Two ancient bacterial endosymbionts have coevolved with the planthoppers (Insecta: Hemiptera: Fulgoroidea)

ABSTRACT: BACKGROUND: Members of the hemipteran suborder Auchenorrhyncha (commonly known as planthoppers, tree- and leafhoppers, spittlebugs, and cicadas) are unusual among insects known to harbor endosymbiotic bacteria in that they are associated with diverse assemblages of bacterial endosymbionts. Early light microscopic surveys of species representing the two major lineages of Auchenorrhyncha (the planthopper superfamily Fulgoroidea; and Cicadomorpha, comprising Membracoidea [tree- and leafhoppers], Cercopoidea [spittlebugs], and Cicadoidea [cicadas]), found that most examined species harbored at least two morphologically distinct bacterial endosymbionts, and some harbored as many as six. Recent investigations using molecular techniques have identified multiple obligate bacterial endosymbionts in Cicadomorpha; however, much less is known about endosymbionts of Fulgoroidea. In this study, we present the initial findings of an ongoing PCR-based survey (sequencing 16S rDNA) of planthopper-associated bacteria to document endosymbionts with a long-term history of codiversification with their fulgoroid hosts. RESULTS: Results of PCR surveys and phylogenetic analyses of 16S rDNA recovered a monophyletic clade of Betaproteobacteria associated with planthoppers; this clade included Vidania fulgoroideae, a recently described bacterium identified in exemplars of the planthopper family Cixiidae. We surveyed 77 planthopper species representing 18 fulgoroid families, and detected Vidania in 40 species (representing 13 families). Further, we detected the Sulcia endosymbiont (identified as an obligate endosymbiont of Auchenorrhyncha in previous studies) in 30 of the 40 species harboring Vidania. Concordance of the Vidania phylogeny with the phylogeny of the planthopper hosts (reconstructed based on sequence data from five genes generated from the same insect specimens from which the bacterial sequences were obtained) was supported by statistical tests of codiversification. Codiversification tests also supported concordance of the Sulcia phylogeny with the phylogeny of the planthopper hosts, as well as concordance of planthopper-associated Vidania and Sulcia phylogenies. CONCLUSIONS: Our results indicate that the Betaproteobacterium Vidania is an ancient endosymbiont that infected the common ancestor of Fulgoroidea at least 130 million years ago. Comparison of our findings with the early light-microscopic surveys conducted by Muller suggests that Vidania is Muller's x-symbiont, which he hypothesized to have codiversified with most lineages of planthoppers and with the Sulcia endosymbiont.     

Higher‐level phylogeny of the insect order Hemiptera: is Auchenorrhyncha really paraphyletic?

The higher‐level phylogeny of the order Hemiptera remains a contentious topic in insect systematics. The controversy is chiefly centred on the unresolved question of whether or not the hemipteran suborder Auchenorrhyncha (including the extant superfamilies Fulgoroidea, Membracoidea, Cicadoidea and Cercopoidea) is a monophyletic lineage. Presented here are the results of a multilocus molecular phylogenetic investigation of relationships among the major hemipteran lineages, designed specifically to address the question of Auchenorrhyncha monophyly in the context of broad taxonomic sampling across Hemiptera. Phylogenetic analyses (maximum parsimony, maximum likelihood and Bayesian inference) were based on DNA nucleotide sequence data from seven gene regions (18S rDNA, 28S rDNA, histone H3, histone 2A, wingless, cytochrome c oxidase I and NADH dehydrogenase subunit 4) generated from 86 in‐group exemplars representing all major lineages of Hemiptera (plus seven out‐group taxa). All combined analyses of these data recover the monophyly of Auchenorrhyncha, and also support the monophyly of each of the following lineages: Hemiptera, Sternorrhyncha, Heteropterodea, Heteroptera, Fulgoroidea, Cicadomorpha, Membracoidea, Cercopoidea and Cicadoidea. Also presented is a review of the major lines of morphological and molecular evidence for and against the monophyly of Auchenorrhyncha.     

