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1. For this study a cohort of melanic Harmonia axyridis males homozygous for the spectabilis allele was produced. These were used to produce four kinds of twice‐mated females, comprising all four permutations of melanic and non‐melanic (succinic) males. A series of 12 larvae were then reared from the first and 10th clutches of each female to compare progeny developmental phenotypes. 2. There were no effects of mating treatment on overall female reproductive performance (preoviposition period, 20‐day fecundity, or egg fertility). 3. Age‐specific maternal effects were evident in progeny developmental phenotypes; larvae of 10th clutches developed more slowly, pupation was shorter, and adults emerged at heavier weights. 4. Paternal effects were superimposed on maternal effects and affected progeny independent of their paternity; melanic males induced slower larval development and slower pupation, but only in 10th clutches and only when they mated second. 5. There was a significant three‐way interaction between male mating treatment, clutch number and progeny phenotype, indicating that progeny developmental responses to (mixed) paternal effects varied depending on their own phenotype and the time elapsed since their mother's last mating. 6. Melanic males mating second obtained a P2 advantage over succinic males, which increased from first to 10th clutch, but the reverse was not true when succinic males mated second. Thus, polyandry in H. axyridis facilitates both genetic and epigenetic competition among males while simultaneously enabling the sharing of predominant paternal effects among the progeny of different fathers. [ABSTRACT FROM AUTHOR]

1. The fitness impacts of two levels of superparasitism were compared in a sexual and an asexual strain of Lysiphlebus fabarum (Marshall) developing in black bean aphids. 2. Asexual females were larger than sexuals, had higher eggs loads, and better adult emergence in two of three treatments, but parasitised fewer available aphids in 24 h (80% fewer when foraging alone). 3. Superparasitism resulted in wasps that were larger than those emerging from singly parasitised aphids, and asexual females had larger ovaries, without delayed development. In contrast, sexual wasps took about 2 days longer to develop in superparasitised hosts, and females had smaller ovaries with lower egg loads. 4. The growth of host aphids bearing asexual larvae was not reduced relative to healthy aphids, except when heavily superparasitised, whereas sexual larvae reduced aphid growth in all treatments. 5. Elimination of supernumerary larvae was virtually complete at 4.5 days after parasitism by sexual females, but no elimination occurred among asexual larvae. The evolution of diminished aggression in asexual larvae may be facilitated by greater genetic similarity, without necessarily leading to gregarious development, assuming the extended life of supernumeraries somehow improves survivor fitness. 6. Sons of virgin sexual females developed faster than sons of mated females, implicating parental effects that slowed development of the latter. 7. It is concluded that asexual females of this strain use superparasitism to improve host quality, and thus the fitness of their daughters, whereas females of the sexual strain prioritise offspring number. [ABSTRACT FROM AUTHOR]

1. The fertility restoration hypothesis posits that polyandry can evolve when female fertility is reduced by matings with related males, but restored by matings with unrelated ones. 2. Using a promiscuous ladybird, this hypothesis was tested by mating mature, virgin females twice with sib and non-sib males in all four permutations and observing female fertility. The development of progeny from the first and 10th clutches was also followed to test for differences in paternal effects. 3. Mating treatment did not affect fecundity, but egg viability was reduced by sib matings, and restored by non-sib matings, regardless of mating sequence. In addition, negative paternal effects of sib matings on progeny (lower survival) were compensated by non-sib matings. 4. The survival of offspring in first clutches was sensitive to the paternal mating sequence and was higher if a sibling male was preceded by a non-sib male, compared with the reverse, consistent with a time lag in response to male epigenetic signals. Offspring survival did not differ between these two treatments in the 10th clutch, suggesting a blending of paternal effects over time. 5. The results are indicative of interactions between the paternal effects contributed by different males, and between paternal and maternal effects, the latter causing faster development in later clutches. 6. Thus, the reproductive benefits of polyandry for H. convergens females are potentially both genetic and epigenetic, as both egg fertility and beneficial paternal effects were diminished by sib matings, but restored by matings with unrelated males. [ABSTRACT FROM AUTHOR]

Maternal effects can modify progeny phenotypes to improve their survival under variable conditions, such as changes in food supply. In aphidophagous coccinellids, maternal effects can influence egg size, developmental rate, and final adult body size., Four cohorts of Coleomegilla maculata De Geer larvae were reared from four different points in their mothers' reproductive lives (1st, 12th, 24th, and 36th oviposition days) and divided into two diet treatments for rearing; 30-min daily access to eggs of Ephestia kuehniella Zeller or ad libitum., Progeny survival was lower on restricted food but increased over the first 12 oviposition days in both treatments, suggesting mothers did not conform to the theoretical norm of producing their 'best' progeny first., Larval development was delayed on the restricted diet, but there was no effect of oviposition day on total developmental time, although pupation was faster in the final cohort than in the first., The results suggest that mothers employ a mixed strategy and produce subsets of progeny that vary in response to food limitation. A small fraction adopt an 'optimistic' strategy and undergo an additional instar to take advantage of any possible improvement in the food supply, whereas a larger fraction adopt a 'pessimistic' strategy, forgoing an instar and the costs of a moult to pupate at a small size., The restricted diet increased the percentage of larvae that added or subtracted an instar, but larvae from later clutches were more likely to pupate after only three instars, independent of treatment, suggesting that a larger proportion of later-hatching progeny are maternally programmed for pessimism, as would be adaptive for larvae exploiting aphid populations in decline. [ABSTRACT FROM AUTHOR]

1. We observed native populations of Harmonia axyridis (Pallas) around Beijing, China, over 2 years and performed choice and no-choice mating tests between melanic and succinic (non-melanic) beetles in the laboratory. 2. Succinic phenotypes outnumbered melanics by 5:1 in autumn, but melanics became equally abundant in spring, supporting previous inferences that melanism is advantageous in winter, but costly in summer. 3. Female H. axyridis expressed mate preference overtly, by rejecting less-preferred phenotypes, and cryptically, by retaining their eggs for longer periods after matings with less-preferred males, ostensibly to replace their sperm. 4. Succinic pairs formed more quickly in the spring generation, and melanic pairs in the autumn, and the time to copula was affected by both male and female phenotype. The strength of mate preference was contingent on female phenotype, suggesting melanic alleles had pleiotropic effects. 5. Whereas pair formation was under female control, the duration of copula was under male control and lasted longer in the autumn generation than in the spring. Copulations in the choice test tended to be shorter between similar phenotypes, suggesting that males invested more in dissimilar females when alternative mates were available. 6. Although spring and autumn generations were raised under identical conditions, significant contrasts were observed in their reproductive behaviour. 7. Two alternative hypotheses are advanced to explain why gender-specific reproductive behaviours might vary between generations: maternally-mediated epigenetic factors that influence the expression of genes in progeny as a function of maternal environment, and linkage disequilibria among alleles that cycle in frequency seasonally as a function of assortative mating. [ABSTRACT FROM AUTHOR]