Placental weight mediates the effects of prenatal factors on fetal growth: the extent differs by preterm status

Objective:

Elevated pre‐pregnancy BMI, excessive gestational weight gain (GWG), and gestational diabetes mellitus (GDM) are known determinants of fetal growth. The role of placental weight is unclear. We aimed to examine the extent to which placental weight mediates the associations of pre‐pregnancy BMI, GWG, and GDM with birth weight‐for‐gestational age, and whether the relationships differ by preterm status.

Design and Methods:

We examined 1,035 mother‐infant pairs at birth from the Boston Birth Cohort. Data were collected by questionnaire and clinical measures. Placentas were weighed without membranes or umbilical cords. We performed sequential models excluding and including placental weight, stratified by preterm status.

Results:

We found that 21% of mothers were obese, 42% had excessive GWG, and 5% had GDM. Forty‐one percent were preterm. Among term births, after adjustment for sex, gestational age, maternal age, race, parity, education, smoking, and stress during pregnancy, birth weight‐for‐gestational age z‐score was 0.55 (0.30, 0.80) units higher for pre‐pregnancy obesity vs. normal weight. It was 0.34 (0.13, 0.55) higher for excessive vs. adequate GWG, 0.67 (0.24, 1.10) for GDM vs. no DM, with additional adjustment for pre‐pregnancy BMI. Adding placental weight to the models attenuated the estimates for pre‐pregnancy obesity by 20%, excessive GWG by 32%, and GDM by 21%. Among preterm infants, GDM was associated with 0.67 (0.34, 1.00) higher birth weight‐for‐gestational age z‐score, but pre‐pregnancy obesity and excessive GWG were not. Attenuation by placental weight was 36% for GDM.

Conclusions:

These results suggest that placental weight partially mediates the effects of pre‐pregnancy obesity, GDM, and excessive GWG on fetal growth among term infants.     

Colony cycle in the south-eastern coastal populations of Ropalidia plebeiana, the only Ropalidia wasp occurring in temperate Australia

Of the 22 species of Ropalidia occurring in Australia, only R. plebeiana is distributed in temperate areas. This wasp is abundant in the south‐eastern coastal regions of Australia, where it forms huge nest aggregations. Based on our observations in late autumn and early spring, as well as information in the literature, we outline the colony cycle of R. plebeiana in the south‐eastern coastal area of New South Wales. The nesting period lasts for approximately 9.5 months, which is unusually long for temperate polistine wasps. Most foundresses seem to return to their natal nests in early spring (mid‐August to early September) to start their own colonies by reusing pre‐existing nest combs, and the pre‐emergence stage (before the emergence of the first adult brood) lasts for approximately 3.5 months. Reproductives (gynes and males) start to emerge as adults in early March, and the reproductive‐producing period lasts until the end of May. Both the pre‐emergence stage and the reproductive‐producing period are much longer than in other temperate polistine wasps, which is discussed in terms of fluctuating temperature conditions in the area and the formation of nest aggregations, a peculiar habit for temperate populations of R. plebeiana.     

Gestational and early life influences on infant body composition at 1 year

Excess weight gain during both pre‐ and postnatal life increases risk for obesity in later life. Although a number of gestational and early life contributors to this effect have been identified, there is a dearth of research to examine whether gestational factors and weight gain velocity in infancy exert independent effects on subsequent body composition and fat distribution.

Objective:

To test the hypothesis that birth weight, as a proxy of prenatal weight gain, and rate of weight gain before 6 months would be associated with total and truncal adiposity at 12 months of age.

Design and Methods:

Healthy, term infants (N = 47) were enrolled in the study and rate of weight gain (g/day) was assessed at 0‐3 months, 3‐6 months, and 6‐12 months.

Results:

Total and regional body composition were measured by dual‐energy X‐ray absorptiometry (DXA) at 12 months. Stepwise linear regression modeling indicated that lean mass at 12 months, after adjusting for child length, was predicted by rate of weight gain during each discrete period of infancy (P < 0.05), and by maternal pre‐pregnancy BMI (P < 0.05). Total fat mass at 12 months was predicted by rate of weight gain during each discrete period (P < 0.01), and by older maternal age at delivery (P < 0.05). Trunk fat mass at 12 months, after adjusting for leg fat mass, was predicted by rate of weight gain from 0‐3 months and 3‐6 months (P < 0.05).

