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1.
Predators exert strong top-down pressure on herbivorous insects, but research on how predators affect herbivore fitness often focuses on the more active juvenile and adult life stages while ignoring the pupal or cocoon life stage. Few studies have investigated predation of lepidopteran pupae or cocoons and even fewer have investigated species that are not forest pests. Here we present a study on overwinter survival for two moth species in the family Limacodidae, a group of polyphagous species found in deciduous forests. We placed cocoons of the saddleback caterpillar, Acharia stimulea (Clemens), and the spiny oak-slug caterpillar, Euclea delphinii (Boisduval), in the field under saplings of six different tree species and monitored predation and survival. This is the first study to examine predation rate among different host plants within a site. We found that cocoon predation was fairly high and differed significantly between limacodid species (29% for A. stimulea vs. 22% for E. delphinii). Predation rate did not differ among the six host plant species that we tested and also did not vary annually. Through phenotypic selection analyses, we found that cocoon mass affected both the likelihood of predation and overwinter survival; larger cocoons were less likely to be depredated and more likely to successfully emerge the following year. Overall our results indicate that cocoon predation is an important source of mortality for these two limacodid species and that there may be positive selection for greater cocoon mass for both limacodid species.  相似文献   

2.
Burnet moths of the genus Zygaena are a striking group of primarily diurnal Lepidoptera displaying an exceptional phenotypic plasticity. Previous attempts to elucidate the phylogenetic history of the group had been confounded by a perplexing pattern of characters or insufficient taxon sampling. In the present study, we infer a phylogeny of the genus Zygaena by analysing 5.4 kb of their nuclear and mitochondrial DNA. Eighty‐four of the 98 currently recognized species in this genus are considered, including representatives of all described species groups. RNA coding sequences are aligned with reference to zygaenoid moth specific secondary structure models of corresponding molecules. We conduct phylogenetic analyses within a Bayesian framework applying partition specific substitution parameters; covariation of paired sites in RNA gene sequences is accommodated by using doublet substitution models. The molecular data reveal that a considerable number of currently recognized species groups in Zygaena are not monophyletic. The traditional subgeneric classification proves to be artificial as well; Agrumenia and Zygaena (sensu stricto) are polyphyletic. Only the subgenus Mesembrynus can be confirmed as a monophyletic species cluster. Optimization of larval host–plant associations and forewing patterns on sampled trees of the Bayesian analyses suggest convergent evolution of similar wing pattern types in distantly related species clusters and a shift from cyanogenic to acyanogenic host‐plants. The phylogenetic results challenge the classic assumption that early species diversification in Zygaena took place in the Irano–Turkestanian region. Rather, the molecular data point to the western Mediterranean area as the geographical origin of the group and imply a subsequent colonization of the Middle East and Central Asia. We discuss the apparently convergent evolution of similar wing patterns in context with the chemical defence system of burnet moths and suggest a species group concept for the genus Zygaena that accounts for the recent findings. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92 , 501–520.  相似文献   

3.
All larvae in the family Papilionidae possess osmeteria, eversible glands that release defensive chemicals upon disturbance. These chemicals have been shown to be repellent to ants, mantids, and other predaceous arthropods with chewing mouthparts. In this study, we demonstrate that the pentatomid Podisus maculiventris,an important predator of the black swallowtail Papilio polyxenes,is capable of piercing the body wall of the caterpillar and consuming body fluids without eliciting osmeterial eversion. Tenebrio molitorlarvae coated with osmeterial secretions of Papilio polyxeneswere universally rejected by Podisus maculiventris,suggesting that the predator is in fact repelled by the swallowtail defensive chemistry. By circumventing the defensive behavior of the caterpillar, the pentatomid is able to utilize an otherwise chemically unsuitable prey species.  相似文献   

