Survival and predation rate of wild-caught and commercially produced Orius majusculus (Reuter) (Hemiptera: Anthocoridae)

Author(s):  
Kim Jensen ◽  
Søren Toft ◽  
Jesper G. Sørensen ◽  
Martin Holmstrup

Abstract The quality of biological control agents used in augmentative releases may be affected by rearing conditions due to inbreeding or laboratory adaptation, or to phenotypic effects of the rearing environment. We hypothesized that individuals from a wild population would be in better body condition and kill more prey than individuals from a commercially produced population. We caught wild Orius majusculus (Reuter) in a maize field and compared their initial body mass, survival, and prey reduction capacity to commercially produced O. majusculus. Predation capacity and survival were compared in short-term Petri dish tests with Frankliniella tenuicornis (Uzel) thrips, Ephestia kuehniella (Zeller) moth eggs, or Rhopalosiphum padi (L.) aphids as prey, and in longer-term outdoor mesocosms containing live seedling wheat grass with thrips or aphids as prey. Wild-caught O. majusculus were typically heavier and overall had higher survival during tests than commercially produced O. majusculus. Females were heavier than males and typically killed more prey. However, we found no difference between wild-caught and commercially produced individuals on prey reduction, neither in Petri dishes nor in mesocosms. Our study suggests that commercially produced O. majusculus have lower body condition than wild O. majusculus due to their lower body mass and survival, but that this does not have any negative effect on the number of pest prey killed over the timelines and conditions of our tests. Commercially produced O. majusculus thus did not have a lower impact on pest prey numbers than wild-caught individuals and therefore had similar biological control value under our study conditions.

The Condor ◽  
2005 ◽  
Vol 107 (3) ◽  
pp. 694-702 ◽  
Author(s):  
Matthieu Féret ◽  
Joël Bêty ◽  
Gilles Gauthier ◽  
Jean-François Giroux ◽  
Gérald Picard

AbstractAbdominal profile indices were developed to evaluate body condition in birds without capturing or handling them. We assessed the reliability of abdominal profile indices in predicting condition of spring staging Greater Snow Geese (Chen caerulescens atlantica). We first calibrated profile scores assigned to females against two direct measures of nutrient stores, abdominal fat and body mass corrected for body size. Abdominal profile indices were linearly and significantly related to both abdominal fat and body mass but the variance was high for individuals assigned to the same profile score (R2 = 0.08 and R2 = 0.09, respectively, n = 230). On average, an increase of one profile score corresponded to an increase of 100 g in body mass. Abdominal profiles were better predictors of average abdominal fat and body mass of birds assigned to the same profile category. To assess the usefulness of abdominal profiles in the field, we also examined if the technique could detect the negative effect of a spring hunt on nutrient storage by staging geese, an effect previously detected with internal measures of nutrient reserves. We monitored seasonal changes in abdominal profile indices of staging geese in years without (1997 and 1998) and with the spring hunt (1999 and 2000). In two out of three regions, abdominal profiles revealed that condition increased at a higher rate in nonhunting than in hunting years. The lack of a negative effect of hunting in the other region was likely due to variability among observers in abdominal profile scoring. We conclude that abdominal profile indices can be useful to assess body condition of spring staging Greater Snow Geese although the technique has serious limitations at the individual level, especially without proper training of observers.¿Son los Perfiles Abdominales Útiles para Determinar la Condición Corporal de Chen caerulescens atlantica durante Escalas Migratorias de Primavera?Resumen. Los índices de perfil abdominal fueron desarrollados para evaluar la condición corporal de las aves sin tener que capturarlas o manipularlas. En este estudio examinamos la confiabilidad de dichos índices para predecir la condición corporal de gansos Chen caerulescens atlantica durante la época de escalas migratorias de primavera. Inicialmente, calibramos los puntajes de los perfiles asignados a un grupo de hembras con respecto a dos medidas directas de reservas nutritivas, la grasa abdominal y la masa corregida por el tamaño corporal. Los índices de perfil abdominal estuvieron lineal y significativamente relacionados con la grasa abdominal y la masa corporal (R2 = 0.08 y R2 = 0.09, respectivamente, n = 230), pero la varianza entre individuos asignados al mismo puntaje del perfil fue alta. En promedio, un incremento de un punto en el perfil correspondió a un incremento de 100 g en la masa corporal. Los perfiles abdominales predijeron de mejor manera los promedios de grasa abdominal y masa corporal de aves asignadas a la misma categoría del perfil. Para evaluar la utilidad de los perfiles abdominales en el campo, también examinamos si la técnica podía detectar el efecto negativo de la cacería de primavera sobre el almacenamiento de nutrientes en gansos que estaban haciendo escalas migratorias, un efecto previamente detectado por medio de medidas internas de las reservas nutritivas. Monitoreamos los cambios estacionales en los índices de perfil abdominal de gansos en años que estuvieron (1997 y 1998) y no estuvieron (1999 y 2000) expuestos a cacería en la primavera. En dos de las tres regiones, los perfiles abdominales indicaron que la condición corporal se incrementó a una tasa mayor en los años sin cacería. La ausencia de un efecto negativo de la cacería en la otra región probablemente fue debida a la variabilidad entre distintos observadores al establecer los valores del perfil abdominal. Concluimos que los índices de perfil abdominal pueden ser útiles para evaluar la condición corporal de estos gansos durante la época de escalas migratorias, pero la técnica tiene limitaciones serias a nivel individual, especialmente cuando los observadores no han sido entrenados adecuadamente.


