Body Size and Flight Activity Effects on Male Reproductive Success in the Pitcherplant Mosquito (Diptera: Culicidae)

Facultative sex ratio manipulation has been examined in a limited number of diploid species, mainly vertebrates. We tested the prediction that mothers would preferentially place males in conditions conducive to large size in the diploid pine engraver bark beetle, Ips pini. In this species, males are the larger sex and therefore male reproductive success was expected to be more dependent on body size than female reproductive success. Because body size is largely environmentally determined in bark beetles, mothers were expected to alter sex ratios in response to habitat quality. Contrary to predictions, offspring sex ratios tended to be more female biased in situations conducive to large offspring size than in situations producing offspring of small size. We were able to rule out nonadaptive explanations such as differential mortality or development times of males and females, suggesting that the observed pattern is adaptive. This study provides a rare example of sex ratio manipulation in diploid insects. However, the unexpected direction of sex ratio biases suggests that daughters gain a yet unknown benefit from being reared in high-quality conditions that surpasses the fitness that would be gained from producing relatively larger sons.

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Floral Resources Enhance Fecundity, but Not Flight Activity, in a Specialized Aphid Predator, Hippodamia convergens (Coleoptera: Coccinellidae)

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.748870 ◽

2021 ◽

Vol 9 ◽

Author(s):

Hannah E. Stowe ◽

J. P. Michaud ◽

Tania N. Kim

Keyword(s):

Body Size ◽

Reproductive Success ◽

Prey Availability ◽

Flight Activity ◽

Flight Behavior ◽

Floral Resources ◽

Adult Survival ◽

Adult Size ◽

Hippodamia Convergens ◽

Adult Diet

Adult aphid predators disperse across the landscape seasonally in search of prey aggregations that are patchily distributed and temporally variable. However, flight is energetically costly and consumes resources that could be invested in reproduction. Hippodamia convergens is an important aphid predator in North American cereal crops and other agricultural systems. Consumption of floral resources can enhance adult survival during periods of low prey availability and may improve reproductive success. We tested how an omnivorous adult diet containing floral resources (diluted honey and pulverized bee pollen) interacts with body size to influence reproduction and flight behavior compared to a prey-only diet. Two sizes of beetles were produced by controlling larval access to food—3 h daily access produced small beetles; ad libitum access produced large beetles with faster development. Reproductive performance was tracked for 18 days, and female flight activity was assayed via 3 h bouts of tethered flight. Diet composition and body size interacted to influence preoviposition period, with large females in prey-only treatments delaying oviposition the longest. The omnivorous adult diet improved 18-day fecundity relative to a prey-only diet, but egg fertility was unaffected. Adult size affected oviposition pattern, with small beetles laying smaller, but more numerous, clutches. Females flew up to 7 km in 6 h, but neither body size nor adult diet influenced flight distance, suggesting that all diet treatments generated energy reserves sufficient to power flights of short duration. However, pre-reproductive females flew > 60% further than they did post-reproduction, likely due to the energetic costs of oviposition. Thus, access to pollen and nectar increased reproductive success and altered oviposition patterns in H. convergens, indicating the importance of floral resources in the agricultural landscape to conservation of this predator and its biological control services.

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Dominance, body size and internal relatedness influence male reproductive success in eastern grey kangaroos (Macropus giganteus)

Reproduction Fertility and Development ◽

10.1071/rd09061 ◽

2010 ◽

Vol 22 (3) ◽

pp. 539 ◽

Cited By ~ 27

Author(s):

Emily J. Miller ◽

Mark D. B. Eldridge ◽

Desmond W. Cooper ◽

Catherine A. Herbert

Keyword(s):

