Phylogenetic analyses of the rhipicephaline ticks indicate that the genus Rhipicephalus is paraphyletic

We inferred the phylogeny of 21 species and subspecies of ticks from the subfamilies Rhipicephalinae and Hyalomminae using cytochrome c oxidase subunit I (COI) and 12S rRNA mitochondrial gene sequences. Two members of the subfamily Haemaphysalinae were used for outgroup reference. The largest rhipicephaline genus, Rhipicephalus, was represented by ticks from six of the species groups, the second largest genus, Dermacentor, by species from two of three of its subgenera, and the genus Boophilus by 3 of its 5 species. We analyzed the 12S and COI sequences separately and together; statistically significant incongruence between the 12S rDNA and the COI sequences was not detected in the combined dataset using the incongruence length difference test. The combined dataset provided greater phylogenetic resolution than the individual datasets, and although the 12S rDNA data had only 25% of the parsimony-informative characters, it provided half of the total partitioned Bremer support for the combined dataset. We present the first hypothesis of phylogenetic relationships among some species groups of Rhipicephalus but our most controversial result was that the genus Rhipicephalus is apparently paraphyletic, unless species of Boophilus are included in it. The species of Rhipicephalus most closely related to Boophilus spp. were from the R. pravus and R. evertsi species groups, which may implicate an African origin for this important group of ticks.     

A re-evaluation of relationships in the Metastriata (Acari: Parasitiformes: Ixodidae)

A systematic analysis of generic/subgeneric relationships in the ixodid lineage Metastriata was conducted based on 82 structural and developmental characters, 15 of which have multiple states. Results of the analysis show considerable agreement with current classifications of the Ixodidae, including good support for monophyly of the Metastriata, the genera Ixodes and Haemaphysalis, and the grouping of Hoogstraal's Rhipicephalinae and Hyalomminae, and fair support for the genus Hyalomma. Our results differ from these classifications most notably by rejecting monophyly of the genera Aponomma and Amblyomma. Instead, the analysis provides weak support for a hypothesis in which the basal two to three lineages in the Metastriata are all composed of Aponomma species, and in which a fourth lineage within that genus, Aponomma elaphense, clusters with Amblyomma quadricavum to form a more derived lineage. Resolution is insufficient to support or reject monophyly of the genera Dermacentor and Rhipicephalus, or to resolve the position of the genus Haemaphysalis relative to the other Metastriata. Overall resolution within the Rhipicephalinae/Hyalomminae is quite good, but it is quite poor among the Amblyomminae and Haemaphysalinae. These results are similar to the results of recent 16S and 18S rDNA based molecular analyses. There are few indications of host specificity among the lineages analysed. The basal metastriate lineages contain a large number of squamate associates, but the pattern is not sufficiently clear to reject the hypothesis that these ticks will feed on all available vertebrate hosts. On the other hand, nearly all of the basal taxa are Australian. This suggests a possible origin of the Metastriata in Australia, with subsequent dispersal to other parts of the world.     

Phylogeny, Evolution and Historical Zoogeography of Ticks: A Review of Recent Progress

There has been much progress in our understanding of the phylogeny and evolution of ticks, particularly hard ticks, in the past 5 years. Indeed, a consensus about the phylogeny of the hard ticks has emerged. Our current working hypothesis for the phylogeny of ticks is quite different to the working hypothesis of 5 years ago. So that the classification reflects our knowledge of ticks, several changes to the nomenclature of ticks are imminent. One subfamily, the Hyalomminae, will probably be sunk, yet another, the Bothriocrotoninae n. subfamily, will be created. Bothriocrotoninae n. subfamily, and Bothriocroton n. genus, are being created to house an early-diverging (‘basal’) lineage of endemic Australian ticks that used to be in the genus Aponomma (ticks of reptiles). There has been progress in our understanding of the subfamily Rhipicephalinae. The genus Rhipicephalus is almost certainly paraphyletic with respect to the genus Boophilus. Thus, the genus Boophilus will probably become a subgenus of Rhipicephalus. This change to the nomenclature, unlike other options, will keep the name Boophilus in common usage. Rhipicephalus (Boophilus) microplus may still called B. microplus, and Rhipicephalus (Boophilus) annulatus may still be called B. annulatus, but the nomenclature will have been changed to reflect our knowledge of the phylogeny and evolution of these ticks. New insights into the historical zoogeography of ticks will also be presented. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synonymy of Boophilus Curtice, 1891 with Rhipicephalus Koch, 1844 (Acari: Ixodidae)

