Female choosiness and mating opportunities in the blood-sucking bug Rhodnius prolixus

Behaviour ◽  
2016 ◽  
Vol 153 (15) ◽  
pp. 1863-1878 ◽  
Author(s):  
Lorena Pompilio ◽  
Martín González Franco ◽  
Lucía B. Chisari ◽  
Gabriel Manrique
Keyword(s):  
Sex Ratio ◽  
Rhodnius Prolixus ◽  
Male Mating ◽  
Sexually Active ◽  
Adaptive Function ◽  
Blood Sucking ◽  
Mating Opportunities ◽  
The Cost ◽  
The Relationship ◽  
Female Choosiness

We investigated the relationship between female choosiness and mating opportunities in the blood sucking bug Rhodnius prolixus. Rhodnius prolixus females exhibit active discrimination behaviour to male mating attempts which delays or prevents copulation. Female rejection behaviours can be beneficial if mating opportunities are readily available and the pool of males varies in their quality. Thus, the benefits of finding a better quality male may override the cost of rejecting a mating opportunity. Since the availability of mating opportunities is affected by the ratio of sexually active males to females, we randomly assigned focal pairs to arenas with a sex ratio biased toward males, females or without other individuals. More females exhibited rejection behaviour when conspecifics were present, however, no differences were found when the sex ratio was biased toward either males or females. We discuss possible explanations for these results and hypothesize about the adaptive function of female rejection behaviour.

scholarly journals Virgin Male Mating Advantage in Sagebrush Crickets: No Role for an Acoustically-Mediated Female Preference

1997 ◽  
Vol 21 ◽  
pp. 60-63
Author(s):  
Scott Sakaluk ◽  
Pamela Brady ◽  
Tracie Ivy ◽  
Marion Sakaluk ◽  
Jennifer Schaus
Keyword(s):  
Field Studies ◽  
Male Mating ◽  
Sexually Active ◽  
Bodily Fluids ◽  
Mating Advantage ◽  
Extant Species ◽  
Mating Opportunities ◽  
Virgin Male ◽  
Cyphoderris Strepitans ◽  
Number Of Males

The sagebrush cricket, Cyphoderris strepitans, is one of only five extant species belonging to an obscure orthopteran lineage, the Haglidae, closely related to the true crickets (Gryllidae) and katydids (Tettigoniidae) (Morris & Gwynne 1978). C. strepitans occurs exclusively in mountainous areas of the western United States, where it is found primarily in high-altitude sagebrush meadow habitat. Adults become sexually active in late spring, shortly after snow melt, and remain active for the following 4-6 weeks. The acoustic signals produced by males function to attract females (Snedden & Irazuzta 1994), thereby enhancing male mating opportunities (Snedden & Sakaluk 1992). Copulation is initiated when a receptive female climbs onto the dorsum of a male, at which time he attempts to transfer a spermatophore. During copulation, the female feeds on the male's fleshy hind wings and bodily fluids leaking from the wounds she inflicts. Previous field studies involving the mark­recapture of a large number of males have shown that once a male has mated, his probability of obtaining an additional copulation is reduced relative to that of a virgin male securing his first mating (Morris et al. 1989). One explanation for the virgin-male mating advantage is that non-virgin males, having lost a substantial portion of their energy reserves through sexual cannibalism by females and the transfer of a large spermatophore, may be unable to sustain the costly acoustical signaling activity required to attract additional females. In support of the "male fatigue" hypothesis, electronic assays of male signaling behavior have shown that virgin male C. strepitans call for significantly longer durations than recently mated males (Sakaluk et al. 1987; Sakaluk & Snedden 1990).

Relationship between mated status of females and their stage of ovarian development in field populations of the australian sheep blowfly, lucilia cuprina(wiedemann) (diptera: calliphoridae)

1987 ◽  
Vol 77 (4) ◽  
pp. 609-615 ◽  
Author(s):  
L. Barton Browne ◽  
A. C. M. Van Gerwen ◽  
P. H. Smith
Keyword(s):  
Sex Ratio ◽  
Ovarian Development ◽  
Operational Sex Ratio ◽  
Lucilia Cuprina ◽  
Sexually Active ◽  
Australian Sheep ◽  
Rich Material ◽  
Protein Rich ◽  
The Relationship

AbstractIn field populations of Lucilia cuprina (Wiedemann) in Australia, there was a very low percentage of mating in females that, on the evidence of their stage of ovarian development, had not yet consumed protein-rich material. Virtually all females whose oocytes had reached early vitellogenesis had mated. Thus, most females of this anautogenous species had mated soon after their ovarian development had proceeded beyond the resting stage at which development ceases in females that have not consumed protein. The relationship between mated status and ovarian development of hand-caught females did not differ from that for females which had been allowed to remain for more than 1 h with sexually active males in the collection chamber of traps. Thus mating occurred rarely, if at all, in the trap chambers, which suggests that females in the field mate soon after first becoming sexually receptive. This, together with knowledge that females of this species do not remate readily, indicates that the operational sex ratio in L. cuprina is heavily male-biased.

