Geoffrey E. Morse

Reliance on pollinators predicts defensive chemistry across tobacco species

Defensive traits are typically studied in the context of avoiding antagonists, but may also mediate key interactions with mutualists. Plant chemical defences occur in flowers, suggesting pollinators may be agents of selection on defence. We hypothesised that floral defences would deter pollinators, and therefore, pollinators would select for lower defences in outcrossing than self-pollinating species. We measured pollinator reliance and alkaloid levels in 32 greenhouse-grown Nicotiana species. Using a comparative phylogenetic approach, we found significantly lower nectar, floral and leaf nicotine concentrations in outcrossing than selfing species, with a 15-fold decrease in leaf nicotine levels. Nicotine concentrations were positively correlated across tissues, suggesting that selection against floral defences could constrain the evolution of leaf defences. Thus, pollinators could shape the evolution not only of floral defences but also of defences in other tissues where herbivores have traditionally been considered the dominant agent of selection.

Parthenogenesis in the Aspidiotus nerii Complex (Hemiptera: Diaspididae): A Single Origin of a Worldwide, Polyphagous Lineage Associated with Cardinium Bacteria

Abstract Aspidiotus nerii Bouché, the oleander scale, is a nearly cosmopolitan pest that attacks >100 families of woody plants. A. nerii has long been suspected of comprising multiple cryptic parthenogenetic and sexual species. We amplified and sequenced a 760-bp fragment of cytochrome oxidase 1 and 2 (COI-COII) from 59 individuals representing four laboratory stocks and 16 wild populations from four biogeographic regions (United States, several Mediterranean countries, South Africa, and New Zealand), along with three outgroup species. We also used polymerase chain reaction (PCR) to assay 92 individuals representing five laboratory stocks and seven wild populations for the presence of the intracellular bacteria Cardinium. We find three highly (>5%) divergent groups of mitochondrial DNA (mtDNA) haplotypes in A. nerii. Two of these are associated with males and not associated with Cardinium and are inferred to represent sexual populations. The other haplotype group is not associated with males, is associated with Cardinium, and includes laboratory stocks known to be parthenogenetic; this haplotype group is inferred to represent a parthenogenetic lineage. Although Cardinium is associated with the parthenogenetic lineage, a “curing” experiment that would demonstrate direct parthenogenesis induction by Cardinium has not been done. The parthenogenetic lineage is 5.5–7.3% divergent at COI-II from the closest sexual lineage and comprises five moderately divergent (≤3.5%) haplotypes. This amount of mtDNA divergence within the parthenogenetic lineage may imply an ancient (≥1 Mya) origin; however, the amount of amino acid sequence diversity within the parthenogenetic lineage is much greater than in the sexual sister-lineage, implying an elevated rate of nonsynonymous substitution in the parthenogenetic lineage. The highest haplotype diversity is found in New Zealand, and the closest outgroup is found in Australia, suggesting a possible Australasian origin of A. nerii.

A dated molecular phylogeny for the Chironomidae (Diptera)

