Loeia Duan, 2017

Dietrich, Christopher H., 2025, Review of the Southeast Asian leafhopper genus Loeia Duan (Hemiptera: Cicadellidae: Deltocephalinae), Zootaxa 5666 (2), pp. 195-210 : 196-200

Loeia Duan , in Duan et al. 2017, new tribal placement

Type species: Loeia tamtipi Duan, 2017

Diagnosis. Loeia may be separated from other Punctulini by the following combination of features: body relatively large, elongated (males 4.5–6.4 mm, females 5.2–7.4 mm long); dorsal color pattern pale with irregular dark spots and larger symmetrical maculae; crown between eyes little or no wider than eye width, anterior margin rounded to face; forewing with extra crossveins; front tibia row PD with numerous close-set macrosetae; male pygofer elongate and tapered in lateral view; connective linear and fused to aedeagus; first valvula dorsal sculpture strigate and confined to narrow submarginal band; second valvulae without distinct teeth.

Description. Elongate white to tan leafhoppers (length of male 4.5–6.4 mm, female 5.2–7.4 mm) with dorsal markings consisting of sparse, symmetrical reddish, brown and black spots ( Fig. 1 ). Crown usually with pair of orange submedial maculae, pronotum with two pairs of incomplete longitudinal orange stripes and pair of lateral black maculae, forewing with conspicuous black spots at apex of vein Pcu, apex of clavus and laterad of R-M fork near base of corium; other markings consisting of small brown dots and larger brownish or ocher markings. Head wider than pronotum; crown short, depressed, not or only weakly produced anteriorly, distance between eyes subequal to eye width in dorsal view; ocelli unusually large, closely adjacent to eye just dorsad of crown margin; crown face transition angulate in profile but without transverse carina; face wider than long in anterior view; eye emarginate adjacent to antennal base; antenna elongate, distinctly longer than head width; frontoclypeus moderately convex; anteclypeus flat with slight median longitudinal ridge, parallel-sided or slightly widened from base to apex; lorum flat, well separated from genal margin; maxillary sensillum adjacent to middle of lorum; rostrum extended to middle of front trochanters. Pronotum longer than crown, with indistinct transverse striations. Forewing macropterous, venation partly reticulate, with extra crossveins in clavus and brachial cell and incomplete crossveins in corium; appendix narrow; first r-m crossvein connected to Rs distally; CuA joining wing margin well distad of clavus; three anteapical cells present; outer cell usually triangular and extended to or near costal margin, with apex attenuate and petiolate; inner cell either closed or open. Hind wing unmodified. Front femur AM1 seta enlarged, close to ventral margin; row AV with well-delimited elongate AV1 and several short, stout setae in basal half; tibial row AD with single distal macrosetae, PD with numerous close-set macrosetae. Hind femur macrosetae 2+2+1, tibial rows PD, AD and AV with ca. 12, 9 and 20 macrosetae, respectively; PD and AD with 1–4 shorter setae between successive macrosetae; PD macrosetae much longer than AD macrosetae; tarsomere I with two plantar rows of stout setae, pecten with three platellae. Male 1S apodemes ( Figs 7 O-P) somewhat enlarged, convergent, extended posterad but not beyond midlength of sternite III; 2S apodemes flaplike oriented obliquely and appearing tapered and curved mesad in ventral view, no longer than 1S apodemes. Pygofer ( Figs. 2 , 3 ) moderately to strongly elongate, distinctly longer than twice basal height, more or less evenly tapered in lateral view, with or without paired ventral preapical processes near midlength, macrosetae scattered over most of surface; anal tube short and weakly sclerotized. Subgenital plate triangular, much shorter than pygofer, usually with short convex margined basal section and elongated tapered distal section, with single lateral row of macrosetae in basal half. Style broadly bilobed at base, mesal arm extended dorsomesad to attachment with connective, preapical lobe obtusely rounded, apex hook- or footlike, curved laterad; connective linear with arms closely appressed through most of length and fused anteriorly, fused posteriorly to aedeagus. Aedeagus highly variable among species, with or without single or paired processes, sometimes asymmetrical. Female sternite VII ( Figs 7E–N ) variable among species. Ovipositor elongate, extended well beyond pygofer apex. First valvula ( Fig. 7A, B ) straight, slender, dorsal margin slightly humped near midlength; distal half gradually tapered; dorsal sculpture vertically strigate and confined to narrow submarginal band in distal half; ventral band of oblique strigate sculpture extended over most of length, ventroapical sculpture area elliptical, irregularly strigate. Second valvula ( Figs 7C, D ) elongate, slender, broadly and slightly humped near midlength, basal fused section slightly longer than distal blades, distal blades parallel-sided through most of length, without conspicuous teeth but with some pores connected to oblique dorsal ducts terminating on dorsal margin, apex abruptly narrowed with slightly attenuate, bluntly rounded tip. Gonoplac ( Fig. 7C ) wider than first and second valvulae, with sparse, inconspicuous setae.

Distribution: Thailand.

Notes. Comparison of females of the 10 species of Loeia for which females are available indicates that the ovipositor structure of this genus is highly conserved, with no obvious differences between species other than relative length proportional to differences in overall body length. The shape of the pregenital sternite is distinctive for some species but highly similar among others (cf. Figs 7E–N ).

