Sexual conflicts arise when there is a difference in how females and males of a species or population achieve their maximum reproductive fitness. In intralocus sexual conflicts, alleles at a given locus are exposed to conflicting, or antagonistic, selection pressures. Based on a Genome-wide association study on sexually antagonistic genes in Drosophila melanogaster (fruit flies), the aim of this study was to investigate whether the candidate gene CG3598 exhibits sexually antagonistic effects on fitness between the 2 identified alleles of the gene. The study was performed on females from a Canton-S population of D. melanogaster who, by genetic manipulation through CRISPR Cas9, carried one of the 2 alleles of the CG3598. 6 excision lines of females had allele 1 and 5 excision lines had allele 2. The females were mated with "wild type" males from a Canton-S population in mediums prepared with about 6 mg of live dry yeast, after which the females were moved to separate mediums to lay their eggs. After 12 days, the adult offspring were counted and statistical calculations were performed on the average number of offspring per female for each line and allele. An Independent sample t-test showed that the females’ average fecundity did not differ between alleles (p = 0.059) and a Nested ANOVA analysis indicated that the average fecundity for each line within each allele differed (p = 0.023). Due to the fact that similar studies have found the same result, it may be necessary to investigate and possibly change the experimental design of the method to enable competition between females with different genetic conditions in order to observe a difference in fertility based on the females' ability to compete. / Sexuella konflikter uppstår när det finns en skillnad i hur honor och hanar i en art eller population uppnår sin maximala reproduktiva fitness. Vid intralocus sexuella konflikter utsätts alleler vid ett givet locus för motstridiga, eller antagonistiska, selektionstryck. Baserat på en Genome-wide association study om sexuellt antagonistiska gener hos Drosophila melanogaster (bananflugor) syftade denna studie till att undersöka huruvida genkandidaten CG3598 uppvisar sexuellt antagonistiska effekter på fitness mellan de 2 identifierade allelerna av genen. Undersökningen utfördes på honor från en CantonS-population av D. melanogaster som genom genmodifiering av CRISPR Cas9 bar en av de olika alleler av genen CG3598. 6 linjer av honor bar allel 1 och 5 linjer bar allel 2. Honorna parades med ”wild type”-hanar från en CantonS-population i rör preparerade med ca 6 mg levande torrjäst, varpå honorna förflyttades till separata rör för att lägga sina ägg. Efter 12 dagar räknades de vuxna avkommorna och statistiska beräkningar utfördes på det genomsnittliga antalet avkommor per hona för respektive linje och allel. Ett oberoende t-test visade att honornas genomsnittliga fekunditet inte skiljde sig mellan alleler (p=0,059) och en Nested ANOVA-analys indikerade att genomsnittlig fekunditet för varje linje inom respektive allel skiljde sig (p=0,023). Då även liknande studier funnit samma resultat kan det vara nödvändig att studera och eventuellt förändra den experimentella designen av metoden för att möjliggöra konkurrens mellan honor med olika genetiska förutsättningar för att kunna observera en skillnad i fekunditet baserat på honornas förmåga att konkurrera.

cotutelle / La biotrémologie est l’étude de la vibration du substrat (ex. végétal) et de ses effets sur les animaux. En protection des cultures, la vibration du substrat s’utilise à la fois pour dépister les insectes ravageurs de culture et réduire leurs populations. Dans cette étude, nous avons évalué les effets de la vibration du substrat végétal sur l’acceptation de la plante hôte, la rétention, la fécondité et les comportements en période de mue du puceron vert du pêcher Myzus persicae, ravageur important des cultures notamment dans les serres de poivrons. Des vibreurs ont été utilisés en laboratoire pour vibrer le substrat végétal en continu et à une même intensité de 24 h à 48 h. La vibration a réduit l’acceptation des plants vibrés par les pucerons ailés (-75%), comparativement aux plants témoins. Elle a également réduit la rétention des adultes, ailés et aptères (-33 à -46%, respectivement) et de leurs juvéniles (-50 à -65%, respectivement). Ces effets réducteurs ont augmenté avec la durée d’exposition vibrationnelle. Le traitement vibrationnel a eu également comme conséquence de réduire la fécondité des femelles aptères (réduction de 39% des juvéniles:adulte), après exposition au traitement. Les comportements de mobilité ont été plus longs avant la mue, alors que ceux d’alimentation ont été plus courts avant et après la mue chez les juvéniles soumis aux vibrations. La vibration induit un rejet de la plante hôte, réduit la fécondité et altère l’alimentation. La vibration du substrat se profile comme une méthode de lutte mécanique potentielle contre M. persicae. / Biotremology is the study of substrate-bone vibrations (e.g. via plants) and its effects on animals. In crop protection, substrate-borne vibrations are used both to detect crop pests and to reduce their populations. In this study, we evaluated the effects of plant substrate-borne vibrations on host plant acceptance, retention, fecundity and behaviour during the molting period of the green peach aphid Myzus persicae, a major crop pest particularly in bell peppers in greenhouses. Shakers were used in the laboratory to vibrate the plant substrate continuously and at the same intensity from 24 h to 48 h. Vibrations reduced the acceptance of vibrated plants by alate aphids (-75%), compared with control plants. It also reduced the retention of adults, both alate and apterous (-33 to -46%, respectively) and their juveniles (-50 to -65%, respectively). These reducing effects increased with the duration of vibrational exposure. Vibrational treatment also resulted in reduced fecundity of apterous females (reduction of 39% of the juveniles: adult), after exposure to treatment. Mobility behaviours were longer before molting, while feeding behaviours were shorter before and after molting for vibration-treated juveniles. Substrate-borne vibrations induce rejection of the host plant, reduces fecundity and alters feeding. Substrate-borne vibration is emerging as a potential mechanical control method against M. persicae.

