11. |
- Kodandaramaiah, Ullasa, et al.
(author)
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Population structure in relation to host-plant ecology and Wolbachia infestation in the comma butterfly
- 2011
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In: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 24:10, s. 2173-2185
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Journal article (peer-reviewed)abstract
- Experimental work on Polygonia c-album, a temperate polyphagous butterfly species, has shown that Swedish, Belgian, Norwegian and Estonian females are generalists with respect to host-plant preference, whereas females from UK and Spain are specialized on Urticaceae. Female preference is known to have a strong genetic component. We test whether the specialist and generalist populations form respective genetic clusters using data from mitochondrial sequences and 10 microsatellite loci. Results do not support this hypothesis, suggesting that the specialist and generalist traits have evolved more than once independently. Mitochondrial DNA variation suggests a rapid expansion scenario, with a single widespread haplotype occurring in high frequency, whereas microsatellite data indicate strong differentiation of the Moroccan population. Based on a comparison of polymorphism in the mitochondrial data and sequences from a nuclear gene, we show that the diversity in the former is significantly less than that expected under neutral evolution. Furthermore, we found that almost all butterfly samples were infected with a single strain of Wolbachia, a maternally inherited bacterium. We reason that indirect selection on the mitochondrial genome mediated by a recent sweep of Wolbachia infection has depleted variability in the mitochondrial sequences. We also surmise that P. c-album could have expanded out of a single glacial refugium and colonized Morocco recently.
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12. |
- Midega, Charles A. O., et al.
(author)
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Host plant selection behaviour of Chilo partellus and its implication for effectiveness of a trap crop
- 2011
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In: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703 .- 1570-7458. ; 138:1, s. 40-47
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Journal article (peer-reviewed)abstract
- Female lepidopterans can display a hierarchy of preference among potential host species, a trait thought to arise from the balance between attractants and deterrents to which the insects respond. Host plant ranking by moths and larvae of Chilo partellus Swinhoe (Lepidoptera: Crambidae), an important pest of cereals in Africa, was investigated, and whether eggs deposited on specific host plants yield larvae of particular host preferences. Trap plants are used in management of this pest. However, any 'disagreement' in host ranking between moths and larvae could potentially reduce effectiveness of trap crops as larvae emigrate to the main crop from the parent's preferred trap plant. We also investigated whether host plant preference is influenced by the diet upon which larvae fed as part of an integrated assessment of the relationship between host plant selection and learning in C. partellus. Five host plants (all Poaceae) were used: maize (Zea mays L.), sorghum (Sorghum bicolor Moench), Napier grass (Pennisetum purpureum Schumach), and two varieties of signal grass [Brachiaria brizantha (A. Rich.) Stapf], viz., local (henceforth signal grass) and improved ('Mulato'). In multiple choice tests, C. partellus female moths preferentially oviposited on Napier grass, followed by sorghum, maize, and signal grass, and least preferred 'Mulato'. Larvae however equally orientated and settled on leaf cuts of maize, sorghum, signal grass, and Napier grass, but least preferred 'Mulato'. Moreover, eggs from specific host plants did not yield larvae of particular host preferences. Furthermore, oviposition preference was not altered by the larval food. These results imply only a slight 'disagreement' in host ranking behaviour between moths and larvae, which is beneficial for trap cropping as larvae would not 'reject' the trap plant and appreciably disperse to the neighboring plants. Moreover, absence of larval learning behaviour indicates that regardless of the larval food C. partellus moths would still be attracted to the selected trap plant.
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13. |
- Mozuraitis, Raimondas, et al.
(author)
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Nonvolatile Chemical Cues Affect Host-Plant Ranking by Gravid Polygonia c-album Females
- 2012
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In: Zeitschrift für Naturforschung C - A Journal of Biosciences. - : Walter de Gruyter GmbH. - 0939-5075 .- 1865-7125. ; 67:1-2, s. 93-102
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Journal article (peer-reviewed)abstract
- In a multiple-choice test, the preference of egg-laying Polygonia c-album (comma butterfly) females was studied for oviposition on plants bearing surrogate leaves treated with crude methanol extracts obtained from leaves of seven host-plant species: Humulus lupulus, Urtica dioica, Ulmus glabra, Salix caprea, Ribes nigrum, Corylus avellana, and Betula pubescens. The ranking order of surrogate leaves treated with host-plant extracts corresponded well to that reported on natural foliage, except R. nigrum. Thus, host-plant choice in P c-album seems to be highly dependent on chemical cues. Moreover, after two subsequent fractionations using reversed-phase chromatography the nonvolatile chemical cues residing in the most polar water-soluble fractions evidently provided sufficient information for egg-laying females to discriminate and rank between the samples of more and less preferred plants, since the ranking in these assays was similar to that for natural foliage or whole methanol extracts, while the physical traits of the surrogate leaves remained uniform.
