Chaeridiona mayuri Shameem & Prathapan

Shameem, K. M. & Prathapan, K. D., 2014, A new species of Chaeridiona Baly (Coleoptera: Chrysomelidae: Cassidinae: Oncocephalini) infesting ginger (Zingiber officinale Roscoe) and turmeric (Curcuma longa L.) in India and redescription of Chaeridiona pseudometallica Basu, Zootaxa 3815 (4), pp. 575-582 : 576-580

Chaeridiona mayuri Shameem & Prathapan , n. sp.

(Figs 1–5)

Material examined. Holotype: ♀, with labels as follows: “(1) India: Kerala / Tirurangadi / 30.ix.2012 / Shameem K. Coll. / Ex Costus (white label). (2) HOLOTYPE / Chaeridiona mayuri n. sp. / des. Shameem & Prathapan, 2013 (red label)” ( BMNH). Paratypes (83 specimens, all specimens with a white locality label as given below, besides a second pink label: “ PARATYPE / Chaeridiona mayuri n. sp. / des. Shameem & Prathapan, 2013”): 1♂, 30 unsexed, the same labels as for holotype; 4 unsexed, same data except host is Turmeric, instead of Costus ; 2♀, 19 unsexed, same data except date 1.xi.2012; 1♀, 5 unsexed, same data as for holotype, without host plant information; 2 unsexed, same data except date 27.x.2012, without host plant information; 4 unsexed, India: Kerala / Perinthalmanna / N 11°03′ 05.6″ E76°13′ 55.6″/ 13.x.2012 81.9 m / Prathapan & Shameem Coll. / Ex Costus ; 1 unsexed, same data except host Zingiber officinale ; 1♀, 1 unsexed, same data except host Curcuma longa ; 1 unsexed, same data, without host plant information; 1♀, 1♂, 4 unsexed, India: Kerala / Arippa / N 08°50′ 11.0″ / E77°01′ 46.1″ 236 m / 20.viii.2013 / Prathapan D & Shameem K Coll.; 1♀, India: Karnataka / Jamboti / 11.xi.2012 / Prathapan KD Coll.; 1 unsexed, India: Karnataka / Castle Rock / 12.xi.2012 / Prathapan KD Coll.; 2 unsexed, same data except date 14.xi.2012; 1♀, India: Nilgiris South / Naduvattam / N 11°29′ 48.4″ E76° 31′ 01.5″/ 15.x.2012 1222 m / Prathapan & Shameem Coll.; (6 BMNH, 6 USNM, 6 UASB, 17 NBAII, 42 NPC, 6 PKDC).

Description of adult. Length 3.84–4.61mm, width 1.80–2.24 mm. Dorsum metallic emerald green to dull green except coppery brown laterally and preapically, elytral apex yellow; color of head dorsally varies from metallic emerald green to dark coppery (Fig. 1). Antennomeres 1–7 reddish yellow, proximal ones darker; distal four antennomeres black with apex of 11 brown. Frontoclypeus, gena, gula, mouth parts concolorous with basal antennomeres, labrum and mandibles often darker. Pro- and mesothoracic sterna and pleurites rufous brown; metathoracic sterna darker. All abdominal ventrites brown, distal ones lighter. All trochanters red brown; all femora and tibiae yellow; all tarsi darker than respective tibia (Fig. 2).

Head (Fig. 3): vertex proximally with medial sulcus, deeply punctate except basally and apically; sulci present near eyes; frons coarsely granulate, without deep punctures; clypeus strongly punctate in middle, with rows of widely placed weak setae. Antenna: 0.60–0.68 times longer than body. Proportionate length of antennomeres I–XI: 1: 0.64–0.74: 0.81–1.0: 0.81–0.92: 0.77–0.88: 0.64–0.81: 0.67–0.77: 0.68–0.86: 0.72–0.82: 0.71–0.95: 1.0–1.30. Labial palpus absent. Pronotum: convex; 0.87–0.96 times longer than wide; lateral margin bisinuate, weakly convex in middle; anterolateral angle (Fig. 3) with obtuse denticle posterior to acute tooth, size of denticle variable; posterior angle with acute tooth smaller than anterior; weak transverse basal impression present; deeply coarsely punctate; with fine medial sulcus, reaching neither anterior nor posterior margin, visible only when viewed at certain angle (Fig. 3). Scutellum subquadrate with weakly rounded posterior margin, deeply depressed along middle, impunctate, coarsely granulate. Elytron with lateral margin narrowed at anterior 1/3, expanding to apex, crenulate; exterior apical angle laminate, acute with lateral margin weakly concave and posterior margin strongly concave; apical margin crenulate, laminate. Elytra with 10 regular rows of punctures and a scutellar row; punctures rather circular; interspaces 2, 4, 6 and 8 costate, costa 3 interrupted in middle. Venter (Fig. 2): prosternum coarsely punctate; mesosternum with a row of 3–6 large punctures anteriorly, rest of surface impunctate; metasternum with a row of deep, large punctures near anterior margin, laterally with two rows of deep punctures, inner row being shorter, rugged posterolaterally. Legs: all coxae, pro- and midtrochanters punctate; hind trochanter sparsely punctate; femur, tibia impunctate.