We provide the first highly sampled phylogeny estimate for the dipteran family Chironomidae using molecular data from fragments of two ribosomal genes (18S and 28S), one nuclear protein‐coding gene (CAD), and one mitochondrial protein‐coding gene (COI), analysed using mixed‐model Bayesian and maximum likelihood inference methods. The most recently described subfamilies Chilenomyiinae and Usambaromyiinae proved elusive, and are unsampled. We confirm monophyly of all sampled subfamilies except Prodiamesinae, which contains Propsilocerus Kieffer, previously in Orthocladiinae. The semifamily Chironomoinae is confirmed only if Telmatogetoninae is included, which is closer to Brundins original suggestion. Buchonomyiinae is excluded from Chironomoinae: it is a sister group to all remaining Chironomidae, conforming more to Murray and Ashes argumentation. Semifamily Tanypodoinae is a grade and unsupported as monophyletic: the austral Aphroteniinae alone is sister to all Chironomidae (less Buchonomyiinae). Podonominae is weakly supported as the next sister group, in contrast to some estimates that place this subfamily as sister group to Tanypodinae alone. In Diamesinae, the southern African Harrisonini is confirmed as a member, but embedded within austral tribe Heptagiini, which is confirmed as sister to the undersampled Diamesini. Tribe Pentaneurini and ‘non‐Pentaneurini’ taxa are reciprocally monophyletic in Tanypodinae. Recent molecular findings concerning Podonominae are substantiated, with a monophyletic tribe Podonomini, Boreochlini forming a grade and Lasiodiamesa Kieffer placed as sister to all other Podonominae, but with uncertainty. In Orthocladiinae, a postulated two‐tribe system of Orthocladiini and Metriocnemini can be supported after exclusion of a Corynoneura group and a Brillia group, which is revealed as sister to Stictocladius Edwards. The marine Clunio Haliday and Thalassosmittia Strenzke & Remmert (given high rank in the past) are clearly embedded deep in Orthocladiinae. The finding of Shangomyia Sæther & Wang + Xyiaomyia Sæther & Wang as sister group to all other Chironominae justifies high rank, as their authors suggested. Pseudochironomini (untested by sampling shortfall) is sister to a monophyletic Tanytarsini (with a weakly supported inclusion of the enigmatic Nandeva Wiedenbrug, Reiss & Fittkau). The tribe Chironomini can be supported only by excluding Shangomyia + Xyiaomyia, and a postulated monophyletic clade comprising several taxa such as Microtendipes Kieffer, with six‐segmented larval antennae and alternate Lauterborn organs, that is sister group to Pseudochironomini + Tanytarsini. The tempo of diversification of the family, deduced by divergence time analysis (beast), shows Permian origination with subfamily stem‐group origination from the mid–late Triassic to the early Cretaceous. Crown‐group origination ranged from Podonominae on a short stem originating in the mid Jurassic to long‐stemmed Aphroteninae from the late Cretaceous. Node dates allow inference of some vicariance via Gondwanan fragmentation, including certain nodes involving southern Africa.

A molecular phylogenetic study of armoured scale insects (Hemiptera: Diaspididae)

Abstract.  Armoured scale insects are economically important parasites of woody plants and grasses. They are promising subjects for the evolutionary study of physiology (no complete gut), genetics (chimerism, paternal genome elimination, frequent parthenogenesis) and coevolution (with host plants, parasitoids, Septobasidium fungi, endosymbiotic bacteria). Little phylogenetic work has been accomplished with armoured scales, and uncertainty surrounds their classification. Here, we report the phylogenetic results of Bayesian and parsimony analyses of 705 base pairs of Elongation Factor 1α and 660 base pairs of 28S from eighty‐nine species of armoured scale insects, representing forty‐seven genera and five tribes in the subfamilies Diaspidinae and Aspidiotinae, together with two outgroups. 28S was aligned based on a secondary structural model. Our results broadly corroborate the major features of the existing classification, although we do not find perfect monophyly of any of the traditionally recognized subfamilies or tribes. The subfamily Aspidiotinae is paraphyletic with respect to the subfamily Diaspidinae. Diaspidinae consists of two main clades that only roughly correspond to the tribes Lepidosaphidini and Diaspidini. Diaspidini is nearly monophyletic, except that it includes a single aspidiotine species. Other members of the tribe Aspidiotini form a clade, except that the clade includes a single species of Leucaspidini and excludes Maskellia and Pseudaonidia. Our results weakly support the hypothesis that the most recent common ancestor of the Diaspididae had adult females that were permanently enclosed within the derm of the second instar (the pupillarial habit) and had diploid adult males that eliminated their paternal genomes during spermatogenesis (late paternal genome elimination).