Fecundity and Gonado-somatic Index of Trichiurus lepturus (Linnaeus, 1758) Along the Zamboanga del Norte Coast

2018 ◽  
Vol 6 (7) ◽  
pp. 120
Author(s):  
Ma. Dulce C. Guillena
Keyword(s):  
Sex Ratio ◽  
Stock Assessment ◽  
Chi Square ◽  
Moon Phases ◽  
Ovary Weight ◽  
Moment Coefficient ◽  
Trichiurus Lepturus ◽  
Significant Difference ◽  
The Relationship ◽  
Somatic Index

Gonado-somatic index and fecundity are tools for measuring the sexual maturity and ability of animals to reproduce.  This study investigates the reproduction of Trichiurus lepturus. Specifically, this aimed to determine the sex ratio, the GSI, the relationship between fecundity and total length, fecundity and total weight, fecundity and ovary weight. The Descriptive Method of research was used.  Percentage and chi-square was utilized in determining the percentage of occurrence and sex ratio respectively.   Pearson r Product Moment Coefficient of Correlation was used to determine the relationships of the parameters. The study revealed that females outnumbered males and the sex ratio for different month showed significant difference.  Spawning season was observed to occur in November and December as revealed in its GSI values and it synchronized with the full and new moon phases.  Fecundity is positively correlated with body weight, body size, and ovary weight where ovary weight is observed to be the best index for fecundity.  The results of this study could be used further for formal stock assessment of cutlassfish fishery.

The Awareness Level of the Safety and Health of the Operational Level

2017 ◽  
Vol 3 (1) ◽  
pp. 42
Author(s):  
Roshanira Che Mohd Noor ◽  
Nur Atiqah Rochin Demong
Keyword(s):  
Health And Safety ◽  
Health Conditions ◽  
Effective Strategies ◽  
Operational Level ◽  
Safety And Health ◽  
Health Factors ◽  
The Cost ◽  
The Relationship ◽  
Awareness Level

Providing a safe and healthy workplace is one of the most effective strategies in for holding down the cost of doing construction business. It was a part of the overall management system to facilitate themanagement of the occupational health and safety risk that are associated with the business of the organization. Factors affected the awareness level inclusive of safety and health conditions, dangerous working area, long wait care and services and lack of emergency communication werethe contributed factors to the awareness level for the operational level. Total of 122 incidents happened at Telekom Malaysia Berhad as compared to year 2015 only 86 cases. Thus, the main objective of this study was to determine the relationship between safety and health factors and the awareness level among operational workers.The determination of this research was to increase the awareness level among the operational level workerswho committing to safety and health environment.

Pound Wise and Penny Foolish? Weight Loss and The Dynamics of Health Care Spending

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch
Keyword(s):  
Weight Loss ◽  
Cost Savings ◽  
Cost Effective ◽  
Economic Consequences ◽  
Health Care Spending ◽  
Order Of Magnitude ◽  
Dynamic Measures ◽  
The Cost ◽  
The Impact ◽  
The Relationship

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.

Marginal assessment of the cost and benefits of aphasia treatment: Evidence from community-based telerehabilitation treatment for aphasia

2021 ◽  
pp. 1357633X2098277
Author(s):  
Molly Jacobs ◽  
Patrick M Briley ◽  
Heather Harris Wright ◽  
Charles Ellis
Keyword(s):  
Cost Effectiveness ◽  
Economies Of Scale ◽  
Reference Group ◽  
Unit Cost ◽  
Community Based ◽  
Face To Face ◽  
Conduction Aphasia ◽  
Aphasia Treatment ◽  
The Cost ◽  
The Relationship

Introduction Few studies have reported information related to the cost-effectiveness of traditional face-to-face treatments for aphasia. The emergence and demand for telepractice approaches to aphasia treatment has resulted in an urgent need to understand the costs and cost-benefits of this approach. Methods Eighteen stroke survivors with aphasia completed community-based aphasia telerehabilitation treatment, utilizing the Language-Oriented Treatment (LOT) delivered via Webex videoconferencing program. Marginal benefits to treatment were calculated as the change in Western Aphasia Battery-Revised (WAB-R) score pre- and post-treatment and marginal cost of treatment was calculated as the relationship between change in WAB-R aphasia quotient (AQ) and the average cost per treatment. Controlling for demographic variables, Bayesian estimation evaluated the primary contributors to WAB-R change and assessed cost-effectiveness of treatment by aphasia type. Results Thirteen out of 18 participants experienced significant improvement in WAB-R AQ following telerehabilitation delivered therapy. Compared to anomic aphasia (reference group), those with conduction aphasia had relatively similar levels of improvement whereas those with Broca’s aphasia had smaller improvement. Those with global aphasia had the largest improvement. Each one-point of improvement cost between US$89 and US$864 for those who improved (mean = US$200) depending on aphasia type/severity. Discussion Individuals with severe aphasia may have the greatest gains per unit cost from treatment. Both improvement magnitude and the cost per unit of improvement were driven by aphasia type, severity and race. Economies of scale to aphasia treatment–cost may be minimized by treating a variety of types of aphasia at various levels of severity.