Conclusion:

Results suggest that growth during early infancy may be a critical predictor of subsequent body composition and truncal fat distribution.     

PNLDC1, mouse pre‐piRNA Trimmer,is required for meiotic and post‐meiotic male germ cell development

PIWI‐interacting RNAs (piRNAs) are germ cell‐specific small RNAs essential for retrotransposon gene silencing and male germ cell development. In piRNA biogenesis, the endonuclease MitoPLD/Zucchini cleaves long, single‐stranded RNAs to generate 5′ termini of precursor piRNAs (pre‐piRNAs) that are consecutively loaded into PIWI‐family proteins. Subsequently, these pre‐piRNAs are trimmed at their 3′‐end by an exonuclease called Trimmer. Recently, poly(A)‐specific ribonuclease‐like domain‐containing 1 (PNLDC1) was identified as the pre‐piRNA Trimmer in silkworms. However, the function of PNLDC1 in other species remains unknown. Here, we generate Pnldc1 mutant mice and analyze small RNAs in their testes. Our results demonstrate that mouse PNLDC1 functions in the trimming of both embryonic and post‐natal pre‐piRNAs. In addition, piRNA trimming defects in embryonic and post‐natal testes cause impaired DNA methylation and reduced MIWI expression, respectively. Phenotypically, both meiotic and post‐meiotic arrests are evident in the same individual Pnldc1 mutant mouse. The former and latter phenotypes are similar to those of MILI and MIWI mutant mice, respectively. Thus, PNLDC1‐mediated piRNA trimming is indispensable for the function of piRNAs throughout mouse spermatogenesis.     

Use of ultrasound to monitor prenatal growth and development in the common marmoset (Callithrix jacchus)

The increasing use of non-human primates to study fetal development and neonatal management has necessitated the availability of fetuses of known gestational history. In this study, prenatal development and growth were investigated in the common marmoset (Callithrix jacchus) using ultrasound. The objectives of this study were: (1) to determine the accuracy of ultrasound for monitoring prenatal growth and development in common marmosets, (2) to determine if litter size influences prenatal growth trajectories, and (3) to assess growth discordancy among litter mates. Fifty pregnancies were monitored longitudinally using real-time abdominal sonography. During each examination the number of fetuses was recorded, and crown-rump length (CRL) and biparietal diameter (BPD) were measured. The results indicate that ultrasound is a reliable method for observation of gross morphological changes during prenatal development in this species. Measures of CRL and BPD taken early in gestation using ultrasound were in agreement with those from gross specimens. Triplets were significantly (P < 0.05) smaller than twins for both BPD and CRL. No significant relationship was found between litter size and within litter variation in CRL or BPD. This study is the first longitudinal investigation of prenatal growth and development in C. jacchus. The observations from this study will be of use for determining approximate gestational age of fetuses, as well as providing guidelines for routine monitoring of pregnancy in this species. © 1995 Wiley-Liss, Inc.     

Influence of larval experience on preference of a subterranean insect Delia antiqua on Allium hosts

Numerous studies have reported that larval experience can affect subsequent host plants selection and future oviposition decisions of many different species, but the investigation of pre‐imaginal experiences on host preference of adults has rarely been tested for soil‐dwelling insects. In this study, we present evidence that larval feeding experience can affect adult host preference in the onion maggot, Delia antiqua. By rearing D. antiqua on different host plants, we were able to examine the role of the natal host of different generations and the effect of larval density on host‐choice behaviour. We also performed bioassays by means of switched host treatment to evaluate the host‐selection principle. Choice bioassays among the three host species demonstrated that D. antiqua females preferred to oviposit on their natal host in each generation and host‐switching treatments. Additionally, increasing larval density could intensify this ovipositional preference on the natal host. The overall results showed that host preference of female D. antiqua is determined by larval experience and density. These findings also add support for the controversial Hopkins’ host‐selection principle.     

Assessing range‐wide conservation status change in an unmonitored widespread African bird species

Aim

With the exception of South Africa there are no systematic, long‐term, large‐scale bird monitoring programmes in Africa, and for much of the continent the most comprehensive available data for most species are incidental occurrence records. Can such data be used to assess range‐wide conservation status of widespread low‐density species? We examine this using Kori Bustard Ardeotis kori, a large, easily identifiable species with an extensive African range.