Recent molecular and morphological studies of the genera Rhipicephalus Koch, 1844 and Boophilus Curtice, 1891 revealed that the five species of Boophilus make the genus Rhipicephalus paraphyletic. Thus, Rhipicephalus Koch, 1844 is not a monophyletic (natural) lineage and some species of Rhipicephalus are more closely related to the species of Boophilus than to other species of Rhipicephalus. Here, we revise these genera: Boophilus is synonymised with Rhipicephalus, and Rhipicephalus (sensu lato) (including Boophilus) is redefined. By synonymising Boophilus with Rhipicephalus, we have changed the nomenclature so that it reflects our understanding of the phylogeny of these ticks. Boophilus is retained as a subgenus of Rhipicephalus, so the synonymy of Boophilus with Rhipicephalus does not result in the loss of the name Boophilus. In addition, Rhipicephalus is a well-known genus and the change proposed is simple -- all five species of Boophilus become members of Rhipicephalus (Boophilus).     

The value of idiosyncratic markers and changes to conserved tRNA sequences from the mitochondrial genome of hard ticks (Acari: Ixodida: Ixodidae) for phylogenetic inference

Idiosyncratic markers are features of genes and genomes that are so unusual that it is unlikely that they evolved more than once in a lineage of organisms. Here we explore further the potential of idiosyncratic markers and changes to typically conserved tRNA sequences for phylogenetic inference. Hard ticks were chosen as the model group because their phylogeny has been studied extensively. Fifty-eight candidate markers from hard ticks (family Ixodidae) and 22 markers from the subfamily Rhipicephalinae sensu lato were mapped onto phylogenies of these groups. Two of the most interesting markers, features of the secondary structure of two different tRNAs, gave strong support to the hypothesis that species of the Prostriata (Ixodes spp.) are monophyletic. Previous analyses of genes and morphology did not strongly support this relationship, instead suggesting that the Prostriata is paraphyletic with respect to the Metastriata (the rest of the hard ticks). Parallel or convergent evolution was not found in the arrangements of mitochondrial genes in ticks nor were there any reversals to the ancestral arthropod character state. Many of the markers identified were phylogenetically informative, whereas others should be informative with study of additional taxa. Idiosyncratic markers and changes to typically conserved nucleotides in tRNAs that are phylogenetically informative were common in this data set, and thus these types of markers might be found in other organisms.     

蜱类系统学研究进展

本文介绍了近年来蜱的编目和分类及系统发育和演化等方面的研究进展。对软蜱科(Argasidae)说明了属的变动;硬蜱科(Ixodidae)介绍了璃眼蜱亚科(Hyalomminae)和凹沟蜱亚科(Bothriocrotoninae)以及相应变动的属(新建的凹沟蜱属Bothriocroton和须角蜱属Cornupalpatum,合并的牛蜱属Boophilus、暗眼蜱属Anocentor和盲花蜱属Aponomma)。根据新的分类变更对已知种类进行了分析。至2006年,世界已知蜱类有3科18属897种,中国有2科10属119种。阐明了有关蜱类系统发育研究的主要观点,并讨论了其不足和有待深入研究的问题。目前,把形态学和分子生物学数据结合在一起的全证据方法,并结合蜱类和不同宿主之间的关系、动物地理学、古生物学以及比较寄生虫学的资料,成为解决蜱类系统发育问题的有效途径。     

