Effects of body size and larval diet type on reproductive traits in two diverse clades of European Lepidoptera

A Statistical Model Relating the Oxygen Consumption of a Mollusk (Littorina littorea) to Activity, Body Size, and Environmental Conditions

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Effect of body size and sugar meals on oviposition of the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae)

:Litter characteristics of viviparous snakes presumably can be influenced by the mother’s state (e.g., mass) at the onset of pregnancy, by food acquired during vitellogenesis, or by food eaten by the mother during pregnancy and delivered to the developing embryos via the placenta. Alternatively, food consumed while pregnant could be allocated to the female herself, potentially influencing her future survivorship and/or reproduction. We tested the effects of food consumption during pregnancy on litter traits of the garter snake, Thamnophis ordinoides, along with the effects of body size and age of mother. We also measured trade-offs between traits. Age was significantly correlated with body size of female snakes, but it had no direct influence on reproductive traits. Initial body size, by contrast, especially snout-vent length, significantly and positively influenced litter size and mass. Food intake by gravid females declined during pregnancy, and snakes became relatively anorexic prior to giving birth; their appetite resumed following parturition. Snakes offered smaller amounts of food while pregnant ate less than those fed ad lib, but had similar postpartum appetites. Higher food intake during pregnancy resulted in higher postpartum mass of females, but not higher litter mass or size of offspring. There was strong evidence of a trade-off between litter size and offspring size and between postpartum mass and litter mass. Overall, our data are consistent with the hypothesis that reproductive traits of viviparous snakes are determined proximately by previously accumulated stores (capital) and/or food consumed during vitellogenesis (income), but not by resources acquired during pregnancy.

Body Size and Metabolic Rate in Salamanders

Dialysis dose and gender: A different hypothesis

The role of male body size in postmating sexual selection was explored in a semiaquatic insect, the water strider Gerris lateralis. To separate effects of male size per se from those due to numeric sperm competition, male recovery period (shown here to be proportional to ejaculate size) was manipulated independently of body size in a factorial experiment where virgin females were mated first with sterile males and then with focal males. Both relative male fertilization success and female reproductive rate were measured. The number of sperm transferred increased with male recovery period, an effect that was mediated by longer copulation duration, but there were no effects of body size on ejaculate size. Neither male size nor recovery period had any significant direct effects on male fertilization success. However, copulation duration influenced relative fertilization success, suggesting that males able to transfer more sperm also achieved higher fertilization success. Females exercised cryptic female choice by modulating their reproductive rate in a manner favoring large males and males that were successful in terms of achieving high relative fertilization success. Thus, successful males gained a twofold advantage in postmating sexual selection. This study has important implications for previous estimates of sexual selection in this group of insects because pre- and postmating sexual selection will be antagonistic due to limitations in male sperm production: males mating frequently (high mating success) will on average transfer fewer sperm in each mating and will hence tend to fertilize fewer eggs per mating (low fertilization success).

Effects of body size and lung type on desiccation resistance, hypoxia tolerance and thermal preference in two terrestrial isopods species

Male body size is considered to be one of the major determinants of mating success among many insect species. Because the effectiveness of the sterile insect technique (SIT) depends on the ability of released sterile males to mate with and inseminate wild females, it is indispensable to understand the effect of male body size on the mating behavior of both sexes for the progress of the SIT program. We investigated how male body size and the presence of other rival males affect the guarding and copulatory durations of the West Indian sweetpotato weevil, Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae). In this species, males guard females before and after copulation. By observing the mating behavior under two sex‐ratio conditions (male‐to‐female ratios of 1:1 and 2:1), we found that small males hastened to court females when rival males were present, but the females rejected these small males as mates. Therefore, we consider that female weevils adopt a counter‐adaptation for mate preference in response to this male mating strategy. Body size did not affect the durations of copulation and post‐copulatory guarding. Although we found a conditional mating strategy for body size in E. postfasciatus, it is unlikely to have a large influence on the weevil‐eradication program using SIT.

Association Between Body Size and Colorectal Adenoma Recurrence

Recent studies have found that postnatal catch-up growth might have a stronger impact than birth size on health in later life. Because growth is a continuing process, the challenge is to tease out the impact of body size at different critical phases. Ordinary least squares regression cannot differentiate the effects of birth size, growth, and current body size simultaneously, because growth is generally defined as the difference between birth size and current size, giving rise to perfect collinearity. This paper aims to describe and justify the use of a novel approach, partial least squares, to estimate life course effects of body size z-scores on later blood pressure, using longitudinal data from a cohort of 960 Filipino boys. Body weight z-scores and changes in z-score weight were measured from birth to age 19 years, and systolic and diastolic blood pressures (BPs) were measured at age 19. In general, birth size had a very modest association with systolic BP. The early changes in z-scores between birth and the age of 2 years were positively associated with the outcome. Growth after age 8 had a larger effect than early growth, but the confidence intervals are generally large. For diastolic BP, the association was similar for early and later growth. Current body size had the strongest relationships with both outcomes. By creating weighted composites of perfectly collinear variables as components, partial least squares estimates the life course effects of body size on later health according to the correlations between body size and health outcomes.

