Kerria canalis Rajgopal, 2021

Rajgopal, N. N., Mohanasundaram, Arumugam & Sharma, Kewal Krishan, 2021, A new species of lac insect in the genus Kerria Targioni Tozzetti (Hemiptera Coccomorpha: Tachardiidae) on Samanea saman (Fabaceae) from India, Zootaxa 4938 (1), pp. 60-68 : 61-65

Kerria canalis Rajgopal , sp. nov.

Type material. Holotype adult ♀ on a slide together with 2 paratype ♀♀: INDIA, Tamil Nadu / opposite to Madurai Corporation Eco Park, Madurai / 9 ° 56’09”N 78 ° 08’18”E / Rain tree: Samanea saman , 16.XI.2018 / A. Mohanasundaram; holotype specimen indicated by encircling with permanent marker (deposited in ICAR-NBAIR).

Paratypes: total 15 adult ♀♀, all same data as holotype. 4 adult ♀♀, 2 of them on same slide as holotype and the other 2 on another slide ( ICAR-NBAIR) ; 3 adult ♀♀ on 1 slide ( NPC) ; and 8 adult ♀♀ on 3 slides ( ICAR-IINRG) .

Adult female. Unmounted material ( Figs 1 and 2). Lac tests dark crimson red, occurring in aggregations; live mature female inside each test globular and dark crimson.

Slide-mounted material ( Figs 3 A-M and 4A-N), n = 16. Body large, globular, 3.12 – 4.01 (4.00) mm long, without the length of anal tubercle (3.7 to 5.05 mm, including length of anal tubercle); 2.62–3.25 (3.12) mm wide at apex (near mouthparts), 3.50–4.00 (3.90) mm wide at middle and 2.65–3.12 (3.07) mm wide at base (near dorsal spine).

Dorsum: Brachia elevated, cylindrical, sclerotised, each 400–540 (450) µm long. Brachial plate circular, diameter 190–230 (190) µm; brachial crater shallow, situated centrally, sub-circular, 100–130 (110) µm wide, with a defined rim, dimples medium to large, distinct, numbering 6 or 7 with nuclear duct visible in most specimens. Anterior spiracles each 170–220 (150) µm long and 120–140 (120) µm wide, situated 280–390 (300) µm away from margin of brachial crater, with a long, rough sclerotised trailing canellar band (sensu Varshney 1976: 28) leading from anterior spiracle towards venter of head, sometimes reaching to mouthparts. Ratio of distance of anterior spiracle from crater rim to width of brachial plate 1: 1.47–1.69. Ratio of length of anterior spiracle to width of brachial plate 1: 0.89–0.95. Dorsal spine well developed, 300–390 (390) µm long and 90–120 (120) µm wide at base of pedicel; pedicel large, square to near-rectangular, becoming more sclerotised distally, 130–190 (180) µm long; spine 160–200 (200) µm long, more sclerotised, with 2 or 3 spinosites at its base. Ratio of lengths of pedicel to spine 1: 0.81–0.95. Ratio of lengths of dorsal spine including pedicel to brachial plate 1: 1.58–1.65. Anal tubercle well developed; pre-anal plate membranous, shorter than wide, 290–450 (350) µm long, 600–720 (490) µm wide; supra-anal plate 301–590 (460) µm long, 339–574 (473) µm wide, ratio of length to width 1: 0.89–1.02, heavily sclerotised, hispid near apex. Ratio of lengths of supra-anal plate to brachium 1: 1.58–2.56. Anal fringes short, fringe maximum height 40–70 µm. Anal ring comprised of 6 sectors and bearing 10 setae. Dorsal duct cluster forming a single row of ducts between dorsal spine and anal tubercle, number of ducts variable, with 1 or 2 dorsal setae among the ducts. Spermatoid ducts present.

Venter: Antennae each 40–50 µm long, probably 3 segmented but segmentation obscure, apical segment tipped with 3 long fleshy setae and 2 short setae. Clypeolabral shield 280–310 µm long, 140–170 wide. Pre-oral lobes elongate, membranous, present along sides of clypeolabral shield. Post-oral lobes each 160–210 µm long, membranous, dome-shaped. Posterior spiracle smaller than anterior spiracle, each 70–90 (80) µm long, situated on a sclerotised plate, with 28–41 (32) spiracular pores present along one side of spiracle. Marginal duct clusters distinct, numbering 6 (3 on each side), arranged in a convoluted line ( Fig. 4L ), each cluster consisting of 26–53 (26–30) ducts with surrounding sclerotisation. Perivulvar pore clusters numbering 5–8 (6) on each side ( Fig. 4E ), each cluster irregular in shape and sometimes clusters conjoined, with thinly distributed pores, each pore containing 7-10 loculi ( Fig. 4F ). Ventral duct clusters present, irregular in shape, totalling 3 on each side: first pair situated anterior to mouthparts, second pair antero-lateral to mouthparts and third pair posterior to posterior spiracle but anterior to brachium. Star pores usually present near mouthparts, numbering 0–7, each pore containing 3–5 loculi ( Fig. 4P ). Spermatoid ducts present.

Etymology. The species epithet is derived from the Latin word canalis , meaning canal, and alludes to the rough trailing canellar band present as a chitinous extension below each anterior spiracle in this species.