Location

Southern and East Africa, 14 countries.

Methods

A comprehensive and systematic review of published and unpublished sources provided 1948 unique locality records spanning the years 1863–2009; these included 410 non‐atlas records and 97 historical (pre‐1970) records. Range‐size changes were examined by comparing minimum convex polygons to quantify Extent of Occurrence pre‐ and post‐1970, and by testing whether more historical records fell outside the recent (post‐1970) 95% probability kernel than expected by chance. Additionally, qualitative evidence of changes in abundance was obtained from historical published accounts and contemporary assessments by in‐country experts.

Results

Since the late 19th century, range‐size (measured as Extent of Occurrence) has contracted, by 21% in East Africa and 8% in southern Africa. There is strong qualitative evidence of considerable pre‐ and post‐1970 population declines in all range states, except Zambia (slight increase) and Angola (trend unclear). In some countries, declines occurred from the early 1900s. Thus, while relatively modest change in range‐size has occurred in over 100 years, numbers have greatly reduced throughout the species’ range.

Main conclusions

Our methodology allowed objective appraisal of continent‐wide Kori status. Despite lacking quantitative population estimates and trends, and poor understanding of the species’ autecology, common issues for many African species, incidental occurrence records can be used to assess range‐wide changes in status. We recommend that this or similar approaches be applied to other widespread low‐density species that probably also have rapidly declining populations despite apparently stable range extents.

     

Multi‐locus phylogenetics,lineage sorting,and reticulation in Pinus subsection Australes

Premise of the Study

Both incomplete lineage sorting and reticulation have been proposed as causes of phylogenetic incongruence. Disentangling these factors may be most difficult in long‐lived, wind‐pollinated plants with large population sizes and weak reproductive barriers.

Methods

We used solution hybridization for targeted enrichment and massive parallel sequencing to characterize low‐copy‐number nuclear genes and high‐copy‐number plastomes (Hyb‐Seq) in 74 individuals of Pinus subsection Australes, a group of ~30 New World pine species of exceptional ecological and economic importance. We inferred relationships using methods that account for both incomplete lineage sorting and reticulation.

Key Results

Concatenation‐ and coalescent‐based trees inferred from nuclear genes mainly agreed with one another, but they contradicted the plastid DNA tree in recovering the Attenuatae (the California closed‐cone pines) and Oocarpae (the egg‐cone pines of Mexico and Central America) as monophyletic and the Australes sensu stricto (the southern yellow pines) as paraphyletic to the Oocarpae. The plastid tree featured some relationships that were discordant with morphological and geographic evidence and species limits. Incorporating gene flow into the coalescent analyses better fit the data, but evidence supporting the hypothesis that hybridization explains the non‐monophyly of the Attenuatae in the plastid tree was equivocal.

Conclusions

Our analyses document cytonuclear discordance in Pinus subsection Australes. We attribute this discordance to ancient and recent introgression and present a phylogenetic hypothesis in which mostly hierarchical relationships are overlain by gene flow.     

The effects of host race, gender, and host plant distribution on alighting behavior, mating, and oviposition in Eurosta solidaginis

Eurosta solidaginis Fitch (Diptera: Tephritidae) has formed host races on Solidago altissima L. and Solidago gigantea Ait. (Asteraceae), and reproductive isolation between these host races is brought about in part by host‐associated assortative mating. Any non‐assortative mating creates the potential for gene flow between the populations, and we investigated the conditions that favored non‐assortative mating. We hypothesized that the frequency of non‐assortative mating would be influenced by differences in the behaviors of the host races and sexes and by the presence and pattern of distribution of the two host species. To test these hypotheses, we caged flies on four combinations of 32 potted host plants: all S. altissima, all S. gigantea, and cages with both host species arranged in either two pure species blocks or randomly dispersed. We recorded the number of flies of each host race that alighted on each host species and the frequency of mating within and between the host races. Males of both host races were observed on plants more frequently than females. Flies of the host race from S. gigantea (gig flies) were observed on plants in greater absolute numbers, and they mated more frequently than flies of the host race from S. altissima (alt flies). In all treatments, gig flies of both sexes were found on non‐natal host plants significantly more frequently than alt flies, and gig females showed a weaker preference for their host species than did gig males or alt flies of either gender for their respective natal hosts. Assortative mating predominated in all treatments, and flies from each host race mated more frequently in cages containing their own host plant. The frequency of non‐assortative mating varied among treatments, with the matings between alt ♀ × gig ♂ being more common in the pure S. altissima treatment and the gig ♀ × alt ♂ being more frequent in the pure S. gigantea and random treatments. Matings between gig ♂ × alt ♀ were more common overall than the reciprocal mating, because gig males were more active in pursuing matings and in alighting on the non‐natal host plant than alt flies. Non‐assortative matings were more frequent in the random than in the block treatments, but this difference was not significant. Because of strong selection against oviposition into the alternate host, we hypothesized that host plant distribution would not affect oviposition preference. We tested this hypothesis by examining the oviposition behavior of naïve, mated females in two treatments in which both host species were present: either arranged in blocks or randomly dispersed. Females oviposited only into their natal host, regardless of host plant distribution.     

