scholarly journals Size-structured mating niche differentiation in the male-polyphenic mite Rhizoglyphus robini

2021 ◽  
Author(s):  
Flor T. Rhebergen ◽  
Maarten Wijstma ◽  
Isabel M. Smallegange
Keyword(s):  
Body Size ◽  
Niche Differentiation ◽  
The Body ◽  
Size Difference ◽  
Rhizoglyphus Robini ◽  
Rival Male ◽  
Mating Opportunities ◽  
Alternative Mating Tactic ◽  
Bulb Mite ◽  
Male Polyphenism

Condition-dependent expression of alternative male morphs evolves when males of different sizes experience different mating niches, requiring different morphologies. Such mating niche differentiation can be due to competitive asymmetry between large and small males in contests over mating opportunities. Here, we tested the hypothesis that aggressive interactions among males cause size-structured mating niches in an acarid mite with condition-dependent male polyphenism: the bulb mite Rhizoglyphus robini. In this species, large males mature as armed fighters with enlarged legs, and small males as scramblers without modified legs. We staged experimental dyadic contests over a mating opportunity between either a pair of fighter males, or a fighter and a scrambler male. We predicted that the larger male would have a higher likelihood of mating first in contests among fighters, that the fighter male would have a higher likelihood of mating first in fighter-scrambler contests, that fighters would have a higher likelihood of interrupting ongoing copulations if they are larger than their mating rival, and that copulations in the presence of a fighter rival therefore last shorter than copulations with a scrambler rival present. We found that in contests among fighters, the larger male had a higher probability of mating first. In contests among a fighter and scrambler, the fighter male was more likely to mate first regardless of the body size difference between the contestants. Ongoing copulations were only rarely interrupted by the rival male (always by a fighter), and the probability of interruption did not depend on the body size difference between the mating male and its rival. Copulations lasted shorter in the presence of a rival fighter, but this effect was not attributable to interruption of copulations. We conclude that the fighting niche is particularly accessible for large males, as larger males have a higher probability of winning pre-copulatory contests. Such mating niche differentiation likely contributes to evolutionary maintenance of condition-dependent male polyphenism, where small males are forced to adopt an alternative mating tactic and hence develop a dedicated morphology.

Variation in mating pattern in a population of the Andean frog Hyla labialis

2001 ◽  
Vol 22 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Horst Lüddecke
Keyword(s):  
Body Size ◽  
Mate Choice ◽  
Female Mate Choice ◽  
Male Competition ◽  
The Body ◽  
Size Difference ◽  
Mating Pattern ◽  
Colombian Andes ◽  
Reproductive Females ◽  
Breeding Seasons

AbstractUnmated frogs and mated pairs from a population of individually marked Hyla labialis were captured, measured and released over four consecutive years in a highland valley of the Colombian Andes. Across eight prolonged breeding seasons, three times more males than females were captured. On average, females were significantly larger than males. Although the largest reproductive males were larger than the smallest reproductive females, amplexing males were always smaller than the females they clasped. Larger males had no mating advantage, because the body size distribution of males was the same for mated and unmated males, and the average snout-vent length of mated males was similar to that of unmated males. There was no indication of larger males taking over clasped females during male-male competition, because there was no size difference between males clasping gravid, spawning and spent females. Significantly size-assortative matings occurred on days when male availability per female was moderately high, but not when it was low, suggesting that female mate choice is relatively more important than male-male competition in shaping mating pattern.

Appraising Behaviour During Male-male Interaction in the Japanese Horned Beetle Trypoxylus Dichotomus Septentrionalis (Kono)

Behaviour ◽  
2003 ◽  
Vol 140 (4) ◽  
pp. 501-517 ◽  
Author(s):  
Yoshihito Hongo
Keyword(s):  
Body Size ◽  
The Body ◽  
The Other ◽  
Size Difference ◽  
Horn Length ◽  
Horned Beetle ◽  
The Difference ◽  
Contest Behaviour ◽  
Trypoxylus Dichotomus ◽  
Stage 1

