scholarly journals Scarcity of hosts for gregarious parasitoids indicates an increase of individual offspring fertility by reducing their own fertility

2021 ◽  
Author(s):  
Alena Samková ◽  
Jan Raška ◽  
Jiří Hadrava ◽  
Jiří Skuhrovec
Keyword(s):  
Body Size ◽  
Reproductive Potential ◽  
Female Offspring ◽  
The Body ◽  
Individual Offspring ◽  
Single Host ◽  
Gregarious Parasitoid ◽  
Lower Mobility ◽  
Lower Fertility ◽  
F2 Generation

ABSTRACTThe gregarious parasitoid strategy allows multiple larvae to complete development in a single host due to their tolerance and/or lower mobility and thus flexibly adjust their reproductive potential amidst changing environmental conditions. Reproductive success is generally measured as the number of each mother’s offspring. We propose that with scarcity of host, for gregarious parasitoids is important the view on the fertility not only of a mother but also of her offspring (F1 generation). Due to the body size-fitness correlation, each female deliberately adjusts the clutch size, determining the offspring body size and their reproductive potential. In our study, using Anaphes flavipes as a model species, we showed that under a limited number of hosts, the females reduced their fertility. We propose that the lower fertility of mothers can cause higher fertility in the F2 generation using a larger offspring body while halving fertility. The females increase their individual offspring’s fertility by reducing their own fertility. Moreover, we showed that with a scarcity of hosts, the mothers increased the number of their female offspring, and thus, they obtained more offspring in the F2 generation. Additionally, other costs and benefits of the gregarious strategy in relation to superparasitism were tested and discussed.

scholarly journals A novel two-generation approach for understanding the population dynamics of gregarious parasitoids

2021 ◽  
Author(s):  
Alena Samková ◽  
Jan Raška ◽  
Jiří Hadrava ◽  
Jiří Skuhrovec
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Clutch Size ◽  
Traditional Approach ◽  
The Body ◽  
Natural Ecosystems ◽  
Individual Fitness ◽  
Novel Approach ◽  
F2 Generation ◽  
F1 Generation

AbstractParasitoids, as important natural enemies, help maintain balance in natural ecosystems. Their population dynamics is generally predicted from the number of individuals. Here, using gregarious parasitoids as models, we show that this traditional approach omits one important parameter: the mother’s manipulation of offspring fertility due to the clutch size–body size– fertility correlation. As a result of this correlation, when females deliberately adjust the number of offspring laid in a host, they determine not only the number but also the body sizes and reproductive potentials of those offspring. For the first time in the model speciesAnaphes flavipes, we determined the parasitoid’s offspring fertility from clutch size. Using this, we experimentally clarified the advantage of specific clutch size combinations and we show that identical fertility in the F1 generation can lead to distinctly different fertility values in the F2 generation. Even with the same number of hosts, lower fertility in the F1 generation can cause higher fertility in the F2 generation. Based on these results, we propose a novel two-generation approach which includes the clutch size–body size–fertility correlation. Our novel approach provides a new perspective for determining the individual fitness levels of gregarious parasitoids with new options for the modelling of parasitoid population dynamics.

scholarly journals Effect of host switching simulation on the fitness of the gregarious parasitoid Anaphes flavipes from a novel two-generation approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alena Samková ◽  
Jan Raška ◽  
Jiří Hadrava ◽  
Jiří Skuhrovec
Keyword(s):  
Host Plants ◽  
Host Switching ◽  
New Host ◽  
Individual Offspring ◽  
Gregarious Parasitoid ◽  
And Performance ◽  
F2 Generation ◽  
The Cost ◽  
The Impact ◽  
F1 Generation

AbstractHerbivorous insects can escape the strong pressure of parasitoids by switching to feeding on new host plants. Parasitoids can adapt to this change but at the cost of changing their preferences and performance. For gregarious parasitoids, fitness changes are not always observable in the F1 generation but only in the F2 generation. Here, with the model species and gregarious parasitoid Anaphes flavipes, we examined fitness changes in the F1 generation under pressure from the simulation of host switching, and by a new two-generation approach, we determined the impact of these changes on fitness in the F2 generation. We showed that the parasitoid preference for host plants depends on hatched or oviposited learning in relation to the possibility of parasitoid decisions between different host plants. Interestingly, we showed that after simulation of parasitoids following host switching, in the new environment of a fictitious host plant, parasitoids reduced the fictitious host. At the same time, parasitoids also reduced fertility because in fictitious hosts, they are not able to complete larval development. However, from a two-generation approach, the distribution of parasitoid offspring into both native and fictitious hosts caused lower parasitoid clutch size in native hosts and higher individual offspring fertility in the F2 generation.

scholarly journals Dynamics of reproductive ecology of the fish Ompok bimaculatus (Siluriformes: Siluridae) in six tropical rivers of the Ganges basin, India

