Pseudaspidimerus trinotatus (Thunberg)

POORANI, J., 2024, An illustrated guide to lady beetles (Coleoptera: Coccinellidae) of the Indian Subcontinent. Part 3. Tribe Aspidimerini, Zootaxa 5431 (1), pp. 1-89 : 64-69

Pseudaspidimerus trinotatus (Thunberg)

( Figs 49–52 )

Coccinella trinotata Thunberg, 1781: 11 .—Korschefsky 1932: 582 (as species incertae sedis).

Pseudaspidimerus trinotatus : Pope 1987: 64.— Poorani 2002: 346.

Platynaspis circumflexa Motschulsky, 1858: 118 .— Korschefsky 1931: 172.

Pseudaspidimerus circumflexa : Kapur 1948: 117. Synonymized by Pope 1987: 64.

Pseudaspidimerus circumflexa var. testaceus Weise, 1900: 423 .

Diagnosis. Length: 2.50–2.75 mm; width: 1.80–2.20 mm. Form ( Figs 49a, c , 50a–d ) short oval to slightly broader oval, moderately convex. Ground colour in nominate form yellowish to reddish testaceous with the following markings: a basal median black spot on pronotum and three black elytral spots-one subscutellar and one oblique discal spot just below midline on each elytron ( Figs 49c , 50d ), the subscutellar spot sometimes faint or obsolete or absent ( Figs 50b, c , 52l ). Specimens from southern India mostly immaculate ( var. testaceus Weise ), bright golden yellow to reddish brown, rarely darker reddish testaceous ( Figs 49a , 50a , 51h ), rarely with the complete set of pronotal and elytral spots, with only discal elytral spots. Prosternal carinae ( Fig. 49h ) subparallel to slightly divergent anteriorly, area enclosed by carinae subrectangular, distinctly more elongate and narrower than those of P. flaviceps and P. mauliki . Last visible abdominal ventrite posteriorly broadly and deeply concave. Male genitalia ( Fig. 49k, l ) characteristic, with a broad, u-shaped and medially sinuate penis guide ( Fig. 49k ) and a stout, strongly curved penis ( Fig. 49l ). Female genitalia ( Fig. 49j ) as illustrated.

Immature stages. Immature stages ( Figs 51 , 52 ) as illustrated; larval coloration yellow, greyish yellow, or dark brown with paler, transparent margins, appears to vary with the aphid host; pupation singly ( Fig. 51g ) or in small groups ( Fig. 52m, n ).

Distribution. India (Andamans; Andhra Pradesh; Assam; Karnataka; Kerala; Goa; Gujarat; Lakshadweep Islands; Maharashtra; Tamil Nadu; West Bengal); Sri Lanka; Myanmar.

Prey/associated habitat. Hemiptera : Aleyrodidae : Aleurodicus dispersus Russell. Aphididae : Aphis craccivora Koch , Aphis gossypii Glover , Aphis fabae Scopoli , Aphis malvoides van der Goot , Aphis nerii Boyer de Fonscolombe , Aphis rumicis Linnaeus , Aphis spiraecola Patch (as A. citricola van der Goot ), Hysteroneura setariae (Thomas) , Lipaphis pseudobrassicae (Kaltenbach) (as L. erysimi (Kaltenbach)) , Melanaphis (as Longiunguis ) sacchari (Zehntner) , Pentalonia nigronervosa Coquerel , Aphis (Toxoptera) aurantii Boyer de Fonscolombe , Aphis (Aphis) odinae (van der Goot) , and indet. aphids on brinjal. Coccoidea: Ferrisia virgata (Cockerell) , Pseudococcus sp. , Rastrococcus iceryoides (Green) , associated with Pulvinaria (as Chloropulvinaria ) psidii Maskell. Predatory on sugarcane aphid ( Pushpaveni & Krishnamurty 1971); Aphis craccivora on cowpea, A. gossypii on coccinia and bitter gourd, Ferrisia virgata (Cockerell) and Coccidohystrix insolita (Green) infesting brinjal ( Jose et al. 2005); collected from aphid colonies on brinjal ( Mayadunnage et al. 2007).

Associated with aphids and sometimes with mealybugs on banana, guava, teak, coconut, cowpea, sorghum, maize, sugarcane, lablab, groundnut, gliricidia, citrus, potato, brinjal, pomegranate, sandal, Calotropis gigantea , Boehmeria sp. , Coccinia grandis , Catharanthus roseus , castor, papaya, and neem (label data).

Seasonal occurrence. Commonly collected almost throughout the year in South India.

Natural enemy. Pachyneuron sp. ( Hymenoptera : Pteromalidae ) (see Fig. 5c ) was reared from the pupae of P. trinotatus (unpublished data).

Notes. Pope (1987) mentioned the type locality of Coccinella trinotata Thunberg (1781) as “? Cape of good hope”, which looks anomalous. “ Cape ” is listed as the type locality for Coccinella trinotata and it is expanded as “ Cape Province, South Africa ” in the list of abbreviations given for type localities of Thunberg’s type material by Wallin & Wallin (2001). Pseudaspidimerus trinotatus and P. flaviceps occur together in the plains of south India almost throughout the year, the former usually being more abundant than the latter. In the cool, hilly terrains of Western Ghats, P. trinotatus , P. flaviceps and P. infuscatus appear to coexist whereas in the northeastern region, P. mauliki appears to be the most predominant species. The immaculate forms of these species are best separated by their male genitalia, and to some extent, prosternal carinae. Larvae of P. trinotatus and P. flaviceps are usually dark brown and light yellowish, respectively, and can be separated to some extent by their colour. Immaculate forms of both P. trinotatus and P. flaviceps are also similar to Cryptogonus orbiculus var. antica (Walker) , which occurs in south India (Western Ghats / Kerala).

For more details and illustrations, see Kapur (1948) and Poorani (2001). Puttarudriah & Channabasavanna (1953, 1955, 1956) provided brief notes on its biology and hosts. Poddar & Ghosh (1984) studied its bionomics and illustrated the immature stages. Uttamrao (2008) studied its biology and predatory potential on bean aphid under Gujarat conditions.

Figures

FIGURE 5. Natural enemies of Aspidimerini: a, b. Cowperia indica (Encyrtidae): a. female; b. male; b. Pachyneuron sp. (Pteromalidae).

FIGURE 49. Pseudaspidimerus trinotatus (Thunberg): a, c. dorsal view; b. ventral view; d. head; e. antenna; f. maxilla; g. mandible; h. prosternal process; i. abdominal postcoxal line; j. female genitalia; k, l. male genitalia: k. tegmen, ventral view; l. penis.

FIGURE 50. Pseudaspidimerus trinotatus (Thunberg), variants.

FIGURE 51. Pseudaspidimerus trinotatus (Thunberg): a–d. larva feeding on aphids; e, f. prepupa; g. pupa; h. adult.

FIGURE 52. Pseudaspidimerus trinotatus (Thunberg), life stages: a–c. egg; d–f. early stage larva; g–k. older larvae feeding on aphids; l. prepupae; m, n. pupae; o. adult.