The ecology of a natural population of the Queensland fruit fly, Dacus tryoni. I. The parameters of the pupal and adult populations during a single season

1967 ◽  
Vol 15 (2) ◽  
pp. 303 ◽  
Author(s):  
MA Bateman ◽  
FJ Sonleitner
Keyword(s):  
Young Adults ◽  
Natural Population ◽  
Adult Population ◽  
Adult Emergence ◽  
Fruit Fly ◽  
Fruit Trees ◽  
High Rate ◽  
Larval Food ◽  
Gravid Females ◽  
Pupal Mortality

The ecology of a natural population of Dacus tryoni is being studied at an orchard near Sydney, N.S.W. Changes in numbers observed during a single year are described and discussed. Estimates of pupal numbers were based on the weekly total pupal production of a random sample of the fruit trees in the orchard. Parameters of the adult population were measured by means of mark-recapture sampling and analysed by means of three mathematical models. Discrepancies between some of the estimates of numbers given by these models are explained by extensive adult emergence at those times, and the lower survival factors of the young adults. Evidence for the random sampling of adults is presented. The decline of the population towards the end of the season was brought about mainly by (1) high pupal mortality, (2) cessation of pupal production due to diminution and disappearance of larval food, (3) a marked decline in the number of gravid females, apparently in response to diminishing oviposition sites, and (4) a high rate of loss of young adults, presumably by emigration. There was no evidence of overcrowding.

The comparative ecology of two closely related, sympatric species of Dacus (Diptera) in Queensland

1967 ◽  
Vol 15 (6) ◽  
pp. 1123 ◽  
Author(s):  
GW Gibbs
Keyword(s):  
Relative Abundance ◽  
Natural Populations ◽  
Coastal Region ◽  
Late Summer ◽  
Fruit Fly ◽  
Fruit Trees ◽  
Abundant Species ◽  
Sympatric Species ◽  
Larval Food ◽  
Short Supply

Two sibling species of tephritid fruit fly, Dacus neohumeralis and D. tryoni, are common along the coastal region of Queensland. Natural populations of these flies were sampled at Rockhampton and Yeppoon at 2-monthly intervals between May 1962 and March 1964 to determine the extent to which the two species utilize the same resources. Estimates of their relative abundance were obtained by catching adult flies on fruit trees and by collecting fruit containing immature stages. Both species used the same kinds of fruit for oviposition and larval development. At Rockhampton, where D. tryoni constituted 90% of the population, this species utilized five favourable kinds of fruit equally, whereas D. neohumeralis utilized some to a greater extent than others. At Yeppoon, where D. neohumeralis was the more abundant species, it utilized four different kinds of fruit equally whereas D. tryoni utilized some more than others. The same kinds of fruit were available at the two places, suggesting that "preferences" were associated with the locality and the relative abundance of the two species rather than with the kinds of fruit. At Rockhampton, D. neohumeralis remained rare relative to D. tryoni at all times of year and no distinct seasonal changes in their relative abundance were detected. When fruit trees were classified according to the shelter they provided, D. neohumeralis was more abundant in trees with dense foliage than in open, exposed trees. D. tryoni was equally abundant in the fruit from all types of trees. A third species of fruit fly, Afrodacus jarvisi, shared the larval food resources of D. neohumeralis and D. tryoni in late summer. Samples with a high density of A. jarvisi contained fewer D. neohumeralis and D. tryoni than samples with a low density of A. jarvisi, but their relative proportions were unchanged, indicating that the deleterious effect was not differential. The results of this study are examined in the light of the competitive displacement theory. Flies that emerged from fruit were large and not at all like the small flies which can be reared in the laboratory when food is in short supply. Competition between the two species for larval food thus appears to be unimportant. Moreover, there was no evidence that one species might be displacing the other in the Rockhampton area. Both species preferred the same kinds of fruit and fruit trees when a choice was available, suggesting that both species can live together without exerting any deleterious effects on one another.

scholarly journals Young adults’ coping strategies against loneliness during the COVID-19-related quarantine in Greece

2021 ◽  
Author(s):  
Adrianos Golemis ◽  
Panteleimon Voitsidis ◽  
Eleni Parlapani ◽  
Vasiliki A Nikopoulou ◽  
Virginia Tsipropoulou ◽  
...  
Keyword(s):  
Social Media ◽  
Young Adults ◽  
Social Responsibility ◽  
Coping Strategies ◽  
Online Survey ◽  
Adult Population ◽  
Psychological Impact ◽  
Well Being ◽  
Daily Routine ◽  
Cross Sectional