2017 ◽  
Vol 9 (1) ◽  
pp. 73-85
Author(s):  
Agnihotri Praveen ◽  
Sarkar Uttam Kumar ◽  
Nagpure Naresh Sahebrao ◽  
Mishra Rahsya Mani ◽  
Kumar Ravindra ◽  
...  
Keyword(s):  
Body Size ◽  
Gonadosomatic Index ◽  
Reproductive Potential ◽  
The Body ◽  
Tropical Rivers ◽  
Mountain Regions ◽  
Gonad Weight ◽  
Ganges Basin ◽  
The Ganges ◽  
Ompok Bimaculatus

The silurid butter catfish, Ompok bimaculatus (Bloch, 1794), is widely distributed in the plains and sub-mountain regions of India, but not enough is known about its reproductive potential is still insufficient. The present study evaluated the comparative reproductive potential (in terms of sex ratio, spawning season, body size at first go­nadal maturity, gonadosomatic index, fecundity, egg dimension, egg weight etc.) of fish (n=1223) from six tropical tributaries of the Ganges basin during January 2011-December 2013. The females had relatively greater weight and length. The body size at 50% first gonadal matu­rity (L50%) ranged between 228-262mm in females and 198-247mm in males. The population has high and low fecundities. The correlations between absolute fecundity and total length, as well as between body weight and gonad weight, were significant (p<0.05) and positive in all the population.

The Body Size of Headstarted and Wild Juvenile European Pond Turtles (Emys orbicularis)

2017 ◽  
Vol 25 (2) ◽  
pp. 161
Author(s):  
Sławomir Mitrus ◽  
Bartłomiej Najbar ◽  
Adam Kotowicz ◽  
Anna Najbar
Keyword(s):  
Body Size ◽  
The Body ◽  
Emys Orbicularis

scholarly journals First record of Pachycrocuta brevirostris (Gervais, 1850) from Ukraine on the background of the European occurrence of the species

2021 ◽  
Author(s):  
Adrian Marciszak ◽  
Yuriy Semenov ◽  
Piotr Portnicki ◽  
Tamara Derkach
Keyword(s):  
Body Size ◽  
First Record ◽  
The Body ◽  
Crocuta Crocuta ◽  
Early Pleistocene ◽  
Eastern Asia ◽  
South Eastern

AbstractCranial material ofPachycrocuta brevirostrisfrom the late Early Pleistocene site of Nogaisk is the first record of this species in Ukraine. This large hyena was a representative of the Tamanian faunal complex and a single specialised scavenger in these faunas. The revisited European records list ofP.brevirostrisdocumented the presence of this species in 101 sites, dated in the range of 3.5–0.4 Ma. This species first disappeared in Africa, survived in Europe until ca. 0.8–0.7 Ma, and its last, relict occurrence was known from south-eastern Asia. The main reason of extinction ofP.brevirostrisprobably was the competition withCrocuta crocuta. The cave hyena was smaller, but its teeth were proportionally larger to the body size, better adapted to crushing bones and slicing meat, and could also hunt united in larger groups.

scholarly journals Insect body size changes under future warming projections: a case study of Chironomidae (Insecta: Diptera)

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Rungtip Wonglersak ◽  
Phillip B. Fenberg ◽  
Peter G. Langdon ◽  
Stephen J. Brooks ◽  
Benjamin W. Price
Keyword(s):  
Body Size ◽  
Ambient Temperature ◽  
Wing Length ◽  
The Body ◽  
Mesocosm Experiments ◽  
Future Warming ◽  
Increasing Temperature ◽  
Emergence Date ◽  
Average Body

AbstractChironomids are a useful group for investigating body size responses to warming due to their high local abundance and sensitivity to environmental change. We collected specimens of six species of chironomids every 2 weeks over a 2-year period (2017–2018) from mesocosm experiments using five ponds at ambient temperature and five ponds at 4°C higher than ambient temperature. We investigated (1) wing length responses to temperature within species and between sexes using a regression analysis, (2) interspecific body size responses to test whether the body size of species influences sensitivity to warming, and (3) the correlation between emergence date and wing length. We found a significantly shorter wing length with increasing temperature in both sexes of Procladius crassinervis and Tanytarsus nemorosus, in males of Polypedilum sordens, but no significant relationship in the other three species studied. The average body size of a species affects the magnitude of the temperature-size responses in both sexes, with larger species shrinking disproportionately more with increasing temperature. There was a significant decline in wing length with emergence date across most species studied (excluding Polypedilum nubeculosum and P. sordens), indicating that individuals emerging later in the season tend to be smaller.

scholarly journals Potential host ranges of three Asian larval parasitoids of Drosophila suzukii

2021 ◽  
Author(s):  
Kent M. Daane ◽  
Xingeng Wang ◽  
Brian N. Hogg ◽  
Antonio Biondi
Keyword(s):  
Body Size ◽  
Host Species ◽  
Classical Biological Control ◽  
Developmental Time ◽  
The Body ◽  
Phylogenetic Position ◽  
Egg Load ◽  
Drosophila Suzukii ◽  
Larval Parasitoids ◽  
Female Body Size