Assessment of trophic interactions between increasing populations of New Zealand fur seals (Arctocephalus forsteri) and fisheries in southern Australia is limited due to a lack of species specific demographic data and an understanding of the factors influencing population growth. To establish species specific demographic parameters a cross-sectional sample of New Zealand fur seal females (330) and males (100) were caught and individually-marked on Kangaroo Island, South Australia between 2000 and 2003. The seals were aged through examination of a postcanine tooth, which was removed from each animal to investigate age-specific life-history parameters. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known-age. Indirect methods of assessing reproductive maturity based on mammary teat characteristics indicated that females first gave birth between 4-8 years of age, with an average age at reproductive maturity of 5 years. Among reproductively mature females, age-specific reproductive rates increased rapidly between 4-7 years of age, reaching maximum rates of 70-81% between 8-13 years, and gradually decreased in older females. No females older than 22 years were recorded to pup. Age of first territory tenure in males ranged from 8-10 years. The oldest female and male were 25 and 19 years old, respectively. Post-weaning growth in females was monophasic, characterised by high growth rates in length and mass during the juvenile growth stage, followed by a gradual decline in growth rates after reproductive maturity. In contrast, growth in males was biphasic and displayed a secondary growth spurt in both length and mass, which coincided with sexual and social maturation, followed by a rapid decline in growth rates. Age-specific survival rates were high (0.823-0.953) among prime-age females (8-13 yrs of age) and declined in older females. Relative change in annual pup production was strongly correlated with reproductive rates of prime-age females and adult female survival between breeding seasons.