Phylogenetic relationships and evolutionary history of the shrimp genus Penaeus s.l. derived from mitochondrial DNA

Mitochondrial DNA sequences were used to reconstruct the phylogeny of the Penaeus s.l. genus of marine shrimp. This phylogeny was used to test the validity of hypotheses on the species groupings, in particular the subgenus/genus subdivision, and on the species' evolutionary history. Newly derived sequences of both 16S rRNA and COI genes from 19 species of Penaeus s.l. and one outgroup were combined with previous sequences from seven additional species to allow analysis of 26 of the 28 recognised (or nominated) species. Phylogenetic analyses do not support the validity of all the previously created six subgenera (or genera) but provide evidence for division of the genus into two previously unrecognised clades (Melicertus+Marsupenaeus and Penaeus s.s.+Fenneropenaeus+Farfantepenaeus+Litopenaeus). A key conclusion from a previous molecular study, that the subgenera Farfantepenaeus and Litopenaeus are paraphyletic, was rejected. The molecular data support an Indo-West Pacific origin of the genus, with a single relatively recent colonisation of the Western Hemisphere, and subsequent subdivision into two clades prior to the emergence of the Panamanian isthmus.     

On molecular taxonomy: what is in a name?

Gene sequences of small portions of the genome are often used for premature detailed taxonomic changes, neglecting polyphasic taxonomy, which should also consider phenotypical characteristics. Three examples are given: (i) Recently, members of the genera Eperythrozoon and Haemobartonella have been moved, correctly so, from the Rickettsiales to the Mycoplasmatales, but were assigned to the genus Mycoplasma, mostly on the basis of 16S rRNA sequence analysis. Not only is the 16S rRNA sequence similarity between 'classical' Mycoplasma and these species of Eperythrozoon and Haemobartonella less than that between some other well-recognised bacterial genera, but their biological differences amply justify their classification in different genera of the Mycoplasmatales. Furthermore, the move creates considerable confusion, as it necessitates new names for some species, with more confusion likely to come when the 16S rRNA sequences of the type species of Eperythrozoon, a name which has priority over Mycoplasma, will be analysed. (ii) In the Rickettsiales, members of the genera Anaplasma, Ehrlichia, Cowdria, Neorickettsia and Wolhbachia are so closely related phylogenetically on the basis of 16S rRNA sequences, and for some also of groESL operon sequences, that they have recently been fused, correctly so, into one family, the Anaplasmataceae, while the tribes Ehrlichieae and Wolbachieae have been abolished. Sequence diversity within the 'classical' genus Ehrlichia has led to classifying E. phagocytophila (including E. equi and the agent of human granulocytic ehrlichiosis), E. platys and E. bovis in the genus Anaplasma, while others have been retained in Ehrlichia, which also includes Cowdria ruminantium. E. sennetsu and E. risticii have been transferred to the genus Neorickettsia. 16S rRNA and GroEL sequences of 'classical' Anaplasma and some members of 'classical' Ehrlichia do show a close relationship, but differences in citrate synthase gene sequences, the GC content of this gene, and sequences of the gene encoding the beta-subunit of RNA polymerase, not to speak of the phenotypical differences, do not justify the fusion into one genus. Because of the phylogenetical diversity in Ehrlichia it is recommended that a new genus name be created for the E. phagocytophila genogroup (and E. platys and E. bovis). (iii) One of the conclusions of studies on the phylogeny of ticks of the subfamilies Rhipicephalinae and Hyalomminae, based on nucleotide sequences from 12S rRNA, cytochrome c oxidase I, the internal transcribed spacer 2, 18S rRNA, as well as morphological characters, is that Boophilus should be considered as a subgenus of Rhipicephalus. While Boophilus and Rhipicephalus are undoubtedly close, the obviously important morphological and biological differences between the genera Rhipicephalus and Boophilus are thus overruled by similarities in the sequences of a number of genes and this leads to considerable confusion. Polyphasic taxonomy amply justifies maintaining Boophilus as a separate genus, phylogenetically near to Rhipicephalus. This note is a plea for a cautious and balanced approach to taxonomy, taking into account molecular genotypical information, as far as is possible from different genes, as well as phenotypical characteristics.     

