| 1. |
- Sigvald, Roland, et al.
(författare)
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Molecular identification of bloodmeals and species composition in Culicoides biting midges
- 2013
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Ingår i: Medical and Veterinary Entomology. - : Wiley. - 0269-283X .- 1365-2915. ; 27, s. 104-112
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Tidskriftsartikel (refereegranskat)abstract
- Investigations of host preferences in haematophagous insects, including Culicoides biting midges (Diptera: Ceratopogonidae), are critical in order to assess transmission routes of vector-borne diseases. In this study, we collected and morphologically identified 164 blood-engorged Culicoides females caught in both light traps and permanent 12-m high suction traps during 20082010 in Sweden. Molecular analysis of the mitochondrial cytochrome c oxidase subunit I (COI) gene in the biting midges was performed to verify species classification, discern phylogenetic relationships and uncover possible cryptic species. Bloodmeal analysis using universal vertebrate cytochrome b primers revealed a clear distinction in host selection between mammalophilic and ornithophilic Culicoides species. Host sequences found matches in horse (n = 59), sheep (n = 39), cattle (n = 26), Eurasian elk (n = 1) and 10 different bird species (n = 18). We identified 15 Culicoides species previously recorded in Scandinavia and four additional species haplotypes that were distinctly different from the described species. All ornithophilic individuals (n = 23) were caught exclusively in the suction traps, as were, interestingly, almost all mammalophilic species (n = 41), indicating that many biting midge species may be able to cover long distances after completing a bloodmeal. These results add new information on the composition of Culicoides species and their host preferences and their potential long-distance dispersal while blood-engorged.
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| 2. |
- Witzgall, Peter, et al.
(författare)
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"This is not an Apple"-Yeast Mutualism in Codling Moth
- 2012
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 1573-1561 .- 0098-0331. ; 38:8, s. 949-957
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Tidskriftsartikel (refereegranskat)abstract
- The larva of codling moth Cydia pomonella (Tortricidae, Lepidoptera) is known as the worm in the apple, mining the fruit for food. We here show that codling moth larvae are closely associated with yeasts of the genus Metschnikowia. Yeast is an essential part of the larval diet and further promotes larval survival by reducing the incidence of fungal infestations in the apple. Larval feeding, on the other hand, enables yeast proliferation on unripe fruit. Chemical, physiological and behavioral analyses demonstrate that codling moth senses and responds to yeast aroma. Female moths are attracted to fermenting yeast and lay more eggs on yeast-inoculated than on yeast-free apples. An olfactory response to yeast volatiles strongly suggests a contributing role of yeast in host finding, in addition to plant volatiles. Codling moth is a widely studied insect of worldwide economic importance, and it is noteworthy that its association with yeasts has gone unnoticed. Tripartite relationships between moths, plants, and microorganisms may, accordingly, be more widespread than previously thought. It, therefore, is important to study the impact of microorganisms on host plant ecology and their contribution to the signals that mediate host plant finding and recognition. A better comprehension of host volatile signatures also will facilitate further development of semiochemicals for sustainable insect control.
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| 3. |
- Eggers, Sönke, et al.
(författare)
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Differential demographic responses of sympatric Parids to vegetation management in boreal forest
- 2014
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 319, s. 169-175
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale removal of small-diameter trees (i.e. thinning from below) in boreal forest can diminish niche diversity for birds that rely on a well-developed understory for nesting and foraging. Yet, few studies have examined how reduced niche diversity in managed forests affects fitness measures in closely-related species and the ability of competing species to co-exist. We related forest thinning to population trends of the willow tit Poecile montana (declining) and its dominant competitor the crested tit Lophophanes cristatus (stable), and conducted a 3-year comparative study to determine how variation in understory spruce density differentially influences survival and reproduction in these species. In line with our prediction that crested tits would gain resource priority under conditions of reduced forest understory complexity, willow tits and their nestlings suffered a disproportionate decline in both nest and adult survival prospects relative to crested tits as understoiy spruce density declined. Willow tits also had increased numbers of tail feather fault bars with decreasing understory complexity, further supporting the idea that willow tits suffer from food shortage and increased predation risk in areas of reduced understory. The long-term population declines of willow tits in boreal forest appears linked to large scale harvest of small-diameter spruce trees that provide important understory vegetation. A patchy arrangement of different thinning treatments through 'Understory Retention Thinning' (URT) may provide a cost-effective way to restore long-term structural complexity and biodiversity in densely stocked conifer stands. (C) 2014 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
- Kvarnemo, Charlotta, 1963, et al.
