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

Phylloicus bidigitatus , new species

Fig. 27

This species has long, paired, digitate posteroventral processes of tergum X ( Fig. 27A, B ), 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 ) 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 ); lateral ridge present; dorsal pleural setae approximately 10, ventral pleural setae absent ( Fig. 27A ); sternum IX with paired mesolateral ridges; sternum IX ( Fig. 27C ). 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 ). 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 ). Harpago sharply tapered; peglike setae few, apical ( Fig. 27A, C ). 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 ).

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.

Figures

FIGURE 27. Phylloicus bidigitatus. Male (holotype): A—lateral view; B—dorsal view; C—caudoventral view; D—phallus, lateral view; E—phallus, ventral view.