Megalocaria dilatata (Fabricius)

POORANI, J., 2023, An illustrated guide to lady beetles (Coleoptera: Coccinellidae) of the Indian Subcontinent. Part 1. Tribe Coccinellini, Zootaxa 5332 (1), pp. 1-307 : 176-177

Megalocaria dilatata (Fabricius)

( Figs 123 , 124 )

Coccinella dilatata Fabricius, 1775: 82 (Type locality: Java).

Caria dilatata: Mulsant 1850: 232 ; 1866: 167; Crotch 1874: 171.

Anisolemnia dilatata: Korschefsky 1932: 269 .

Megalocaria dilatata: Iablokoff-Khnzorian 1982: 521 ; Poorani 2002: 334; Ren et al. 2009: 212; Yu 2010: 132.

Diagnosis. Length: 10.00–13.00 mm, width: 9.00–12.00 mm. Form ( Fig. 123a ) round, dorsum hemispherical and strongly convex, glabrous. Ground colour bright reddish/orange yellow; head with a pair of small oblique black maculae below the posterior margin of eyes and a larger transverse posterior macula ( Fig. 123c ); pronotum having two oval spots (one on either side above scutellar shield) on posterior margin; scutellar shield black; each elytron with five black spots arranged in a 1-2-2 pattern ( Fig. 124e–l ). Ventral side uniformly reddish or yellowish brown. Male genitalia ( Fig. 123f–h ) and spermatheca ( Fig. 123e ) as illustrated.

Immature stages. Eggs ( Fig. 124a ) yellow and spindle shaped, usually laid in large groups. Larva ( Fig. 124b– d ) black with a bluish grey pruinosity / thin powdery dusting on dorsal surface, prothorax and abdominal segments 1 and 4 yellow initially ( Fig. 124b ), turn bright orange in later stages ( Fig. 124c, d ).

Distribution. India (Assam, Himachal Pradesh, Karnataka, Kerala, Tamil Nadu, Uttar Pradesh, northeastern region); Nepal; Bhutan; China. In Fabricius’s original description, there is an erroneous mention of “Habitat in America” as pointed out by Iablokoff-Khnzorian (1982).

Prey/associated habitat. Hemiptera: Aphidoidea : Adelges spp. on silver fir, Aiceona sp. , Aphis nasturtii Kaltenbach , Aphis spiraecola Patch , Astegopteryx (as Oregma ) bambusae (Buckton) , Astegopteryx minuta (van der Goot) , Ceratovacuna (as Oregma ) lanigera Zehntner , Ceratovacuna silvestrii (Takahashi) , Cervaphis schouteniae van der Goot , Greenideoida ceyloniae van der Goot , Mollitrichosiphum montanum (van der Goot) , Pentalonia nigronervosa Coquerel , Pseudoregma alexanderi (Takahashi) , Pseudoregma (as Oregma ) bambusicola (Takahashi) , Pseudoregma bucktoni Ghosh et al. , Pyrolachnus (as Lachnus ) pyri (Buckton) on pear, Aphis (Toxoptera) aurantii Boyer de Fonscolombe. Collected on sandal, Alnus nepalensis , Brassica napus , Cajanus cajan , radish and cucumber (label data). Predatory on Aiceona sp. infesting Persea bombycina , an economically important field host plant of Muga silkworm in West Bengal ( Ponnusamy et al. 2021).

It coexists with the giant bamboo ladybird, Synonycha grandis (Thunberg) on aphids infesting bamboo ( Bambusa arundinacea ), but is relatively less abundant than S. grandis in South India. It is more commonly found feeding on the bamboo leaf aphid ( A. bambusae ) in south India and C. silvestrii in northeastern India. Its seasonal occurrence, feeding habits and life history in general, closely resemble those of S. grandis ( Puttarudriah & Channabasavanna, 1953) . It survives and reproduces on aphids infesting cowpea, groundnut, cotton, pea, rose, jack, brinjal, cabbage, radish, citrus, sorghum, etc. in the laboratory, but apparently bamboo aphids are essential/preferred food.

Seasonal occurrence. Particularly abundant on bamboo during July–December in and around Bangalore ( Puttarudriah & Channabasavanna 1953), and January–February in northeastern region (Agarwala et al. 1984). Collected during March, June–July, and September–November in South India (label data).

Natural enemy. Tetrastichus epilachnae (Giard) (Eulophidae) .

Note. This species was transferred to Megalocaria by Iablokoff-Khnzorian (1982), but the name Anisolemnia dilatata is more widely known and used in the Indian literature. Puttarudriah & Channabasavanna (1952, 1953) provided brief notes on its biology and hosts. Agarwala et al. (1984) described the immature stages and studied the biology and predatory potential. Ponnusamy et al. (2021) studied its biology and predatory potential on Aiceona sp. , an aphid pest of Persea bombycina . Ren et al. (2009) and Yu (2010) included it in their works on Chinese Coccinellini .

Figures

FIGURE 123. Megalocaria dilatata (Fabricius): a. adult, dorsal view; b. antenna; c. head; d. abdominal postcoxal line; e. female genitalia: spermatheca; f–h. male genitalia: f. tegmen, ventral view; g. penis; h. penis apex.

FIGURE 124. Megalocaria dilatata (Fabricius), life stages: a. eggs; b. early–stage larva; c, d. grown larva; e–l. live adult.