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14. |
- Nylin, Sören, et al.
(author)
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HOST PLANT UTILIZATION, HOST RANGE OSCILLATIONS AND DIVERSIFICATION IN NYMPHALID BUTTERFLIES : A PHYLOGENETIC INVESTIGATION
- 2014
-
In: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 68:1, s. 105-124
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Journal article (peer-reviewed)abstract
- It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the oscillation hypothesis. In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies.
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15. |
- Nylin, Sören
(author)
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Induction of diapause and seasonal morphs in butterflies and other insects : knowns, unknowns and the challenge of integration
- 2013
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In: Physiological entomology (Print). - : Wiley. - 0307-6962 .- 1365-3032. ; 38:2, s. 96-104
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Journal article (peer-reviewed)abstract
- The choice' of whether to enter diapause or to develop directly has profound effects on the life histories of insects, and may thus have cascading consequences such as seasonal morphs and other less obvious forms of seasonal plasticity. Present knowledge of the control of diapause and seasonal morphs at the physiological and molecular levels is briefly reviewed. Examples, mainly derived from personal research (primarily on butterflies), are given as a starting point with the aim of outlining areas of research that are still poorly understood. These include: the role of the direction of change in photoperiod; the role of factors such as temperature and diet in modifying the photoperiodic responses; and the role of sex, parental effects and sex linkage on photoperiodic control. More generally, there is still a limited understanding of how external cues and physiological pathways regulating various traits are interconnected via gene action to form a co-adapted complete phenotype that is adaptive in the wild despite environmental fluctuation and change.
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16. |
- Peña, Carlos, et al.
(author)
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Biogeographic history of the subtribe Euptychiina (Lepidoptera, Nymphalidae, Satyrinae)
- 2010
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In: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 39, s. 243-258
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Journal article (peer-reviewed)abstract
- The diverse butterfly subtribe Euptychiina was thought to be restricted to the Americas. However, there is mounting evidence for the Oriental Palaeonympha opalina being part of Euptychiina and thus a disjunct distribution between it (in eastern Asia) and its sister taxon (in eastern North America). Such a disjunct distribution in both eastern Asia and eastern North America has never been reported for any butterfly taxon. We used 4447 bp of DNA sequences from one mitochondrial gene and four nuclear genes for 102 Euptychiina taxa to obtain a phylogenetic hypothesis of the subtribe, estimate dates of origin and diversifica- tion for major clades and perform a biogeographic analysis. Euptychiina originated 31 Ma in South America. Early Euptychiina dispersed from North to South America via the tem- porary connection known as GAARlandia during Eocene–Oligocene times. The current disjunct distribution of the Oriental Palaeonympha opalina is the result of a northbound dis- persal of a lineage from South America into eastern Asia via North America. The common ancestor of Palaeonympha and its sister taxon Megisto inhabited the continuous forest belt across North Asia and North America, which was connected by Beringia. The closure of this connection caused the split between Palaeonympha and Megisto around 13 Ma and the severe extinctions in western North America because of the climatic changes of the Late Miocene (from 13.5 Ma onwards) resulted in the classic ‘eastern Asia and eastern North America’ disjunct distribution.
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17. |
- Peña, Carlos, et al.
(author)
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The radiation of Satyrini butterflies (Nymphalidae: Satyrinae) : a challenge for phylogenetic methods
- 2011
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In: Zoological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4082 .- 1096-3642. ; 161:1, s. 64-87
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Journal article (peer-reviewed)abstract
- We have inferred the most comprehensive phylogenetic hypothesis to date of butterflies in the tribe Satyrini. In order to obtain a hypothesis of relationships, we used maximum parsimony and model-based methods with 4435 bp of DNA sequences from mitochondrial and nuclear genes for 179 taxa (130 genera and eight out-groups). We estimated dates of origin and diversification for major clades, and performed a biogeographic analysis using a dispersal–vicariance framework, in order to infer a scenario of the biogeographical history of the group. We found long-branch taxa that affected the accuracy of all three methods. Moreover, different methods produced incongruent phylogenies. We found that Satyrini appeared around 42 Mya in either the Neotropical or the Eastern Palaearctic, Oriental, and/or Indo-Australian regions, and underwent a quick radiation between 32 and 24 Mya, during which time most of its component subtribes originated. Several factors might have been important for the diversification of Satyrini: the ability to feed on grasses; early habitat shift into open, non-forest habitats; and geographic bridges, which permitted dispersal over marine barriers, enabling the geographic expansions of ancestors to new environ- ments that provided opportunities for geographic differentiation, and diversificatio
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18. |
- Söderlind, Lina, et al.