4.
Evolution of epiphytes in Davalliaceae and related ferns   总被引:3,自引:0,他引:3  
The evolution of epiphytes in Davalliaceae was investigated by field observations and molecular phylogenetic analyses. Field studies revealed that in Davalliaceae and related ferns, epiphytes in a broad sense are classified into climber, secondary hemi-epiphyte, and obligate epiphyte, based on combinations of the places (ground vs. tree) of inferred spore germination and sporophyte growth. Some species of Davalliaceae have multiple life forms, i.e. secondary hemi-epiphyte and obligate epiphyte, whereas others are obligate epiphytes. Phylogenetic trees obtained from rbcL and accD gene sequences supported that secondary hemi-epiphytic Oleandra is sister to the epiphytic Davalliaceae and polygrammoid ferns. Analyses of life form evolution based on the phylogenetic relationships suggested that obligate epiphytes of the Davalliaceae and polygrammoid ferns evolved from secondary hemi-epiphytes, or less likely from climbers. We hypothesized a scenario for the evolution of life forms in Davalliaceae and related groups that involves successive changes in rhizome habit, root function, and germination place. Rhizome dorsiventrality and scale morphology, shared by climbers, secondary hemi-epiphytes, and obligate epiphytes examined, may be other innovations for the ferns to have evolved into epiphytes.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 495–510.  相似文献   

5.
广义铃兰族包括6属200余种单子叶植物,具有较为稳定的染色体数目以及明显的核型变化,是研究植物染色体进化非常理想的类群.该研究采用常规压片法对铃兰族5个物种植物的染色体形态、数目及其核型进行了观察分析,并全面收集和整理了铃兰族所有已报道的共81种253条的染色体记录,通过综合统计、重建系统发育树,探讨铃兰族属间以及各属...  相似文献   

6.
Micromorphological characters of the fruiting bodies, such as ascus-type and hymenial amyloidity, and secondary chemistry have been widely employed as key characters in Ascomycota classification. However, the evolution of these characters has yet not been studied using molecular phylogenies. We have used a combined Bayesian and maximum likelihood based approach to trace character evolution on a tree inferred from a combined analysis of nuclear and mitochondrial ribosomal DNA sequences. The maximum likelihood aspect overcomes simplifications inherent in maximum parsimony methods, whereas the Markov chain Monte Carlo aspect renders results independent of any particular phylogenetic tree. The results indicate that the evolution of the two chemical characters is quite different, being stable once developed for the medullary lecanoric acid, whereas the cortical chlorinated xanthones appear to have been lost several times. The current ascus-types and the amyloidity of the hymenial gel in Pertusariaceae appear to have been developed within the family. The basal ascus-type of pertusarialean fungi remains unknown.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 615–626.  相似文献   

7.
漆酚是漆树科植物独有的化学成分,具有良好的抗氧化、抗肿瘤、抗病毒等生物活性,极具药物和工业生产开发价值。该研究通过对国内外有关漆树科各类群有关漆酚数据的搜集和整理,开展漆树科漆酚的多样性与分布情况的综合统计;同时在利用核基因ETS和叶绿体基因rps16和trnL-F重建漆树科系统发育树的基础上,探讨漆酚在漆树科及各属间的起源和演化关系。结果表明:(1)漆树科漆酚具有较高的多样性,在其苯环和-R链上都有很大的变异。(2)发现漆酚仅存在于Anacardioideae亚科中,是该亚科的一个重要界定特征。(3)基于漆酚苯环结构和-R链特征的祖先性状重建分析表明,漆树科的漆酚是由邻苯二酚向间苯二酚演化,而漆酚-R链的十五烃(烯)基则是向十七烃(烯)基平行演化。  相似文献   

8.
Abstract. Polyclad flatworms are acoelomate bilaterians found in benthic communities worldwide, predominantly in marine environments. Current polyclad systematics is unstable, with two non-concordant classification schemes resulting in a poor understanding of within-group relationships. Here we present the first phylogenetic framework for the suborder Cotylea using a morphological matrix. Representatives of 34 genera distributed among all cotylean families (except four, excluded due to their dubious taxonomic status) were investigated. The number of families included ranges from a conservative eight to a revisionary 11. Outgroup analysis indicated that the suborder is monophyletic and defined by the presence of a ventral adhesive structure, a short posteriorly positioned vagina, and cement glands. Of the eight to 11 families included, we confirmed that three were monophyletic: Boniniidae, Prosthiostomidae, and Pseudocerotidae. Boniniidae was consistently recovered as the sister group to other Cotylea, based on the retention of the plesiomorphic Lang's vesicle. The clade consisting of Anonymus, Marcusia , and Pericelis is sister to the Boniniidae and the rest of the Cotylea. Above this clade there is little resolution at the base of the sister group. The Euryleptidae are found to be paraphyletic and give rise to the Pseudocerotidae. Neither classification scheme received unequivocal support. The intrafamilial relationships of the diverse Pseudocerotidae and Euryleptidae were examined. Color pattern characters (used for species identification) were highly homoplasious but increased cladogram resolution within genera. The monophyly of seven genera within the Pseudocerotidae and Euryleptidae was not supported and many genera showed no autapomorphies, highlighting the need for taxonomic revision of these families.  相似文献   