A Preliminary Molecular Phylogeny of Planthoppers (Hemiptera: Fulgoroidea) Based on Nuclear and Mitochondrial DNA Sequences

The planthopper superfamily Fulgoroidea (Insecta: Hemiptera) is one of the most dominant groups of phytophagous insects. It comprises about 20 families, containing a total of 9000 species worldwide. Despite several recent studies, the phylogeny of Fulgoroidea is not yet satisfactorily resolved and the phylogenetic positions of several key families, especially Cixiidae, Delphacidae, Tettigometridae, Nogodinidae, Acanaloniidae and Issidae, are contentious. Here, we expand upon recent phylogenetic work using additional nuclear (18S and 28S) and novel mitochondrial (16S and cytb) markers. Maximum likelihood and Bayesian analyses yielded robust phylogenetic trees. In these topologies, a group containing Cixiidae and Delphacidae is recovered as the sister group to the remaining taxa. Tettigometridae is placed in a more nested position and is grouped with Caliscelidae. Sister relationships are found between Flatidae and Ricaniidae, and between Dictyopharidae and Fulgoridae. Nogodinidae and Issidae are confirmed to be non-monophyletic families. For major nodes of interest, divergence date estimates are generally older than those from the fossil record.     

蜡蝉总科(昆虫纲:半翅目)系统分类研究进展

蜡蝉总科隶属于半翅目头喙亚目,大致可分为18～21个科。中国记载16科。蜡蝉总科的科级系统发育关系一直存在着广泛争议,至今尚无一个为大多数学者所接受的分类系统。因此,研究蜡蝉总科的系统发育具有重要的理论价值。本文从种及种下阶元的分类鉴定、种上阶元的系统发育、生物地理学等方面对蜡蝉总科的分类研究进行综述。     

Molecular phylogenetics of cixiid planthoppers (Hemiptera: Fulgoromorpha): new insights from combined analyses of mitochondrial and nuclear genes

The planthopper family Cixiidae (Hemiptera: Fulgoromorpha) comprises approximately 160 genera and 2000 species divided in three subfamilies: Borystheninae, Bothriocerinae and Cixiinae, the later with 16 tribes. The current paper represents the first attempt to estimate phylogenetic relationships within Cixiidae based on molecular data. We use a total of 3652 bp sequence alignment of four genes: the mitochondrial coding genes Cytochrome c Oxidase subunit 1 (Cox1) and Cytochrome b (Cytb), a portion of the nuclear 18S rDNA and two non-contiguous portions of the nuclear 28S rDNA. The phylogenetic relationships of 72 terminal specimens were reconstructed using both maximum parsimony and Bayesian inference methods. Through the analysis of this empirical dataset, we also provide comparisons among different a priori partitioning strategies and the use of mixture models in a Bayesian framework. Our comparisons suggest that mixture models overcome the benefits obtained by partitioning the data according to codon position and gene identity, as they provide better accuracy in phylogenetic reconstructions. The recovered maximum parsimony and Bayesian inference phylogenies suggest that the family Cixiidae is paraphyletic in respect with Delphacidae. The paraphyly of the subfamily Cixiinae is also recovered by both approaches. In contrast to a morphological phylogeny recently proposed for cixiids, subfamilies Borystheninae and Bothriocerinae form a monophyletic group.     

Insights into the phylogenetic relationships within Cixiidae (Hemiptera: Fulgoromorpha): cladistic analysis of a morphological dataset

Abstract.  According to the most recent classifications proposed, the planthopper family Cixiidae comprises three subfamilies, namely Borystheninae, Bothriocerinae and Cixiinae, the latter with 16 tribes. Here we examine morphological characters to present the first phylogenetic reconstructions within Cixiidae derived from a cladistic analysis. We scored 85 characters of the head, thorax, and male and female genitalia for 50 taxa representative of all cixiid subfamilies and tribes and for six outgroup taxa. Analyses were based on maximum parsimony – using both equally weighted and successive weighting procedures – and Bayesian inferences. The monophyly of most currently accepted tribes and subfamilies was investigated through Templeton statistical tests of alternative phylogenetic hypotheses. The cladistic analyses recover the monophyly of Cixiidae, the subfamily Bothriocerinae, and the tribes Pentastirini, Mnemosynini, and Eucarpiini. Successive weighting and Bayesian inference recover the monophyly of the tribe Gelastocephalini, but only Bayesian inference supports the monophyly of Semoniini. The relationships recovered support the groups [Stenophlepsini (Borystheninae + Bothriocerinae)] arising from the tribe Oecleini, and [Andini + Brixiidini + Brixiini (polyphyletic) + Bennini]. Templeton tests reject the alternative hypothesis of a monophyletic condition for the tribe Pintaliini as presently defined.     

