scholarly journals Geographical variation in house-fly (Musca domestica L.) sex determinants within the British Isles

1986 ◽  
Vol 47 (1) ◽  
pp. 19-27 ◽  
Author(s):  
I. Denholm ◽  
M. G. Franco ◽  
P. G. Rubini ◽  
M. Vecchi
Keyword(s):  
House Fly ◽  
British Isles ◽  
House Flies ◽  
North East ◽  
Dominant Female ◽  
Males And Females ◽  
South East England ◽  
Female Determinant ◽  
Breeding Farms ◽  
Determination Mechanism

SummaryGenetic and cytological analyses of house-flies collected from 12 pig-breeding farms throughout the British Isles demonstrated that the non-standard sex determination mechanism prevailing in South-East England, involving a dominant female determinant (F) and virtual homozygosity for a male determinant on the X chromosome (Xm, both males and females morphologically XX), was not typical of the country as a whole. Instead there was a gradual decrease in the frequency of F, Xm and a rarer male determinant M III, and a concomitant increase in the standard male determining Y chromosome, on moving north, east and west of this region. Only the Scottish and probably the Irish populations were fully standard (XX females XY males), although one from the East Anglian coast in which non-standard determinants were rare was predominantly of this type. Populations from intermediate areas possessed complex multifactorial mechanisms in which Y, F Xm and M III coexisted. It is hypothesized that this radial cline in sex determinants, like the latitudinal cline known from mainland Europe, represents a transient polymorphism caused by the recent and continuing invasion of non-standard determinants into originally standard populations. The cause(s) of this apparently rapid evolutionary change, however, remain unclear.

scholarly journals Identification of a male determinant on the X chromosome of housefly (Musca domestica L.) populations in South-East England

1983 ◽  
Vol 42 (3) ◽  
pp. 311-322 ◽  
Author(s):  
I. Denholm ◽  
M. G. Franco ◽  
P. G. Rubini ◽  
M. Vecchi
Keyword(s):  
Sex Determination ◽  
X Chromosome ◽  
Secondary Constriction ◽  
Dominant Male ◽  
Chromosome X ◽  
Active Involvement ◽  
South East England ◽  
Female Determinant ◽  
Breeding Farms ◽  
Determination Mechanism

SUMMARYHouseflies collected from eight pig-breeding farms were used to investigate the nature of sex determinants in fly populations of South-East England. Earlier observations had shown that their sex determination mechanism was not of the standard (XX females, XY males) type.Most flies of both sexes were XX; the male determining Y chromosome of standard populations was rare. Test-crosses to females of standard multimarked strains and crosses using aneuploid (OX) flies identified two dominant male determinants, one on autosome 3 (M III) and another on the X chromosome (Xm), and provided the first demonstration in this species of an active involvement of the X chromosome in sex determination. A small secondary constriction on X appeared to indicate reliably the presence of Xm. Most individuals in field populations were Xm homozygotes, implying the presence of an unlocated female determinant F,† epistatic to Xm and M III.M III was less common and differed in frequency between samples. Its increased frequency in a strain selected in the laboratory with the pyrethroid insecticide permethrin might be due either to genetic drift, or to linkage between M III and a gene on autosome 3 that confers resistance to pyrethroids in houseflies.

Gender Diversity in Computing: An Environmental Perspective

10.28945/3248 ◽  
2008 ◽  
Author(s):  
Cecille Marsh
Keyword(s):  
Gender Diversity ◽  
Household Head ◽  
Female Students ◽  
Political Factors ◽  
Female Household Head ◽  
Dominant Female ◽  
Computer Confidence ◽  
Males And Females ◽  
Research Questions

Previous research conducted by the author investigated the socio-political backgrounds of two groups of female students studying computer-related university programmes. They came from distinctly different backgrounds and were enrolled at two institutions with very different legacies. The author found that socio-political factors, in particular the role of a dominant female household head and aggressive governmental affirmative action, had a significant effect on the girls’ levels of confidence and subsequently on their decision to study computer-related courses. Based on this insight, the researcher undertook to look further into gender diversity with respect to self-perceived general computer confidence and self-perceived ability to program a computer. A sample of both female and male Information T echnology students from very similar disadvantaged socio-economic backgrounds was surveyed. The sample of 204 students was drawn from all three years of the National Diploma in Information Technology. The author considered the following research questions: (i) Do males and females studying computer-related courses have differing computer selfefficacy levels? (ii) Do males and females studying computer programming have differing attitudes towards their ability to program? (iii) Do males and females differ in their attitudes towards the programming learning environment?