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 889
Author(s):  
Jian-Feng Liu ◽  
Xiu-Qin Wang ◽  
Jacqueline R. Beggs ◽  
Hou-Ding Ou ◽  
Xiao-Fei Yu ◽  
...  

Intraguild predation interactions have substantial theoretical and practical implications for the dynamics of natural competitor populations used for biological control. Intraguild predation on parasitized aphids not only has a direct, negative effect on the parasitoid species, but it may indirectly influence the predator’s development, survival, reproduction and predation rates. In this study, we used two-sex life table theory, life table parameters and predation rates of Aphidoletes aphidimyza (Rondani) to compare when its populations fed on aphids (Myzus persicae Sulzer) (Hemiptera: Aphididae) that were either unparasitized or parasitized by Aphidius gifuensis (Ashmead) (Hymenoptera: Braconidae). Our results showed that individuals of A. aphidimyza were capable of completing their development and attaining maturity when they fed on parasitized aphids. Although feeding on parasitized aphids did not influence the survival rates of immature A. aphidimyza, it did significantly slow their development and extended their longevity, thereby reducing the fecundity and predation rates of A. aphidimyza. These findings may be pivotal for better understanding the sustained coexistence of predators with parasitoids in the biological control of aphids.


2011 ◽  
Vol 6 (2) ◽  
pp. 164-171 ◽  
Author(s):  
Julie Gast ◽  
Hala Madanat ◽  
Amy Campbell Nielson

The purpose of this study was to determine where men fall on the motivation continuum based on intuitive eating status and if motivation for physical activity and intuitive eating are correlated. Results indicate that being an intuitive eater was associated with a lower body mass index. In terms of demographic variables, as age increased, intuitive eating status decreased and body mass index increased. Men scored high on the antidieting and self-care subscales of the Intuitive Eating Scale. Men who were classified as intuitive eaters scored higher on the external and introjected regulation of the Behavioral Regulation in Exercise Questionnaire but no significant differences were reported by eating status and the identified and intrinsic motivation subscales. Intuitive eating holds promise as a weight management and weight loss tool for men. Intuitive eating may also influence initial motivation for physical activity for men.


