Limnocassis regularis, Borowiec & Sekerka, 2015

Borowiec, Lech & Sekerka, Lukáš, 2015, On the genus Limnocassis Spaeth, with description of two new species from South Africa (Coleoptera: Chrysomelidae: Cassidinae), Zootaxa 3999 (2), pp. 272-278 : 273-275

Limnocassis regularis sp. nov.

( Figs 1–2 , 5–7 , 14 ).

Type material. Holotype: “ Hogsback / 1480 m, 1.x.86 // S Afr. Cape Prov. / Wittmer, Macpherson ” ( NHMB); four paratypes: the same data ( NHMB , NMPC , DBET , LSC ); one paratype: “ km 15–20 Kirdkwood- / Brakkefontein / 29.ix.1986 // S Afr. Cape Prov. / Wittmer,Macpherson ” ( NHMB). Both localities are situated in the Eastern Cape Province. Hogsback is a village and name of State Forest in the Amatola Mountains while Kirdkwood is a small village situated in the Sundays River Valley about 100 m a.s.l. The Kirdkwood specimen was probably collected along the road between km 15 and 20 on the way to Brakkefontein and is placed 160 km south-west from the locus typicus.

Diagnosis. Limnocassis regularis sp. nov. differs from L. pumilio in finer and more regular elytral punctation. The new species has punctures arranged mostly in regular rows, only in the middle of the third and the fifth intervals there are several additional irregular punctures while L. pumilio has only the first two sutural and two marginal rows more or less regular, and all intervals, except impunctate elevations, are coarsely and irregularly punctate. Impunctate intervals in L. regularis are flat and the fourth is not elevated in the apical part while in L. pumilio has a thin impunctate elevation on the second interval and on the fourth interval a moderately broad elevation forming an elevated longitudinal fold on apex. The second new species L. compacta sp. nov. is very similar to L. regularis in fine and mostly regular elytral punctation but differs in smaller (length 3.20–3.40 mm vs. 3.65–4.15 mm) and stouter body (length/width ratio: 1.48–1.60 vs. 1.62–1.80).

Description. Length: 3.65–4.15 mm, width: 2.30–2.40 mm, length of pronotum: 1.30–1.40 mm, width of pronotum: 1.85–2.00 mm, length/width ratio: 1.62–1.80, pronotum width/length ratio: 1.37–1.48. Body slightly cuneiform ( Fig. 1 ).

Body completely yellow, including head, legs and antennae.

Pronotum irregularly elliptical, with maximum width in 1/3 length, sides broadly rounded without basal corners, external margin of pronotum transparent. Disc convex, indistinctly bordered from the explanate margin, area above head placed slightly lower than top and lateral parts of disc. Surface of disc micro-reticulate and, except area above head, with sparse fine and shallow punctation, appears slightly alutaceous. Explanate margin of pronotum with transparent honeycomb structure, very shallowly punctate and its surface appears regular but slightly alutaceous.

Scutellum triangular. Base of elytra slightly wider than pronotum, humeri strongly protruding anterad but in lateral view humeral angles rounded ( Fig. 2 ). Punctation of disc mostly forms more or less regular rows, two first rows in apical half slightly impressed, intervals 2, 4 and 6 in the middle with several additional irregular punctures but punctation of elytra at first glance appears regular. Punctures in row moderately coarse, moderately dense, distance between punctures from as wide as to twice wider than puncture diameter. Marginal row distinct, its punctures as coarse as punctures in central rows. Intervals flat, first three intervals approximately 1.5 times as wide as rows, interval 4 in punctate central part twice wider than in impunctate anterior and posterior part, interval 5 narrow but well marked as impunctate band, interval 6 broad, in punctate part thrice as wide as interval 5, interval 7 in anterior part as narrow as interval 5 in posterior third forms a broad, impunctate but not elevated field, three marginal intervals approximately as wide as three sutural intervals. Interspaces smooth, from slightly alutaceous to slightly shiny. Explanate margin of elytra extremely declivous, almost perpendicular to the abdominal surface, narrow, in the widest part as wide as 1/4 width of disc. Surface with fine to moderate but shallow and moderately dense punctation, appears regular, punctures mostly finer than punctures in rows of disc, interspaces smooth, form slightly alutaceous to slightly shiny. Apex of elytral epipleura without erect setae.

Clypeus broad, slightly wider than long, flat, with fain clypeal grooves converging in triangle, along inner margin of eyes runs a row of setose punctures. Surface of clypeal plate flat, with 5 to 6 punctures, interspaces smooth and shiny. Eyes large but gena well marked, slightly longer than length of the last palpomere. Labrum moderately broad with broad median emargination, as deep as 1/4 length of labrum ( Fig. 5 ). Prosternal collar well marked but short, as long as half length of the last palpomere. Prosternum between coxae very narrow and deeply canaliculate, as wide as 1/4 width of coxa. Apical part of prosternal process moderately wide, rhomboidal, its surface regular with few small punctures ( Fig. 5 ). Prosternal alae on sides elevated, ventral surface of pronotum close to sides of prosternal alae form a shallow gutter to accommodate antennae but the gutter is not as distinct as in genera of the tribe Cassidini with antennal grooves.

Antennae short, antennomeres IX and X slightly wider than long, length ratio of antennomeres: 100:50:40:37:37:27:43:33:40:40:67. Segment II approximately 1.25 times as long as segment III, segment IV slightly shorter than segment III ( Fig. 6 ).

Tarsi narrow with distinct setose sole, last segment slightly shorter than third segment, claws simple ( Fig. 7 ).

Sexual dimorphism indistinct, genitalia not diagnostic.

Etymology. Named after mostly regular punctation of elytra.

Distribution. South Africa: Eastern Cape Province ( Fig. 14 ).

Figures

FIGURE 14. Distribution of Limnocassis Spaeth in Hincks, 1952 in South Africa: Limnocassis compacta sp. nov. (blue circle), L. pumilio (Boheman, 1854) (green circles), and L. regularis sp. nov. (red circles).

FIGURES 1 – 2. Limnocassis regularis sp. nov.: (1) dorsal, (2) lateral; Figs 3 – 4. Limnocassis pumilio (Boheman, 1854): (3) dorsal, (4) lateral.

FIGURES 5 – 7. Limnocassis regularis sp. nov.: (5) head and prosternum, (6) antenna, (7) tarsal claw; Fig. 8. Limnocassis compacta sp. nov., head and prosternum.