AbstractDetailed contest behaviour of the Japanese horned beetle, Trypoxylus dichotomus septentrionalis, was examined in the field. Male-male interactions have three sequences, and in these sequences four behavioural stages were recognized. After two males encountered (Stage 1), they always faced and shoved each other with their horns (Stage 2: 'Shoving'). Then, if the horn length or body size difference between the contestants was large, one male began to retreat and was chased by the other male, and the interactions terminated (Stage 4A: 'Chasing'). If the difference was small, the interactions proceeded to the escalated fighting stage (Stage 3: 'Pry'), in which two males put their horns under their opponents and push and try to flip them up each other. The interactions, which proceeded to Stage 3, have two ways of termination. If the body size difference was large, one male was flipped up by the other male, and the interactions was terminated quickly (Stage 4B). If the difference was small, the interactions was not terminated so quickly and continued until one male began to retreat, proceeding to Stage 4A. It is suggested that males with shorter horns relative to the opponents avoid the escalated fighting stage, 'Pry', after perceiving the horn length difference during 'Shoving', which would be an appraising behaviour. Thus, 'Shoving' is the most important stage among all the interaction processes in that the highest proportion of judgement is made here. The great allometric variation of horn length would presently function more greatly for enhancing the efficiency of mutual appraisal than that in actual fighting.

Response to chemical cues from conspecifics reflects male mating preference for large females and avoidance of large competitors in the European pond turtle, Emys orbicularis

Behaviour ◽  
2006 ◽  
Vol 143 (5) ◽  
pp. 569-587 ◽  
Author(s):  
Martin Plath ◽  
Yvonne Meyer-Lucht ◽  
Jens R. Poschadel
Keyword(s):  
Body Size ◽  
Chemical Communication ◽  
Chemical Cues ◽  
The Body ◽  
Size Difference ◽  
Male Mating ◽  
Emys Orbicularis ◽  
Strength Of Preference ◽  
Pond Turtle ◽  
Untreated Water

AbstractWe examined chemical communication in male and female European pond turtles (Emys orbicularis). In simultaneous binary choice tests, a focal animal was given a choice between pheromones from a conspecific and a choice chamber containing untreated water. Females did not show a preference, both when male and when female stimuli were presented. On the contrary, males preferred the odor of a female over untreated water, suggesting that males actively search for females. The strength of preference was positively correlated with the body size difference between the female and the focal male, indicating that males prefer to mate with larger females. Female fecundity is positively correlated with female size in E. orbicularis, which may account for male choosiness. No overall preference for the stimulus animal was observed when males were presented cues from another male. However, the strength of preference was negatively correlated with the difference in body size. Males avoided large males, but oriented towards smaller stimulus males. This reflects that males form dominance hierarchies, where large males aggressively attack smaller ones. Far-range chemical communication probably enables males to minimize the risk of costly aggressive interactions. This is, to our knowledge, the first study on the role of chemical cues for inter and intrasexual communication in the European pond turtle.

scholarly journals Development of a Mobile-Based Application Software Body Size Calculator

2018 ◽  
Vol 26 (2(128)) ◽  
pp. 104-107
Author(s):  
Emine Utkun ◽  
Erkan Yeşil ◽  
Nezla Ünal
Keyword(s):  
Body Size ◽  
Mass Production ◽  
The Body ◽  
Size Difference ◽  
Application Software ◽  
Body Measurements ◽  
Factors Affecting ◽  
Production Body ◽  
Purchasing Behaviour ◽  
Clothing Fit

Clothing fit is one of the important factors affecting consumers’ purchasing behaviour and clothing satisfaction. The aim of this study was to develop a mobile-based body size calculator program to compare standard mass production body measurements with female body measurements taken individually. Another aim of the study was to investigate the effects of size difference between the body measurements taken individually and mass productionbased measurements on pattern drafting. At the end of the study, the program developed was run, the differences between the patterns examined and pattern modifications made according to the results obtained.

Body Size and Movement

2018 ◽  
Vol 7 (1) ◽  
pp. 88-93 ◽  
Author(s):  
John H. Challis
Keyword(s):  
Body Size ◽  
Human Movement ◽  
Human Locomotion ◽  
The Body ◽  
Size Difference ◽  
Endurance Running ◽  
Body Strength ◽  
Geometric Scaling ◽  
Body Sizes ◽  
Walking Velocity

Humans of different sizes move in very similar ways despite the size difference. The principles of geometric scaling provide insight into the reasons for the similar movement patterns observed. In human locomotion, body size influences endurance running performance, with shorter body sizes being an advantage due to better heat exchange compared with their taller counterparts. Scaling can also show the equivalence of child gait with that of adults in terms of stride length and walking velocity. In humans, maximum jump height is independent of standing height, a scaling result which has been validated by examining jumps with mass added to the body. Finally, strength scales in proportion to body mass to the two-thirds power, which explains why shorter people have greater relative body strength compared with taller individuals. Geometric scaling reveals the underlying principles of many human movement forms.

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.

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