2012 ◽  
Vol 39 (4) ◽  
pp. 301 ◽  
Author(s):  
Gina M. Morgan ◽  
Travis E. Wilcoxen ◽  
Michelle A. Rensel ◽  
Stephan J. Schoech

Context Anthropogenic disturbances induce physiological and behavioural responses in numerous species. The negative effects of human disturbance are of special concern to threatened and endangered species. Aims The present study aims to compare physiological stress measures and reproductive success of Florida scrub-jays (Aphelocoma coerulescens) living near roads with jays that live away from roads. Specifically, it aims to test whether roads are stressful. Methods We assessed physiological measures that can serve as indicators of ‘stress’ to determine whether a highway that bisects our study site had physiological effects on adult male Florida scrub-jays. We captured male breeders from three territory types, including scrub habitat that (1) bordered a highway with a grassy shoulder that created an ‘edge’ habitat (roadside), (2) bordered human-maintained habitat (a plowed firebreak of sand with adjacent pasture) that served as a control for the edge-effect of the road (pasture) and (3) contained only natural scrub habitat (interior). We measured baseline concentrations of the stress hormone corticosterone (CORT), body mass, and a suite of longitudinal body measures to generate a body condition index in males from each territory type over three breeding seasons. Key results Roadside jays had greater body mass than did interior and pasture jays, although there were no differences in overall baseline CORT concentrations or body condition among territory classes. There was no difference in clutch initiation date or size and nestling and independent-young survival. Conclusions Our results suggest that the road through our study site has physiological effects on Florida scrub-jays; however, there is mixed evidence as to whether it acts as a chronic stressor. Implications Our findings provide evidence that roads and road-associated disturbance has neutral or potentially beneficial physiological effects of roads on Florida scrub-jays. Knowledge of these effects of roads and disturbance on jays will hopefully provide additional opportunities to improve conservation of this species.


2018 ◽  
Vol 3 (3) ◽  
pp. 43 ◽  
Author(s):  
Angeliki Kavvoura ◽  
Nikolaos Zaras ◽  
Angeliki-Nikoletta Stasinaki ◽  
Giannis Arnaoutis ◽  
Spyridon Methenitis ◽  
...  

The rate of force development (RFD) is vital for power athletes. Lean body mass (LBM) is considered to be an essential contributor to RFD, nevertheless high RFD may be achieved by athletes with either high or low LBM. The aim of the study was to describe the relationship between lower-body LBM and RFD, and to compare RFD in taekwondo athletes and track and field (T&F) throwers, the latter having higher LBM when compared to taekwondo athletes. Nine taekwondo athletes and nine T&F throwers were evaluated for countermovement jumping, isometric leg press and leg extension RFD, vastus lateralis (VL), and medial gastrocnemius muscle architecture and body composition. Lower body LBM was correlated with RFD 0–250 ms (r = 0.81, p = 0.016). Taekwondo athletes had lower LBM and jumping power per LBM. RFD was similar between groups at 30–50 ms, but higher for throwers at 80–250 ms. RFD adjusted for VL thickness was higher in taekwondo athletes at 30 ms, but higher in throwers at 200–250 ms. These results suggest that lower body LBM is correlated with RFD in power trained athletes. RFD adjusted for VL thickness might be more relevant to evaluate in power athletes with low LBM, while late RFD might be more relevant to evaluate in athletes with higher LBM.


2020 ◽  
Vol 113 (4) ◽  
pp. 1735-1740
Author(s):  
Md Arefur Rahman ◽  
Souvic Sarker ◽  
Eunhye Ham ◽  
Jun-Seok Lee ◽  
Un Taek Lim

Abstract The polyphagous predator Orius species is a dominant predator of thrips, mites, and aphids. Orius laevigatus (Fieber) is a well-known commercialized and effective biological control agent, whereas Orius minutus (L.) distributed widely over the world has not been commercialized. To assess potentials of developing O. minutus as a commercial biological control agent, we compared the biological parameters of O. minutus with O. laevigatus when reared on mixed stages of Tetranychus urticae Koch at 27.5°C. Nymphal development of O. laevigatus was shorter (11.30 d) than that of O. minutus (12.25 d), but there was no significant difference in survivorship between the two species. Also, no significant difference was found in either the preoviposition or oviposition periods, lifetime fecundity, or longevity between the two species. However, O. minutus eggs had a higher hatch rate (0.77) than O. laevigatus (0.71). In life table analysis, no difference was found in any parameters, i.e., R0, rm, λ, T, and DT, between O. laevigatus and O. minutus in two-tailed t-tests. In a predation bioassay, O. minutus consumed 1.39 times more adult T. urticae in 24 h than did O. laevigatus, although the predation rate on T. urticae eggs was similar between the two species. These results suggest that O. minutus native to Korea could be developed as a biological control agent against T. urticae.