Body Size ◽

Reproductive Success ◽

Serum Testosterone ◽

Male Dominance ◽

Molecular Evidence ◽

Male Reproductive Success ◽

Testis Size ◽

Leg Length ◽

Genetic Traits ◽

Internal Relatedness

Knowledge of the determinants of reproductive success is essential for understanding the adaptive significance of particular traits. The present study examined whether particular behavioural, morphological, physiological or genetic traits were correlated with male dominance and reproductive success using three semi-free-ranging captive populations (n = 98) of the eastern grey kangaroo (Macropus giganteus). The morphological traits measured included bodyweight, head, forearm, tail, pes and leg length, forearm and bicep circumference, and testis size. Blood samples were collected to determine serum testosterone concentrations. All individuals were typed for 10 microsatellite loci and paternity determined for each pouch young. To determine the influence of relatedness and genetic diversity on male reproductive success, internal relatedness, standardised heterozygosity and mean d2 were calculated. Dominant males sired a significantly higher proportion of offspring than smaller, lower-ranked males and had higher testosterone concentrations. Males that sired offspring were significantly heavier and had larger body size. Sires were significantly more heterozygous and genetically dissimilar to breeding females than non-sires. Despite the wealth of knowledge on the social organisation of kangaroos, this is the first study to assign parentage and male reproductive success using molecular evidence.

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Sexual Selection in Dung Beetles .2. Female Fecundity as an Estimate of Male Reproductive Success in Relation to Horn Size, and Alternative Behavioral Strategies in Onthophagus-Binodis Thunberg (Scarabaeidae, Onthophagini)

Australian Journal of Zoology ◽

10.1071/zo9880521 ◽

1988 ◽

Vol 36 (5) ◽

pp. 521 ◽

Cited By ~ 36

Author(s):

D Cook

Keyword(s):

Body Size ◽

Reproductive Success ◽

Mate Guarding ◽

Mating Strategies ◽

Male Reproductive Success ◽

Male Mating ◽

Behavioral Strategies ◽

Alternative Tactics ◽

Female Fecundity ◽

Similar Body

One component of the reproductive success (fitness) of Onthophagus binodis Thunberg males was estimated by the number of offspring their mate produced relative to male horn and body size. O. binodis males consist of large horned and small hornless morphs. Female fecundity was significantly increased when reproducing with: (1) large horned males compared with small hornless males; (2) the horned morph compared with the hornless morph of males with similar body size. Horned males cooperating with females invest a considerable effort in providing each egg with dung. Hornless males do not appear to assist females after mating. Alternative male mating strategies are predicted under intense intrasexual competition. As hornless O. binodis males persist in large numbers alongside cooperative, mate guarding horned males, selection should favour alternative tactics by hornless males to gain reproductive opportunities.

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Quantitative trait locus mapping of fitness-related traits in Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672300004894 ◽

2001 ◽

Vol 77 (1) ◽

pp. 107-116 ◽

Cited By ~ 43

Author(s):

M. L. WAYNE ◽

J. B. HACKETT ◽

C. L. DILDA ◽

S. V. NUZHDIN ◽

E. G. PASYUKOVA ◽

...

Keyword(s):

Genetic Variation ◽

Body Size ◽

Reproductive Success ◽

Quantitative Trait ◽

Recombinant Inbred Lines ◽

Male Reproductive Success ◽

Female Reproductive Success ◽

Mapping Procedure ◽

Ovariole Number ◽

Early Fecundity

We examined the genetic architecture of four fitness-related traits (reproductive success, ovariole number, body size and early fecundity) in a panel of 98 Oregon-R × 2b3 recombinant inbred lines (RILs). Highly significant genetic variation was observed in this population for female, but not male, reproductive success. The cross-sex genetic correlation for reproductive success was 0·20, which is not significantly different from zero. There was significant genetic variation segregating in this cross for ovariole number, but not for body size or early fecundity. The RILs were genotyped for cytological insertion sites of roo transposable elements, yielding 76 informative markers with an average spacing of 3·2 cM. Quantitative trait loci (QTL) affecting female reproductive success and ovariole number were mapped using a composite interval mapping procedure. QTL for female reproductive success were located at the tip of the X chromosome between markers at cytological locations 1B and 3E; and on the left arm of chromosome 2 in the 30D–38A cytological region. Ovariole number QTL mapped to cytological intervals 62D–69D and 98A–98E, both on the third chromosome. The regions harbouring QTL for female reproductive success and ovariole number were also identified as QTL for longevity in previous studies with these lines.