Phylogeny of the hard ticks (Ixodidae) inferred from 18S rRNA indicates that the genus Aponomma is paraphyletic

We examined the phylogeny of ticks (Acari:Parasitiformes:Ixodida) and their closest known mite relatives (Acari:Parasitiformes:Mesostigmata and Holothyrida) using 18S rRNA sequences. In our analyses, we included sequences from 36 taxa. Sequences for 13 hard ticks (Family Ixodidae), 5 soft ticks (Family Argasidae), and 2 mesostigmatid mites were obtained from the GenBank database and we generated sequences for 15 hard ticks and 1 holothyrid mite. Ten of these tick species were endemic to Australia. Our analyses indicated that the suborder Holothyrida is more closely related to Ixodida than to Mesostigmata, the group used as outgroup in earlier molecular studies. This finding is consistent with Lehtinen's (1991) hypothesis that the Holothyrida rather than the Mesostigmata is the sister-group to the Ixodida. Within the hard ticks the genus Aponomma and thus the family Amblyomminae were paraphyletic. Taxonomic revision of these taxa is needed. The genus Amblyomma was paraphyletic without the inclusion of "typical" Aponomma species (Ap. latum and Ap. fimbriatum). There was a basal divergence between endemic Australian and other species in both the Metastriata and the Prostriata divisions of the hard ticks.     

Phylogeny of the lice (Insecta, Phthiraptera) inferred from small subunit rRNA

There has been much argument about the phylogenetic relationships of the four suborders of lice (Insecta: Phthiraptera). Lyal's study of the morphology of lice indicated that chewing/biting lice (Mallophaga) are paraphyletic with respect to sucking lice (Anoplura). To test this hypothesis we inferred the phylogeny of 33 species of lice from small subunit (SSU) rRNA sequences (18S rRNA). Liposcelis sp. from the Liposcelididae (Psocoptera) was used for outgroup reference. Phylogenetic relationships among the four suborders of lice inferred from these sequences were the same as those inferred from morphology. The Amblycera is apparently the sister-group to all other lice whereas the Rhynchophthirina is apparently sister to the Anoplura; these two suborders are sister to the Ischnocera, i.e. (Amblycera (Ischnocera (Anoplura, Rhynchophthirina))). Thus, the Mallophaga (Amblycera, Ischnocera, Rhynchophthirina) is apparently paraphyletic with respect to the Anoplura. Our analyses also provide evidence that: (i) each of the three suborders of lice that are well represented in our study (the Amblycera, Ischnocera, and Anoplura) are monophyletic; (ii) the Boopiidae is monophyletic; (iii) the genera Heterodoxus and Latumcephalum (Boopiidae) are more closely related to one another than either is to the genus Boopia (also Boopiidae); (iv) the Ricinidae and Laemobothridae may be sister-taxa; (v) the Philopteridae may be paraphyletic with respect to the Trichodectidae; (vi) the genera Pediculus and Pthirus are more closely related to each other than either is to the genus Pedicinus ; and (vii) in contrast to published data for mitochondrial genes, the rates of nucleotide substitution in the SSU rRNA of lice are not higher than those of other insects, nor do substitution rates in the suborders differ substantially from one another.     