Summary COVID-19 and the related quarantine disrupted young adults’ academic and professional life, daily routine and socio-emotional well-being. This cross-sectional study focused on the emotional and behavioural responses of a young adult population during the COVID-19-related quarantine in April 2020, in Greece. The study was conducted through an online survey. A total of 1559 young adults, aged 18−30 years, completed Steele’s Social Responsibility Motivation Scale and the De Jong Gierveld Loneliness Scale, and answered questions about compliance with instructions, quarantine-related behaviours and coping strategies. According to the results, participants displayed a relatively high sense of social responsibility (M = 16.09, SD = 2.13) and a trend towards moderate feeling of loneliness (M = 2.65, SD = 1.62); young women reported significantly higher levels of loneliness than men. The majority complied with instructions often (46.4%) or always (44.8%). Significantly more women created a new social media account and used the social media longer than 5 h/day, compared with men. Resorting to religion, practicing sports and sharing thoughts and feelings about COVID-19 with others predicted higher levels of social responsibility; humour, practicing sports and sharing thoughts and feelings about COVID-19 with others predicted lower levels of loneliness. Conclusively, COVID-19 is expected to have a significant psychological impact on young adults. Currently, Greece is going through the second quarantine period. This study raises awareness about loneliness in young adults during the COVID-19-related quarantine and highlights the importance of developing online programmes, attractive to younger people, to nurture adaptive coping strategies against loneliness.

Effectiveness of Entomopathogenic Nematodes Against Ceratitis capitata (Diptera: Tephritidae) Pupae and Nematode Compatibility with Chemical Insecticides

2021 ◽  
Author(s):  
Maguintontz Cedney Jean-Baptiste ◽  
Andressa Lima de Brida ◽  
Daniel Bernardi ◽  
Sérgio da Costa Dias ◽  
Juliano de Bastos Pazini ◽  
...  
Keyword(s):  
Biological Control ◽  
Entomopathogenic Nematodes ◽  
Ceratitis Capitata ◽  
Integrated Management ◽  
Fruit Fly ◽  
Steinernema Carpocapsae ◽  
Mediterranean Fruit Fly ◽  
Fruit Crops ◽  
Class 1 ◽  
Pupal Mortality

Abstract The Mediterranean fruit fly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is among the main pests of fruit crops worldwide. Biological control using entomopathogenic nematodes (EPNs) may be an alternative to suppress populations of this pest. Thus, the aim of this study was to evaluate the pathogenicity and virulence of six EPN isolates (Heterorhabditis bacteriophora HB, H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47, and S. brazilense IBCB-n06) against C. capitata pupae. The compatibility of EPNs with different chemical insecticides that are registered for management of C. capitata was also assessed. Isolates of H. bacteriophora HB and S. brazilense IBCB-n06 at a concentration of 1,000 infective juveniles (IJ)/ml proved to be most pathogenic to C. capitata (70 and 80% mortality, respectively). In contrast, the isolates H. amazonensis IBCB-n24, Steinernema carpocapsae IBCB-n02, S. rarum PAM-25, S. glaseri IBCB-n47 provided pupal mortality of less than 60%. Bioassays to determine lethal concentrations indicated that concentrations of 600 IJ/ml (H. bacteriophora HB) and 1,000 IJ/ml (S. brazilense IBCB-n06) showed the highest virulence against C. capitata pupae. In contrast, the highest numbers of IJs emerged at concentrations of 1,200 and 200 IJ/ml. In compatibility bioassays, malathion, spinetoram, phosmet, acetamiprid, and novaluron were considered compatible with and harmless (Class 1) to H. bacteriophora HB and S. brazilense IBCB-n06, according to IOBC/WPRS. This information is important for implementing integrated management programs for C. capitata, using biological control with EPNs, whether alone or in combination with chemical insecticides.

scholarly journals Seasonal occurrence of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) in southern Syria

2016 ◽  
Vol 85 (3) ◽  
pp. 311-323 ◽  
Author(s):  
Mohammed Mansour ◽  
Fater Mohamad
Keyword(s):  
Ceratitis Capitata ◽  
Fruit Fly ◽  
Fruit Trees ◽  
Fruit Production ◽  
Small Population ◽  
Mediterranean Fruit Fly ◽  
Diospyros Kaki ◽  
Population Fluctuations ◽  
Sampling Studies ◽  
The Mediterranean