AbstractAsobara japonica (Hymenoptera: Braconidae), Ganaspis brasiliensis and Leptopilina japonica (Hymenoptera: Figitidae) are Asian larval parasitoids of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae). This study evaluated these parasitoids’ capacity to attack and develop from 24 non-target drosophilid species. Results showed that all three parasitoids were able to parasitize host larvae of multiple non-target species in artificial diet; A. japonica developed from 19 tested host species, regardless of the phylogenetic position of the host species, L. japonica developed from 11 tested species; and G. brasiliensis developed from only four of the exposed species. Success rate of parasitism (i.e., the probability that an adult wasp successfully emerged from a parasitized host) by the two figitid parasitoids was low in hosts other than the three species in the melanogaster group (D. melanogaster, D. simulans, and D. suzukii). The failure of the figitids to develop in most of the tested host species appears to correspond with more frequent encapsulation of the parasitoids by the hosts. The results indicate that G. brasiliensis is the most host specific to D. suzukii, L. japonica attacks mainly species in the melanogaster group and A. japonica is a generalist, at least physiologically. Overall, the developmental time of the parasitoids increased with the host’s developmental time. The body size of female A. japonica (as a model species) was positively related to host size, and mature egg load of female wasps increased with female body size. We discuss the use of these parasitoids for classical biological control of D. suzukii.

Prey Body Size and Ranking in Zooarchaeology: Theory, Empirical Evidence, and Applications from the Northern Great Basin

2011 ◽  
Vol 76 (3) ◽  
pp. 403-428 ◽  
Author(s):  
Jack M. Broughton ◽  
Michael D. Cannon ◽  
Frank E. Bayham ◽  
David A. Byers
Keyword(s):  
Body Size ◽  
Great Basin ◽  
Diet Breadth ◽  
Foraging Theory ◽  
Return Rate ◽  
The Body ◽  
Foraging Efficiency ◽  
Large Prey ◽  
Abundance Indices ◽  
Game Hunting

The use of body size as an index of prey rank in zooarchaeology has fostered a widely applied approach to understanding variability in foraging efficiency. This approach has, however, been critiqued—most recently by the suggestion that large prey have high probabilities of failed pursuits. Here, we clarify the logic and history of using body size as a measure of prey rank and summarize empirical data on the body size-return rate relationship. With few exceptions, these data document strong positive relationships between prey size and return rate. We then illustrate, with studies from the Great Basin, the utility of body size-based abundance indices (e.g., the Artiodactyl Index) when used as one component of multidimensional analyses of prehistoric diet breadth. We use foraging theory to derive predictions about Holocene variability in diet breadth and test those predictions using the Artiodactyl Index and over a dozen other archaeological indices. The results indicate close fits between the predictions and the data and thus support the use of body size-based abundance indices as measures of foraging efficiency. These conclusions have implications for reconstructions of Holocene trends in large game hunting in western North America and for zooarchaeological applications of foraging theory in general.

Annual variations in body-size spectra of planktonic ciliate communities and their relationships to environmental conditions: a case study in Jiaozhou Bay, northern China

2012 ◽  
Vol 93 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Henglong Xu ◽  
Yong Jiang ◽  
Wei Zhang ◽  
Mingzhuang Zhu ◽  
Khaled A. S. Al-Rasheid ◽  
...  
Keyword(s):  
Body Size ◽  
Water Temperature ◽  
Environmental Conditions ◽  
Jiaozhou Bay ◽  
Northern China ◽  
The Body ◽  
The Yellow Sea ◽  
Size Spectra ◽  
Annual Variations ◽  
Planktonic Ciliate

The annual variations in body-size spectra of planktonic ciliate communities and their relationships to environmental conditions were studied based on a 12-month dataset (June 2007 to May 2008) from Jiaozhou Bay on the Yellow Sea coast of northern China. Based on the dataset, the body sizes of the ciliates, expressed as equivalent spherical diameters, included five ranks: S1 (5–35 μm); S2 (35–55 μm); S3 (55–75 μm); S4 (75–100 μm); and S5 (100–350 μm). These body-size ranks showed a clear temporal succession of dominance in the order of S2 (January–April) → S1 (May–July) → S4 (August–September) → S3 (October–December). Multivariate analyses showed that the temporal variations in their body-size patterns were significantly correlated with changes in environmental conditions, especially water temperature, salinity, dissolved oxygen concentration (DO) and nutrients. In terms of abundance, rank S2 was significantly correlated with water temperature, DO and nutrients, whereas ranks S4 and S5 were correlated with the salinity and nutrients respectively (P < 0.05). These results suggest that the body-size patterns of planktonic ciliate communities showed a clear temporal pattern during an annual cycle and significantly associated with environmental conditions in marine ecosystems.

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