Complete Mitochondrial Genomes of Metcalfa pruinosa and Salurnis marginella (Hemiptera: Flatidae): Genomic Comparison and Phylogenetic Inference in Fulgoroidea

The complete mitochondrial genomes (mitogenomes) of two DNA barcode-defined haplotypes of Metcalfa pruinosa and one of Salurnis marginella (Hemiptera: Flatidae) were sequenced and compared to those of other Fulgoroidea species. Furthermore, the mitogenome sequences were used to reconstruct phylogenetic relationships among fulgoroid families. The three mitogenomes, including that of the available species of Flatidae, commonly possessed distinctive structures in the 1702–1836 bp A+T-rich region, such as two repeat regions at each end and a large centered nonrepeat region. All members of the superfamily Fulgoroidea, including the Flatidae, consistently possessed a motiflike sequence (TAGTA) at the ND1 and trnS₂ junction. The phylogenetic analyses consistently recovered the familial relationships of (((((Ricaniidae + Issidae) + Flatidae) + Fulgoridae) + Achilidae) + Derbidae) in the amino acid-based analysis, with the placement of Cixiidae and Delphacidae as the earliest-derived lineages of fulgoroid families, whereas the monophyly of Delphacidae was not congruent between tree-constructing algorithms.     

Elevational filtering and the evolution of planthoppers (Hemiptera,Fulgoromorpha) in Papua New Guinea

Along elevational gradients, phylogenetic relatedness patterns constitute a considerable source of information and may shed light on ecological processes that structure communities. This study focuses on community phylogenetic structure of planthoppers, specifically the species-rich and abundant Fulgoromorpha families (Hemiptera, Auchenorrhyncha), Cixiidae and Derbidae + Achilidae, along an elevational gradient on Mount Wilhelm (Papua New Guinea). In order to assess the factors driving planthoppers community composition, we recorded abundance data for planthoppers species at each elevation and we generated a molecular phylogeny of the local species, using Bayesian inference. We analyzed 168 individuals representing 59 local morphospecies. Using a fully resolved and well-supported phylogeny, we then investigated the phylogenetic structure of the communities by performing a Spatial Analysis of Community Diversity. We show that Cixiidae are phylogenetically clustered along the elevational gradient, whereas Derbidae + Achilidae harbor a random structure, suggesting that local adaptation to elevation shapes community structure of Cixiidae, but not that of Derbidae + Achilidae. Our findings highlight the importance of phylogenies in the study of tropical elevational gradients.     

Molecular phylogeny of the homoptera: a paraphyletic taxon

Homoptera and Heteroptera comprise a large insect assemblage, the Hemiptera. Many of the plant sap-sucking Homoptera possess unusual and complex life histories and depend on maternally inherited, intracellular bacteria to supplement their nutritionally deficient diets. Presumably in connection with their diet and lifestyles, the morphology of many Homoptera has become greatly reduced, leading to major controversies regarding the phylogenetic affiliations of homopteran superfamilies. The most fundamental question concerns whether the Homoptera as a whole are monophyletic. Recent studies based on morphology have argued that the Homoptera Sternorrhyncha (Aphidoidea, Coccoidea, Psylloidea, Aleyrodoidea) is a sister group to a group comprising the Homoptera Auchenorrhyncha (Fulgoroidea, Cicadoidea, Cercopoidea, Cicadelloidea) and the Heteroptera, making the Homoptera paraphyletic. We sequenced the 5 580-680 base pairs of small-subunit (18S) ribosomal DNA from a selection of Homoptera, Hemiptera, and their putative outgroups, the Thysanoptera and Psocoptera, to apply molecular characters to the problem of Homoptera phylogeny. Parsimony, distance, maximum-likelihood, and bootstrap methods were used to construct trees from sequence data and assess support for the topologies produced. Molecular data corroborate current views of relationships within the Sternorrhyncha and Auchenorrhyncha based on morphology and strongly support the hypothesis of homopteran paraphyly as stated above. In addition, it was found that Homoptera Sternorrhyncha have extra, GC-rich sequence concentrated in a variable region of the 18S rDNA, which indicates that some unique evolutionary processes are occurring in this lineage.Correspondence to: C.D. von Dohlen     