scholarly journals Thermal limits for flight activity of field-collected Culicoides in the United Kingdom defined under laboratory conditions

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Laura A. Tugwell ◽  
Marion E. England ◽  
Simon Gubbins ◽  
Christopher J. Sanders ◽  
Jessica E. Stokes ◽  
...  
Keyword(s):  
Companion Animals ◽  
Flight Activity ◽  
Cold Temperature ◽  
Threshold Temperature ◽  
Thermal Limits ◽  
Laboratory Conditions ◽  
North East ◽  
Temperature Thresholds ◽  
South East England ◽  
The Uk

Abstract Background Culicoides biting midges (Diptera: Ceratopogonidae) are biological vectors of internationally important arboviruses and inflict biting nuisance on humans, companion animals and livestock. In temperate regions, transmission of arboviruses is limited by temperature thresholds, in both replication and dissemination of arboviruses within the vector and in the flight activity of adult Culicoides. This study aims to determine the cold-temperature thresholds for flight activity of Culicoides from the UK under laboratory conditions. Methods Over 18,000 Culicoides adults were collected from the field using 4 W down-draught miniature ultraviolet Centers for Disease Control traps. Populations of Culicoides were sampled at three different geographical locations within the UK during the summer months and again in the autumn at one geographical location. Activity at constant temperatures was assessed using a bioassay that detected movement of adult Culicoides towards an ultraviolet light source over a 24-h period. Results The proportion of active adult Culicoides increased with temperature but cold temperature thresholds for activity varied significantly according to collection season and location. Populations dominated by the subgenus Avaritia collected in South East England had a lower activity threshold temperature in the autumn (4 °C) compared with populations collected in the summer (10 °C). Within the subgenus Avaritia, Culicoides scoticus was significantly more active across all temperatures tested than Culicoides obsoletus within the experimental setup. Populations of Culicoides impunctatus collected in the North East of England were only active once temperatures reached 14 °C. Preliminary data suggested flight activity of the subgenus Avaritia does not differ between populations in South East England and those in the Scottish Borders. Conclusions These findings demonstrate seasonal changes in temperature thresholds for flight and across different populations of Culicoides. These data, alongside that defining thresholds for virus replication within Culicoides, provide a primary tool for risk assessment of arbovirus transmission in temperate regions. In addition, the study also provides a comparison with thermal limits derived directly from light-suction trapping data, which is currently used as the main method to define adult Culicoides activity during surveillance.

CONTROL OF EGG FERTILIZATION BY NASONIA VITRIPENNIS (HYMENOPTERA: PTEROMALIDAE) WHEN LAYING ON PARASITIZED HOUSE FLY PUPAE

1973 ◽  
Vol 105 (5) ◽  
pp. 709-718 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
Musca Domestica ◽  
House Fly ◽  
Nasonia Vitripennis ◽  
House Flies

AbstractFemales of Nasonia vitripennis (Walk.) lay a smaller percentage of fertilized (i.e. female) eggs on house fly, Musca domestica L., pupae previously parasitized by their own species, by Muscidifurax zaraptor K. & L., or by Spalangia cameroni Perk. (Hymenoptera: Pteromalidae) than on unparasitized hosts. They respond to changes in the fly pupae associated with death, and in the case of house flies attacked by N. vitripennis, to "venoms" injected at that time or to changes unrelated to death. By not fertilizing eggs that they lay on attacked hosts, the females also conserve sperm, for immature N. vitripennis on previously-attacked fly pupae are usually killed by parasite larvae already present.

scholarly journals Evaluation of triflumuron and pyriproxyfen as alternative candidates to control house fly, Musca domestica L. (Diptera: Muscidae), in Riyadh city, Saudi Arabia

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249496
Author(s):  
Saad M. Alzahrani
Keyword(s):  
Saudi Arabia ◽  
Musca Domestica ◽  
Laboratory Strain ◽  
Insect Growth Regulator ◽  
House Fly ◽  
House Flies ◽  
Resistance Factors ◽  
Control Programs ◽  
Riyadh City ◽  
Susceptibility And Resistance