When molecules and morphology concur: the ‘Gondwanan’ midges (Diptera: Chironomidae)

A phylogeny of the Chironomidae subfamily Podonominae, significant in the history of phylogenetic biogeography, is estimated from an analysis of four genes. Fragments of two ribosomal genes (18S and 28S), one nuclear protein‐coding gene (CAD), and one mitochondrial protein‐coding gene (COI) were sequenced from specimens representing 13 of 15 genera, and analysed using mixed model Bayesian and maximum likelihood inference methods. Podonominae is monophyletic and sister to Tanypodinae – the shared development of the larval ligula is synapomorphic and diagnostic. Tribe Podonomini is monophyletic with the inclusion of Trichotanypus; tribe Boreochlini is a grade. Monophyly is confirmed for the genera Podonomus Philippi, Podonomopsis Brundin, Podochlus Brundin, Archaeochlus Brundin and Austrochlus Cranston, Edward & Cook: Parochlus Enderlein becomes monophyletic through the inclusion of Zelandochlus Brundin (n.syn.) with its type species, P. latipalpis (Brundin) n.comb. The ‘mandibulate’Archaeochlus plus Austrochlus is monophyletic with nonmandibulate Afrochlus weakly supported as a member of, or sister to, the African Archaeochlus. Subtending this group is Lasiodiamesa, although it associates in some analyses with the sister group Tanypodinae. Generic relationships coincide with those proposed based on morphology, particularly as understood via all life history stages of some problematic (autapomorphic, adult‐based) taxa. Divergence time analysis (beast) allows inference of Mesozoic diversification of higher taxa in Podonominae, of appropriate timing for fragmentation of Gondwana, post‐African divergence, to have caused vicariance. Shallower nodes (within genera) imply both younger vicariance involving Antarctica and some recent dispersal, including southern to northern hemisphere movement in the New World. New Zealand taxa test controversial biogeographical relationships and show proximity to southern South America without direct Australian sister taxon pairs: dating implies persistence of midges through the ‘Oligocene’ bottleneck.

A phylogenetic analysis of armored scale insects (Hemiptera: Diaspididae), based upon nuclear, mitochondrial, and endosymbiont gene sequences

Armored scale insects (Hemiptera: Diaspididae) are among the most invasive insects in the world. They have unusual genetic systems, including diverse types of paternal genome elimination (PGE) and parthenogenesis. Intimate relationships with their host plants and bacterial endosymbionts make them potentially important subjects for the study of co-evolution. Here, we expand upon recent phylogenetic work (Morse and Normark, 2006) by analyzing armored scale and endosymbiont DNA sequences from 125 species of armored scale insect, represented by 253 samples and eight outgroup species. We used fragments of four different gene regions: the nuclear protein-coding gene Elongation Factor 1α (EF1α), the large ribosomal subunit (28S) rDNA, a mitochondrial region spanning parts of cytochrome oxidase I (COI) and cytochrome oxidase II (COII), and the small ribosomal subunit (16S) rDNA from the primary bacterial endosymbiont Uzinura diaspidicola. Maximum likelihood, and Bayesian analyses were performed producing highly congruent topological results. A comparison of two datasets, one with and one without missing data, found that missing data had little effect on topology. Our results broadly corroborate several major features of the existing classification, although we do not find any of the subfamilies, tribes or subtribes to be monophyletic as currently constituted. Using ancestral state reconstruction we estimate that the ancestral armored scale had the late PGE sex system, and it may as well have been pupillarial, though results differed between reconstruction methods. These results highlight the need for a complete revision of this family, and provide the groundwork for future taxonomic work in armored scale insects.

Phylogenetic analysis reveals positive correlations between adaptations to diverse hosts in a group of pathogen-like herbivores

A jack of all trades can be master of none—this intuitive idea underlies most theoretical models of host‐use evolution in plant‐feeding insects, yet empirical support for trade‐offs in performance on distinct host plants is weak. Trade‐offs may influence the long‐term evolution of host use while being difficult to detect in extant populations, but host‐use evolution may also be driven by adaptations for generalism. Here we used host‐use data from insect collection records to parameterize a phylogenetic model of host‐use evolution in armored scale insects, a large family of plant‐feeding insects with a simple, pathogen‐like life history. We found that a model incorporating positive correlations between evolutionary changes in host performance best fit the observed patterns of diaspidid presence and absence on nearly all focal host taxa, suggesting that adaptations to particular hosts also enhance performance on other hosts. In contrast to the widely invoked trade‐off model, we advocate a “toolbox” model of host‐use evolution in which armored scale insects accumulate a set of independent genetic tools, each of which is under selection for a single function but may be useful on multiple hosts.