9.
A morphology-based phylogenetic analysis of the eight species of Rhombognathides (Acari: Halacaridae) demonstrated some evolutionary tendencies of character transformation. In the course of the evolution of Rhombognathides, idiosomal plates increased in size or fused. Simple filiform setae transformed into spiniform or bipectinate setae. The number of tarsal claws, the length of median claw and leg chaetotaxy of telofemora and tibiae were reduced. The fusion or expansion of dorsal plates, transformation from filiform to other setal forms, and reduction of leg setae would have recurrently occurred in halacarid evolution. The claw structure most likely reflects adaptation to specific habitat.  相似文献   

10.
Clitellata (earthworms, leeches, and allies) is a clade of segmented annelid worms that comprise more than 5000 species found worldwide in many aquatic and terrestrial habitats. According to current views, the first clitellates were either aquatic (marine or freshwater) or terrestrial. To address this question further, we assessed the phylogenetic relationships among clitellates using parsimony, maximum likelihood and Bayesian analyses of 175 annelid 18S ribosomal DNA sequences. We then defined two ecological characters (Habitat and Aquatic‐environment preferences) and mapped those characters on the trees from the three analyses, using parsimony character‐state reconstruction (i.e. Fitch optimization). We accommodated phylogenetic uncertainty in the character mapping by reconstructing character evolution on all the trees resulting from parsimony and maximum likelihood bootstrap analyses and, in the Bayesian inference, on the trees sampled using the Markov chain Monte Carlo algorithm. Our analyses revealed that an ‘aquatic’ ancestral state for clitellates is a robust result. By using alterations of coding characters and constrained analyses, we also demonstrated that the hypothesis for a terrestrial origin of clitellates is not supported. Our analyses also suggest that the most recent ancestor of clitellates originated from a freshwater environment. However, we stress the importance of adding sequences of some rare marine taxa to more rigorously assess the freshwater origin of Clitellata. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 447–464.  相似文献   

11.
The morphology of the scoli of Eudia pavonia, Saturnia pyri and Eupackardia calleta last instar caterpilars has been clarified. Chemical and biochemical comparisons of scolus secretions and corresponding caterpillar haemolymphs indicate two differing defensive strategies: Eudia and Saturnia contain phenolic and related compounds, whereas Eupackardia additionally synthesizes biogenic amines (e.g. neurotransmitters) in considerable amounts. For most aromatic compounds from the caterpillars a theoretical biogenetic scheme is proposed. Deterrent effects of all secretions and most haemolymphs on particular predatory ants were ascertained.Abbrevations CI chemical ionisation - EI electronimpact ionisation - GC-MS gas chromatography-mass spectrometry - GS gland secretion - HL haemolymph - PMSF phenylmethylsulphonyl fluoride - SDS-PAGF sodium dodecyl sulphate-polyacrylamide gel electrophoresis - SEM scanning electron microscope  相似文献   

12.
Since the erection of the weevil subfamily Baridinae by Schönherr in 1836, no phylogenetic hypothesis using cladistic methods has been proposed for this extraordinarily diverse group. This study provides the first hypothesis for the evolution of Baridinae using phylogenetic methods, including 301 taxa and 113 morphological characters. Despite fairly well‐resolved results, indicating paraphyly of nearly all of the currently recognized intrasubfamilial divisions, no change to the current classification is made. Even though groupings are proposed based on the final results, it is believed that more rigorous analyses need to be made prior to a re‐evaluation and subsequent alteration of the current classification. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010.  相似文献   