This study was conducted to determine the susceptibility and resistance of some house fly strains of Musca domestica L. to the insect growth regulator insecticides triflumuron and pyriproxyfen in some locations in Riyadh city. Field-collected strains of M. domestica L. from five sites in Riyadh city that represented five slaughterhouse sites where flies spread significantly were tested against triflumuron and pyriproxyfen. Triflumuron LC50 values for the five collected strains ranged from 2.6 to 5.5 ppm, and the resistance factors (RFs) ranged from 13-fold to 27-fold that of the susceptible laboratory strain. Pyriproxyfen LC50 values for the field strains ranged from 0.9 to 1.8 ppm with RFs of 3-fold to 5-fold. These results indicate that pyriproxyfen is an effective insecticide to control house flies and should be used in rotation with other insecticides in the control programs applied by Riyadh municipality.

scholarly journals PERANAN Musca domestica SEBAGAI VEKTOR MEKANIK TELUR INFEKTIF Ascaris lumbricoides

2018 ◽  
Vol 2 (1) ◽  
pp. 8
Author(s):  
Suriyani Tan ◽  
Machrumnizar Machrumnizar
Keyword(s):  
Musca Domestica ◽  
Ascaris Lumbricoides ◽  
Light Microscope ◽  
Breeding Site ◽  
Gastrointestinal Diseases ◽  
House Fly ◽  
Animal Waste ◽  
House Flies ◽  
Fish Meat

Muscadomestica (house fly) is an insect that is considered useless by humans although they lived very close to humans. Breeding site of flies in human or animal waste, the rubbish, or unorganic objects that have decayed greatly support their role as mechanical vectors. More than 20 species of flies have been reported as an agent of gastrointestinal diseases. The purpose of this study is to examnine the role of houseflies as mechanical vectors Ascarislumbricoides’seggs.The research sample was 500 house flies (Muscadomestica) captured in the Legok area. Houseflies were trapped by fly trap containing rotten fish meat and then stored at a temperature of 4 degree celcius. The samples were divided into six groups according to the sampling areas, crushed and checked directly by using a light microscope. Ascarislumbricoides eggs are not found in all groups of samples. The study concluded that Muscadomestica is not a mechanical vector of infective eggs of Ascarislumbricoides in Tangerang City, Banten Province.

Growth of the edible crab (Cancer pagurusL.) off south-west England

1974 ◽  
Vol 54 (4) ◽  
pp. 803-823 ◽  
Author(s):  
D. B. Bennett
Keyword(s):  
Egg Production ◽  
Carapace Width ◽  
Large Male ◽  
Annual Growth ◽  
Published Data ◽  
North East ◽  
South West ◽  
Males And Females ◽  
Moulting Cycle ◽  
South West England

Moult increments, annual moult frequency and hence annual growth were determined from suture-tagged edible crabs (Cancer pagurusL.) released and recaptured off Devon, Cornwall, and Dorset.The average moult increments of males and females at a premoult carapace width of 100 mm were similar; at larger sizes the average moult increment of females was considerably less than that of males. Annual moult frequency ofC. pagurusin south-west England decreased with increase in size, females more so than males.As a result of the smaller moult increments and lower moult frequency of females, their annual growth is considerably less than that of males. This appears to be the result of three aspects of sex and reproduction: (1) reduction in moult increments, probably as a result of competition for nutritive resources between egg production and body growth; (2) the interruption of the moulting cycle by successive annual spawnings from a single impregnation at the previous moult; and (3) accentuation of the larger increments in weight at moulting of male crabs due to the allometric growth of their chelae. A consequence of the higher growth rate of males is the presence of very large male crabs – a distinctive feature of the population structure of the stock off south-west England.The growth of C.pagurusin south-west England was compared with published data for stocks off the east and north-east coast. Moult increments were similar for both areas, but there were considerable differences in the moult frequencies. In the south-west, males moult more frequently than females; the opposite is the case for the east and north-east crab stocks. A valid reason for this difference has not yet been established.

Behavioral Inhibition of the House Fly (Diptera: Muscidae) When Exposed to Commercial Equine Fly Repellents

2019 ◽  
Author(s):  
Elizabeth V Tuorinsky ◽  
Erika T Machtinger
Keyword(s):  
Natural Products ◽  
Behavioral Inhibition ◽  
Control Method ◽  
House Fly ◽  
Synthetic Pyrethroids ◽  
Negative Consequences ◽  
House Flies ◽  
Fly Control ◽  
Horse Owners ◽  
Better Than