Cryptic Diversity in the Aspidiotus nerii Complex in Australia

ABSTRACT Aspidiotus nerii Bouché (Hemiptera: Diaspididae), oleander scale, is a cosmopolitan pest that feeds on >100 families of plants. A previous study of mitochondrial DNA variation in A. nerii suggested a possible Australian origin for the species. Here, we expand upon that study to include four gene regions and multiple Australian samples. We sequenced fragments of three nuclear genes (CAD, elongation factor 1&agr;, and 28S rDNA) and one mitochondrial region (spanning parts of cytochrome oxidase I and II), for a total aligned sequence length of 2448 bp, from 22 individuals identified as A. nerii. We infer an allele genealogy for each gene region, and we interpret branches that are congruent across gene regions as indicative of species boundaries. Using this criterion, we recognize three species within our sample of A. nerii. One of these corresponds to the cosmopolitan pest species and the other two are found only in Australia. The two putative Australian species have overlapping ranges and both are found on multiple hosts. Contrary to previous suggestions, the cosmopolitan sexual and parthenogenetic lineages of A. nerii are not recognized as distinct species by both of our methods of phylogenetic reconstruction. Cryptic diversity within what seem to be single cosmopolitan armored scale insect species is a potential serious problem for plant quarantine.

Armored Scale Insects (Hemiptera: Diaspididae) of San Lorenzo National Park, Panama, with Descriptions of Two New Species

ABSTRACT Armored scale insects include invasive economic pests that have been widely studied in human-altered habitats but have received less attention in natural habitats. Although armored scale insects are nearly ubiquitous associates of woody plants, they generally go uncollected in general surveys because they are not susceptible to mass collecting techniques, such as fogging, beating, or trapping. San Lorenzo National Park in Panama was the subject of a recent high-profile effort to quantify the arthropod diversity in a tropical forest (Basset et al. 2012). Here, we contribute to understanding the biodiversity of this classic site by reporting the armored scale insect species we found there in August 2010. We found that, unlike other rainforest canopy taxa, the armored scale insect fauna is dominated by highly polyphagous cosmopolitan pests. However, we also found new species, and we describe two of them here: Furcaspis douglorum Okusu & Normark n. sp. and Hemiberlesia andradae Okusu & Normark n. sp. We provide amendments to the relevant keys, including a new key to New World species of Hemiberlesia Cockerell that lack perivulvar pores. In this context, we treat Abgrallaspis Balachowsky as asubjective synonym of Hemiberlesia, and we transfer its species to Hemiberlesia, except for the following assignments to other genera Affirmaspis flavida (De Lotto), n. comb., Aspidiotus furcillae Brain, rev. comb., Clavaspis perseae (Davidson), n. comb., Diaspidiotus fraxini (McKenzie), n. comb., and Davidsonaspis aguacatae (Evans, Watson, and Miller), n. comb. Davidsonaspis Normark, n. gen. We regard Abgrallaspis azadirachti Ojha and A narainus Dutta & Singh as synonyms of Aonidiella orientalis (Newstead), new synonymy.

The New World Gibbobruchus Pic (Coleoptera, Chrysomelidae, Bruchinae): description of a new species and phylogenetic insights into the evolution of host associations and biogeography

The seed beetle Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. is described from the Amazon basin in Brazil (Acre) and Ecuador (Napo), and is included in an updated key to the species of Gibbobruchus Pic. This new species and the recently described G. bergamini Manfio & Ribeiro-Costa are incorporated into a phylogenetic reanalysis of the genus and into a comparative analysis of host plant use and biogeography. Species groups previously proposed were supported and the evolutionary history in host plant-use shows Gibbobruchus conserved at tribe level, Cercideae (Caesalpinioideae), with coordination between biogeographic expansion and host genus shifts. Both species, Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. and G. bergamini, were placed within the group scurra (G. tridentatus (G. scurra (G. cavillator+G. bolivianus+G. bergamini))) and supported by one synapomorphy. Additionally, we update geographic distributions and host plant records. Two hosts, Bauhinia argentinensis Burkart and B. tarapotensis Benth. are recorded for the first time as hosts for the genus and for the subfamily.