Relationship among social tactics, job embeddedness, and affective commitment in newcomers: the moderating effect of workplace spirituality

2021 ◽  
pp. 1-21
Author(s):  
Hsien-Long Huang ◽  
Li-Keng Cheng ◽  
Pi-Chuan Sun ◽  
Yi Shiuan Jiang ◽  
Hsin Hua Lin
Keyword(s):  
Work Experience ◽  
Affective Commitment ◽  
Human Resources Management ◽  
Workplace Spirituality ◽  
Job Embeddedness ◽  
Moderating Effect ◽  
Empirical Examination ◽  
Employee Survey ◽  
The Cost ◽  
The Relationship

Abstract The cost of recruitment and training of newcomers can be a burden for enterprises, causing adverse effects on human resources management. Although much research has addressed employee turnover, less attention has been paid to methods of improving the retention of new hires. This study is an empirical examination of the increase in predictive strength of antecedents of affective commitment for comparing newcomers’ workplace spirituality. The results of an employee survey completed by 237 newcomers with under two years of work experience indicate that socialization tactics have a direct impact on job embeddedness, which in turn has a direct effect on affective commitment. Workplace spirituality has a significant moderating effect on the relationship between socialization tactics and job embeddedness. Also, workplace spirituality has a significant moderating effect on the relationship between job embeddedness and affective commitment.

scholarly journals Natural variation in social conditions affects male mate choosiness in the amphipod Gammarus roeselii

2021 ◽  
Author(s):  
Konrad Lipkowski ◽  
Sophie Steigerwald ◽  
Lisa M Schulte ◽  
Carolin Sommer-Trembo ◽  
Jonas Jourdan
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Natural Variation ◽  
Natural Populations ◽  
Social Background ◽  
Social Conditions ◽  
Background Information ◽  
Male Mating ◽  
Natural Environments ◽  
Male Mate

Abstract The extent of male mate choosiness is driven by a trade-off between various environmental factors associated with the costs of mate acquisition, quality assessment and opportunity costs. Our knowledge about natural variation in male mate choosiness across different populations of the same species, however, remains limited. In this study, we compared male mate choosiness across 10 natural populations of the freshwater amphipod Gammarus roeselii (Gervais 1835), a species with overall high male mating investments, and evaluated the relative influence of population density and sex ratio (both affecting mate availability) on male mate choosiness. We investigated amplexus establishment after separating mating pairs and presenting focal males with a novel, size-matched female from the same population. Our analysis revealed considerable effects of sex ratio and (to a lesser extent) population density on time until amplexus establishment (choosiness). Male amphipods are able to perceive variable social conditions (e.g., sex ratio) and modify their mating strategy accordingly: We found choosiness to be reduced in increasingly male-biased populations, whereas selectivity increases when sex ratio becomes female biased. With this, our study expands our limited knowledge on natural variations in male mate choosiness and illustrates the importance of sex ratio (i.e., level of competition) for male mating decisions in natural environments. Accounting for variation in sex ratios, therefore, allows envisioning a distinctive variation of choosiness in natural populations and highlights the importance of considering social background information in future behavioral studies.

Investigating the Relationship between Company Competitiveness and Environmental Regulation in European Food Processing: Results of a Matched Firm Comparison

1998 ◽  
Vol 30 (9) ◽  
pp. 1585-1602 ◽  
Author(s):  
D M W N Hitchens ◽  
J E Birnie ◽  
A McGowan ◽  
U Triebswetter ◽  
A Cottica
Keyword(s):  
Environmental Regulation ◽  
Food Processing ◽  
Value Added ◽  
Effluent Treatment ◽  
Environmental Costs ◽  
The European Union ◽  
The Republic ◽  
The Cost ◽  
The Relationship ◽  
Regulation Costs

The authors use a method of matched-plant comparisons between food processing firms in Germany, Italy, Northern Ireland, and the Republic of Ireland to investigate the relationship between environmental regulation and company competitiveness across the European Union. Comparative competitiveness was indicated by measures of value-added per employee, physical productivity, export share, and employment growth. The cost of water supply (public or well), effluent treatment (in-plant treatment and/or sewerage system), and disposal of sludge and packaging were also compared. Total environmental costs in Germany, Italy, and Ireland were small: usually less than 1% of turnover. Compared with the Irish firms, German companies had relatively high environmental costs as well as productivity levels. There was, however, a lack of a clear relationship between company competitiveness and the size of regulation costs: in Ireland and Italy environmental costs were similar but German firms had much higher productivity; compared with German counterparts, Italian firms had lower environmental costs but higher productivity.

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