Arthropoda Linnavuori 1965

Arrugadini Linnavuori, 1965

Fig. 10

Type genus: Arrugada Oman, 1938.

Diagnosis

Arrugadini are large brown and yellow leafhoppers. They can be easily identified by the strongly rugose texture of the head and face, lateral margins of the pronotum longer than the basal width of the eye, first valvula dorsal sculpturing pattern granulose and submarginal, first valvula with distinctly delimited ventroapical sculpturing, and second valvula gradually expanded apically and without teeth.

Description

HEAD. Head subequal to or wider than pronotum. Discal portion of crown rugose or longitudinally striate. Anterior margin of head irregularly textured, rugose. Frontoclypeus tumid or not tumid; texture rugose. Clypellus widening apically. Clypellus apex following or slightly surpassing normal curve of gena. Lorum subequal to or wider than clypellus near base. Antennal bases near middle or posteroventral (lower) corners of eyes. Antennae short, less than 1.5 x width of head. Gena obtusely incised laterally; with fine erect seta beside laterofrontal suture. Antennal ledge weakly developed (carinate or weakly carinate). Ocelli present; close to or somewhat distant from eyes; on anterior margin of head.

THORAX. Pronotum not exceeding or exceeding (female of A. rugosa) eyes anteriorly; lateral margin carinate; lateral margin as long as or longer than basal width of eye.

WINGS. Forewing macropterous or submacropterous; appendix restricted to anal margin; with 3 anteapical cells; veins distinctly raised or carinate; without reflexed costal veins; A1-A2 crossvein absent.

LEGS. Profemur with AM1 seta only; intercalary row with one row of five or more fine setae; row AV with relatively long macrosetae. Protibia dorsal surface flat, AD and PD margins at ~90º angles but not carinate. Metafemur apex macrosetae 2+2+1 or 2+1+1. Metatarsomere I not expanded apically; plantar setae simple, tapered.

MALE GENITALIA. Sternal apodemes of segments I and II small, not well developed. Valve articulated with pygofer; lateral margin short, articulating with pygofer at a point. Pygofer basolateral membranous cleft present; macrosetae well differentiated into several rows. Subgenital plates free from each other; articulated with valve; macrosetae uniseriate laterally. Style broadly bilobed basally, median anterior lobe pronounced. Basal processes of the aedeagus/connective absent or reduced. Aedeagus with single shaft and gonopore. Connective anterior arms somewhat divergent, Y -shaped; articulated with aedeagus.

FEMALE GENITALIA. Pygofer macrosetae reduced or absent. First valvula not strongly convex; dorsal sculpturing pattern granulose or maculose; sculpturing submarginal; with ventroapical sculpturing distinctly delimited. Second valvula gradually broadened medially or subapically; without dorsal median tooth; teeth absent.

Geography and ecology

Distribution: Neotropical. Host plants are not known. Large numbers of males of Arrugada affinis (Osborn, 1924) were observed and collected while “mud-puddling” in Peru (Rakitov et al. 2005).

Remarks

Arrugadini contains only the type genus and 4 valid species from Bolivia and Peru. This small group was considered a separate subfamily until it was recently included as a tribe of Deltocephalinae (Zahniser & Dietrich 2010). Based on some characters of the female genitalia (first valvula dorsal sculpturing pattern granulose and submarginal, first valvula with distinctly delimited ventroapical sculpturing, second valvula without dorsal teeth), it appears to be related to the grass-feeding tribe Hecalini, a relationship that was marginally supported in the combined parsimony analyses presented here. However, the shapes of the first and second valvulae are not very similar to Hecalus and Attenuipyga which have humpbackshaped valvulae. The relationships within Hecalini and between this and other tribes seem particularly difficult to recover given the data in this study. More data are needed to resolve the relationships between Arrugadini and other Deltocephalinae. Preliminary phylogenetic analyses of Hecalini (Catanach, unpublished) suggest that Arrugada is related to another South American-endemic genus, Egenus. Egenus was removed from Hecalini by Hamilton (2000), tentatively placed in Faltalini by Zahniser & Dietrich (2010), and is transferred to Athysanini here (see below).

Selected references

Linnavuori & DeLong (1978a), Zahniser & Dietrich (2010).

Included genera

Arrugada Oman, 1938.