Pollen as an alternative food for Harmonia axyridis

Abstract

The current study examines the potential of the multicoloured Asian lady beetle Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) to use pollen as a food to sustain development and reproduction in the absence of insect prey. Three populations of H. axyridis were used in this study: a long-term laboratory population (since 1998) and a melanic and non-melanic population originating from field collected individuals in Belgium. The insects were allowed to develop and reproduce on frozen eggs of Ephestia kuehniella Zeller (Lepidoptera: Phycitidae), frozen moist bee pollen or an even mixture of the two. Females of the field population offered the mixed diet initiated oviposition sooner than those fed only E. kuehniella eggs, but other developmental and reproductive traits were similar on these diets. A diet of pollen alone allowed 35-48% of the larvae of the field population of H. axyridis to successfully reach adulthood. However, developmental time for these individuals was prolonged by 31-49% and adult body weight was reduced by 37-68%, compared to individuals offered the diets containing E. kuehniella eggs. When fed exclusively on pollen in their larval and adult life, about 40% of the adult females of either field population were able to produce a small number of viable eggs. The laboratory and field strains differed in their response to diet for a number of developmental and reproductive traits. The exploitation of pollen and other plant foods at times when insect prey is scarce, may offer a further competitive advantage to the non-indigenous coccinellid H. axyridis over native European predatory lady beetles that share the same niche and are less capable of using pollen as an alternative food

Dealing with food shortage: larval dispersal behaviour and survival on non‐prey food of the hoverfly Episyrphus balteatus

“…Similar effects of a non-prey diet were observed for ladybird and lacewing development. These larvae survived well on non-prey diets, but development was prolonged or not completed (Limburg & Rosenheim, 2001;Berkvens et al, 2008;Meissle et al, 2014). Interestingly, E. balteatus larval weight and survival did not differ between the different types of non-prey diet (honey, pollen, honey + pollen), indicating that none of the non-prey diets, whether protein-rich, sugar-rich or containing ample protein and sugar, was more suitable for larval survival than any of the others.…”

Do flower mixtures with high functional diversity enhance aphid predators in wildflower strips?

“…Leucanthemum vulgare is typically visited by hoverfl ies, ladybeetles and lacewings (Ricci et al, 2005;Carrié et al, 2012;Wäckers & Van Rijn, 2012), because it is a rich source of nectar and pollen (Brodie et al, 2015). This resource might be of particular benefi t to ladybeetles, for which pollen is one its most nutritious nonprey food sources, enabling them to complete their development and survive when prey are scarce (Berkvens et al, 2008;Lundgren, 2009).…”

Predators and parasitoids of the harlequin ladybird, Harmonia axyridis, in its native range and invaded areas

“…Harmonia axyridis, for example, may switch among various kinds of prey or plant food (pollen, nectar, fruit) (Koch 2003;Lucas 2012). Many aphids and other hemipterans (Adelgidae, Psyllidae, Aleyrodidae), and even pollen were found to be essential food for this species (Berkvens et al 2008;Hodek and Honȇk 2009;Hodek and Evans 2012). Despite this broad polyphagy, H. axyridis can be regarded as principally aphidophagous (Koch 2003), and therefore we restrict the usage of the term ''intraguild predators of H. axyridis'' to other primarily aphidophagous species that can also prey on H. axyridis.…”