshoe­shaped ( Fig. 27D, E View FIGURE 27 ).

Female. Unknown.

Holotype male: BRAZIL: Rio de Janeiro: Itatiaia, 16­26.x.1927, Zerny ( NMW).  

Distribution. Brazil.

Etymology. Bidigitatus, from the Latin bi­, “two” and digitatus, “having fingers,” referring to the paired digitate processes of tergum X.


Naturhistorisches Museum, Wien