Genetic Diversity of Hard Ticks (Acari: Ixodidae) in the South and East Regions of Kazakhstan and Northwestern China

To date, there is no report on the genetic diversity of ticks in these regions. A total of 370 representative ticks from the south and east regions of Kazakhstan (SERK) and Xinjiang Uygur Autonomous Region (XUAR) were selected for molecular comparison. A fragment of the mitochondrial cytochrome c oxidase subunit I (cox1) gene, ranging from 631 bp to 889 bp, was used to analyze genetic diversity among these ticks. Phylogenetic analyses indicated 7 tick species including Hyalomma asiaticum, Hyalomma detritum, Hyalomma anatolicum, Dermacentor marginatus, Rhipicephalus sanguineus, Rhipicephalus turanicus and Haemaphysalis erinacei from the SERK clustered together with conspecific ticks from the XUAR. The network diagram of haplotypes showed that i) Hy. asiaticum from Almaty and Kyzylorda Oblasts together with that from Yuli County of XUAR constituted haplogroup H-2, and the lineage from Chimkent City of South Kazakhstan was newly evolved; and ii) the R. turanicus ticks sampled in Israel, Almaty, South Kazakhstan, Usu City, Ulugqat and Baicheng Counties of XUAR were derivated from an old lineage in Alataw City of XUAR. These findings indicate that: i) Hy. asiaticum, R. turanicus and Ha. erinacei shared genetic similarities between the SERK and XUAR; and ii) Hy. marginatum and D. reticulatus show differences in their evolution.     

Molecular phylogeny and biogeography of an ancient Holarctic lineage of mygalomorph spiders (Araneae: Antrodiaetidae: Antrodiaetus)

The mygalomorph spider genera Antrodiaetus and Atypoides (Antrodiaetidae) belong to an ancient lineage that has persisted since at least the Cretaceous. These spiders display a classic disjunct Holarctic distribution with species in the eastern Palaearctic plus the western and eastern Nearctic. Prior phylogenetic analyses of this group have been proposed on the basis of morphology, but lack strong support and independent corroboration. Here we present the first phylogenetic analysis of species-level relationships based on molecular data obtained from the mitochondrial (cytochrome c oxidase subunit I) and nuclear (18S and 28S rRNA) genomes. Analyses corroborate earlier findings that Atypoides forms a paraphyletic grade with respect to Antrodiaetus, and consequently, that genus is formally synonymized under Antrodiaetus. In addition, our results support the relatively early divergence of Antrodiaetus roretzi. Antrodiaetus pacificus is "paraphyletic" with respect to the A. lincolnianus group and is likely an assemblage of numerous species. The final topology based on a combined molecular dataset, in conjunction with two different molecular dating techniques (penalized likelihood plus a Bayesian approach) and ancestral distribution reconstructions, was used to infer the historical biogeography of these spiders. Trans-Beringian and trans-Atlantic routes appear to account for the present-day distribution of Antrodiaetus in Japan and North America. Future studies on Antrodiaetus phylogeny will be used to address questions regarding morphological stasis and the evolution of quantitative morphological characters.     

Monthly dynamics of ticks (Acari: Ixodida) infesting N'Dama cattle in the Republic of Guinea

The occurrence of ixodid ticks on N'Dama cattle was studied in the Republic of Guinea between June 1994 and May 1995. Monthly tick collections were performed on 80 animals from 14 villages located in Dabola, Kouroussa and Dinguiraye prefectures. A total of 19,804 ticks was collected and classified using standard taxonomic keys. The following tick species were identified: Amblyomma variegatum, Hyalomma marginatum rufipes, Hyalomma trunctum, Hyalomma nitidum, Rhipicephalus lunulatus, Rhipicephalus muhsamae, Rhipicephalus senegalensis, Rhipicephalus sulcatus, Rhipicephalus turanicus, Boophilus annulatus, Boophilus geigyi. Boophilus spp. were the most numerous adult ticks (57.1%), Am. variegatum adults constituted 27.4%, while 12.4% were Rhipicephalus spp. and 2.5% Hyalomma spp. Rhipicephalus turanicus and Hyalomma nitidum were recorded for the first time in the country. Am. variegatum and Boophilus spp. were present throughout the year, whereas Am. variegatum adults showed a peak during the rainy season between April and September. Immature stages collected belonged exclusively to the genera Amblyomma and Boophilus. Am. variegatum larvae and nymphs showed a peak during the dry season (October-March); no significant variation between seasons was observed for Boophilus immatures. A significantly higher infestation of cattle by Rhipicephalus spp. was found in Dabola and Kouroussa prefectures, located in the southern part of the study area, with similar climatic, vegetation and rainfall characteristics. Possible options for the control of ticks in the study area are briefly discussed.     

