Chilocorus nigrita (Fabricius)

POORANI, J., 2023, An illustrated guide to the lady beetles (Coleoptera: Coccinellidae) of the Indian Subcontinent. Part II. Tribe Chilocorini, Zootaxa 5378 (1), pp. 1-108 : 54-58

Chilocorus nigrita (Fabricius)

( Figs 40–43 )

Coccinella nigrita Fabricius, 1798: 79 .

Chilocorus nigritus : Mulsant 1850: 463; Crotch, 1874: 184; Korschefsky 1932: 240; Greathead & Pope 1977: 264.

Chilocorus nigrita : Bielawski 1957: 86; Samways 1989: 345; Booth et al. 1990: 90; Booth 1998: 362; Poorani 2002: 312; Kovář 2007: 593; Li et al. 2018: 9 .

Diagnosis. Length: 3.20–4.00 mm; width: 2.90–3.90 mm. Form ( Fig. 40a–c ) subrounded, dorsum hemispherical and strongly convex, shiny and glabrous. Head dull orange yellow. Pronotum dark pitchy brown to black in middle, paler on sides, anterolateral flanks orange yellow to yellowish-testaceous. Elytra black, shiny, finely punctate. Ventral side including legs and inner half of elytral epipleura orange yellow to yellowish brown, outer margins of epipleura pitchy brown to black. Male genitalia ( Figs 40h–k , 41a–d ) and spermatheca ( Fig. 40g ) as illustrated.

Immature stages. Life stages ( Fig. 43 ) as illustrated.

Distribution. India: Widely distributed (Andamans; Andhra Pradesh; Assam; Goa; Gujarat; Karnataka; Kerala; Maharashtra; Orissa; Punjab; Tamil Nadu; Uttar Pradesh; West Bengal); Sri Lanka; Bangladesh; Pakistan; Nepal; Myanmar; Malaysia; Chagos Archipelago; Indonesia; Oman; Madagascar; Reunion; Mauritius; Seychelles; Togo; Ghana; East Africa; Kenya; Tanzania; South Africa; Brazil; Dominica; USA.

It is a native of the Indian subcontinent and the most widely distributed species of this genus. It has been successfully introduced for the biological control of scale insects into, and naturally invaded, many different climatically appropriate regions of the world, including South America and Africa ( Samways et al. 1999). Established in the US (Hawaii and Florida) ( Thomas & Blanchard 2013).

Prey/associated habitat. Recorded on numerous hosts, mostly diaspine scales, infesting coffee, arecanut, coconut, citrus, neem, bamboo, mango, castor, brinjal, sugarcane, Morinda tinctoria , Nerium indicum , Cassia corymbosa , Thevetia , etc. Most commonly and almost invariably collected on coconut.

Specific host records are as follows: Hemiptera : Coccoidea: Aonidiella aurantii (Maskell) , Aonidiella citrina (Coquillett) , Aonidiella orientalis (Newstead) , Aonidiella simplex (Grandpré & Charmoy) (= A. andersoni Laing ), Aspidiotus destructor Signoret , A. nerii Bouché , Aspidiotus spp. , Asterolecanium miliaris (Boisduval) , Asterolecanium sp. , Aulacaspis tegalensis (Zehntner) , Aulacaspis tubercularis Newstead , Ceroplastes actiniformis Green , Ceroplastodes cajani (Maskell) , Chionaspis sp. , Aulacaspis vitis (Green) (= Chionaspis vitis Green ), Chrysomphalus aonidum (Linnaeus) (= C. ficus Ashmead ), Chrysomphalus dictyospermi (Morgan) , Chrysomphalus pinnulifer diversicolor Green , Coccus colemani Kannan , Coccus hesperidum Linnaeus , Coccus viridis (Green) , Diaspis bromeliae (Kerner) , Diaspis echinocacti (Bouché) , Diaspidiotus prunorum (Laing) , Drepanococcus chiton (Green) , Eucalymnatus tessellatus (Signoret) , Hemiberlesia lataniae (Signoret) , Hsuia sp. , Icerya seychellarum (Westwood) , Ischnaspis longirostris (Signoret) , Lepidosaphes beckii (Newman) , Lepidosaphes gloverii (Packard) , Lepidosaphes sp. , Megapulvinaria (as Pulvinaria ) maxima (Green), Gannaspis glomerata (Green) , Parasaissetia nigra (Nietner) , Parlatoria blanchardi (Targioni Tozzetti) , Parlatoria crypta McKenzie , Parlatoria orientalis Ramakrishna Ayyar , Parlatoria ziziphi (Lucas) , Phoenicococcus marlatti Cockerell , Pinnaspis aspidistrae (Signoret) , Pinnaspis buxi (Bouché) , Serenaspis minima (Maskell) (as Hemichionaspis minor Maskell ), Pinnaspis strachani (Cooley) , Palmicultor sp. , Planococcus citri (Risso) , Prococcus acutissimus (Green) , Pseudaulacaspis cockerelli (Cooley) , Pseudaulacaspis pentagona (Targioni Tozzetti) , Pseudaulacaspis sp. , Pseudococcus cryptus Hempel (= P. citriculus Green ), Pseudococcus gilbertensis Beardsley , Pseudococcus sp. , Pulvinaria psidii Maskell , Pulvinaria polygonata Cockerell , Pulvinaria spp. , Comstockaspis perniciosa (Comstock) , Rastrococcus invadens Williams , Saccharicoccus sacchari (Cockerell) , Selenaspidus articulatus (Morgan) , Tecaspis sp. , Ceroplastes stellifer (Westwood) (= Vinsonia stellifera (Westwood)) . Aleyrodidae : Aleurolobus barodensis (Maskell) , Aleurodicus dispersus Russell , Aleurothrixus floccosus (Maskell) . Aphididae : Aphis sp. , Brachycaudus cardui (Linnaeus) , Aphis (Toxoptera) citricidus (Kirkaldy) , indigo aphid. Psyllidae : Diaphorina citri Kuwayama , Trioza erytreae (Del Guercio) .

