scholarly journals A novel experimental approach for studying life-history traits of phytophagous arthropods utilizing an artificial culture medium

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kamila Karpicka-Ignatowska ◽  
Alicja Laska ◽  
Lechosław Kuczyński ◽  
Brian G. Rector ◽  
Mariusz Lewandowski ◽  
...  

AbstractExperimental approaches to studying life-history traits in minute herbivorous arthropods are hampered by the need to work with detached host plant material and the difficulty of maintaining that material in a suitable condition to support the animal throughout the duration of the test. In order to address this shortcoming, we developed a customizable agar-based medium modified from an established plant cell-culture medium to nourish detached leaves laid atop it while also preventing arthropods from escaping the experimental arena. The artificial culture medium was tested with two herbivorous mite species: the wheat curl mite (Aceria tosichella; Eriophyidae) and two-spotted spider mite (Tetranychus urticae; Tetranychidae). The proposed approach was a major improvement over a standard protocol for prolonged studies of individual eriophyid mites and also provided some benefits for experiments with spider mites. Moreover, the described method can be easily modified according to the requirements of host plant species and applied to a wide range of microherbivore species. Such applications include investigations of life-history traits and other ecological and evolutionary questions, e.g. mating or competitive behaviours or interspecific interactions, assessing invasiveness potential and predicting possible outbreaks. The approach presented here should have a significant impact on the advancement of evolutionary and ecological research on microscopic herbivores.

2015 ◽  
Vol 8 (1) ◽  
pp. 57-71 ◽  
Author(s):  
John M. Wallace ◽  
Pamela L. S. Pavek ◽  
Timothy S. Prather

AbstractVentenata dubia is an exotic winter annual grass that has invaded Conservation Reserve Program (CRP) lands, improved pastures, intensively managed hay fields, and rangelands within the Intermountain Pacific Northwest (PNW). Currently, producers are attempting to develop V. dubia management strategies with little knowledge of its life history traits. We conducted several studies to characterize V. dubia life history patterns. Preliminary germination trials were completed to describe primary and secondary dormancy characteristics. Field studies were conducted to evaluate (1) seed bank persistence patterns, (2) seedling emergence patterns under V. dubia litter, and (3) seedling emergence and phenological development patterns within timothy hay, CRP, and rangeland habitats. Preliminary germination trials suggest that the after-ripening period required for loss of dormancy does not exceed 30 d and that dormancy breakdown peaks at approximately 90 d, after which germination occurs over a wide range of temperatures (9 to 29 C). A small fraction (< 1%) of the seed bank remained germinable up to 3 yr after burial at 2 cm depth in a grassland habitat. Seedling emergence and survival was significantly greater under high V. dubia litter layers (100% cover) compared with bare surface during the drier study year because of higher soil moisture levels maintained under litter. Across habitat types, mean seedling emergence (50% of total) occurred between 33 and 94 growing degree days (GDD) after soil moisture rose above the permanent wilting point in the fall. Seedling emergence periodicity varied among habitat types in relation to spring seedling emergence, ranging from 0 to 13% of total emergence per year. Phenological development differed across sites and years by up to several hundred GDDs but was closely aligned to Julian days. This collection of studies improves our understanding of V. dubia life history traits and will aid integrated weed management strategies in the Intermountain PNW.


2013 ◽  
Vol 65 (2) ◽  
pp. 525-531
Author(s):  
Marija Mrdakovic ◽  
Vesna Peric-Mataruga ◽  
Larisa Ilijin ◽  
Milena Vlahovic ◽  
D. Mircic ◽  
...  

The influence of allelochemical stress and population origin on the patterns of phenotypic and genetic correlations among life history traits and digestive enzyme activities were investigated in larvae of the gypsy moth (Lymantria dispar L.; Lepidoptera: Lymantriidae). Thirty-two full-sib families from oak (suitable host plant, Quercus population), and twenty-six full-sib families from locust-tree (unsuitable host plant, Robinia population) forests were reared on an artificial diet, with or without a 5% tannic acid supplement. Comparison of correlation matrices revealed significant similarity between the two populations in the structure of phenotypic and genetic correlations of life history traits and of digestive enzyme activities. The patterns of correlations of the examined traits, within each of the two locally adapted populations and in the presence of allelochemical stress, remained stabile despite the different selection pressures that mold these traits.


