EUROPEAN JOURNAL OF ENTOMOLOGY

Eur. J. Entomol. 107 (2): 189-195, 2010 | DOI: 10.14411/eje.2010.025

Alternative foods for the multicoloured Asian lady beetle Harmonia axyridis (Coleoptera: Coccinellidae)

Nick BERKVENS¹, Carmen LANDUYT¹, Koen DEFORCE², Dirk BERKVENS^3,4, Luc TIRRY¹, Patrick DE CLERCQ^*,1

¹ Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; e-mails: Nick.Berkvens@UGent.be; carmenlanduyt@yahoo.co.uk; Luc.Tirry@UGent.be; Patrick.DeClercq@UGent.be

² Flemish Heritage Institute, Koning Albert II laan 19 bus 5, B-1210 Brussels, Belgium; e-mail: koen.deforce@rwo.vlaanderen.be

³ Department of Animal Health, Prince Leopold Institute of Tropical Medicine, Nationalestraat 155, B-2000 Antwerp, Belgium; e-mail: dberkvens@itg.be

⁴ Department of Animal Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium

The multicoloured Asian lady beetle Harmonia axyridis (Coleoptera: Coccinellidae) may potentially exploit a range of "alternative" food sources. The nutritional value of three common non-prey food groups, i.e. fruit, fungi and pollen, is examined in this study. Development, reproduction and survival of the species were assessed in the laboratory on diets of apple, pear and raspberries and the fungi Oidium lycopersicum, Botrytis cinerea, Sclerotinia sclerotiorum and Rhizoctonia solani. When fed exclusively on these foods this ladybird failed to complete its development or reproduce. However, larval and adult survival was prolonged by 4 to 8 days and 55 to 67 days, respectively, when fruit was offered compared with only water. During a field study H. axyridis adults were collected monthly from March to October at two locations near Ghent, Belgium. Gut analysis demonstrated that, despite the continued presence of aphids, over 90% of all the adults collected contained pollen throughout the year. The pollen belonged to 53 different pollen types. Monthly average numbers of pollen grains in the gut varied from 5 to 233 grains. In contrast, there were about 35,000 grains in the guts of H. axyridis females that successfully developed and reproduced in the laboratory on diet that consisted of only pollen. This suggests that in the field in the majority of cases pollinivory mainly only provided complementary nutrients for this coccinellid. The use of alternative non-prey foods like pollen and fruit may play a role in sustaining populations of this coccinellid at times when the optimal prey is absent.

Keywords: Coccinellidae, Harmonia axyridis, invasive species, development, frugivory, fungivory, pollinivory, reproduction

Received: November 16, 2009; Revised: January 14, 2010; Accepted: January 14, 2010; Published: April 15, 2010  Show citation