Seasonal occurrence. Collected almost throughout the year in south India. Mass assemblages of overwintering or aestivating populations common on banyan trees ( Ficus benghalensis L., Moraceae ), particularly during hot months ( Tirumala Rao et al. 1954; Ketkar 1959). Small to large congregations are seen on bamboo in southern India (label data).

Natural enemies. Larvae are parasitized by Homalotylus hemipterinus (De Stefani) , Homalotylus mexicanus Timberlake , and Homalotylus sp. ( Hymenoptera : Encyrtidae ).

Notes. This species is more commonly known in the literature as ‘ Chilocorus nigritus ’, which is incorrect. As per the rules of Zoological Nomenclature, the species name nigrita being a noun, does not change its ending when combined with Chilocorus , a generic name of different gender from the original genus, namely Coccinella ( Grenstead 1951; Booth et al. 1990; Booth 1998).

The male genitalia show some intraspecific variations, particularly the penis differs in terms of overall length and curvature but the shape of the penis capsule appears to be constant. The male genitalia illustrations of ‘ C. nigrita ’ in Li et al. (2018) appear to differ from typical C. nigrita material from India in having slightly differently shaped parameres and penis capsule without a triangular expansion. In some examples studied from Assam, north-eastern India ( Fig. 42a–i ), the male genitalia ( Fig. 42e–h ) are somewhat similar to those illustrated by Li et al. (2018) as ‘ C. nigrita ’, but differ from C. nigrita in having a darker head in female with narrowly yellowish pronotal flanks ( Fig. 42a ) and yellowish-testaceous head and slightly more broadly yellowish pronotal anterolateral corners in male ( Fig. 42b ) as in C. melas . Chilocorus nigrita and C. melas are not easily separated even by male genitalia due to the overall similarity.

Numerous works have been published on its bioecology, hosts, distribution, etc. and some notable works are as follows: Stebbing 1903 (description of adult, brief notes on life history); Puttarudriah & Channabasavanna 1953, 1955; Greathead & Pope 1977 (notes on biology, hosts); Nagaraja & Hussainy 1967, Booth 1998 (detailed descriptions, key, and illustrations of habitus & genitalia); Ahmad 1970 (description of immature stages, biology); Raghunath & Rao 1982 (biology); Samways 1984 (review of biology, host range, economic importance); Samways & Wilson 1988 (feeding behaviour); Samways 1989 (areography and distribution in relation to climate diagrams); Samways et al. 1999 (geographical range prediction by climate matching).

Figures

FIGURE 40. Chilocorus nigrita (Fabricius): a. adult, dorsal view; b. adult, lateral view; c. adult, frontal view; d. head; e. maxilla; f. antenna; g. spermatheca; h–k. male genitalia: h. tegmen, lateral view; i. tegmen, ventral view; j. penis; k. penis apex.

FIGURE 41. Chilocorus nigrita (Fabricius), male genitalia, variations: a, e. tegmen, lateral view; b, f. tegmen, ventral view; c, g. penis; d. penis apex.

FIGURE 42. Chilocorus nigrita-group (from Assam, NE India): a. adult female, frontal view; b. adult male, frontal view; c. abdomen, male; d. spermatheca; e–h. male genitalia: e. tegmen, lateral view; f. tegmen, ventral view; g. penis; h. penis apex; i. coxites.

FIGURE 43. Chilocorus nigrita (Fabricius), life stages: a. egg, magnified; b, c. eggs; d–h. larva; i–l. pupae; m. eclosing adult; n. adult; o. Homalotylus hemipterinus (Encyrtidae), its larval parasitoid.