Research in Action South African Journal of Science 103, March/April 2007 123 adults and larvae of an unfamiliar lady- Discovery of an alien invasive, bird beetle species were collected from wheat. These beetles attracted attention predatory insect in South Africa: the as both larvae and adults were numerous and were clearly efficient predators of all multicoloured Asian ladybird beetle, the aphid species on wheat at the time. The beetles were positively identified as Harmonia axyridis (Pallas) HA at the South African National Collec- (Coleoptera: Coccinellidae) tion of Insects (SANC), Pretoria. Voucher specimens have been deposited in the SANC, the Transvaal Museum (TMSA), Riaan Stalsa* and Goddy Prinsloob Pretoria, and the Iziko South African Museum (SAMC), Cape Town. This species was previously observed, HE ASIAN LADYBIRD BEETLE, HARMONIA because it preys voraciously on diverse but not collected, at Tygerhoek in Sep- axyridis (HA) (Insecta: Coleoptera: pestiferous aphids and other soft-bodied tember/October 2004, when fairly large TCoccinellidae), is a generalist predator long arthropod pests on various cultivated numbers of aphids were present on valued as a biocontrol agent of pestiferous crops.6–9 Recently, it began ‘changing’ its aphids and other invertebrates. However, HA wheat. They were not detected during has become highly invasive in North America spots to emerge as a potentially invasive 2005, when aphid infestations were very 6,7,9,10 and Europe. The beetle is eurytopic, broadly and harmful organism. low. In October 2006, adults, larvae and polyphagous, very dispersive and pheno- The main aim of this paper is to record eggs (field-collected and positively associ- typically highly plastic. In the United States the presence and apparent establishment ated through laboratory rearing) were and Europe, this pest is implicated in adverse of the beetle in South Africa. To facilitate found. Copulation was observed in the ecological impacts involving changes in its recognition, we present a brief descrip- field. From these observations combined invaded communities through interspecific tion and photographs of HA and compare we infer that a population of HA has competition and intraguild predation. Addi- it to resident Coccinellidae with which it tionally, HA can be a household nuisance, and established and is reproducing at Tyger- affect human health and agricultural produc- may be confused. Initial field observa- hoek. In November 2006, large numbers tion. The beetle has now reached South Africa. tions in South Africa are outlined, and the of HA were encountered on durum A founder population has become established principal features of the invasiveness of wheat at Tygerhoek. Incidental observa- in the Western Cape province, and the species HA as observed in the northern hemi- tion did not reveal the beetle on plants has also been collected in the Eastern Cape sphere are summarized. We consider other than cereals. HA individuals were province. We present illustrated diagnoses of future studies of the insect in South Africa observed intermingling freely with an- HA and selected resident South African to be imperative. other aphidophagous ladybird beetle, the Coccinellidae with which it may be confused. The voluminous literature on HA has There is reason to suspect that HA will spread naturalized Hippodamia (Adonia) variegata rapidly through much of South Africa and been reviewed three times in the recent (Goeze). 6,7,9 beyond and bring to bear its negative conse- past. More generally, the use of preda- In March 2007, the SANC identification quences here. The early detection of this in- tory Coccinellidae in classical biological service received HA specimens collected cursion presents a rare opportunity to study control has also recently been reviewed at in the Eastern Cape province, in Capisicum an anticipated biological invasion virtually least three times.10–12 In even broader plantations on two farms in the Bellmont from its beginning. terms, the ecological effects of invasive Valley, about 10 km east of Grahamstown. arthropod generalist predators, including This is more than 600 km east of Tyger- Introduction HA and other Coccinellidae, were re- hoek. On Varnam Farm (33°19’30”S, Invasions of ecosystems by non-native viewed most recently by Snyder and 26°38’05”E), HA were captured in No- organisms are accelerating due to a Evans.13 Avoiding undue repetition, we vember 2005, October 2006 and March burgeoning human population and rising, refer the reader to these reviews and their 2007, and on Lower Melrose Farm rapid human movement and the global substantial reference lists. Recurrent both (33°19’45”S, 26°38’40”E), in May 2006 (C. 1,2 transportation of goods. Little is known in these reviews and in the pertinent Hepburn, pers. comm.). about the vast number of species that primary literature is a polarization of Upon enquiry among coccinellid experts have spread throughout the world, inten- opinions: in strict terms, whether HA is a worldwide, it came to light