Scymnus (Pullus) spicatus Poorani, 2024

Poorani, J., Anuradha, C., Thanigairaj, R. & Mol, P. Prashina, 2024, Coccinellid predators of mealybugs infesting banana in South India, including a new species and a new record of Scymnus Kugelann (Coleoptera: Coccinellidae), with notes on other natural enemies, Zootaxa 5419 (4), pp. 525-544 : 535-538

Scymnus (Pullus) spicatus Poorani , sp. n.

( Figs 6 , 7 )

Diagnosis. This species has a yellowish-testaceous ground colour with the elytra usually having a darker brownish or infuscate discal patch similar to S. victoris Motschulsky ( Figs 6a, b ; 7g, h ); the discal brown area is paler or smaller ( Fig. 6b ) or obsolete in some specimens, externally resembling the immaculate form of S. coccivora Ayyar and S. dyadechkoi Ukrainsky, 2010 (= Scymnus utilis Hoàng, 1982 ). Males of this species can be easily separated from other congeners by the presence of a short, dark brown, triangular, tooth-like projection in the middle of the apical margin of abdominal ventrite 5 ( Fig. 6d, f ). The male genitalia ( Fig. 6g –j ) are also diagnostic.

Description. TL: 1.03–1.24 mm; TW: 0.77–0.90 mm; TL/TW: 1.26–1.41; EL/EW: 0.99–1.13; PL/PW: 0.36– 0.50. Male. Form broad oval, dorsum convex, with dense, silvery white pubescence, lateral sides of elytra with few erect marginal setae. Dorsum yellowish to reddish testaceous, elytra medially with a pale infuscate area or a clearly distinct dark brown patch covering most of elytra except lateral and apical margins; ventral side yellowish-testaceous except meso- and metaventrites and middle of abdominal ventrite 1 darker, brownish; legs paler yellowish. Head ( Fig. 6c ) 3.17–3.23x as wide as an eye, interocular distance 1.50–1.70x eye width; with shallowly impressed punctures. Elytral punctation dense, punctures more or less similar to those on pronotum, very shallowly impressed, separated by 1-4 diameters. Prosternal intercoxal process with a pair of carinae progressively divergent towards apex. Abdomen with six ventrites, posterior margin of ventrite 5 with a short, dark brown, triangular median tooth ( Fig. 6d ), ventrite 6 only narrowly visible and very shallowly emarginate. Tarsal claws trifid ( Fig. 6o ). Male genitalia ( Fig. 6g –j ) with penis guide of tegmen broadly lanceolate in ventral view ( Fig. 6h ), medially broadest and apically triangular with a very short, tubular apex; with a characteristic basal keel in lateral view ( Fig. 6g ); penis ( Fig. 6i, k, l ) with a prominent capsule ( Fig. 6j ), penis apex with a membranous flap ( Fig. 6m ) as illustrated.

Female. Externally similar to male except abdominal ventrite 5 posteriorly without a median tooth, ventrite 6 only slightly visible, apically arcuate. Female genitalia ( Fig. 6n ) and spermatheca as illustrated.

Etymology. The specific epithet is a Latin adjective in reference to the acutely pointed median tooth on the posterior margin of abdominal ventrite 5 in male.

Material examined. Holotype male, “ India: Tamil Nadu: Podavur , NRCB research farm, N°1047’20.16” E078°34’29.88”, Ex. Jack Beardsley mealybug on banana, R. Thanigairaj ” ; Paratypes: with same data as holotype, except dates of collection 24.iv.19, 29.i.21, 28.vii.21, 11.viii.21 ( ICAR-NBAIR) .

Immature stages. Larva ( Fig. 7a–d ) and pupa ( Fig. 7e, f ) yellowish orange, with dense waxy filamentation on the dorsal and lateral sides as in other Scymnini .

Hosts / associated host plants. Scymnus (Pullus) spicatus sp. n. was collected as a predator of Jack Beardsley mealybug and F. virgata infesting banana in and around Trichy, Tamil Nadu. It was also found feeding on F. virgata infesting eggplant ( Solanum melongena L.) in and around the banana orchards at the NRCB research farm.

Distribution. India: Tamil Nadu.

Notes. Indigenous natural enemies such as Mallada desjardinsi (Navás) (= M. boninensis (Okamoto)) ( Neuroptera : Chrysopidae ), Cryptolaemus montrouzieri Mulsant ( Coleoptera : Coccinellidae ), Spalgis epeus (Westwood) ( Lepidoptera : Lycaenidae ) and some species of gnats ( Diptera : Cecidomyiidae ) have been recorded earlier as predators of P. jackbeardsleyi in Karnataka and Tamil Nadu, South India ( Shylesha 2013; Mani et al. 2013).

Figures

FIGURE 6. Diagnostic characters of Scymnus (Pullus) spicatus Poorani, sp. n.: a, b. dorsal view; c. head; d. abdomen, male; e. abdominal postcoxal line; f. terminal ventrites, male; g–m. male genitalia: g. tegmen, lateral view; h. tegmen, ventral view; i. penis; j. penis capsule; k, l. penis, variants; m. penis apex; n. female genitalia; o. tarsi.

FIGURE 7. Life stages of Scymnus (Pullus) spicatus Poorani, sp. n. on Pseudococcus jackbeardsleyi: a–d. larvae feeding on mealybugs; e, f. pupa; g, h. adult, dorsal view.