(author)
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Genetics of diapause in the comma butterfly Polygonia c-album
- 2011
-
In: Physiological entomology (Print). - : Wiley. - 0307-6962 .- 1365-3032. ; 36:1, s. 8-13
-
Journal article (peer-reviewed)abstract
- The processes of local adaptation and ecological speciation can be better understood by studying the genetic background of life-history decisions. The sex chromosomes host genes for many population differences in the Lepidoptera and therefore the inheritance of diapause determination in the butterfly Polygonia c-album may be hypothesized to be sex-linked. In the present study, Polygonia c-album (L.) from Spain and Sweden and hybrid offspring are raised under an LD 17 : 7 h photocycle that induces most pure Swedish individuals to develop into the diapausing dark morph and most pure Spanish individuals into the light and directly-developing morph. If inheritance of the daylength threshold for diapause is X-linked, as is known to be the case for host-plant preferences, females should follow the developmental path of their male parents' populations. However, female hybrids instead have a diapause propensity intermediate to that of their parental stocks and, consequentially, diapause determination is not X-linked. However, male hybrids eclose as the diapausing morph to a higher extent than females and, moreover, this pattern is more pronounced in the Spanish female x Swedish male cross than in the reciprocal cross. Hence, it is concluded that the genetic determination of the critical daylength for diapause is mainly autosomal but with some influence of sex-linked genes and/or parental effects, possibly as an effect of the importance of protandry for males. Such sex effects could provide a starting point for the evolution of population differences inherited on the sex chromosomes.
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19. |
- Söderlind, Lina, 1982-
(author)
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Life-history consequenses of host plant choice in the comma butterfly
- 2012
-
Doctoral thesis (other academic/artistic)abstract
- There is much evidence that herbivory is a key innovation for the tremendous success of insect. In this thesis I have investigated different aspects of host plant utilization and phenotypic plasticity using the polyphagous comma butterfly, Polygonia c-album. Even though external conditions affect a phenotypic plastic response, the outcome is often influenced by a genetic background which may differ among populations. In Paper I we suspected the genetic background to seasonal polymorphism to be X-linked. However, results from interspecific hybridization between two populations suggested that diapause response is instead inherited in a mainly autosomally additive fashion, with a possible influence of sexual antagonism on males. In Paper II we showed that female oviposition preference is not a plastic response influenced by larval experience, but has a genetic background coupled to host plant suitability. Further, there is a strong individual correlation between larval host plant acceptance and female host plant specificity (Paper III). We believe this to be a larval feed-back genetically linked to female host specificity: offspring to ‘choosy’ specialist mothers benefit by remaining on the original host while offspring to less discriminating generalist mothers should risk inspecting the surroundings, thus compensating for potential poor female choice. In the larval mid-gut, genes are differentially expressed depending on host plant diet (Paper IV). Therefore, we expected to find fitness consequences of host plant switch. However, although growth rate was affected in a few treatments, larvae were generally surprisingly good at adjusting to new diets (Paper V). To conclude, host plant choice in both female and larval life stage is connected to performance. Combined with increased understanding about the plastic response to diet intake and seasonal polymorphism we have gained further insights into the processes of local adaptations and speciation in the Lepidoptera.
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20. |
- Wang, Houshuai, et al.
(author)
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Phylogeny, Systematics and Biogeography of the Genus Panolis (Lepidoptera : Noctuidae) Based on Morphological and Molecular Evidence
- 2014
-
In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:3, s. e90598-
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Journal article (peer-reviewed)abstract
- The genus Panolis is a small group of noctuid moths with six recognized species distributed from Europe to East Asia, and best known for containing the widespread Palearctic pest species P. flammea, the pine beauty moth. However, a reliable classification and robust phylogenetic framework for this group of potentially economic importance are currently lacking. Here, we use morphological and molecular data (mitochondrial genes cytochrome c oxidase subunit I and 16S ribosomal RNA, nuclear gene elongation factor-1 alpha) to reconstruct the phylogeny of this genus, with a comprehensive systematic revision of all recognized species and a new one, P. ningshan sp. nov. The analysis results of maximum parsimony, maximum likelihood and Bayesian inferring methods for the combined morphological and molecular data sets are highly congruent, resulting in a robust phylogeny and identification of two clear species groups, i.e., the P. flammea species group and the P. exquisita species group. We also estimate the divergence times of Panolis moths using two conventional mutation rates for the arthropod mitochondrial COI gene with a comparison of two molecular clock models, as well as reconstruct their ancestral areas. Our results suggest that 1) Panolis is a young clade, originating from the Oriental region in China in the Late Miocene (6-10Mya), with an ancestral species in the P. flammea group extending northward to the Palearctic region some 3-6 Mya; 2) there is a clear possibility for a representative of the Palearctic clade to become established as an invasive species in the Nearctic taiga.
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