Notes. There is apparently no sexual dimorphism, except for slightly larger females compared to males.

Etymology. The specific epithet mayuri , from the Sanskrit word mayur for peacock, alludes to the metallic green color of the beetle.

Distribution. Endemic to southern India (Karnataka, Kerala, Tamil Nadu).

Remarks. Chaeridiona mayuri resembles C. angulata Staines from Laos, and C. semiviridis Pic occurring in Thailand and Vietnam, in having strongly angulate apical angle of the elytra. Chaeridiona mayuri can be separated from C. angulata by the shorter medial sulcus not reaching beyond basal half of vertex (medial sulcus on vertex in C. angulata extends from base to apex of the projection); larger size ( C. mayuri is 3.84–4.61 mm long, while C. angulata is only 3.6 mm); and subequal seventh and eighth antennomeres (eighth is distinctly longer than seventh in C. angulata ). The elytral margin at apical angle in C. semiviridis Pic is wider than in C. mayuri ; and the elytral puncture rows 5–7 are confused in C. semiviridis , while the same are regular in C. mayuri . The lateral margin of the apical elytral angle in C. mayuri is comparatively more concave than in C. angulata and C. semiviridis . Moreover, C. mayuri is geographically widely separated from the other two species. Chaeridiona mayuri can easily be differentiated from all other Indian species by the strongly angulate apical angle of elytra, as the same is rounded in all of them, except C. picea . However, the angulation in C. picea is far less pronounced and resembles that of a denticle. Chaeridiona picea is quite distinct from C. mayuri in color and structure of elytral costae. Specimens of C. mayuri from Arippa in southern Kerala (3.84–3.94 mm) are distinctly smaller than those from all other localities (4.13–4.61).

FIGURES 1–8. 1–5. Chaeridiona mayuri n. sp. 1) dorsal habitus; 2) ventral habitus; 3) head and pronotum; 4) linear feeding troughs on ginger leaf; 5) feeding troughs on Cheilocostus speciosus leaf. 6–8. Chaeridiona pseudometallica Basu ; 6) dorsal habitus; 7) ventral habitus; 8) head and pronotum.

Biology. Recorded host plants are: Costaceae : Cheilocostus speciosus (J. Koenig) C. D. Specht ; Zingiberaceae : Curcuma longa L., Globba sessiliflora Sims , Zingiber officinale Roscoe and Zingiber zerumbet (L.) Smith.

Adult beetles assume a characteristic posture and merge well with the background color of the leaves and feed by scraping on the adaxial side. Feeding troughs formed on Cheilocostus speciosus (Fig. 5) were much wider and shorter while those formed on the leaves of ginger (Fig. 4) were much longer and narrow. Larva is a leaf miner that deposits thread-like faeces outside the leaf mines on the adaxial surface of the leaf. It pierces the epidermis near the margin of the leaf mine, more or less at regular intervals, with the posterior end, which is extended towards the exterior to extrude the fecal threads. Świętojańska & Kovac (2007) reported similar behavior in C. thailandica Kimoto.

Chaeridiona pseudometallica Basu (Figs 6–8)

Chaeridiona pseudometallica Basu, 1999: 163 –164 [type locality: India, Darjeeling; holotype (ZSI) examined]; Staines 2007: 25 –26.

Material examined. Holotype (left antenna, except scape, missing; right protarsomeres, except basal, missing) with the following labels: “(1) India: W.B. / Darjeeling dist., / Rangiroom (= Rangaroon), / 2000m, 13.IV.1978 / C.R. Basu Coll.; (2) Chaeridiona / pseudometallica n. sp. / C.R. Basu det., 1997; (3) Holotype (red, printed letters

on white label) (4) blank red label (5) ”. Non-types. 1♀, 1 ♂, 8 unsexed. India: West Bengal / Darjeeling, Rangaroon / N27° 00' 45.6" / E88° 17' 11.2" 1996m / 16.vi.2013 / Prathapan K D Coll. / Ex Zingiberaceae (2 BMNH, 2 USNM, 2 UASB, 1 NBAII, 2 NPC, 1 PKDC).