Prevalence of ixodid ticks on cattle in Mazandaran province, Iran

A survey was carried out to investigate the prevalence of hard tick species (Acari: Ixodidae) on cattle in Mazandaran province, Iran. A total of 953 ticks were collected from 86 infested cattle during activating seasons of ticks during 2004-2005. Nine species were identified: Boophilus annulatus (51.3%), Rhipicephalus bursa (16.8%), Haemaphysalis punctata (6.3%), Ixodes ricinus (6.8%), Hyalomma marginatum (12.5%), Hyalomma anatolicum excavatum (5.2%), Hyalomma asiaticum (0.6%), Hyalomma detritum (0.2 %), and Dermacentor spp. (0.1%). The results show that Boophilus annulatus, Rhipicephalus bursa, and Hyalomma species are dominant tick species in the surveyed area.     

Ixodid ticks (Acari: Ixodidae) infesting humans in Tokat Province of Turkey: species diversity and seasonal activity

Ixodid ticks (Acari: Ixodidae) are the major vectors of pathogens threatening animal and human health. Tokat Province, Turkey, is a suitable habitat for extended tick activity with its moderate climate and vegetation. In the present study, we surveyed humans visiting health centers to determine the species diversity, geographical distribution, and seasonal activity of ixodid ticks infesting them. Out of 5,999 adult ticks collected from humans from April to September, 2008, 800 ticks were identified to species, while the remaining were identified to genus according to their distinct morphological characteristics. Hyalomma marginatum, Hyalomma detritum, Rhipicephalus bursa, Rhipicephalus (Boophilus) annulatus, Haemaphysalis punctata, Dermacentor marginatus, and Ixodes laguri were the most prevalent tick species among 24 ixodid tick species infesting humans in the region. One of these tick species, Hyalomma isacii was identified as a new record for the ixodid tick fauna of Turkey. Hyalomma species were the most abundant in summer, while Dermacentor and Ixodes species displayed the lowest frequency. Hyalomma aegyptium infestation was very common on humans in the province. Results indicated that a variety of ixodid tick species infest humans depending on the season in the target area. It is possible that a variety of ixodid tick species may contribute to the spread of tick‐borne diseases such as Crimean‐Congo haemorrhagic fever virus (CCHFV), which is endemic in the region.     

Higher‐level molecular phylogeny of jumping plant lice (Hemiptera: Sternorrhyncha: Psylloidea)

Jumping plant lice (Hemiptera: Psylloidea) are known for a few deleterious pest species worldwide, yet the phylogeny of the group has been poorly understood until very recently. Here, we reconstruct the higher‐level phylogeny for the superfamily Psylloidea based on multilocus DNA sequences, three mitochondrial (COI‐tRNA^leu‐COII, 12S, 16S) and five nuclear (18S, 28S D2, 28S D3, 28S D6–7a, 28S D9–10) gene fragments, using maximum likelihood and Bayesian inference phylogenetic frameworks. Our results are largely congruent with the recent phylogenomic study and partly support prior classification of Psylloidea based mainly on morphology, with the following major exceptions: the family Calophyidae is revealed as polyphyletic, Aphalaridae as paraphyletic with respect to most other taxa of Psylloidea, and Liviidae as paraphyletic with respect to Calophyinae, Psyllidae and Triozidae. Our phylogenetic hypothesis identifies Phacopteronidae and the genus Cecidopsylla Kieffer as the very basal taxa within extant Psylloidea. Sister‐group relationships of Rhinocolinae with Togepsyllinae and of Pachypsyllinae with Homotomidae are also suggested. We present specific discussions for each group of interest recovered in our phylogenetic analysis. One nomenclatorial change is proposed: Spanioneura longicauda (Konovalova) comb.n. , from Psylla Geoffroy.     