Photoperiodic and temperature control of nymphal development and induction of reproductive diapause in two predatory Orius bugs: interspecific and geographic differences

Abstract The effects of day‐length and temperature on pre‐adult growth and induction of reproductive diapause are studied in Orius sauteri and Orius minutus (Heteroptera: Anthocoridae) from northern (43.0°N, 141.4°E) and central (36.1°N, 140.1°E) Japan. In the north, at 20 °C, pre‐adult growth is slower under an LD 14 : 10 h photoperiod than under shorter or longer photophases. At 24 and 28 °C, the longer photophases result in shorter pre‐adult periods. Acceleration of nymphal growth by short days in autumn appears to be adaptive. In the central region, this response is less pronounced, suggesting that timing of adult emergence is less critical than in the north. Day length also influences the thermal requirements for pre‐adult development. The slope of the regression line representing temperature dependence of pre‐adult development is significantly smaller and the lower development threshold (LDT) is significantly lower under an LD 12 : 12 h photoperiod than under long‐day conditions. The weaker dependence of nymphal growth on temperature and the lower LDT in autumn might be adaptive. In the north, increased temperature shifts the critical day length of diapause induction and suppresses the photoperiodic response in O. sauteri but not in O. minutus. Further south, the incidence of diapause in both species is low even under short‐day conditions but the same interspecific difference is observed (i.e. increase of temperature affects the response in O. sauteri but not in O. minutus). This suggests seasonally earlier diapause induction with weaker temperature dependence in O. minutus than in O. sauteri.     

Comparison of defence and performance traits between one widespread clone and native populations in a major invasive plant species

Aim

The success of invasive species in their introduced range is often assumed to result from evolutionary changes in defence and growth traits, or as a response to more favourable conditions. The latter is assumed particularly for species exhibiting low, or even no, sexual reproduction in the introduced range.

Location and Methods

Here, we compared Japanese (native range) and French (introduced range) populations of Fallopia japonica under common growth conditions in a glasshouse. We measured height, aboveground and belowground mass, stem stiffness, leaf toughness and secondary metabolites found in hydroalcoholic extracts of rhizomes of F. japonica, as well as the competitive response of Rubus caesius (a co‐occurring native species in the invaded range) in the presence of F. japonica from both ranges.

Results

Aboveground biomass, height, stem stiffness and composition of secondary metabolites were not significantly different between the two ranges, showing that increased aboveground vigour observed in situ in France is probably the result of a plastic response following the release of abiotic or biotic constraints from the native range. On the other hand, belowground mass, effect on R. caesius, and leaf toughness were all higher in French populations, suggesting increases in competitive ability and defence mechanisms. These differences between France and Japan may be explained either by post‐introduction evolution or by the introduction in Europe, in nineteenth century, of an exceptionally vigorous clone (pre‐adaptation).

Main conclusions

Our results provide evidence that the high vigour of this major invasive species in its introduced range is probably due to both a response to more favourable conditions and rapid evolution.

     

The effectiveness of pre‐ and post‐zygotic barriers in avoiding hybridization between two snapdragons (Antirrhinum L.: Plantaginaceae)

Reproductive barriers play an important role in the maintenance of species boundaries. However, to date, few studies have provided a detailed analysis of reproductive isolation barriers between species or examined their importance in maintaining species identity. This is the first detailed study into pre‐ and post‐zygotic reproductive isolation barriers in Antirrhinum, based on a mixed population with two species that rarely co‐occur. The study revealed that pollinator constancy and preference and poor hybrid seed viability were the most important reproductive isolating mechanisms. Reproductive isolation was practically complete by both pre‐ and post‐zygotic barriers. Average pre‐zygotic isolation was greater than post‐zygotic isolation, in accordance with the trend observed in flowering plants in which reproductive isolation is principally caused by pre‐zygotic mechanisms. However, average post‐zygotic isolation was also high, in contrast to what was expected among Antirrhinum spp. This case highlights the importance of quantifying the reproductive isolation barriers thoroughly to understand how and why species boundaries are maintained. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 159–172.     