Redescription. Length 3.26–3.45mm, width 1.50–1.56 mm. Dorsum (Fig. 6) metallic emerald green medially; coppery brown laterally; preapically with a dark, coppery area, widest medially, narrowing laterally, almost rhomboidal in shape, extending to external apical angle; apex lemon yellow; color of head dorsally varies from metallic emerald green to dark coppery. Antennomeres 1–7 yellow brown, 8–11 black. Frontoclypeus, gena, gula, mouth parts, hypomeron, pro- and mesosternum, meso- and metaepisterna and epimera, all coxae, all trochanters, all tarsi more or less concolorous with basal antennomeres; clypeus, labrum and mandibles often darker. Metasternum dark brown to piceous. First two abdominal ventrites more or less dark brown; ventrites 3–5 progressively turn lighter, the last being nearly yellow brown; all femora and tibiae lemon yellow, concolorous with elytral apex (Fig. 7).

Head: vertex proximally with medial sulcus, deeply punctate except basally and apically; sulci present near eyes; frons uniformly, coarsely granulate, without deep punctures, with sharply raised ridge along middle; clypeus weakly granulate compared to frons, with sparse, irregularly arranged, weak setae. Antenna: 0.64–0.66 times longer than body. Proportionate length of antennomeres I–XI: 1: 0.67–0.78: 0.78–0.86: 0.86–0.92: 0.80–0.93: 0.69–0.78: 0.64–0.77: 0.93–1.07: 0.93–1.08: 1.0–1.15: 1.64–1.71. Labial palpus absent. Pronotum: convex; 0.88–0.95 times longer than wide; lateral margin indistinctly bisinuate, weakly convex in middle; anterolateral angle (Fig. 8) with small obtuse denticle posterior to acute tooth, indistinct in most specimens; tooth on posterolateral angle not laterally projecting; transverse basal impression indistinct; deeply coarsely punctate; with very fine medial sulcus, visible only when viewed at certain angle. Scutellum: subquadrate with weakly rounded posterior margin, gently depressed on top, impunctate, coarsely granulate. Elytron with lateral margin not distinctly narrowed in middle, expanding to apex, indistinctly crenulate along posterior margin; exterior apical angle obtuse, laminate. Elytra with 10 regular rows of punctures and a scutellar row, 6th and 7th rows merge in middle; punctures more or less circular; interspaces 2, 4, 6 and 8 costate, costae 1–3 only slightly raised in anterior half, costa 3 interrupted in middle. Venter (Fig. 7): prosternum coarsely punctate; mesosternum with a row of about 5–7 deep, large punctures near anterior margin, rest of surface impunctate; metasternum with a row of deep, large punctures near anterior and lateral margins, additional inner semiregular row of 3–5 punctures near lateral margin, rest of surface impunctate. Legs: all coxae with a few coarse punctures; trochanters sparingly punctate; femur, tibia impunctate.

Distribution. India (Darjeeling).

Remarks. Chaeridiona pseudometallica closely resembles C. metallica and C. mayuri , both from southern India, by the general structure of the elytral costae and the metallic green dorsum. However, it can be easily separated from C. metallica by its size, structure of anterolateral pronotal angle, extent of development of elytral costae, and crenulations on elytral margin. Chaeridiona pseudometallica is the smallest member of the genus (3.26–3.45mm), while C. metallica is distinctly larger (4.3–5.0 mm). The denticle posterior to the anterolateral angle of pronotum in C. pseudometallica is obtuse and much smaller (indistinct in most specimens) whereas in C. metallica , the denticle adjacent to the anterolateral angle is as prominent as the anterolateral angle itself, so that the anterolateral angle appears as if double toothed. The first and second elytral costae are weakly developed in C. pseudometallica , especially in the anterior 2/3 of the elytra. In C. metallica , the first costa is sharply raised throughout, while the second costa is well developed except for a short interruption anteriorly and another short interruption posteriorly. In C. pseudometallica , punctures of elytral rows 6 and 7 merge inseparably in the middle, where the third costa is interrupted. In C. metallica too the third costa is interrupted in the middle, however, the 6th and 7th elytral rows of punctures do not merge and are distinct. The elytral margin is distinctly crenulate, except anteriorly, in C. metallica . The elytral margin in C. pseudometallica is not crenulate except for the indistinct crenulations along posterior margin. The yellow apical marks on elytra in C. pseudometallica are much lighter and more well defined than in C. metallica . The abdominal ventrites in C. metallica are darker than in C. pseudometallica .

Chaeridiona pseudometallica can be separated from C. mayuri by the body size, structure of the anterolateral pronotal angle and the shape of the apical elytral angle. Chaeridiona mayuri is larger (3.84–4.61mm) than C. pseudometallica . The anterolateral pronotal angle in C. mayuri appears double toothed (Fig. 3) while the same is single toothed in C. pseudometallica (Fig. 8). Strongly angulate apical angle of the elytra in C. mayuri (Fig. 1) is useful in separating it from both C. metallica and C. pseudometallica (Fig. 6).

The lone paratype of C. pseudometallica deposited by Basu (1999) in ZSI could not be traced.

Biology. Adults were collected on an unidentified species of Zingiberaceae (? Globba clarkei Baker ). Adult beetles feed by scraping on the adaxial side of the leaves.