This genus was originally placed in Deltocephalini a widespread grass-specialist tribe recognized by the linear connective fused to the aedeagus. Loeia differs from most genera of Deltocephalini in its much larger body size, short crown with anterior and posterior margins usually subparallel, anteclypeus with lateral margins divergent distally, and lora well separated from the ventral margin of the face. Species of Deltocephalini are usually small with the crown distinctly produced anteriorly, the anteclypeus tapered distally, and the lora extended to or very near the ventral margin of the face. Thus, the linear connective fused to the aedeagus is one of few diagnostic characters of Deltocephalini shared by Loeia and this trait also occurs in some other deltocephaline tribes (see Introduction).

The structure of the head of Loeia is more similar to that of Punctulini , particularly the genera included in the tribe by Dietrich et al. (2020) and Ramaiah et al. (2023). The dorsal color pattern, consisting of numerous small brown spots merging to form larger areas, is also shared with Pseudocestius Dietrich, Nguyen & Pham, 2020 and the presence of supernumerary crossveins in the forewing is shared with Hochiminhus Dietrich, Nguyen & Pham, 2020 . The linear connective is similar to that of Bambuphaga Ramiah, Meshram & Dey, 2023 but species of the latter genus are much smaller and the male pygofer is not elongate. The ovipositor of Loeia , with a submarginal band of sculpture on the first valvula and teeth reduced or absent on the second valvula, resembles that of Hecalusina He, Zhang & Webb, 2008 , a genus previously placed in Hecalini that also grouped with Punctulini in the analyses of Cao et al. (2022). These morphological traits, along with the available molecular evidence, support transferring Loeia to Punctulini . Loeia lacks one of the main diagnostic morphological traits shared by genera previously placed in Punctulini ; the elongated, divergent and capitate male second abdominal apodemes. Species of Loeia have these apodemes well developed, but they are relatively short, flaplike, and oriented obliquely such that they appear tapered in ventral aspect ( Figs 7 O-P). Maximum likelihood-based phylogenomic analyses of concatenated nucleotide or amino acid sequences ( Cao et al. 2022) consistently placed Loeia as sister to the remaining Punctulini , within a larger clade of leafhoppers belonging to the bamboo-specialist deltocephaline tribes Mukariini and Vartini as well as bamboo-associated genera currently placed in the polyphyletic tribe Athysanini . This placement seems consistent with the absence of capitate 2S abdominal apodemes in Loeia , which may have retained a more plesiomorphic condition of this trait than is present in other members of Punctulini . Ecological data for Punctulini are sparse, but their close relationship to other deltocephaline leafhoppers that specialize on bamboos ( Poaceae : Bambusoidea), strongly suggests that Loeia and other Punctulini are also bamboo specialists.

The presently known species of Loeia appear to be nearly identical in external appearance including structure and coloration, except for overall body size and head proportions, which overlap somewhat among species. Slight differences in color pattern, wing venation, and leg chaetotaxy evident in the habitus photos ( Fig. 1 ) often vary among specimens within species. Thus, species of the genus are most reliably distinguished by the male genitalia ( Figs 2–6 ) and, in some cases, by the shape of posterior margin of the female pregenital sternite ( Fig. 7 ).

Figures

FIGURE 1. Loeia new species, dorsal and lateral habitus, males. A, L. articulata; B, L. biclavata; C, L. brevis (left forewing missing); D, L. cetacea; E, L. chelata; F, L. compressa; G, L. decidua; H, L. elongata; I, L. robusta; J, L. serrata (right forewing missing); K, L. sinuata; L, L. tridentata. Scale bars = 1 mm.

FIGURE 2. Loeia male genital capsule and genitalia. A–E, L. articulata: A, genital capsule, lateral view; B, enlargement of ventral pygofer process; C, genital capsule, ventral view; D–E, genitalia, lateral and ventral views. F–J, L. biclavata: F–G, genital capsule, lateral and ventral views; H, enlargement of ventral pygofer process (right) and accessory spines (left); I–J, genitalia, lateral and ventral views. K–O, L. brevis: K–L, genital capsule, lateral and ventral views; M, subgenital plate and valve, ventral view; N–O, genitalia, lateral and ventral views (apex of aedeagus broken off and missing).

FIGURE 3. Loeia male genital capsule and genitalia. A–D, L. cetacea: A–B, genital capsule, lateral and ventral view; C–D, genitalia, lateral and ventral view. E–H, L. chelata: E–F, genital capsule, lateral and ventral view (apices of pygofer lobes broken); G–H, genitalia, lateral and ventral views. I–L, L. compressa: I–J, genital capsule, lateral and ventral view; K–L, genitalia, lateral and ventral views.

FIGURE 7. A–D, Loeia serrata ovipositor: A–B, first valvula with enlargement of apex; C–D, second valvulae and gonoplac with enlargement of second valvulae apex. E–N, sternite VII: E, L. articulata; F, L. cetacea; G, L. chelata; H, L. compressa; I, L. decidua; J, L. elongata; K, L. robusta; L, L. serrata; M, L. tamtipi; N, L. tridentata. O, L. tamtipi, base of abdomen, ventral view, showing 1S and 2S apodemes; P, same showing apodemes only.