Inhibitory effects of Eucalyptus globulus on understorey plant growth and species richness are greater in non‐native regions

Aim

We studied the novel weapons hypothesis in the context of the broadly distributed tree species Eucalyptus globulus. We evaluated the hypothesis that this Australian species would produce stronger inhibitory effects on species from its non‐native range than on species from its native range.

Location

We worked in four countries where this species is exotic (U.S.A., Chile, India, Portugal) and one country where it is native (Australia).

Time period

2009–2012.

Major taxa studied

Plants.

Methods

We compared species composition, richness and height of plant communities in 20 paired plots underneath E. globulus individuals and open areas in two sites within its native range and each non‐native region. We also compared effects of litter leachates of E. globulus on root growth of seedlings in species from Australia, Chile, the U.S.A. and India.

Results

In all sites and countries, the plant community under E. globulus canopies had lower species richness than did the plant community in open areas. However, the reduction was much greater in the non‐native ranges: species richness declined by an average of 51% in the eight non‐native sites versus 8% in the two native Australian sites. The root growth of 15 out of 21 species from the non‐native range were highly suppressed by E. globulus litter leachates, whereas the effect of litter leachate varied from facilitation to suppression for six species native to Australia. The mean reduction in root growth for Australian plants was significantly lower than for plants from the U.S.A., Chile and India.

Main conclusions

Our results show biogeographical differences in the impact of an exotic species on understorey plant communities. Consistent with the novel weapons hypothesis, our findings suggest that different adaptations of species from the native and non‐native ranges to biochemical compounds produced by an exotic species may play a role in these biogeographical differences.     

No need for stepping stones: Direct,joint dispersal of the lichen‐forming fungus Mastodia tessellata (Ascomycota) and its photobiont explains their bipolar distribution

Aim

The hypotheses proposed to explain the high percentage of bipolar lichens in Antarctica have never been explicitly tested. We used the strictly bipolar, coastal lichenized fungus Mastodia tessellata (Verrucariaceae, Ascomycota) and its photobionts (Prasiola, Trebouxiophyceae, Chlorophyta) as model species to discern whether this extraordinary disjunction originated from vicariance or long‐distance dispersal.

Location

Coasts of Antarctica, Tierra del Fuego (Chile), Alaska (USA) and British Columbia (Canada).

Methods

Based on a comprehensive geographical (315 specimens and 16 populations from Antarctica, Tierra del Fuego and North America) and molecular sampling (three and four loci for the fungus and algae respectively), we implemented explicit Bayesian methods to compare alternative hypotheses of speciation and migration, and performed dating analyses for the fungal and algal partner, in order to infer the timing of the colonization events and the direction of gene flow among distant, disjunct areas.

Results

Mastodia tessellata comprises two fungal species which in turn associate with three photobiont lineages along the studied distribution range. Independent estimation of divergence ages for myco‐ and photobionts indicated a middle to latest Miocene species split in the Southern Hemisphere, and a late Miocene to Pleistocene acquisition of the bipolar distribution. Comparison of migration models and genetic diversity patterns suggested an austral origin for the bipolar species.

Main conclusions

The complex evolutionary history of Mastodia tessellata s.l. can be explained by a combination of vicariant and long‐distance dispersal mechanisms. We provide novel evidence of a pre‐Pleistocene long‐term evolution of lichens in Antarctica as well as for bipolar distributions shaped by Southern to Northern Hemisphere migratory routes without the need for stepping stones.     

Small trees,big problems: Comparative leaf function under extreme edaphic stress

Premise of the Study

The pygmy forest, a plant community of severely stunted conifers and ericaceous angiosperms, occurs on patches of highly acidic, nutrient‐poor soils along the coast of Northern California, USA. This system is an excellent opportunity to study the effect of severe nutrient deficiency on leaf physiology in a naturally‐occurring ecosystem. In this study, we seek to understand the physiological mechanisms stunting the plants' growth and their implications for whole plant function.

