Sex dimorphism of life-history traits and their response to environmental factors in spider mites

Author(s):  
Guang-Yun Li ◽  
Zhi-Qiang Zhang
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Steve B. S. Baleba

Abstract Background In holometabolous insects, environmental factors experienced in pre-imaginal life stages affect the life-history traits within that stage and can also influence subsequent life stages. Here, I assessed tolerance to water immersion by the larval instars of the stable fly, Stomoxys calcitrans L. (Diptera: Muscidae) and its impact on the life-history traits of their subsequent life stages. Results After submerging the three larval instars of S. calcitrans in distilled water, I found that the first instar larvae remained active for longer as compared to the second and third instar larvae. Also, the first instar larvae took a longer period to recover from the stress-induced immobility when removed from the water and returned to ambient temperature. When I followed the development of individuals of each larval instar that survived from water immersion, I found that their developmental time, weight, pupation percentage, adult emergence percentage and adult weight were negatively affected by this stressor. However, the weight of S. calcitrans adults developed from immersed first larval instar individuals was not affected by water immersion whereas their counterparts developed from immersed second and third larval instars had lower body weight. This suggests that in S. calcitrans, water immersion stress at the earlier stage is less detrimental than that experienced at late stages. Conclusion This study provides a comparative overview of the fitness consequences associated with water immersion stress during S. calcitrans larval ontogeny. The results prove that the fitness shift induced by water immersion in S. calcitrans is stage-specific. My results illustrate the importance of considering each larval instar when assessing the impact of environmental factors on holometabolous insect performance as these may be decoupled by metamorphosis.


2017 ◽  
Vol 22 (2) ◽  
pp. 170 ◽  
Author(s):  
Kaori Tamura ◽  
Katsura Ito

Spider mites show various life types characterized by spinning behavior, web structure, and sociality. Individuals of the woven-nest (WN) species construct silken nests on the undersurface of host leaves, inside which they develop and reproduce. This nesting behavior may be related with the defense mechanism and life history traits of mites in the stable habitat (e.g., evergreen trees). If the WN life type affects the life-history traits, these traits may be similar within WN species. The WN species are known to be fragmentarily distributed in diverse genera, Stigmaeopsis, Schizotetranychus, Eotetranychus, and Oligonychus, and their life types are suspected to have secondarily converged. However, their life histories have not been elucidated except for several species in specific genera. To supply the information in Schizotetranychus, we investigated the demographic traits and the sex ratio of Schizotetranychus brevisetosus, which shows the WN life type and lives on the evergreen Japanese blue oak Quercus glauca. We estimated the development time of females as 22.6 ± 3.1 days (mean ± SD, n = 22) and the fecundity of fertilized females as 13.7 ± 5.9 (n = 37) at 25°C. The sex ratio of males to the total number of adults at emergence was low (0.072). The intrinsic rate of natural increase (rm) was estimated as 0.060 day-1, one of the lowest ever reported for spider mites at the same temperature. The present results were similar to other WN species in that fecundity and male ratio were low. 


2013 ◽  
Vol 16 (6) ◽  
pp. 1096-1102
Author(s):  
Lucía Colodro-Conde ◽  
Frühling Rijsdijk ◽  
Juan R. Ordoñana

Life history theory studies the evolution of traits related to reproductive fitness. Fertility and parental investment are key life history traits which, from an evolutionary standpoint, appear strongly interrelated. The aim of this work was to analyze the genetic and environmental structure and relationship of two behaviors associated with reproductive fitness: total number of offspring and mean duration of breastfeeding. A total of 1,347 women distributed in 239 monozygotic pairs, 236 dizygotic pairs, and 393 individual twins from opposite sex pairs provided information about their reproductive history. We conducted separate univariate analyses to study the sources of variance of both variables; and a bivariate analysis, with threshold liability models. The sources of variance for number of children and breastfeeding were best explained by a model including familial and unique environmental factors, being E = 0.54 (CI 95%: 0.44, 0.66) and E = 0.46 (CI 95%: 0.34, 0.61), respectively. The phenotypic correlation between number of children and breastfeeding was low but significant (r = 0.16, CI 95%: 0.07, 0.25). Familial correlation between these variables did not reach significance, but unique environmental correlation did (re = 0.20, CI 95%: 0.02, 0.37). In conclusion, results do not support the existence of a clear common structure for the number of children a woman has and the time she spends breastfeeding them, at least in modern societies. The relationship found was mainly due to unique environmental factors. More research on these and related phenotypes is needed to better understand women's reproductive decisions and how natural selection acts on the life history traits.


2014 ◽  
Vol 129 ◽  
pp. 244-284 ◽  
Author(s):  
Webjørn Melle ◽  
Jeffrey Runge ◽  
Erica Head ◽  
Stéphane Plourde ◽  
Claudia Castellani ◽  
...  

2000 ◽  
Vol 18 (4) ◽  
pp. 218-223
Author(s):  
P.D. Pratt ◽  
B.A. Croft

Abstract To select a biological control agent for suppression of spider mites on landscape plants in western regions of the Pacific Northwest, we compared life history traits of Galendromus occidentalis Nesbitt, Neoseiulus californicus (McGregor) and Neoseiulus fallacis (Garman). We also evaluated abilities of these predatory mites to suppress spider mites in 4 landscape plant species under field conditions. Comparing life history traits from the literature, intrinsic rate of increase was similar between the 2 Neoseiulus species but lower for G. occidentalis. Prey killed per day was greatest for G. occidentalis > N. fallacis > N. californicus. For overwintering abilities, N. fallacis and G. occidentalis are indigenous to the Pacific Northwest and will survive winter assuming overwintering sites are available, but survival of N. californicus is unlikely. Neoseiulus californicus has the widest prey range, G. occidentalis the narrowest, with N. fallacis intermediate. When inoculated into spider mite infested landscape plants, N. fallacis was equally effective at suppressing spider mites as G. occidentalis in either Malus rootstock or Acer shade trees. Further tests with N. fallacis or N. californicus on Spiraea and Rhododendron plants suggested that N. fallacis is equally or more effective at suppressing pest mites, respectively. Compared with the other candidates, N. fallacis was equally effective at controlling pest mites and has a wider prey range than G. occidentalis. Neoseiulus fallacis appears to be the best candidate for biological control of multiple spider mite species on landscape plants in these parts of the Pacific Northwest.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Leydy J. Cardona-Salazar ◽  
Ana Busi ◽  
Daniela Gómez Castillo ◽  
Paula A. Ossa-López ◽  
Fredy A. Rivera-Páez ◽  
...  

Abstract: Breeding biology in a population of Rufous-collared Sparrow (Zonotrichia capensis, Statius Müller, 1776) at different elevations in the Tropical Andes. Elevation strongly influences the evolution of life history traits associated with bird physiology and reproduction. Since life history traits in birds are modulated by environmental factors that vary with elevation, we expected to find changes in breeding biology traits of Z. capensis at different elevations. In this study, we compared the breeding biology (clutch size, egg volume, and reproductive activity) of a non-migratory population of Z. capensis in two localities at different elevations (low and high elevations, 1 800 m a.s.l., and 3 800 m a.s.l., respectively) and same latitude in the Colombian Tropical Andes for a one-year period. We found no differences in clutch size between the localities; however, egg volume was higher at high elevation. Furthermore, the reproductive activity differed significantly between localities. We propose that clutch size is likely conserved throughout the altitudinal distribution of Z. capensis since the species evolved in Tropical lowlands. On the other hand, the larger egg volume at high elevation could obey local environmental factors that may favor the reproductive success of the population.


2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.


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