Author(s):  
Dharmvir Ranjan Bharati ◽  
Seema Kumari ◽  
Kranti Chand Jaykar ◽  
Ajay Kumar ◽  
Sanjay Kumar Choudhary ◽  
...  

Background: The dermatologic consultation might be a precious opportunity to recognize and treat depression associated with suicidal ideation in these patients. This study aimed to find the prevalence of suicidal ideation among patients with dermatologic conditions, and identifying demographic variables of suicidal ideation. Methods: This institution based cross-sectional study was conducted during February to March 2017, at dermatological out-patients department of the teaching hospital Indira Gandhi Institute of Medical Sciences (IGIMS), Patna, India. Results: Of 396 adults with skin disease 272 (68.69%) were male. Prevalence of suicidal tendency was significantly more among young adults and higher in females (38.7%) than males (1.5%). In males, suicidal tendency was in patients suffering from tinea infection while among females, significantly more observed among patients suffering from tinea 38.71%, psoriasis 22.58% and chronic idiopathic urticaria 16.13%. The risk of suicidal tendency in males were significantly higher among 18–20 years, unemployed, belongs to smaller family, having lower body mass index and suffering from depression. While in females, suicidal tendency was significantly higher among early adulthood, not or lower education, unemployed, no personal income and vegetarian, belongs to large family, no family support, having lower body mass index and suffering from depression as well as suffering from some other medical comorbidity in addition to skin diseases. Conclusions: Risk correlates of suicidal ideation with skin diseases were early adulthood, lower education, unemployment with no personal income, vegetarian diet, large family, no family support, lower body mass index and suffering from depression and comorbidities. 


2020 ◽  
Vol 32 (1) ◽  
pp. 1-8
Author(s):  
Danielle Smith ◽  
Larissa Adams ◽  
Rosa Du Randt ◽  
Jan Degen ◽  
Stefanie Gall ◽  
...  

Background: Information about the relationships between physical fitness, body composition and nutrition has increased in recent years; however, little is known about physical fitness and the coexistence of under-/overnutrition among children living in disadvantaged areas. Objectives: To determine the physical fitness status and its association with body composition, growth and selected socio- demographics in primary schoolchildren from disadvantaged communities in the Nelson Mandela Bay region. Methods: Nine hundred and sixty-five children (49% girls, M=9.5 years) participated in this cross-sectional study. Height and weight were measured to establish body mass index, and height-for-age z-scores. Physical fitness was assessed using tests from the Eurofit Physical Fitness test battery (flexibility, upper/lower body muscular strength and cardiorespiratory fitness). Between- group differences and cross-sectional associations were examined with univariate (Chi2-tests, analyses of variance) and multivariate methods (mixed linear/logistic regression). Results: Most children had normal weight (76.7%), while 4.5% were underweight and 18.7% were overweight/obese. Underweight children and children with stunted growth (11.5%) had lower average upper body strength (p<0.001). Overweight/obese children had lower scores in weight-bearing activities (p<0.001). Children with higher socio-economic status were more likely to be overweight and obese (p<0.001). In the multivariate analyses, sex, age, body mass index, and stunting were associated with children’s physical fitness. Conclusion: Fitness assessments seem to be a relevant measure of the current health status of children in disadvantaged settings. Compared to international norms, the children in this study had relatively low scores for both upper- and lower body muscular strength. Therefore, effective school-based intervention programmes should be developed to improve children’s physical fitness in disadvantaged schools.


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