We examined the possible effects of host body size and throat gland development on the abundance of blood-feeding nycteribiid and streblid flies parasitizing a Malagasy fruit bat, Rousettus madagascariensis G. Grandidier, 1928. Data were collected in the Parc National d'Ankarana in northern Madagascar during four visits: September 2014, 2015 (dry season), and January 2015, 2016 (wet season). Two bat fly species were identified, Eucampsipoda madagascarensis Theodor, 1955 (Nycteribiidae) and Megastrebla wenzeli (Jobling, 1952) (Streblidae). A positive correlation was found between host body size and abundance of E. madagascarensis during the four visits, suggesting that larger hosts have more parasites, and for M. wenzeli, this relationship was identified only during the wet season visits. In male hosts, body size and throat gland development are correlated with variation in E. madagascarensis abundance during the two seasons; this relationship was not found for M. wenzeli. We present some explanations for the observed patterns of bat fly abundance associated with throat gland development: increased vascularization and easier access to bloodmeals, chemical properties of gland secretions acting as attractants or perhaps being consumed, and modification of hair around the gland providing protection from bat grooming.

Nutrient resorption is essential for plant nutrient conservation. Large-bodied plants potentially have large nutrient sink pools and high nutrient flux. Whether and how nutrient resorption can be regulated by plant size and biomass allocation are yet unknown. Using the herbaceous plant Amaranthus mangostanus in greenhouse experiments for two consecutive years, we measured plant biomass, height, and stem diameter and calculated the root to shoot biomass ratio (R/S ratio) and nutrient resorption efficiency (NuRE) to assess the effects of plant body size and biomass allocation on NuRE. NuRE was calculated as the percentage reduction in leaf nutrient concentration from green leaf to senesced leaf. NuRE increased with plant biomass, height, and stem diameter, suggesting that the individuals with larger bodies, which led to a larger nutrient pool, tended to resorb proportionally more nutrients from the senescing leaves. NuRE decreased with increasing root to shoot ratio, which might have reflected the nutrient acquisition trade-offs between resorption from the senescent leaves and absorption from the soil. Increased root biomass allocation increased the proportion of nutrient acquisition through absorption more than through resorption. This study presented the first experimental evidence of how NuRE is linked to plant size (indicated by biomass, height, and stem diameter) and biomass allocation, suggesting that nutrient acquisition could be modulated by the size of the nutrient sink pool and its partitioning in plants, which can improve our understanding of a conservation mechanism for plant nutrients. The body size and root to shoot ratio effects might also partly explain previous inconsistent reports on the relationships between environmental nutrient availability and NuRE.

Shoreline spiders have been proposed as sentinels to monitor aquatic contaminants including methylmercury (MeHg). The present study examined the effect of spider body size on MeHg concentrations in shoreline spiders. We collected 6 taxa of spiders belonging to 4 families (orb-weavers [Araneidae], long-jawed orb weavers [Tetragnathidae: Tetragnatha sp.], jumping spiders [Salticidae], and wolf spiders [Lycosidae: Pardosa sp., Rabidosa sp., and Schizocosa sp.]) from the shorelines of 14 human-made ponds at the Lyndon B. Johnson National Grasslands in north Texas (USA). As a proxy for body size, we measured leg length (tibia + patella) of each spider. Spider taxa differed by 3-fold in mean MeHg concentration, and MeHg concentrations in 4 of 6 spider taxa increased significantly with leg length. The present study is the first to demonstrate that shoreline spider MeHg concentrations increase as a function of spider body size. Because spider size may account for some within-taxa variation in MeHg concentrations, future studies that utilize spiders as sentinels of aquatic contamination by MeHg or other biomagnifying contaminants should take spider size into account. Environ Toxicol Chem 2021;40:1149-1154. © 2020 SETAC.

The cynipoid wasp Gronotoma micromorpha (Perkins) (Hymenoptera: Figitidae) is a parasitoid of the leaf miner Liriomyza trifolii (Burgess) (Diptera: Agromyzidae). The effects of adult age and body size on egg maturation in G. micromorpha were determined. The results showed that its egg load (number of mature eggs per female) increased when offered honey, water, but not hosts for 3 or 6 days after adult emergence. However, there was no significant difference in the egg loads of 3- and 6-day-old wasps. These findings and the results of previous studies on other cynipoid parasitoids suggest that when hosts are not available, females of parasitoid Cynipoidea enhance their reproductive capacity in anticipation of a future improvement in the availability of hosts by using carbohydrates and reserves stored during the larval stage. Moreover, large female wasps had higher egg loads throughout their lifetime. Given that rapid increases in the population density of L. trifolii are commonly reported in greenhouses, the demographic data of 0- and 3-day-old G. micromorpha females fed honey, need to be compared in the future. The effects of body size on the fecundity and longevity of G. micromorpha wasps should also be determined.