that at least tionally or inadvertently introduced to valuable biocontrol agent or a pest; and, 1,3 one HA specimen had been collected in new areas by humankind. One such more broadly,whether generalist predators South Africa previously (H. Fürsch and species is the multicoloured Asian ladybird are at all suitable in classical biological M. Uhlig, pers. comms). This specimen, beetle, or harlequin ladybird beetle, Har- control of invertebrate pests, or not. deposited in the Natural History Museum monia axyridis (Pallas, 1773) (Coleoptera: Participation in these debates is beyond of the Humboldt University, Berlin, Coccinellidae). Harmonia axyridis (HA) the scope of the present paper. Germany, was collected in December exemplifies what has somewhat brazenly 2002, 30 km NW of Swellendam, Western been termed the ‘Achilles’ heel of classical Discovery of Harmonia axyridis in Cape (33°54’S, 20°11’E), which is c. 40 km biological control’, namely, non-target South Africa 4–7 NW of Tygerhoek. The substantial collec- effects. HA is valued and exploited The non-native ladybird beetle Harmonia tions of both identified and unidentified axyridis apparently has become estab- Coccinellidae in the SANC and the TMSA aNational Collection of Insects, ARC-Plant Protection Research Institute, Private Bag X134, Queenswood, lished in South Africa. In mid-October were scoured for additional specimens of Pretoria 0121, South Africa. 2006, on the Tygerhoek Experimental HA, but none was found. The SAMC bPlant Protection Division, ARC-Small Grain Institute, Private Bag X29, Bethlehem 9700, South Africa. Farm (34°09’12”S, 19°54’15”E), Rivier- holds no specimens of HA identified as *Author for correspondence. E-mail: [email protected] sonderend, Western Cape province, such (M. Cochrane, pers. comm.), but we 124 South African Journal of Science 103, March/April 2007 Research in Action have not yet had the opportunity to study the unidentified Coccinellidae there. This is the first report of HA being pres- ent in the field in South Africa. Currently, we do not know whether the beetle is restricted to the aforementioned localities or whether it is more widespread. Inci- dental observation in October 2006 near Caledon (c. 34°12’S, 19°20’E), about 60 km WSW of Tygerhoek, failed to reveal HA. Also unknown is how long HA has been in South Africa, how it gained entry to the country, and whence it originated. Our confirmation of HA’s presence in South Africa is of considerable concern, given its potentially aggressive and invasive nature, as is presently being evaluated and documented in North America and Europe.6,8,14–24 Identity, prey and geographical distribution of Harmonia axyridis Figs 1–6. Dorsal views of the alien ladybird beetle species Harmonia axyridis (Pallas) and some resident South Harmonia axyridis is a ‘typical’ member African Coccinellidae with which it may be confused. 1, H. axyridis, fully spotted colour form. 2, H. axyridis, of the beetle family Coccinellidae, sub- virtually spotless colour form. 3, Cheilomenes lunata (Fabricius), yellow colour form. 4, Harmonia family Coccinellinae, tribe Coccinellini. It vigintiduosignata (Mulsant), spotted colour form. 5, Hippodamia (Adonia) variegata (Goeze), nine-spotted colour form. 6, Henosepilachna bifasciata (Fabricius). Scale bars = 1 mm. Arrows on Figs 1, 2: top arrows: the is primarily an arboreal species, but in its yellowish-white oval areas at the sides of the pronotum; bottom arrows: the transverse ridges above the elytral expanded range common also in an array apices. of field crops.6,7 As are all Coccinellinae, HA is predatory, and, as is typical for the Appearance and recognition of spottilessness (Figs 1, 2). No black speci- Coccinellini, aphids (Hemiptera: Sternor- Harmonia axyridis mens have yet been found in South Af- rhyncha: Aphididae) are the essential The following brief descriptions of the rica. prey of both adults and larvae.11,25 HA is, adults and late-instar larvae of HA are Two species of the genus Harmonia however, not solely aphidophagous, but based on those of Koch7 and of Gordon Mulsant are native to South Africa, namely is a generalist predator. It can develop on and Vandenberg.34 H. vigintiduosignata (Mulsant) and H. par- foods with very different biochemical Adult HA (Figs 1, 2) are 4.9–8.2 mm dalina (Gerstaecker). The appearance of composition.26 The beetle has been re- long and 4.0–6.6 mm wide. The body is the former (Fig. 4) is also highly variable, corded feeding on various other Sternor- strongly convex, subcircular in outline, and it primarily inhabits the eastern, rhyncha, Acari, eggs of Chrysopidae glossy and hairless. Dorsal colouration mesic regions of South Africa. Harmonia (Neuroptera), Lepidoptera eggs and and markings are highly variable. The pardalina is scarce in local collections, and larvae, and immature stages of Coleoptera pronotum bears black central markings of occurs from the Limpopo province north- (significantly including other coccinellid up to five spots, two curved lines, fre- wards.