Abstract Population fluctuations of the Mediterranean fruit fly (medfly), Ceratitis capitata, were investigated between 1999 and 2001 at several locations representing fruit production areas in the southern part of Syria (Damascus Ghota, Zabadani, Sargaiah, Rankus, Orneh and Ain Al-Arab). Medfly adults were monitored weekly all year around using Jackson traps baited with trimedlure dispensers. Larvae were also sampled in Damascus Ghota by collecting fruits from ripe or ripening fruit trees and recording the number of larvae emerged from these fruits. In addition, suspected overwintering refuges were sampled at weekly intervals during the three coldest months of the year (December – February) and the number of collected larvae was recorded. The results of trap catches and fruit sampling studies showed a similar pattern of occurrence of medfly populations in the study areas, particularly in Damascus Ghota, during the three years of the study. In Damascus Ghota, flies were caught continuously from early June to late December with some variability between years. Two distinct periods of high fly activity were observed: the first one occurred in August and the second in November with a much higher amplitude. In general, seasonal fluctuations in the pattern of occurrence were influenced by differences in temperature and abundance of preferred host fruits. Traps on fig Ficus carica and oriental persimmon Diospyros kaki trees caught the highest numbers of flies, and fruits collected from these trees showed the highest level of infestation, reaching 100% for fig fruit late in the season. Sampling fruits (in Damascus Ghota) from trees during the three coldest months of the year showed that a small population of medfly larvae was able to survive winter conditions in prickly pear Opuntia vulgaris fruit left on the trees. In the other areas of the study (Zabadani, Sargaiah, Rankus, Orneh and Ain Al-Arab), only a few flies were caught.

Analysis of acute naproxen administration on memory in young adults: A randomized, double-blind, placebo-controlled study

2017 ◽  
Vol 31 (10) ◽  
pp. 1374-1376
Author(s):  
Jack H Wilson ◽  
Amy H Criss ◽  
Sean A Spangler ◽  
Katherine Walukevich ◽  
Sandra Hewett
Keyword(s):  
Young Adults ◽  
Healthy Adult ◽  
Adult Population ◽  
Critical Role ◽  
Random Order ◽  
Controlled Study ◽  
High Dose ◽  
Short Term ◽  
Double Blind ◽  
Inflammatory Drugs

Nonsteroidal anti-inflammatory drugs work by non-selectively inhibiting cyclooxygenase enzymes. Evidence indicates that metabolites of the cyclooxygenase pathway play a critical role in the process of learning and memory. We evaluated whether acute naproxen treatment impairs short-term working memory, episodic memory, or semantic memory in a young, healthy adult population. Participants received a single dose of placebo or naproxen (750 mg) in random order separated by 7–10 days. Two hours following administration, participants completed five memory tasks. The administration of acute high-dose naproxen had no effect on memory in healthy young adults.

Pathological gambling and behavior addiction in adulthood

2011 ◽  
Vol 26 (S2) ◽  
pp. 95-95
Author(s):  
L. Romo ◽  
A. Morvannou ◽  
N. Cheze ◽  
C. Legauffre ◽  
C. Lucas ◽  
...  
Keyword(s):  
Young Adults ◽  
Young People ◽  
Problem Gambling ◽  
Pathological Gambling ◽  
Adult Population ◽  
Professional Schools ◽  
Problematic Use ◽  
Young Adult Population ◽  
And Behavior ◽  
Assessment Scales

Gambling behaviors of young adults may begin in adolescence and continue or even worsen in adulthood (Goudriaan et al., 2009).Even if the young adult population is not an homogeneous group, studies show that almost 5% of young people, against 1% in general population showed pathological gambling (Dyke, 2009)Our objective was to study the presence of problem gambling among a population of young adults in professional-schools.We included 629 people, average age 20 and 66.4% of men. We used a battery of assessment scales of consumption of alcohol, tobacco, cannabis, pathological gambling, compulsive shopping, video games addiction, anxiety and depression.The results show a prevalence of 1.6% of young people with a score of pathological gambling in the Canadian Problem Gambling Index (CPGI) and 7% with a score of problematic use.The findings regarding depression, anxiety and other dependencies will be discussed.

Phenology of the sugar beet weevil, Bothynoderes punctiventris Germar (Coleoptera: Curculionidae), in Croatia

2018 ◽  
Vol 109 (4) ◽  
pp. 518-527
Author(s):  
Z. Drmić ◽  
M. Čačija ◽  
H. Virić Gašparić ◽  
D. Lemić ◽  
R. Bažok
Keyword(s):  
Sugar Beet ◽  
Dynamic Models ◽  
Developmental Stages ◽  
Adult Population ◽  
Regional Scale ◽  
Adult Emergence ◽  
Soil Samples ◽  
Population Characteristics ◽  
Degree Day ◽  
Development Threshold

