Ledrinae (ledrine leafhoppers)

The Ledrinae (Hemiptera: Cicadellidae) constitute a modest-sized group (~280 spp.) of primarily arboreal leafhoppers distributed worldwide, but primarily in the Old World tropics. Most appear to exhibit some measure of crypsis, mimicking in form or texture the plants they feed on. They are often green or brown and their dorsal surfaces resembling that of bark or leaves; some species mimic stem nodes of woody shrubs. Members of one tribe—Xerophloeini—live in grasses, and these species are green or yellow and resemble grass seeds. A few (undescribed) ledrines are flightless and beetle-like.

Ledrinae occur in all world regions except Oceania, with the greatest numbers of species found in the Indomalayan biogeographic region. Important smaller radiations of extant species occur in Australia, sub-Saharan Africa, South Africa, and the New World. Two fossil ledrines from Brazil have been described.

Ledrinae can be diagnosed by the following suite of features: relatively large size (~6–24 mm); crown transversely flat to cambered lateroventrally, sometimes depressed dorsally adjacent to longitudinal midline, anterolateral margins lamellate; ocelli situated dorsally on the crown distant from the eyes; face generally concave, but sometimes slightly inflated and convex; lorae small; genae narrow; proepisternum visible, small and tablike to large and well-developed and wrapping around onto pronotum in a collar-like fashion; forewings without an appendix (except in most Xerophloeini); forewing venation simple or, commonly, reticulate in apical two-thirds; hind wings with the R and M veins free and not confluent distally; the metathoracic femoral macrosetae grouped at the apex with a formula of 2+0 or 2+1 (rarely 2+2); and the metathoracic tibial row II with some or all macrosetae cucullate, less than 9 in number, with hairlike intercalary setae. As mentioned, many ledrines have distinctive dorsal textures and colors, and in addition some exhibit highly produced pronotal processes, a phenomenon that led to some ledrine species originally being described as treehoppers (Membracidae).

Historically, there have been wide discrepancies in interpretations of the taxonomic limits of the Ledrinae, and little consensus about their tribal classification. Despite the disagreements, until recently virtually no phylogenetic work had been performed in order to evaluate higher-level relationships within the subfamily. In 2009, we (Jones & Deitz 2009) presented a revised classification of the Ledrinae based on rigorous cladistic analysis of a large morphological dataset (235 characters). In that analysis, Petalocephalini (which was determined to be an unavailable name) was demonstrated to constitute a junior synonym of Ledrini. In addition, 3 new tribes were recognized, and 26 genera were removed to other subfamilies—including 22 genera in two large tribes (Stenocotini and Thymbrini were moved to Tartessinae). Ten genera were removed to an unplaced position within the Cicadellidae, and 1 genus was removed to an unplaced position within the Cicadomorpha. In conclusion, Ledrinae is now recognized to comprise approximately 290 extant described species in 37 genera placed in 5 tribes: Afrorubrini (new), Hespenedrini (new), Ledrini, Rubrini (new), and Xerophloeini. The following table (Table 1) summarizes the new classification:

Table 1. Classification of Ledrinae, Jones & Deitz (2009).

Afrorubrini	Hespenedrini	Ledrini	Rubrini	Xerophloeini	removed from Ledrinae
Afrorubria	Hespenedra	Arenoledra	Rubria	Pariacaca	Stenocotini
Sichaea		Beniledra		Proranus	Thymbrini
		Chatura		Xedreota
		Complanledra		Xerophloea	Bascarrhinus
		Confucius			Betsileonas
		Destinia			Camptelasmus
		Dusuna			Caxia
		Eleazara			Clinonana
		Ezrana			Cololedra
		Funkikonia			Hemipeltis
		Hangklipia			Ledracorrhis
		Jukaruka			Ledromorpha
		Kuohledra			Piezauchenia
		Laticorona			Platyhynna
		Ledra			Stenoledra
		Ledropsella
		Ledropsis
		Midoria
		Neotituria
		Paraconfucius
		Parapetalocephala
		Petalocephala
		Petalocephaloides
		Platycephala
		Platyledra
		Porcorhinus
		Thlasia
		Titiella
		Tituria

The information presented above derives from work performed in preparation of my Master's thesis. Future directions for my work on the Ledrinae include (1) describing several new genera and species discovered during examination of material for thesis preparation; (2) performing genus-level revisions on a taxon-by-taxon basis in order to stabilize alpha-level taxonomy within the Ledrinae; and (3) constructing new molecular datasets for phylogenetic analysis in order to test/corroborate results obtained from analysis of morphology.

A page listing the species of Ledrinae and providing illustrations of their important diagnostic features is under development, and may be found here or by clicking the 'species' tab above. An interactive online key to the subfamily and its tribes and genera, developed in collaboration with Dmitry Dmitriev at INHS, is available here.

References

Jones, J. R. and Deitz, L. L. 2009. Phylogeny and systematics of the leafhopper subfamily Ledrinae (Hemiptera: Cicadellidae). Zootaxa, 2186: 1–120.   [warning: PDF file size is 5.35 MB]