Abstract House flies can have negative consequences on the welfare of horses and other equids. Fly repellents in the form of on-animal sprays, wipes, or spot-ons are the most commonly used fly control method for horses. Many products are available, but repellent efficacy and duration of effectiveness may influence repellent choice by horse owners. A better understanding of the efficacy of common fly repellent products will help guide repellent selection to reduce fly pressure on horses. To evaluate commercially available repellents, house fly behavioral inhibition after application of three products marketed as natural (Ecovet, Equiderma, and Outsmart) and four with synthetic pyrethroids as active ingredients (Bronco, Endure, UltraShield, and Optiforce) was compared at 100, 50, and 25% concentration and at 15, 30, 60, 240, 1,440, and 2,880 min. Time and product were significant at all tested concentrations. The natural products performed as well as or better than the synthetic products at all dilutions and times. Ecovet in particular retained over 75% inhibition of flies for >1 d at the 100 and 50% concentrations. Differences were seen among products with pyrethroids, suggesting that formulation differences significantly affect efficacy. Cost and application suggestions are discussed, and these results will aid horse owners in selecting fly repellents to meet their individual needs.

Factors affecting resistance to insecticides in house-flies, Musca domestica L. (Diptera: Muscidae). IV. The population biology of flies on animal farms in south-eastern England and its implications for the management of resistance

1985 ◽  
Vol 75 (1) ◽  
pp. 143-158 ◽  
Author(s):  
I. Denholm ◽  
R. M. Sawicki ◽  
A. W. Farnham
Keyword(s):  
Gene Flow ◽  
Musca Domestica ◽  
Population Biology ◽  
Marker Gene ◽  
House Fly ◽  
Factors Affecting ◽  
House Flies ◽  
Resistance Selection ◽  
South Eastern ◽  
Brown Body

AbstractWays in which the bionomics and dynamics of populations of Musca domestica L. can influence the development of insecticide resistance, and how resistance genes spread within and between farms was investigated in a three-year study of the biology and movement of flies on 63 pig-rearing farms in south-eastern England. House-flies survived winter only on 12 ‘overwintering’ farms where they bred in heated pig-rearing houses (‘closed buildings’) throughout the year. In late spring they appeared out doors, and their descendents founded populations on neighbouring ‘summer’ farms where pigs breed only in unheated (‘open’) buildings. There, flies reached peak numbers in August–September and died out by mid-November. Gene flow within and between farms was studied indirectly by mark-release-recapture of colour-marked adults, and directly by monitoring the diffusion of the visible marker gene bwb (brown body) introduced into indigenous house-fly populations. Although movement between open buildings within a farm was unrestricted, dispersal between farms was limited, and gene flow between even adjacent closed buildings was indirect, and required more than one generation. Likewise, indirect and gradual gene flow during summer probably accounted for the similarity in type and frequency of other independent genetic markers of local overwintering populations. Thus closed buildings played a key role in house-fly ecology and population genetics. Unfortunately, control with persistent insecticides in these buildings ensures efficient resistance selection, ultimately resulting in its spread to all pig farms. Less selective control practices are needed at these sites.

The social origins of gender differences in anticipated feelings of guilt and shame following delinquency

2017 ◽  
Vol 18 (3) ◽  
pp. 291-313 ◽  
Author(s):  
Arne De Boeck ◽  
Stefaan Pleysier ◽  
Johan Put
Keyword(s):  
Gender Differences ◽  
Interpersonal Relations ◽  
Peer Delinquency ◽  
Gender Role Beliefs ◽  
North East ◽  
The North ◽  
The Social ◽  
Males And Females ◽  
Traditional Masculinity ◽  
Traditional Femininity

In this study, we investigate gender differences in adolescents’ anticipated feelings of guilt and shame for engaging in shoplifting and retaliatory violence. More specifically, we examine the extent to which interpersonal relations with parents and teachers, perceived peer delinquency and traditional gender role beliefs have different effects on levels of shame-guilt among males and females, and to what extent these variables mediate gender differences in shame-guilt. We use data collected in a sample of 852 adolescents in Genk, a multi-ethnic city in the north-east of Belgium. Our findings confirm those of earlier research indicating that females experience a considerably higher threat of shame-guilt for engaging in delinquency than males. Factors explaining males’ and females’ anticipated shame-guilt feelings are similar in the case of shoplifting, but different in the case of violence. Differential exposure to peer delinquency and parental follow-up partially mediate the effect of gender on shame-guilt for engaging in shoplifting. Among males, endorsement of traditional masculinity predicts lower levels of shame-guilt for engaging in shoplifting and violence. Among females, endorsement of traditional femininity predicts lower levels of shame-guilt for engaging in shoplifting, but has no effect on shame-guilt for engaging in violence. We discuss the implications of our findings for understanding the contribution of shame-guilt to the social control of delinquency across gender.

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