BMC Ecology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Noureldin Abuelfadl Ghazy ◽  
Tetsuo Gotoh ◽  
Takeshi Suzuki

Abstract Background The tomato red spider mite, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), is an agricultural pest of solanaceous crops. Although T. evansi is of South American subtropical origin, it has recently expanded its distribution range to many tropical and temperate areas around the world. Its potential distribution range in response to scenarios of global warming was recently modeled, confirming its current and possible future distributions. Here, we experimentally investigated the biological traits of T. evansi in the context of the current and future global warming (2100) scenarios. Using an environmental simulation system, we tested the life-history traits of T. evansi under current summer temperatures (as of June, July, and August 2016) and under expected temperature increases based on two IPCC scenarios: RCP2.6 (+ 1 °C) and RCP8.5 (+ 3.7 °C). The mites were introduced into each scenario on 1 June and their sequential progeny were used for testing in each following month. Results The mite could develop and reproduce under all scenarios. There was a decrease in the duration of lifespan and female fecundity at RCP8.5 during June and August, but this may be compensated for by the high intrinsic rate of increase, which implies faster population growth and shorter generation time. Conclusion Our study and other reports reveal the high adaptability of T. evansi to a wide range of summer temperatures; this may explain its current distribution. We anticipate that global warming will favor the spread of T. evansi and may further expand its distribution to a large area of the globe. These findings should be of ecological and practical relevance for designing prevention and control strategies.


2020 ◽  
Vol 34 (5) ◽  
pp. 659-680 ◽  
Author(s):  
Anh The Than ◽  
Fleur Ponton ◽  
Juliano Morimoto

Abstract Population density modulates a wide range of eco-evolutionary processes including inter- and intra-specific competition, fitness and population dynamics. In holometabolous insects, the larval stage is particularly susceptible to density-dependent effects because the larva is the resource-acquiring stage. Larval density-dependent effects can modulate the expression of life-history traits not only in the larval and adult stages but also downstream for population dynamics and evolution. Better understanding the scope and generality of density-dependent effects on life-history traits of current and future generations can provide useful knowledge for both theory and experiments in developmental ecology. Here, we review the literature on larval density-dependent effects on fitness of non-social holometabolous insects. First, we provide a functional definition of density to navigate the terminology in the literature. We then classify the biological levels upon which larval density-dependent effects can be observed followed by a review of the literature produced over the past decades across major non-social holometabolous groups. Next, we argue that host-microbe interactions are yet an overlooked biological level susceptible to density-dependent effects and propose a conceptual model to explain how density-dependent effects on host-microbe interactions can modulate density-dependent fitness curves. In summary, this review provides an integrative framework of density-dependent effects across biological levels which can be used to guide future research in the field of ecology and evolution.


2015 ◽  
Vol 282 (1811) ◽  
pp. 20150322 ◽  
Author(s):  
M. J. Juan-Jordá ◽  
I. Mosqueira ◽  
J. Freire ◽  
N. K. Dulvy

Larger-bodied species in a wide range of taxonomic groups including mammals, fishes and birds tend to decline more steeply and are at greater risk of extinction. Yet, the diversity in life histories is governed not only by body size, but also by time-related traits. A key question is whether this size-dependency of vulnerability also holds, not just locally, but globally across a wider range of environments. We test the relative importance of size- and time-related life-history traits and fishing mortality in determining population declines and current exploitation status in tunas and their relatives. We use high-quality datasets of half a century of population trajectories combined with population-level fishing mortalities and life-history traits. Time-related traits (e.g. growth rate), rather than size-related traits (e.g. maximum size), better explain the extent and rate of declines and current exploitation status across tuna assemblages, after controlling for fishing mortality. Consequently, there is strong geographical patterning in population declines, such that populations with slower life histories (found at higher cooler latitudes) have declined most and more steeply and have a higher probability of being overfished than populations with faster life histories (found at tropical latitudes). Hence, the strong, temperature-driven, latitudinal gradients in life-history traits may underlie the global patterning of population declines, fisheries collapses and local extinctions.


2020 ◽  
Vol 77 (5) ◽  
pp. 1914-1926
Author(s):  
Simon H Fischer ◽  
José A A De Oliveira ◽  
Laurence T Kell

Abstract Worldwide, the majorities of fish stocks are data-limited and lack fully quantitative stock assessments. Within ICES, such data-limited stocks are currently managed by setting total allowable catch without the use of target reference points. To ensure that such advice is precautionary, we used management strategy evaluation to evaluate an empirical rule that bases catch advice on recent catches, information from a biomass survey index, catch length frequencies, and MSY reference point proxies. Twenty-nine fish stocks were simulated covering a wide range of life histories. The performance of the rule varied substantially between stocks, and the risk of breaching limit reference points was inversely correlated to the von Bertalanffy growth parameter k. Stocks with k&gt;0.32 year−1 had a high probability of stock collapse. A time series cluster analysis revealed four types of dynamics, i.e. groups with similar terminal spawning stock biomass (collapsed, BMSY, 2BMSY, 3BMSY). It was shown that a single generic catch rule cannot be applied across all life histories, and management should instead be linked to life-history traits, and in particular, the nature of the time series of stock metrics. The lessons learnt can help future work to shape scientific research into data-limited fisheries management and to ensure that fisheries are MSY compliant and precautionary.


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