13.
Caterpillars of the parasitic lycaenid butterfly are often adopted by host ants. It has been proposed that this adoption occurs because the caterpillars mimic the cuticular hydrocarbons of the host ant. This study aimed to examine whether caterpillars of the Japanese lycaenid butterfly Niphanda fusca induce adoption by mimicking their host ant Camponotus japonicus. Behavioral observations conducted in the laboratory showed that most second‐instar caterpillars were not adopted, whereas most third‐instar caterpillars were successfully adopted by host workers. A chemical comparison detected no characteristic differences in the cuticular hydrocarbon profiles between second‐ and third‐instar caterpillars. However, morphological features of the caterpillars differed between the second and third instars; third‐instar caterpillars developed exocrine glands (ant organs) such as tentacle organs and a dorsal nectary organ. These results suggest that multiple chemical signatures, not only cuticular hydrocarbons, may be important for invasion of the host ant nest.  相似文献   

14.
Abstract. When free-living organisms evolve into symbiotic organisms (parasites, commensals, or mutualists), their bodyplan is often dramatically modified as a consequence. The present work pertains to the study of this process in a group of marine obligate symbiotic worms, the Myzostomida. These are mainly ectocommensals and are only associated with echinoderms, mostly crinoids. Their usual textbook status as a class of the Annelida is generally accepted, although recent molecular phylogenetic studies have raised doubts on their relationships with other metazoans, and the question of their status remains open. Here, we reconstruct the evolution of their bodyplans by mapping 14 external morphological characters (analyzed using scanning electron microscopy) onto molecular phylogenies using maximum parsimony (MP) and maximum likelihood (ML) optimality criteria. Rooted MP, ML, and Bayesian phylogenetic trees were obtained by analyzing the nucleotide sequences of cytochrome oxidase subunit I, 18S rDNA, and 16S rDNA genes, separately and in combination. Representatives of 34 species distributed among seven extant genera were investigated. Our character evolution analyses, combined with recent ontogenetic and ultrastructural evidence, indicate that the organism at the base of the myzostome tree would have had six body segments and five pairs of polychaete-type parapodia, and that two lineages emerged from it: one comprising parasites, with large females and dwarf males, which gave rise to the extant Pulvinomyzostomum and Endomyzostoma species, and a second lineage comprising simultaneously hermaphroditic ectocommensals, from which all other extant myzostome taxa probably evolved.  相似文献   

15.
Phalacroma currently comprises 69 species of mostly marine heterotrophic dinophysoids. With a round cell body and short sulcal and cingular lists, Phalacroma spp. have a simple morphology compared to other dinophysoid genera. Therefore, species identification is not always a trivial matter. A few Arctic species have been described and, with the exception of Ph. rotundatum, they are not only infrequently recorded but also occur in low cell abundances. Here, we studied a Lugol fixed sample from Denmark Strait. From this sample 13 cells with a Phalacroma‐like morphology were isolated under a stereo microscope, photo documented, and used for single‐cell PCR determination of nuclear‐encoded LSU rDNA sequences. The sequences fell in three groups defined by their ribotype. A single ribotype sequence representing each group was added to an alignment containing a diverse assemblage of dinophysoids and analyzed using Bayesian analysis and maximum likelihood. Based on comparative light microscopy one of the ribotypes (ribotype 1) was similar but not identical to Ph. ruudi and ribotype 2 could not be matched to a known species of Phalacroma. In the phylogeny both clustered with other species of Phalacroma including the type species. The morphology of ribotype 3 was similar but not identical to Ph. braarudii. In the phylogeny ribotype 3 clustered outside the core group of Phalacroma species. Hence, ribotype 3 was designated ‘Phalacroma’ sp. 3 and has to be described as a new genus pending additional data. This study has revealed the existence of cryptic species diversity within the Phalacroma morphotype boundary. Two additional Phalacroma species (Ph. apicatum and Ph. cf. argus) also clustered outside Phalacroma sensu stricto further emphasizing the presence of cryptic species within the genus. Future studies with a polyphasic approach are needed to better address the taxonomy of Phalacroma and Phalacroma‐like dinophysoids.  相似文献   