Remarks. Kerria canalis sp. nov. differs from other described species of Kerria by having a long, rough, sclerotised trailing canellar band (sensu Varshney 1976: 28) leading from each anterior spiracle towards the venter of the head, sometimes reaching to the mouthparts. This sclerotised band is present even in young, pre-reproductive stage, adult females.

Kerria canalis is similar to Kerria dubeyi Ahmad & Ramamurthy in having: (i) marginal duct clusters each surrounded by sclerotisation; (ii) anal tubercle hispid near apex, the supra-anal plate wider than long or subequal; (iii) posterior spiracle borne on a sclerotised plate; (iv) antennal apex with 3 long fleshy setae and 2 short setae; (v) star pores usually present near the mouthparts; and (vi) perivulvar pore clusters numbering 5 to 8 but not more. However, K. canalis differs from K. dubeyi in having (character states for K. dubeyi given in parentheses): (i) brachia elevated, cylindrical, sclerotised (brachia sessile, club-shaped and only slightly sclerotised); (ii) brachial plate circular, diameter 190–230 µm (circular, diameter 315–365 μm), (iii) anterior spiracle 280–390 µm away from brachial crater (0–160 μm away from brachial crater); (iv) long, rough, sclerotised trailing canellar band present below each anterior spiracle, leading towards head and sometimes reaching to mouthparts (sclerotised trailing canellar band absent), and (v) dorsal spine 160–200 µm long (60–145 µm), pedicel 130–190 µm long (75–150 µm), with 2 or 3 spinosites at its base (1 or 2 spinosites).

The new species is not very similar to K. maduraiensis Ahmad & Ramamurthy , but they share the same host ( Samanea saman ) and type locality (Tamil Nadu: Madurai) so the differences between them are discussed here. Kerria canalis differs from K. maduraiensis in having (character states for K. maduraiensis in brackets): (i) brachia elevated, cylindrical, sclerotised (sessile, club-shaped and slightly sclerotised); (ii) brachial plate diameter 190–230 µm (225–285 μm); (i) marginal duct clusters each consisting of 26–53 ducts with surrounding sclerotisation (39–42 ducts, without any surrounding sclerotisation); (iv) posterior spiracle borne on a sclerotised plate (not on a sclerotised plate); (v) antenna 40–50 µm long (35–55 μm long), the apical segment with 3 long fleshy setae and 2 hair-like setae (4 long fleshy setae and 2 short hair-like setae); (vi) distance of anterior spiracle from brachial plate 280–390 µm (85–400 µm); (vii) supra-anal plate wider than long or subequal, 339–574 µm by 301–590 µm (longer than wide, 190–570 μm by 220–400 μm); and (viii) long, rough, sclerotised trailing canellar band below each anterior spiracle leading towards venter of head, sometimes reaching to mouthparts (sclerotised trailing canellar band absent).

The new species shares the same host-plant and has some similarities with K. destructor Talukder and Das : (i) Spermatoid ducts present on both surfaces of body; (ii) anal tubercle hispid near apex, the supra-anal plate wider than long or subequal; (iii) perivulvar pore clusters numbering 6 to 9 but not more; (iv) dimples medium to large, 6 – 9 in number. However, K. canalis differs from K. destructor in having (character states for K. destructor in brackets): (i) star pores present near mouthparts (absent); (ii) long, rough, sclerotised trailing canellar band below each anterior spiracle leading towards venter of head, sometimes reaching to mouthparts (sclerotised trailing canellar band absent); (iii) marginal duct clusters each consisting of 26–53 ducts with surrounding sclerotisation (28–32 ducts, without any surrounding sclerotisation); (iv) posterior spiracle borne on a sclerotised plate (not on a sclerotised plate); (v) distance of anterior spiracle from brachial plate 280–390 µm (157–267 μm); (vi) brachial plate diameter 190–230 µm (258–293 μm); (vii) brachial crater 100–130 µm wide (140–190 μm); and spine length is greater than pedicel, without a bifurcate tip (spine length equal to that of pedicel, with a bifurcate tip).

Figures

FIGURE 3. Diagnostic characters of a slide-mounted adult female of Kerria canalis sp. nov. A. Whole mount; B. Brachia; C. Antenna; D. Star pores near mouthparts; E. Trailing canellar band; F. Ventral duct cluster; G. Marginal duct cluster; H. Posterior spiracle; I. Brachial plate and crater with dimples; J. Dorsal spine; K. Ventral setae; L. Perivulvular duct cluster; M. Anal tubercle.

FIGURE 4. Taxonomic illustration of a slide-mounted adult female of Kerria canalis sp. nov. A. Whole mount; B. Antenna; C. Posterior spiracle; D. Ventral seta; E. Perivulvar pore cluster; F. Individual multilocular pore in perivulvar pore cluster; G. Dorsal seta near dorsal duct cluster; H. Single duct in dorsal duct cluster; I. Dorsal spine; J. Brachium with anterior spiracle; K. Tubular ducts in marginal duct cluster; L. Marginal duct cluster; M. Trailing canellar band; N. Anal tubercle; O. Anal ring setae; P. Star pores; Q. Spermatoid duct. Scale bar in mm.

FIGURES 1 and 2. Kerria canalis sp. nov. 1. Lac encrustation on branches seen from the ground. 2. Individual lac tests and coalescence, viewed after sample collection.