AbstractThe sugar beet weevil (SBW), Bothynoderes punctiventris Germar, 1824, is a significant pest in most of Eastern Europe. Here, the SBW is described and its seasonal activity characterized, in terms of its different developmental stages in relation to Julian days (JDs), degree-day accumulations (DDAs), and precipitation, as a key to improving monitoring and forecasting of the pest. The phenology and population characteristics of SBW were investigated in sugar beet fields in eastern Croatia over a 4-year period (2012–2015). By using the degree-day model (lower development threshold of 5°C, no upper development threshold, biofix 1 January), the first emergence of overwintering adults was determined as becoming established when the DDA reached 20. The adult emergence was completed when the DDA reached 428. SBW males emerged first, following which the females dominated the adult population. Overwintering adults were present in the field until early July. In August, adults of the offspring generation began to appear. The eggs laid by the overwintering generation required, on average, 10–15 days to develop into larvae; however, eggs were found in soil samples over a period of 102 days (between JDs 112 and 214). Larvae were present in the soil samples over a period of a maximum of 143 days (the first larvae were established on JD 122 and the last one on JD 265), and pupae were established in the soil over a period of 102 days (between JDs 143 and 245). This study provides important data for understanding SBW population dynamics and developing potential population dynamic models for pest forecasting on a regional scale.

scholarly journals Social modulation of oogenesis and egg-laying in Drosophila melanogaster

2021 ◽  
Author(s):  
Bailly Tiphaine ◽  
Philip Kohlmeier ◽  
Rampal Etienne ◽  
Bregje Wertheim ◽  
Jean-Christophe Billeter
Keyword(s):  
Drosophila Melanogaster ◽  
Social Context ◽  
Social Systems ◽  
Fruit Fly ◽  
Egg Laying ◽  
Physiological Adaptation ◽  
Group Members ◽  
Selection For ◽  
Underlying Mechanisms ◽  
Gravid Females

Being part of a group facilitates cooperation between group members, but also creates competition for limited resources. This conundrum is problematic for gravid females who benefit from being in a group, but whose future offspring may struggle for access to nutrition in larger groups. Females should thus modulate their reproductive output depending on their social context. Although social-context dependent modulation of reproduction is documented in a broad range of species, its underlying mechanisms and functions are poorly understood. In the fruit fly Drosophila melanogaster, females actively attract conspecifics to lay eggs on the same resources, generating groups in which individuals may cooperate or compete. The tractability of the genetics of this species allows dissecting the mechanisms underlying physiological adaptation to their social context. Here, we show that females produce eggs increasingly faster as group size increases. By laying eggs faster in group than alone, females appear to reduce competition between offspring and increase their likelihood of survival. In addition, females in a group lay their eggs during the light phase of the day, while isolated females lay them during the night. We show that responses to the presence of others are determined by vision through the motion detection pathway and that flies from any sex, mating status or species can trigger these responses. The mechanisms of this modulation of egg-laying by group is connected to a lifting of the inhibition of light on oogenesis and egg-laying by stimulating hormonal pathways involving juvenile hormone. Because modulation of reproduction by social context is a hallmark of animals with higher levels of sociality, our findings represent a protosocial mechanism in a species considered solitary that may have been the target of selection for the evolution of more complex social systems.

scholarly journals Evaluating Opioid Dispensing Rates among Pediatrics and Young Adults based on CURES Data Reporting in California from 2015-2019

2021 ◽  
Vol 67 (4) ◽  
pp. 23-32
Author(s):  
Michael Phan ◽  
Courtney Wong ◽  
Daniel Tomaszewski ◽  
Zeev Kain ◽  
Brooke Jenkins ◽  
...  
Keyword(s):  
Young Adults ◽  
Young Adult ◽  
Evaluation System ◽  
Age Groups ◽  
Secondary Analysis ◽  
Adult Patients ◽  
High Rate ◽  
Utilization Review ◽  
Opioid Use ◽  
Prescription Rates

Background Receipt of opioid prescriptions in pediatric and young adult patients may be a risk factor for future opioid misuse. Data from prescription drug monitoring programs provide insight on outpatient opioid use. In our study, we analyzed the opioid dispensing rates for pediatrics and young adults in California. Methods A secondary analysis was performed from 2015-2019 using Controlled Utilization Review and Evaluation System data. This database provides dispensing data of controlled substances in California. Patients younger than 25 years who were prescribed opiates were analyzed by county. We further divided them into two groups (children: ≤14 years; adolescents and young adult: 15-24 years). Descriptive statistics and heat maps were used to illustrate the trends in opioid usage among different age groups. Results The overall percentages for the number of opioids being dispensed to patients aged <25 years have decreased over the past four years. In 2015, 6 out of 58 counties in California were considered “high-rate” with >2.9% of opioids dispensed to patients younger than 25 years old; in 2019, this number reduced to zero. Patients 25 and older received a higher proportion of opioids compared to younger populations; in 2019, 35.91% of opioids were dispensed to patients 45-64, and 8.92% to patients younger than 25. Conclusion Pediatric opioid prescriptions have declined over the recent years. However, a high degree of variability of prescription rates between demographic counties was noted. More studies are warranted in order to understand this discrepancy in opioid prescribing among pediatric and young adult patients.

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