Methods

We measured 14 traits pertaining to leaf photosynthetic function or physical structure on seven species. Samples were taken from the pygmy forest community and from conspecifics growing on higher‐nutrient soils, where trees may grow over 30 m tall.

Key Results

Pygmy plants of most species maintained similar area‐based photosynthetic and stomatal conductance rates to conspecific controls, but had lower specific leaf area (leaf area divided by dry weight), lower percent nitrogen, and less leaf area relative to xylem growth. Sequoia sempervirens, a species rare in the pygmy forest, had a categorically different response from the more common plants and had remarkably low photosynthetic rates.

Conclusions

Pygmy plants were not stunted by low photosynthetic rates on a leaf‐area basis; instead, several species had restricted whole‐plant photosynthesis due to low leaf area production. Pygmy plants of all species showed signs of greater carbon investment in their leaves and higher production of nonphotosynthetic leaf tissue, further contributing to slow growth rates.     

Ploidy effects on the relationship between floral phenotype,reproductive investment,and fitness in an autogamous species complex

Premise

The relationships between reproductive investment, phenotype, and fitness have been broadly studied in cross-pollinated plants in contrast to selfing species, which are considered less interesting in this area because they are supposed to be a dead end in any evolutionary pathway. Still, selfing plants are unique systems to study these questions since the position of reproductive structures and traits related to flower size play an important role in female and male pollination success.

Methods

Erysimum incanum s.l. is a selfing species complex that has three levels of ploidy (diploids, tetraploids, and hexaploids) and traits that are typically associated with the selfing syndrome. Here, we used 1609 plants belonging to these three ploidies to characterize the floral phenotype and spatial configuration of reproductive structures, reproductive investment (pollen and ovule production), and plant fitness. Then, we used structural equation modelling to analyze the relationship between all these variables across ploidy levels.

Results

An increase in ploidy level leads to bigger flowers with anthers exserted farther and more pollen and ovules. In addition, hexaploid plants had higher absolute values for herkogamy, which is positively correlated with fitness. Ovule production significantly mediated the natural selection acting on different phenotypic traits and pollen production, a pattern that is maintained across ploidies.

Conclusions

The changes in floral phenotypes, reproductive investment, and fitness with ploidy level suggest that genome duplication can be a driver for transitions in reproductive strategy by modifying the investment in pollen and ovules and linking them with plant phenotype and fitness.     

Fabp4‐CreER lineage tracing revealstwo distinctive coronary vascular populations

Over the last two decades, genetic lineage tracing has allowed for the elucidation of the cellular origins and fates during both embryogenesis and in pathological settings in adults. Recent lineage tracing studies using Apln‐CreER tool indicated that a large number of post‐natal coronary vessels do not form from pre‐existing vessels. Instead, they form de novo after birth, which represents a coronary vascular population (CVP) distinct from the pre‐existing one. Herein, we present new coronary vasculature lineage tracing results using a novel tool, Fabp4‐CreER. Our results confirm the distinct existence of two unique CVPs. The 1^st CVP, which is labelled by Fabp4‐CreER, arises through angiogenic sprouting of pre‐existing vessels established during early embryogenesis. The 2^nd CVP is not labelled by Fabp4, suggesting that these vessels form de novo, rather than through expansion of the 1^st CVP. These results support the de novo formation of vessels in the post‐natal heart, which has implications for studies in cardiovascular disease and heart regeneration.     

Brood parasitism,relatedness and sociality: a kinship role in female reproductive tactics