(författare)
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Gravida hanar och konkurrerande honor
- 2014
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Ingår i: Havsutsikt. - 1104-0513. ; 2014:1, s. 6-7
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hos fisken tångsnälla blir pappan gravid. Hanen förser ungarna med syre och näring under utvecklingen, men han kan också själv ta upp näring som kommer från äggen. Honor konkurrerar om att få para sig med hanar som har plats för hennes ägg, och de gillar särskilt att para sig med stora hanar. Trots det ger de ägg med mer näring till små hanar.
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| 6. |
- Sköld, Helen Nilsson, et al.
(författare)
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Hormonal regulation of female nuptial coloration in a fish.
- 2008
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Ingår i: Hormones and behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 54:4, s. 549-56
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Tidskriftsartikel (refereegranskat)abstract
- Physiological color change in camouflage and mating is widespread among fishes, but little is known about the regulation of such temporal changes in nuptial coloration and particularly concerning female coloration. To better understand regulation of nuptial coloration we investigated physiological color change in female two-spotted gobies (Gobiusculus flavescens). Females of this species develop an orange belly that acts as an ornament. The orange color is caused by the color of the gonads combined with the chromathophore based pigmentation and transparency of the skin. Often during courtship and female-female competition, a rapid increase in orange coloration, in combination with lighter sides and back that increases skin and body transparency, gives the belly an intense 'glowing' appearance. To understand how this increased orange coloration can be regulated we analysed chromatic and transparency effects of neurohumoral agents on abdominal skin biopsies in vitro. We found prolactin and alpha-melanocyte stimulating hormone (MSH) to increase orange coloration of the skin. By contrast, melatonin and noradrenaline increased skin transparency, but had a negative effect on orange coloration. However, mixtures of melatonin and MSH, or melatonin and prolactin, increased both orange coloration and transparency. This effect mimics the chromatic 'glow' effect that commonly takes place during courtship and intra sexual aggression. Notably, not only epidermal chromatophores but also internal chromatophores lining the peritoneum responded to hormone treatments. There were no chromatic effects of the sex steroids 17beta-estradiol, testosterone or 11-ketotestosterone. We hypothesize that similar modulation of nuptial coloration by multiple hormones may be widespread in nature.
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| 7. |
- Trona, Federica, et al.
(författare)
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Neural coding merges sex and habitat chemosensory signals in an insect herbivore
- 2013
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 280:1760, s. 20130267-
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the processing of odour mixtures is a focus in olfaction research. Through a neuroethological approach, we demonstrate that different odour types, sex and habitat cues are coded together in an insect herbivore. Stronger flight attraction of codling moth males, Cydia pomonella, to blends of female sex pheromone and plant odour, compared with single compounds, was corroborated by functional imaging of the olfactory centres in the insect brain, the antennal lobes (ALs). The macroglomerular complex (MGC) in the AL, which is dedicated to pheromone perception, showed an enhanced response to blends of pheromone and plant signals, whereas the response in glomeruli surrounding the MGC was suppressed. Intracellular recordings from AL projection neurons that transmit odour information to higher brain centres, confirmed this synergistic interaction in the MGC. These findings underscore that, in nature, sex pheromone and plant odours are perceived as an ensemble. That mating and habitat cues are coded as blends in the MGC of the AL highlights the dual role of plant signals in habitat selection and in premating sexual communication. It suggests that the MGC is a common target for sexual and natural selection in moths, facilitating ecological speciation.