Evidence to show that an agent that cross-reacts serologically with Cowdria ruminantium in Zimbabwe is transmitted by ticks

The serological diagnosis of heartwater based on reactions to the immunodominant Cowdria ruminantium major antigen protein-1 (MAP-1) is impaired by the detection of false-positive reactions. In this study, the prevalence of false-positive reactions on seven heartwater-free farms in Zimbabwe was determined to be 8-94% by immunoblotting against C. ruminantium antigens. The highest prevalence of false-positives on Spring Valley Farm correlated with the presence of Rhipicephalus evertsi evertsi ticks. The other tick species found on these seven farms were Hyalomma truncatum and Hyalomma marginatum rufipes. Rhipicephalus evertsi evertsi ticks collected from Spring Valley Farm and fed on seronegative sheep caused seroconversion in one of two sheep. This sheep developed a mild febrile reaction and C. ruminantium MAP-1 antigen reactive antibodies 3 weeks after the ticks started feeding. Polymerase chain reactions (PCRs), conducted using C. ruminantium-specific primers on ticks collected from the seven farms and on some of the R. e. evertsi ticks that had caused seroconversion in one sheep, were negative. However, some of these ticks gave positive PCRs with DNA primers which amplify a 350 bp DNA fragment of the 16s rRNA gene from all ehrlichial agents indicating the presence of infection with one or more Ehrlichia species. Although attempts to isolate the cross-reacting agent from the sheep were unsuccessful, this study demonstrates that false-positive reactions with the MAP-1 C. ruminantium antigen are associated with agents transmitted by ticks.     

基于12S,16S和28S rRNA基因序列的中国小毛瓢虫属系统发育分析

【目的】小毛瓢虫属Scymnus Kugelann昆虫主要捕食蚜虫、蚧虫等害虫,是一类经济上重要的天敌昆虫。目前针对小毛瓢虫属的系统发育研究尚属空白,亚属之间的系统演化关系尚不明确,为了建立合理的分类系统,亟需对小毛瓢虫属的亲缘关系进行研究和探讨。【方法】以华南农业大学馆藏的小毛瓢虫属5亚属共44种为研究对象,采用PCR技术对12S, 16S和28S rRNA基因的部分序列进行扩增;运用MEGA 7.0分析了小毛瓢虫属内12S, 16S和28S rRNA基因的碱基组成,基于K2P模型计算了小毛瓢虫属44种的种间遗传距离;采用最大似然法(maximum-likelihood, ML)和贝叶斯推断法(Bayesian-inference, BI)构建该属的系统发育树。【结果】扩增获得小毛瓢虫属44种的12S rRNA基因序列平均长度为356 bp, 16S rRNA基因序列平均长度为351 bp, 28S rRNA基因序列平均长度为315 bp;序列分析表明,12S rRNA基因的A, T, G和C平均含量分别为38.8%, 43.5%, 11.9%和5.8%, 16S rRNA基因的A, T, G和C平均含量分别为37.6%, 40.3%, 14.4%和7.7%, 28S rRNA基因的A, T, G和C平均含量分别为26.7%, 18.3%, 31.4%和23.5%;基于联合序列分析的种间遗传距离为0.004～0.276,平均遗传距离为0.115。系统发育分析结果表明,小毛瓢虫属为单系起源,而小毛瓢虫亚属Scymnus(Scymnus) Kugelann、毛瓢虫亚属Scymnus(Neopullus) Sasaji、小瓢虫亚属Scymnus(Pullus) Mulsant和拟小瓢虫亚属Scymnus(Parapullus) Yang均为并系起源。【结论】基于12S, 16S和28S rRNA基因序列的小毛瓢虫属系统发育分析显示传统的形态学分类体系与基于分子数据分析的结果部分不一致,这表明应该对该属内各亚属的鉴别特征进行全面检视,筛选并确立各亚属的形态指标,同时也表明该属内的亚属分类单元需重新厘定。     