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Experimental and molecular evidence that body size and ventral colour interact to influence male reproductive success in a lizard

Ethology Ecology & Evolution ◽

10.1080/08927014.2006.9522696 ◽

2006 ◽

Vol 18 (4) ◽

pp. 275-288 ◽

Cited By ~ 11

Author(s):

J. Stapley ◽

J.S. Keogh

Keyword(s):

Body Size ◽

Reproductive Success ◽

Molecular Evidence ◽

Male Reproductive Success

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Effects of body size on male mating tactics and paternity in black bears, Ursus americanus

Canadian Journal of Zoology ◽

10.1139/z03-111 ◽

2003 ◽

Vol 81 (7) ◽

pp. 1257-1268 ◽

Cited By ~ 48

Author(s):

Adrienne I Kovach ◽

Roger A Powell

Keyword(s):

Body Size ◽

Reproductive Success ◽

Dna Analysis ◽

Ursus Americanus ◽

Mating Behaviour ◽

Black Bear ◽

Lifetime Reproductive Success ◽

Male Reproductive Success ◽

Male Mating ◽

Mating Tactics

The reproductive behaviour of large, solitary mammals is difficult to study. Owing to their secretive nature and wide-ranging habits, aspects of male mating behaviour are poorly documented in solitary than in social species. We used radiotelemetry and microsatellite DNA analysis to investigate the influence of body size on male mating tactics and short-term reproductive success in the black bear, Ursus americanus, a solitary carnivore. We investigated male ranging behaviour and documented male encounters with breeding females to determine whether males employed conditional mating tactics according to their body sizes. We found that male home-range sizes were not positively associated with body size, but encounter rates with breeding females were. Although all males searched widely for females, mating access appeared to be largely determined by fighting ability. Large males encountered more breeding females and had more frequent encounters during the females' estimated receptive periods than did small- and medium-sized males. Paternity was highly skewed toward the three dominant males who fathered 91% of the cubs sampled during the 3-year study. Paternity was correlated with the frequency of male encounters during female receptive periods. Male encounters, however, overestimated the success of medium-sized males and underestimated the overall variance in male reproductive success. Multiple paternity occurred in two of seven litters, indicating that sperm competition is important in black bear mating behaviour. Implications for male lifetime reproductive success are discussed.

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Postweaning maternal care increases male chimpanzee reproductive success

Science Advances ◽

10.1126/sciadv.aaz5746 ◽

2020 ◽

Vol 6 (38) ◽

pp. eaaz5746

Author(s):

Catherine Crockford ◽

Liran Samuni ◽

Linda Vigilant ◽

Roman M. Wittig

Keyword(s):

Reproductive Success ◽

Parental Investment ◽

Maternal Care ◽

Parental Loss ◽

Male Reproductive Success ◽

Complex Societies ◽

Successful Reproduction ◽

Using Data

Humans are unusual among animals for continuing to provision and care for their offspring until adulthood. This “prolonged dependency” is considered key for the evolution of other notable human traits, such as large brains, complex societies, and extended postreproductive lifespans. Prolonged dependency must therefore have evolved under conditions in which reproductive success is gained with parental investment and diminished with early parental loss. We tested this idea using data from wild chimpanzees, which have similarly extended immature years as humans and prolonged mother-offspring associations. Males who lost their mothers after weaning but before maturity began reproducing later and had lower average reproductive success. Thus, persistent mother-immature son associations seem vital for enhancing male reproductive success, although mothers barely provision sons after weaning. We posit that these associations lead to social gains, crucial for successful reproduction in complex social societies, and offer insights into the evolution of prolonged dependency.

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