Harmonia axyridis (Pallas)

(Fig. 86)

Coccinella axyridis Pallas, 1773: 716 (Type locality: Russia, Siberia).

Leis axyridis: Mulsant 1850: 266; Mader 1934: 309.

Ptychanatis axyridis: Crotch 1874: 123; Kamiya 1965a: 57–58.

Coccinella (Harmonia) axyridis: Weise 1885 b: 35; Korschefsky 1932: 441.

Harmonia axyridis: Jacobson 1916: 984; Timberlake 1943: 17; Poorani 2002a: 330; Yu 2010: 118–120.

Harmonia (Ptychanatis) axyridis: Sasaji 1971: 278 .

Diagnosis. Length: 5.40–8.50 mm; width: 3.80–6.00 mm. Form elongate oval, dorsum strongly convex and glabrous. A highly variably coloured and polymorphic species (Fig. 86), that can be reliably identified by the presence of a pair of conspicuous ridges / plicae, sometimes reduced in the apical third of elytra. Genitalia not studied.

Distribution. India (West Bengal); Nepal; China; Taiwan; Japan; Palaearctic; deliberately or accidentally introduced in many parts of Europe, North America, Central America, South America, Africa and New Zealand (Ślipiński et al. 2020).

Notes. This species, commonly known as Multicoloured Asian lady beetle or Harlequin ladybird, has become one of the major alien invasive species in several parts of the world and causes a great deal of nuisance. It has also been reported to reduce the abundance of native lady beetles in many countries, besides causing several other non-target effects (Koch 2003). A single specimen from Nepal (Fig. 86e, f) was examined for this study and it is presumed to be present in the unexplored parts of northwestern and eastern Himalayan region, a hotspot of diversity for Coccinellini and the states on the Indo-Chinese border.

It has been described and illustrated by many authors including Sasaji (1971), Kuznetsov (1997), Ren et al. (2009), Yu (2010) and Ślipiński et al. (2020). Sasaji (1981) carried out crossing experiments with the polymorphic forms. Koch (2003) reviewed its biology, use in biocontrol and non-target impacts. Numerous papers have been published in recent years about its invasive potential and not mentioned here.