The planthopper family Achilixiidae (Homoptera, Fulgoroidea): a synopsis with a revision of the genus Achilixius

Abstract The planthopper family Achilixiidae (Homoptera, Auchenorrhyncha, Fulgoroidea) is reviewed and the Oriental genus Achilixius Muir revised. As here defined, the family consists of two genera: Bobaiotes Muir ( Muirilixius Metcalf is here made a junior synonym, syn.n.) from the Neotropical region and Achilixius from the Oriental region. Sixteen Achilixius species are described or redescribed from Philippines, Sabah and Sulawesi. Females of undescribed species are also reported from the Solomon Islands and New Guinea. The following new species of Achilixius are described: Bakeri, irigae and mayoyae from the Philippines: fennahi and muiri from Sabah; minahassae, danaumoati, torautensis, fasciata, kolintangi, muajati and morowali from Sulawesi. A key to males is given. The following new combinations are established: Bebaiotes banksi (Metcalf), B.guianesus (Fennah) and B.nigrigaster Muir restored to its original combination, comb.rev. The relationship of Achilixiidae to other fulgoroid families is discussed.     

Multiple Independent Losses of Photosynthesis and Differing EvolutionaryRates in the Genus Cryptomonas (Cryptophyceae): Combined Phylogenetic Analyses of DNA Sequences of the Nuclear and the Nucleomorph Ribosomal Operons

In this study, evidence for at least three independent losses of photosynthesis in the freshwater cryptophyte genus Cryptomonas is presented. The phylogeny of the genus was inferred by molecular phylogenetic analyses of the nuclear internal transcribed spacer 2 (nuclear ITS2), partial nuclear large subunit ribosomal DNA (LSU rDNA), and nucleomorph small subunit ribosomal DNA (SSU rDNA, NM). Both concatenated and single data sets were used. In all data sets, the colorless Cryptomonas strains formed three different lineages, always supported by high bootstrap values (maximum parsimony, neighbor joining and maximum likelihood) and posterior probabilities (Bayesian analyses). The three leukoplast-bearing lineages displayed differing degrees of accelerated evolutionary rates in nuclear and nucleomorph rDNA. Also an increase in A+T-content in highly variable regions of the nucleomorph SSU rDNA was observed in one of the leukoplast-bearing lineages.This article contains three online-only supplementary tables.Reviewing Editor: Dr. Yves Van de Peer     

Perils of paralogy: using HSP70 genes for inferring organismal phylogenies

Conserved genes have found their way into the mainstream of molecular systematics. Many of these genes are members of multigene families. A difficulty with using single genes of multigene families for phylogenetic inference is that genes from one species may be paralogous to those from another taxon. We focus attention on this problem using heat shock 70 (HSP70) genes. Using polymerase chain reaction techniques with genomic DNA, we isolated and sequenced 123 distinct sequences from 12 species of sharks. Phylogenetic analysis indicated that the sequences cluster with constituitively expressed cytoplasmic heat shock-like genes. Three highly divergent gene clades were sampled. A number of similar sequences were sampled from each species within each distinct gene clade. Comparison of published species trees with an HSP70 gene tree inferred using Bayesian phylogenetic analysis revealed several cases of gene duplication and differential sorting of gene lineages within this group of sharks. Gene tree parsimony based on the objective criteria of duplication and losses showed that previously published hypotheses of species relationships and two novel hypothesis based on Bayesian phylogenetics were concordant with the history of HSP70 gene duplication and loss. By contrast, two published hypotheses based on morphological data were not significantly different from the null hypothesis of a random association between species relatedness and the HSP70 gene tree. These results suggest that gene tree parsimony using data from multigene families can be used for inferring species relationships or testing published alternative hypotheses. More importantly, the results suggest that systematic studies relying on phylogenetic inferences from HSP70 genes may by plagued by unrecognized paralogy of sampled genes. Our results underscore the distinction between gene and species trees and highlight an underappreciated source of discordance between gene trees and organismal phylogeny, i.e., unrecognized paralogy of sampled genes.     