Conspecific brood parasitism (CBP) is a reproductive tactic in which parasitic females lay eggs in nests of other females of the same species that then raise the joint brood. Parasites benefit by increased reproduction, without costs of parental care for the parasitic eggs. CBP occurs in many egg‐laying animals, among birds most often in species with large clutches and self‐feeding young: two major factors facilitating successful parasitism. CBP is particularly common in waterfowl (Anatidae), a group with female‐biased natal philopatry and locally related females. Theory suggests that relatedness between host and parasite can lead to inclusive fitness benefits for both, but if host costs are high, parasites should instead target unrelated females. Pairwise relatedness (r) in host–parasite (h‐p) pairs of females has been estimated using molecular genetic methods in seven waterfowl (10 studies). In many h‐p pairs, the two females were unrelated (with low r, near the local population mean). However, close relatives (r = 0.5) were over‐represented in h‐p pairs, which in all 10 studies had higher mean relatedness than other females. In one species where this was studied, h‐p relatedness was higher than between nesting close neighbours, and hosts parasitized by non‐relatives aggressively rejected other females. In another species, birth nest‐mates (mother–daughters, sisters) associated in the breeding area as adults, and became h‐p pairs more often than expected by chance. These and other results point to recognition of birth nest‐mates and perhaps other close relatives. For small to medium host clutch sizes, addition of a few parasitic eggs need not reduce host offspring success. Estimates in two species suggest that hosts can then gain inclusive fitness if parasitized by relatives. Other evidence of female cooperation is incubation by old eider Somateria mollissima females of clutches laid by their relatives, and merging and joint care of broods of young. Merging females tended to be more closely related. Eiders associate with kin in many situations, and in some geese and swans, related females may associate over many years. Recent genetic evidence shows that also New World quails (Odontophoridae) have female‐biased natal philopatry, CBP and brood merging, inviting further study and comparison with waterfowl. Kin‐related parasitism also occurs in some insects, with revealing parallels and differences compared to birds. In hemipteran bugs, receiving extra eggs is beneficial for hosts by diluting offspring predation. In eggplant lace bugs Gargaphia solani, host and parasite are closely related, and kin selection favours egg donation to related females. Further studies of kinship in CBP, brood merging and other contexts can test if some of these species are socially more advanced than presently known.     

Local environment,not local adaptation,drives leaf‐out phenology in common gardens along an elevational gradient in Acadia National Park,Maine

Premise of the Study

Climate‐driven changes in phenology are substantially affecting ecological relationships and ecosystem processes. The role of variation among species has received particular attention; for example, variation among species’ phenological responses to climate can disrupt trophic interactions and can influence plant performance. Variation within species in phenological responses to climate, however, has received much less attention, despite its potential role in ecological interactions and local adaptation to climate change.

Methods

We constructed three common gardens across an elevation gradient on Cadillac Mountain in Acadia National Park, Maine, to test population‐level responses in leaf‐out phenology in a reciprocal transplant experiment. The experiment included three native species: low bush blueberry (Vaccinium angustifolium), sheep's laurel (Kalmia angustifolia), and three‐toothed cinquefoil (Sibbaldiopsis tridentata).

Key Results

Evidence for local adaptation of phenological response to temperature varied among the species, but was weak for all three. Rather, variation in phenological response to temperature appeared to be driven by local microclimate at each garden site and year‐to‐year variation in temperature.

Conclusions

Population‐level adaptations in leaf‐out phenology appear to be relatively unimportant for these species in Acadia National Park, perhaps a reflection of strong genetic mixing across elevations, or weak differences in selection on phenological response to spring temperatures at different elevations. These results concur with other observational data in Acadia and highlight the utility of experimental approaches to understand the importance of annual and local site variation in affecting phenology both among and within plant species.     

Differences in the pre‐diapause and pre‐oviposition accumulation of critical nutrients in adult females of the beetle Colaphellus bowringi

In many insect species, the differentiation of development between diapause and reproduction first becomes obvious during the diapause preparation (pre‐diapause) and pre‐oviposition phases. However, the differentiation of nutrient accumulation between these two phases remains unclear. We compared the weights of pre‐diapause and reproductive adult female Colaphellus bowringi Baly (Coleoptera: Chrysomelidae), and measured their triacylglycerol (TAG), protein, and carbohydrate content from emergence until they had fed for 4 days post‐eclosion. We also compared the ovarian development and accumulation of lipid droplets between pre‐diapause and reproductive adult females in order to determine whether we could visually detect differences in nutrient allocation. The weights of both pre‐diapause and reproductive females increased with duration of feeding. The fresh weight and water content of pre‐diapause females was significantly lower than that of reproductive females after feeding for 3 days post‐eclosion. Pre‐diapause females channeled their reserves into TAG in the fat body, whereas reproductive females converted nutrients into proteins and carbohydrates for egg development. These results quantify differences in nutrient accumulation between pre‐diapause and reproductive adult female C. bowringi, and provide clues for understanding the molecular mechanisms underlying differences in the allocation of nutrients between diapause and reproduction in insects.