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| 8. |
- Iwarsson, Mattias
(författare)
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Epifytiska växter i Sverige
- 2015
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Ingår i: Fauna och flora. - 0014-8903. ; 110, s. 26-40
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- A total of 122 vascular plant species arereported growing as epiphytes in Sweden. Wittrock(1894) recorded 105 species, 34 of which were foundalso in the present study. In all, 51 species wew foundin this study, 17 of which were new compared toWittrock (1894).All observations were photo-documented, andthis material can be found in the form of pdf-fileson the Fauna & Flora website http://www.artdata.slu.se/FaunaochFlora/default.asp. Table 3 presents alist of all (122) scientific names in alphabetical order.In accordance with Wittrock (1894), the treesharbouring epiphytes were divided into the followingthree sections: stem-base b 0.1-0.6m above theground, mid-section m 0.6-2m above the ground, oron the unbranched trunk, and crown section k ≥2mabove the ground, or in the tree-crown.When more observations are added, it will probablybecome evident that most epiphytic species cangrow in all three sections.The majority of the epiphytic species (66) are perennials,and six of them are sporophytes. Three speciesare biennial, and 29 are annuals; mainly summer annuals,but also a few winter annuals. 13 shrub speciesand 11 tree species were found as epiphytes. Themost common epiphytic species was, in fact, rowanSorbus aucuparia. The tree species harbouring the largestnumber of epiphytes (31 species) was maple Acerplatanoides.The question of how these species came to growepiphytically is also discussed. None of them is a trueepiphyte, adapted to grow in trees. Evidently some ofthe species are wind-dispersed, whereas many othersare transported by animals (notably ants, squirrels andbirds). Mattias Iwarsson Centrum för biologisk mångfald.E-post: mattias.iwarsson@slu.se and Mattias.Biologi@telia.com
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| 9. |
- Blake, Chelsea A., et al.
(författare)
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Conspecific boldness and predator species determine predation-risk consequences of prey personality
- 2018
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer-Verlag New York. - 0340-5443 .- 1432-0762. ; 72:8, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Individual variation in the behavior of prey can influence predation risk in complex ways. We ran individual roach (Rutilus rutilus), a common freshwater fish, through a standard refuge emergence protocol to characterize their boldness, a key animal personality trait. We then paired a bold and a shy roach and exposed the pair to one of two predator species that have contrasting hunting modes to ascertain how personality traits shaped their survival during predator encounters. When a paired bold and shy prey fish interacted with a perch predator (active foraging mode), bold and shy prey were consumed in almost equal numbers. However, pike predators (ambush foraging mode) selectively consumed more shy prey, and prey body size and boldness score both contributed significantly to which prey fish was eaten. Our findings support the idea that multiple predators with different foraging modes, and hence differential selection on prey personality, could contribute to maintaining variation in personality in prey populations. Furthermore, for social species, including shoaling fish, the ultimate consequences of an individual’s personality may depend upon the personality of its nearby conspecifics. Significance statement: Animals of the same species often look similar, but individuals show differences in their behavior that can have important consequences, for instance when these individuals interact with predators. The common roach is a freshwater fish that shows inter-individual variation in its propensity to take risks, a key personality trait often termed boldness. Variation in boldness may affect the outcome when roach interact with predators, i.e., if they get eaten or survive. However, we found the impact of roachs’ personality type depends on what species of predatory fish they face. When we put a shy and a bold roach together with predatory perch, the roachs’ personality did not significantly affect which individual was eaten. But when the predator was a pike, the predators selectively ate more shy roach, and the likelihood an individual would be eaten depended on their body size.
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| 10. |
- Braga Gonçalves, Inês, et al.
(författare)
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Effects of female mating order and male size on embryo survival in a pipefish.
- 2015
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 114:3, s. 639-645
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Tidskriftsartikel (refereegranskat)abstract
- In species that provide parental care, individuals should invest adaptively in their offspring in relation to the preand post-zygotic care provided by their partners. In the broad-nosed pipefish, Syngnathus typhle L., females transfer large, nutrient-rich eggs into the male brood pouch during mating. The male broods and nourishes the embryos for several weeks before independent juveniles emerge at parturition. Given a choice, females clearly prefer large partners. Yet, females provide protein-richer eggs when the same individual mates with a smaller than a larger male. In the present study, we allowed each female to mate with one small and one large male, in alternated order. We found a strong effect of female mating order, with larger clutches and higher embryo mortality in first- than second-laid broods, which may suggest that eggs over-ripen in the ovaries or reflect the negative effects of high embryo density in the brood pouch. In either case, this effect should put constraints on the possibility of a female being selective in mate choice. We also found that small and large males produced embryos of similar size and survival, consistent with the reproductive compensation hypothesis, suggesting that, in this species, larger males provide better nourishment to the embryos than smaller males.
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