十二种沫蝉的染色体研究 (同翅目： 沫蝉总科)

观察了同翅目头喙亚目12种沫蝉雄性的染色体数目和减数分裂行为。通过对沫蝉总科现有核型资料的分析,认为沫蝉总科的核型特点是：①染色体较小,数目较多,总科内染色体数目变化范围较大,众数为2n=26（24+XO）;②染色体的易位现象极为普遍,因此可以推测,通过染色体的易位导致染色体数目增加是核型进化的主要机制;③减数分裂前期Ⅰ具有典型的花束期,但没有弥散期。因此从精子发生来看沫蝉总科与叶蝉总科、角蝉总科和蝉总科的关系更为密切,而与蜡蝉总科的关系较远。头喙亚目的亲缘关系可能是：蜡蝉总科+{蝉总科+［沫蝉总科+（叶蝉总科+角蝉总科）］}。     

Initial results on the molecular phylogeny of the Nudibranchia (Gastropoda, Opisthobranchia) based on 18S rDNA data

This study investigated nudibranch phylogeny on the basis of 18S rDNA sequence data. 18S rDNA sequence data of 19 taxa representing the major living orders and families of the Nudibranchia were analyzed. Representatives of the Cephalaspidea, Anaspidea, Gymnomorpha, Prosobranchia, and Pulmonata were also sequenced and used as outgroups. An additional 28 gastropod sequences taken from GenBank were also included in our analyses. Phylogenetic analyses of these more than 50 gastropod taxa provide strong evidence for support of the monophyly of the Nudibranchia. The monophyly of the Doridoidea, Cladobranchia, and Aeolidoidea within the Nudibranchia are also strongly supported. Phylogenetic utility and information content of the 18S rDNA sequences for Nudibranchia, and Opisthobranchia in general, are examined using the program SplitsTree as well as phylogenetic reconstructions using distance and parsimony approaches. 0Results based on these molecular data are compared with hypotheses about nudibranch phylogeny inferred from morphological data.     

Phylogeny of Mantodea based on molecular data: evolution of a charismatic predator

Abstract. The previously unknown phylogenetic relationships among Mantodea (praying mantids) were inferred from DNA sequence data. Five genes (16S rDNA, 18S rDNA, 28S rDNA, cytochrome oxidase II and histone 3) were sequenced for sixty‐three taxa representing major mantid lineages and outgroups. The monophyly of mantid families and subfamilies was tested under varying parameter settings using parsimony and Bayesian analyses. The analyses revealed the paraphyly of Hymenopodidae, Iridopterygidae, Mantidae, and Thespidae and the monophyly of the Amorphoscelidae subfamily Paraoxypilinae. All represented subfamilies of Iridopterygidae and Mantidae appear paraphyletic. Mantoididae is sister group to the rest of the sampled mantid taxa. Lineages congruent with current subfamilial taxonomy include Paraoxypilinae, Hoplocoryphinae, Hymenopodinae, Acromantinae and Oligonicinae. The mantid hunting strategy is defined as either generalist, cursorial or ambush predators. By mapping hunting strategy onto our phylogeny, we reconstructed the ancestral predatory condition as generalist hunting, with three independent shifts to cursorial hunting and one shift to ambush hunting, associated with the largest radiation of mantid species.     

Entomologically famous, evolutionarily unexplored: The first phylogeny of the lanternfly family Fulgoridae (Insecta: Hemiptera: Fulgoroidea)

Lanternflies (Insecta: Hemiptera: Fulgoridae) are frequently used as examples of unusual morphological evolution, with some species (such as the peanut-headed bug, Fulgora laternaria Linnaeus) also ubiquitously cited as icons of tropical insect biodiversity. Despite that entomological notoriety, the phylogeny of this charismatic planthopper family has never before been studied. Presented here are the results of a phylogenetic investigation of Fulgoridae based on DNA nucleotide sequence data from five genetic loci (18S rDNA, 28S rDNA, histone 3, wingless, and cytochrome oxidase I). The resulting topologies are used to test the higher classification of Fulgoridae, which is based primarily on characters associated with the curious head morphology of many included species. Analyses include a taxonomic sample of 69 fulgorid species representing 46 (of 110) genera, 10 (of 11) tribes, and all 8 currently recognized subfamilies. Results of this study: (1) demonstrate the need for a revised classification of Fulgoridae, particularly at the higher taxonomic levels; (2) suggest that the genus Zanna is excluded from a monophyletic Fulgoridae; (3) indicate that there have been multiple losses of the extended head process across fulgorid evolution, with what appears to be convergence (in shape and/or loss) in distantly related lineages; and (4) suggest two alternative biogeographic hypotheses to explain the distribution of extant Fulgoridae, with either an Old World origin and a single subsequent colonization of the New World, or a contemporaneous diversification of Old and New World lineages.     