16.
The following new species in the New World Natada complex are described: Natada minuscula, Natada cecilia, Natada lalogamezi, Natada kokii, Natada monteverdensis, Narosopsis iangauldi, and Euprosterna wemilleri. Natada minuscula is the smallest known species in the complex. Of the new species, only Natada kokii, Natada cecilia and Narosopsis iangauldi are known to occur outside of Costa Rica. Previously the New World Natada complex had 43 species in the neotropics. It is anticipated that the proportion of new species in the complex will exceed other major lineages of Limacodidae found in Costa Rica.  相似文献   

17.
Molecular phylogenetic analyses were conducted to determine relationships and to investigate character evolution for the Troidini/Aristolochia interaction, in an attempt to answer the following questions: (1) what is the present pattern of use of Aristolochia by these butterflies; (2) is the pattern we see today related to the phylogeny of plants or to their chemical composition; (3) can the geographical distribution of Aristolochia explain the host plant use observed today; and (4) how did the interaction between Troidini and Aristolochia evolve? Analyses of character optimization suggest that the current pattern of host plant use of these butterflies does not seem to be constrained by the phylogeny of their food plants, neither by the secondary chemicals in these plants nor by their geographical similarity. The current host plant use in these butterflies seems to be simply opportunistic, with species with a wider geographical range using more species of host plants than those with a more restricted distribution. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 90 , 247–261.  相似文献   

18.
武春生  方承莱 《昆虫学报》2009,52(6):684-690
系统整理了中国球须刺蛾属的全部种类,共8种,包括1新种--双带球须刺蛾Scopelodes bicolor Wu et Fang。显脉球须刺蛾S. kwangtungensis Hering从亚种提升为种级阶元。编制了本属中国已知种的检索表,提供了成虫和外生殖器特征照片。新种模式标本保存在中国科学院动物研究所。  相似文献   

19.
武春生  方承莱 《昆虫学报》2009,52(5):561-566
系统整理了中国眉刺蛾属的全部种类,共9种及1亚种,包括1新种--黄眉刺蛾Narosa pseudopropolia Wu et Fang及1新纪录种--齐眉刺蛾N. propolia Hampson。编制了本属中国已知种的检索表,提供了成虫和外生殖器特征照片。新种模式标本保存在中国科学院动物研究所。  相似文献   

20.
We infer for the first time the phylogenetic relationships of genera and tribes in the ecologically and evolutionarily well‐studied subfamily Nymphalinae using DNA sequence data from three genes: 1450 bp of cytochrome oxidase subunit I (COI) (in the mitochondrial genome), 1077 bp of elongation factor 1‐alpha (EF1‐α) and 400–403 bp of wingless (both in the nuclear genome). We explore the influence of each gene region on the support given to each node of the most parsimonious tree derived from a combined analysis of all three genes using Partitioned Bremer Support. We also explore the influence of assuming equal weights for all characters in the combined analysis by investigating the stability of clades to different transition/transversion weighting schemes. We find many strongly supported and stable clades in the Nymphalinae. We are also able to identify ‘rogue’ taxa whose positions are weakly supported (the different gene regions are in conflict with each other) and unstable. Our main conclusions are: (1) the tribe Coeini as currently constituted is untenable, and Smyrna, Colobura and Tigridia are part of Nymphalini; (2) ‘Kallimini’ is paraphyletic with regard to Melitaeini and should be split into three tribes: Kallimini s.s., Junoniini and Victorinini; (3) Junoniini, Victorinini, Melitaeini and the newly circumscribed Nymphalini are strongly supported monophyletic groups, and (4) Precis and Junonia are not synonymous or even sister groups. The species Junonia coenia, a model system in developmental biology, clearly belongs in the genus Junonia. A dispersal‐vicariance analysis suggests that dispersal has had a major effect on the distributions of extant species, and three biotic regions are identified as being centres of diversification of three major clades: the Palaearctic for the Nymphalis‐group, the Afrotropics for Junoniini and the Nearctic for Melitaeini. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 86 , 227–251.  相似文献   

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