Response of passerine birds and chicks to larvae and pupae of ladybirds

Abstract

1. Few, if any, experimental tests have demonstrated the anti‐predator protection of the developmental stages of ladybirds (Coleoptera: Coccinellidae) against vertebrates, despite the fact that both the visual appearance of ladybirds and the content of defensive compounds fulfil the definition of an aposematic prey. 2. In this study, avian predators of three species were confronted with fourth‐instar larvae and pupae of the harlequin ladybird (Harmonia axyridis) – a large, conspicuous, and toxic ladybird species. 3. The selected predators differed in their individual experience and attitude to ladybirds. Wild‐caught great tits (Parus major) strongly avoided attacking ladybirds in general, whereas wild‐caught tree sparrows (Passer montanus) were willing to include ladybirds in their diet. Domestic chicks (Gallus gallus domesticus) have never been confronted with ladybirds but usually show avoidance of aposematic signals. In this study, great tits and domestic chicks avoided both developmental stages, but in the case of chicks the avoidance had to be learned over the course of repeated encounters. Sparrow avoidance was significantly lower, with more than one‐third of the prey being attacked and eaten. 4. The protection of both developmental stages of ladybirds is similar to adults, despite substantially different visual appearance.

Attacks by predators on artificial cryptic and aposematic insect larvae

“…The results of the current study confirm the avoidance of H. axyridis larvae by experienced wild birds during the breeding season, and in an aviary by naïve birds, and quantify the predation rate of aposematic larvae in comparison to less aposematic and cryptic larvae. In the same study (Aslam et al, ), tree sparrows attacked and ate moderate numbers of ladybird larvae. It was previously shown that P. montanus ate ladybirds without significant physiological problems, whereas cadavers of P. major from the same experiments showed evidence of severe liver damage (Kristin, ; Marples et al, ).…”

“…Even closely related species may have different impacts on populations of aposematic prey owing to specific foraging strategies (Brower, ) or may differ in the origin of avoidance (Exnerová et al, ). In our previous laboratory experiment, experienced great tits captured in winter often avoided larvae of H. axyridis (Aslam et al, ). The results of the current study confirm the avoidance of H. axyridis larvae by experienced wild birds during the breeding season, and in an aviary by naïve birds, and quantify the predation rate of aposematic larvae in comparison to less aposematic and cryptic larvae.…”

“…Few, if any, experimental tests have demonstrated the anti‐predator protection of the developmental stages of ladybirds against vertebrates. Only a recent study showed that the predators – experienced P. major and naïve Gallus gallus domesticus (L.) – avoided both Harmonia axyridis (Pallas) larvae and pupae (Aslam et al, ) in winter cage experiments, whereas avoidance of adult H. axyridis was well known before (Marples et al, ; Dolenska et al, ; Průchová et al, ; Veselý et al, ). In contrast to our previous study, the current study focuses on the importance of the full and partial aposematism for naïve and experienced birds in the wild, for the first time.…”

Pupal Warning Coloration of Three Species of Cystidia (Lepidoptera: Geometridae: Ennominae) in Relation to Their Pupation Sites

“…Only a few insects have been proven to be warning colors. One is the toxic two-spotted ladybird beetle, Adalia bipunctata (Linnaeus, 1758), which has warning colors at all stages of its life cycle [ 9 ], and the other is the unpalatable moth, Ivela auripes (Butler, 1877), which pupates at the exposed sites such as tree trunk and rock surface above the ground and displays the conspicuous yellow pupal body with seven longitudinal stripes of blackish dots [ 10 ].…”

Intraspecific and Interspecific Comparison of Toxicity of Ladybirds (Coleoptera: Coccinellidae) With Contrasting Colouration

“…Coccinella septempunctata caused toxic effects and resulted in severe liver damage in the nestlings of blue tits Cyanistes caeruleus [6]. Other studies of bird-ladybird interactions showed strong repellence effect precluding feeding the beetles and thus manifestation of their real toxicity (by tits Parus major, domestic chicks) or no effect after ingestion (in sparrow Passer montanus [10]). Ladybird re ex blood has been also found distasteful to ants [7,11,12].…”