In this study, buckwheat (Fagopyrum esculentum Moench) and alyssum (Lobularia maritima (L.)) flowers were used to examine the effect of floral resources on the efficacy of the leafroller parasitoid Dolichogenidea tasmanica (Cameron) in vineyards. This was done by assessing the influence of these flowers on parasitoid abundance and parasitism rate, and by investigating the consequences of this for leafroller abundance. In laboratory experiments, alyssum flowers were used to investigate the effect of floral food on the longevity, fecundity and sex ratio of D. tasmanica. Dolichogenidea tasmanica comprised more than 95 % of parasitoids reared from field collected leafrollers in this study. The abundance of D. tasmanica during the 1999-2000 growing season was very low compared with previous studies, possibly due to the very low abundance of its leafroller hosts during the experiment. The number of males of this species on yellow sticky traps was increased (although not significantly) when buckwheat flowers were planted in a Marlborough vineyard; however, the number of female D. tasmanica on traps was no greater with flowers than without. The abundance of another leafroller parasitoid, Glyptapanteles demeter (Wilkinson)(Hymenoptera: Braconidae), on traps was also not significantly affected by the presence of buckwheat flowers, although females of this species were caught in greater numbers in the control than in buckwheat plots. Naturally-occurring leafrollers were collected from three vineyard sites in Marlborough, and one in Canterbury during the 2000-2001 season to assess the effect of buckwheat and alyssum flowers on parasitism rate. Parasitism rate more than doubled in the presence of buckwheat at one of the Marlborough vineyards, but alyssum had no effect on parasitism rate in Canterbury. A leafroller release/recover method, used when naturally-occurring leafrollers were too scarce to collect, was unable to detect any effect of buckwheat or alyssum on parasitism rate. Mean parasitism rates of approximately 20 % were common in Marlborough, although rates ranged from 0 % to 45 % across the three vineyard sites in that region. In Canterbury in April, mean parasitism rates were approximately 40 % (Chapter 4). Rates were higher on upper canopy leaves (40-60 %) compared with lower canopy leaves and bunches (0-25 %). Leafroller abundance was apparently not affected by the presence of buckwheat in Marlborough, or alyssum in Canterbury. Buckwheat did, however, significantly reduce the amount of leafroller evidence (webbed leafroller feeding sites on leaves or in bunches) in Marlborough, suggesting that the presence of these flowers may reduce leafroller populations. Leafrollers infested less than 0.1 % of Cabernet Sauvignon leaves throughout the 1999-2000 growing season, but increased in abundance in bunches to infest a maximum of 0.5 % of bunches in late March in Marlborough. In Pinot Noir vines in the 2000-2001 season, leafroller abundance was also low, although sampling was not conducted late in the season when abundance reaches a peak. In Riesling vines in Canterbury, between 1.5 % and 2.5 % of bunches were infested with leafrollers in April. In the laboratory, alyssum flowers significantly increased the longevity and lifetime fecundity of D. tasmanica compared with a no-flower treatment. However, daily fecundity was not increased by the availability of food, suggesting that the greater lifetime fecundity was related to increases in longevity. Parasitoids were also able to obtain nutrients from whitefly honeydew, which resulted in similar longevity and daily fecundity to those when alyssum flowers were present. The availability of food had a significant effect on the offspring sex ratio of D. tasmanica. Parasitoids reared from naturally-occurring leafrollers produced an equal sex ratio, assumed to be the evolutionarily stable strategy (ESS) for this species. In the laboratory, this ESS was observed only when parasitoids had access to alyssum flowers. Without food, or with honeydew only, sex ratios were strongly male-biased. In the field, floral resources affected the sex ratio of D. tasmanica only when this species was reared from leafrollers released and recovered in Marlborough. In that experiment, buckwheat shifted the sex ratio in favour of female production from the equal sex ratio found in control plots. No firm explanations can be given to account for these results, due to a lack of research in this area. Possible mechanisms for the changes in sex ratio with flowers are discussed. This study demonstrated that flowers are an important source of nutrients for D. tasmanica, influencing the longevity, fecundity and offspring sex ratio of this species. However, only some of the field experiments were able to show any positive effect of the provision of floral resources on parasitoid abundance or parasitism rate. More information is needed on the role these parasitoids, and other natural enemies, play in regulating leafroller populations in New Zealand vineyards, and on how they use floral resources in the field, before recommendations can be made regarding the adoption of this technology by growers.

No description available.

In this thesis I present new insights into aspects of Peter Guthrie Tait's life and work, derived principally from largely-unexplored primary source material: Tait's scrapbook, the Tait–Maxwell school-book and Tait's pocket notebook. By way of associated historical insights, I also come to discuss the innovative and far-reaching mathematics of the elusive Frenchman, C.-V. Mourey. P. G. Tait (1831–1901) F.R.S.E., Professor of Mathematics at the Queen's College, Belfast (1854–1860) and of Natural Philosophy at the University of Edinburgh (1860–1901), was one of the leading physicists and mathematicians in Europe in the nineteenth century. His expertise encompassed the breadth of physical science and mathematics. However, since the nineteenth century he has been unfortunately overlooked—overshadowed, perhaps, by the brilliance of his personal friends, James Clerk Maxwell (1831–1879), Sir William Rowan Hamilton (1805–1865) and William Thomson (1824–1907), later Lord Kelvin. Here I present the results of extensive research into the Tait family history. I explore the spiritual aspect of Tait's life in connection with The Unseen Universe (1875) which Tait co-authored with Balfour Stewart (1828–1887). I also reveal Tait's surprising involvement in statistics and give an account of his introduction to complex numbers, as a schoolboy at the Edinburgh Academy. A highlight of the thesis is a re-evaluation of C.-V. Mourey's 1828 work, La Vraie Théorie des quantités négatives et des quantités prétendues imaginaires, which I consider from the perspective of algebraic reform. The thesis also contains: (i) a transcription of an unpublished paper by Hamilton on the fundamental theorem of algebra which was inspired by Mourey and (ii) new biographical information on Mourey.