Phylogeny of shorebirds, gulls, and alcids (Aves: Charadrii) from the cytochrome-b gene: parsimony, Bayesian inference, minimum evolution, and quartet puzzling

Charadrii (shorebirds, gulls, and alcids) have exceptional diversity in ecological, behavioral, and life-history traits. A phylogenetic framework is necessary to fully understand the relationships among these traits. Despite several attempts to resolve the phylogeny of the Charadrii, none have comprehensively utilized molecular sequence data. Complete and partial cytochrome-b gene sequences for 86 Charadrii and five Falconides species (as outgroup taxa) were obtained from GenBank and aligned. We analyzed the resulting matrices using parsimony, Bayesian inference, minimum evolution, and quartet puzzling methods. Posterior probabilities, decay indices, and bootstrapping provide strong support for four major lineages consisting of gulls, alcids, plovers, and sandpipers, respectively. The broad structure of the trees differ significantly from all previous hypotheses of Charadrii phylogeny in placing the plovers at the base of the tree below the sandpipers in a pectinate sequence towards a large clade of gulls and alcids. The parsimony, Bayesian, and minimum evolution models provide strong evidence for this phylogenetic hypothesis. This is further corroborated by non-tree based measures of support and conflict (Lento plots). The quartet puzzling trees are poorly resolved and inconclusive.     

Phylogenetic relationships among gekkotan lizards inferred from C-mos nuclear DNA sequences and a new classification of the Gekkota

A phylogeny of gekkotan lizards was derived from C- mos nuclear DNA sequence data. Forty-one currently recognized genera, representing all major gekkotan lineages, were included in the study. A total of 378 bp of partial C- mos gene sequences was obtained and aligned. Maximum parsimony (MP) and maximum likelihood (ML) trees were generated based on unweighted analysis using P AUP *; similar tree topologies were recovered by both methods. The Eublepharidae were monophyletic and its relationship to other major clades was poorly resolved. The Pygopodidae of Kluge (1987) was monophyletic, but relationships within this group differed from those retrieved by previous analyses. The Diplodactylini + padded carphodactylines were the sister group of pygopods + padless carphodactylines. The Gekkonidae were monophyletic, but we found no evidence in support of the Teratoscincinae, as Teratoscincus was embedded well within the gekkonids. Both MP and ML analyses supported the basal position of Sphaerodactylus within the gekkonids, in contrast to morphologically based hypotheses. We propose a new higher order classification of the Gekkota that reflect these results. Five gekkotan families: Eublepharidae, Gekkonidae, Pygopodidae, Diplodactylidae, and Carphodactylidae are recognized. The higher order status of the sphaerodactyls will require more intensive sampling of this group. Our results support the hypothesis that the early cladogenesis of the Gekkota was associated with the split of Eastern Gondwanaland from Western Gondwanaland. Divergences among living genera in the Eublepharidae and the Eastern Gondwanan lineages (Diplodactylidae, Pygopodidae and Carphodactylidae) may be older than those in the Gekkonidae.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 353–368.     

The evolution of generalization? Parasitoid flies and the perils of inferring host range evolution from phylogenies

It is widely assumed that high resource specificity predisposes lineages toward greater likelihood of extinction and lower likelihood of diversification than more generalized lineages. This suggests that host range evolution in parasitic organisms should proceed from generalist to specialist, and specialist lineages should be found at the 'tips' of phylogenies. To test these hypotheses, parsimony and maximum likelihood methods were used to reconstruct the evolution of host range on a phylogeny of parasitoid flies in the family Tachinidae. In contrast to predictions, most reconstructions indicated that generalists were repeatedly derived from specialist lineages and tended to occupy terminal branches of the phylogeny. These results are critically examined with respect to hypotheses concerning the evolution of specialization, the inherent difficulties in inferring host ranges, our knowledge of tachinid-host associations, and the methodological problems associated with ancestral character state reconstruction. Both parsimony and likelihood reconstructions are shown to provide misleading results and it is argued that independent evidence, in addition to phylogenetic trees, is needed to inform models of the evolution of host range and the evolutionary consequences of specialization.