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1. Adaptations of Coccinella magnifica, a myrmecophilous coccinellid to aggression by wood ants (Formica rufa group). II.. Larval behaviour, and ladybird oviposition location1

Creator:
Sloggett, John J. and Majerus, Michael E.N.
Type:
article, model:article, and TEXT
Subject:
occinella magnifica, Coccinella septempunctata, Formica rufa, ant-tended aphids, myrmecophily, and oviposition
Language:
English
Description:
Like adults, larvae of the myrmecophilous ladybird Coccinella magnifica are rarely attacked by Formica rufa ants on foraging trails, but more often attacked on ant-tended aphid colonies. Larvae of the non-myrmecophile Coccinella septempunctata, to which C. magnifica was compared, were more readily attacked by ants in both situations. To avoid or counter ant aggression when foraging for aphids, C. magnifica larvae exhibit three main tactics: they may feed on un- or non-tended aphids; when feeding on tended colonies they often carry prey away, minimising time spent there; and if attacked, they use limited chemical defence. No novel behaviours were found in C. magnifica larvae, not occurring to some extent in C. septempunctata. Coccinella magnifica eggs were laid distant to ant-tended aphids, although closer to un- or non-tended aphids.
Rights:
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2. Adaptive preferential selection of female coccinellid hosts by the parasitoid wasp Dinocampus coccinellae (Hymenoptera: Braconidae)

Creator:
Davis, Dexter S., Stewart, Sarah L. , Manica, Andrea, and Majerus, Michael E.N.
Type:
article, model:article, and TEXT
Subject:
Parasitoidism, host discrimination, host sex, Dinocampus coccinellae, Braconidae, Coccinella septempunctata, and Coccinellidae
Language:
English
Description:
Females of the parasitoid wasp Dinocampus coccinellae are known to parasitise both male and female coccinellid hosts. It is suggested that female hosts provide more resources for developing wasp larvae because they tend to be larger than male hosts, and female coccinellids have a much greater food intake than males. Thus the wasp's lifetime reproductive success should be increased by ovipositing preferentially in female rather than male hosts when given a choice. Laboratory experiments, using Coccinella septempunctata as a host, show that such a preference does exist. Wasps preferentially oviposit in females, and this preference is not simply a result of the larger mean size of females compared to males. These results corroborate higher rates of prevalence in female compared to male hosts reported previously.
Rights:
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3. Effects of larval diet on female reproductive output of the European coccinellid Adalia bipunctata and the invasive species Harmonia axyridis (Coleoptera: Coccinellidae)

Creator:
Ware, Remy L., Yguel, Benjamin, and Majerus, Michael E.N.
Type:
article, model:article, and TEXT
Subject:
Adalia bipunctata, aphidophagous guilds, cannibalism, Coccinellidae, Harmonia axyridis, intraguild predation, invasive species, larval diet, oviposition, ovariole number, reproductive fitness, and resource competition
Language:
English
Description:
Cannibalism and intraguild predation (IGP) are both common phenomena amongst aphidophagous coccinellids and serve as vital alternative feeding strategies which can prolong survival during periods of aphid scarcity. A reduction in essential prey density and the acceptance of conspecific or heterospecific prey are likely to have a considerable influence on both larval development and adult reproduction. However, little is known about the legacy of larval diet on adult performance. This paper considers the effects of the diet provided to larvae of Harmonia axyridis (Pallas) and Adalia bipunctata (Linnaeus) (Coleoptera: Coccinellidae) on the reproductive output of the resulting females. Results showed that larval diets, including treatments analogous to competition and IGP, did not affect adult longevity, ovipositional lag, proportion of eggs laid in clutches or ovariole number in H. axyridis or A. bipunctata. However, some variation in the maximum clutch size and oviposition rate was seen. A larval diet of unlimited aphids resulted in the largest clutches of eggs being laid by both species. The total number of eggs laid over 30 days was largest for H. axyridis when larvae were reared on unlimited aphids or limited aphids supplemented with either conspecific or heterospecific eggs, whereas oviposition was lower for A. bipunctata females that had received conspecific or heterospecific eggs in their larval diets. The results have also enabled us to make some general comparisons of reproductive parameters between the two species, and to refute the hypothesis that the maximum clutch size laid by a female ladybird is limited by the number of ovarioles within an ovary. We conclude that IGP of A. bipunctata eggs by H. axyridis larvae has a positive effect on reproductive output and is therefore likely to further contribute to the spread and increase of H. axyridis in Britain.
Rights:
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4. Spatial variation in the incidence of a sexually transmitted parasite of the ladybird beetle Adalia bipunctata (Coleoptera: Coccinellidae)

Creator:
Webberley, K Mary, Tinsley, Matthew C., Sloggett, John J. , Majerus, Michael E.N., and Hurst, Gregory D.D.
Type:
article, model:article, and TEXT
Subject:
Coccinellidae, Adalia bipunctata, Coccipolipus hippodamiae, sexual transmission, voltinism, and Hesperomyces virescens
Language:
English
Description:
Whilst sexually transmitted pathogens and parasites are common on insects and other animals, the factors affecting their incidence are currently uncertain. In order to understand the factors important in determining the presence of sexually transmitted parasites, it would be helpful to have information on intraspecific variation in incidence, as the causes of this variation are likely to reflect the likely causes of the presence/absence of sexually transmitted parasites across species. We therefore mapped the incidence of the parasite Coccipolipus hippodamiae within Europe on its primary host, the ladybird Adalia bipunctata. We observed that C. hippodamiae was present widely in Central, Southern and Eastern Europe, but was absent from northerly and north-western populations. The cause of this pattern of incidence variation is discussed, with particular reference to the voltinism of the host. We also note that the distribution of C. hippodamiae on A. bipunctata is not congruent with that of another sexually transmitted parasite of this species, Hesperomyces virescens.
Rights:
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5. Temporal effects of multiple mating on components of fitness in the two-spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae)

Creator:
Haddrill, Penelope R., Shuker, David M., Mayes, Sean , and Majerus, Michael E.N.
Type:
article, model:article, and TEXT
Subject:
Coccinellidae, Adalia, behaviour, cost of mating, ladybird, polyandry, sexual selection, and sexual conflict
Language:
English
Description:
Insects have provided much of the best evidence to date concerning possible costs and benefits of multiple mating, and here we investigate the benefits of polyandry in the two-spot ladybird, Adalia bipunctata, by attempting to replicate the highly promiscuous mating system in this species. We compared the temporal pattern of reproductive success of females mated multiple times to one male with that of females mated an equal number of times to multiple males, and found transient differences in offspring production and hatch rate over time. Our data suggest that polyandrous females benefit from multiple mating in some circumstances, but the patterns are complex. Following how both the costs and benefits to mating accrue over time will be necessary if we are to fully understand why polyandry evolves.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public