Reconsideration of anopheline mosquito phylogeny (Diptera: Culicidae: Anophelinae) based on morphological data

The phylogeny of anopheline mosquitoes (Culicidae: Anophelinae) is re‐examined using morphological data derived from adults, fourth‐instar larvae and pupae. Based on the data set of Sallum et al. (2000), we add some previously missing data and simplify and recode characters to eliminate ambiguities and more accurately reflect homologies, with special emphasis on characters of the male genitalia that provide the main criteria for the subgeneric classification of genus Anopheles. The principal aim of the study is to assess objectively the phylogenetic relationships and classification of two taxa not included by Sallum et al. (2000): Anopheles corethroides, a representative of the Australasian Stigmaticus Group, and An. kyondawensis, an unusual Oriental species whose adult and pupal stages were only recently discovered. The revised data set consists of 167 characters for 66 species representing the three traditionally recognised genera of Anophelinae, the six traditionally accepted subgenera of genus Anopheles and all informal series and most species groups of subgenera Anopheles, Cellia and Nyssorhynchus. The data are analysed using equal weighting (EW) and implied weighting (IW). Analysis under EW generates a strict consensus tree with principal lineages consistent with those reported by Sallum et al. (2000). Analysis under IW supports the monophyly of Anophelinae, the basal position of Chagasia, the monophyly of subgenera Cellia, Kerteszia and Nyssorhynchus, and the sister relationship of Kerteszia + Nyssorhynchus, but otherwise yields relationships that differ significantly in one respect or another from those obtained in all previous analyses of both morphological and molecular data. Subgenus Anopheles is arrayed as a polyphyletic lineage basal to a monophyletic clade comprising the Neotropical Kerteszia + Nyssorhynchus and the Old World Cellia in a sister‐group relationship. Bironella, Lophopodomyia and Stethomyia are firmly nested within subgenus Anopheles, which would nevertheless still be paraphyletic if these taxa were subsumed within it. Anopheles kyondawensis is well supported as the sister group of Bironella + all other Anopheles. Bironella, Stethomyia, An. corethroides and several other Anopheles clades are each strongly supported in a pectinate series of relationships, terminating in the clade comprising subgenera Cellia, Kerteszia and Nyssorhynchus. These relationships and other aspects of the phylogeny are discussed in relation to the formal and informal classification of genus Anopheles.     

Ticks infesting domestic animals in northern Greece

The tick species infesting grazing animals in the countryside of 11 prefectures in Northern Greece were investigated during April-July and September-December of consecutive years 2003-2006. A total of 3,249 (1,952 males, 1,297 females) adult ticks were collected from goats, sheep, cattle and dogs. Ticks were identified as Ixodes ricinus (44.57%), Ixodes gibbosus (4.09%), Rhipicephalus bursa (19.14%), Rhipicephalus sanguineus, Rhipicephalus turanicus (5.79%), Hyalomma marginatum marginatum (12.40%), Dermacentor marginatus (0.31%) and Boophilus annulatus (4.43%). Rhipicephalus spp. and Hyalomma spp. were abundant in all prefectures, Ixodes spp. were present in 9/11 prefectures, Boophilus spp. in 4/11, while Dermacentor spp. were found only in one. Results of this study give an insight into the ecology of ticks and their potential of tick-borne diseases in the country.