Phylogeny of the Heterodoxus octoseriatus group (Phthiraptera: Boopiidae) from rock-wallabies (Marsupialia: Petrogale)

The phylogenetic position of the Heterodoxus octoseriatus group is inferred from morphological characters. Two character states support monophyly of this group. Another indicates that its sister-group is a group of 11 other Heterodoxus species (here called the H. calabyi group), that infest at least seven other genera of macropodid marsupials. Fourteen potential apomorphies, associated with the male and female genitalia, are identified. Evident rapid and divergent evolution of the genitalia, however, precludes determination of their polarity by comparison with an out-group (the sister-group). Consequently, phylogeny in the H. octoseriatus group is inferred from the close similarity of morphological characters. In light of the phylogenetic analysis and a phenogram, speciation and the evolution of morphological characters in the H. octoseriatus group is discussed.     

Genetic variation in the Heterodoxus octoseriatus group (Phthiraptera): a test of Price's model of parasite evolution.

Most of the genetic variation in the H. octoseriatus group is present as fixed gene differences between species which have been described on morphological criteria. Based on allozymes, the taxonomic status of some species was challenged. There was insufficient evidence, however, to demonstrate that these were not 'good' biological species. Overall, the limited intraspecific variation was present as fixed gene differences among lice from different hosts and from different colonies of hosts; heterozygotes were rare. Two predictions derived from Price's model of parasite evolution were met: populations of lice were genetically homogeneous and, where genetic markers were present, we found substantial genetic variation among populations. These data contrast with those for endoparasitic helminths, where, in general, the amount of genetic variation is similar to that of free-living invertebrates.     

The effects of group size and host species on development and survivorship of a gregarious caterpillar Halisidota caryae (Lepidoptera: Arctiidae)

Abstract. 1. The effect on growth and survivorship of the number of Halisidota caryae (Harris) caterpillars in groups feeding on three taxonomically distinct hosts was examined experimentally in the field.
2. Caterpillars grew more rapidly and survived better in larger sized groups than in smaller sized groups.
3. Caterpilliars grew more rapidly and survived better on Carya ovata (Koch) than on Hamamelis virginiana (L) or Quercus velutina (Lam.).
4. There were equal numbers of invertebrate predators on groups of different sizes and thus larger groups had significantly fewer predators per caterpillar than did smaller groups.
5. Invertebrate predators accounted for at least a 10% daily decrease in survivorship.
6. Local movement reduced predation because moving groups had fewer predators than did stationary groups.     

Interplay of host specificity and biogeography in the population structure of a cosmopolitan endoparasite: microsatellite study of Ligula intestinalis (Cestoda)

Organisms with wide geographical or phenotypic diversity often constitute assemblages of genetically distinct species or lineages. Within parasites, an emergence of host-specific lineages is assumed to create such cryptic variability; however, empirical evaluation of these processes is scarce. Here, we analyse populations of a parasite with a complex life cycle, wide host spectrum and global distribution, with the aim to reveal factors underlying the evolution of host- or geography-dependent lineages. Using 15 microsatellite loci, deep genetic distances were observed between populations from distant geographical areas. On the local scale, host-mediated genetic structure was found among sympatric samples. Two lineages differing in the spectrum of infected hosts co-occurred in the Euro-Mediterranean area, and two distinct lineages were recovered from Lake Tana in Ethiopia. Although sampled across several host taxa and multiple localities, a lack of marked genetic structure was seen in the populations belonging to one of the European lineages. Only weak genetic differentiation between sympatric samples from two host species was found. Complexity of the parasite life-cycle contributed to such a stratified pattern. Differences in the immune response between fish hosts were suggested as the factor diversifying the populations locally; conversely, high mobility of the parasite due to migration with its bird (definitive) host were assessed to homogenize populations across the area of distribution. However, despite the high mobility, large bodies of salt water prevent the parasite from long-distance migrations, as was demonstrated in an example of the Mediterranean Sea which represented an effective barrier to gene flow.     

Biology and host range of the leafminer,Pseudonapomyza sp. (Diptera: Agromyzidae), a potential biological control agent for Tecoma stans (Bignoniaceae) in South Africa

Tecoma stans (Bignoniaceae), is an evergreen shrub that has a wide natural distribution in the tropical and subtropical parts of the western hemisphere. This shrub is native to Mexico and the southern regions of the USA. This weed is widely distributed in South Africa and neighbouring countries. As part of the biological control initiative, a leafmining fly, Pseudonapomyza sp. (Diptera: Agromyzidae), was imported into South Africa, and was subsequently studied as a potential biological control agent for T. stans. During no-choice tests involving 46 plant species in 16 families, Pseudonapomyza sp. only oviposited and developed on T. stans. Neither oviposition nor larval development was recorded on the closely related and indigenous plant species. When six plant species in the Bignoniaceae family were exposed to Pseudonapomyza sp. during multi-choice tests, oviposition and larval development only occurred on T. stans. It was concluded that Pseudonapomyza sp. was sufficiently host-specific to be released against T. stans in South Africa. Pseudonapomyza sp. also displayed very promising biological attributes that could enhance its effectiveness to control T. stans.     

Suitability of Bemisia tabaci (Hemiptera: Aleyrodidae) instars for the parasitization by Encarsia bimaculata and Eretmocerus sp. nr. furuhashii (Hymenoptera: Aphelinidae) on glabrous and hirsute host plants

The host instar preferences of Encarsia bimaculata and Eretmocerus sp. nr. furuhashii parasitizing Bemisia tabaci and their development on four host plants, collard, eggplant, cucumber and tomato, were studied in the laboratory. Both of the parasitoids accepted all nymphal stages of B. tabaci, but E. bimaculata preferred third and fourth instars while Er. sp. nr. furuhashii preferred second and third instars under both choice and no choice conditions. Regardless of host stage parasitized, adults of parasitoids emerged only from fourth instars. When given the simultaneous choice of all instars, E. bimaculata reduced parasitization of first and second instars (3.73 and 4.76%, respectively) while increasing parasitization of third and fourth instars (5.44 and 6.93%, respectively), in contrast Er. sp. nr. furuhashii increased its parasitization of second and third instar nymphs (1.27 and 3.17%, respectively) and decreased that of first and fourth instars (7.0 and 3.06%, respectively). Host plants did not significantly influence instar preference for either parasitoid. Developmental periods of both the parasitoids from egg to adult emergence were longest when first instars were parasitized and shortest when fourth instars were selected. Parasitoid developmental time was generally shorter on glabrous plants than on hirsute plants.     

Charipinae (Hymenoptera: Figitidae) from Australia: revision of the genus Thoreauana Girault, 1930 and description of Dilapothor n. gen.

Abstract  The Australian genus Thoreauana Girault is revised: the three known species are redescribed and Thoreauana giraulti sp. n. is described. A new genus of Charipinae from Australia, Dilapothor n. gen., is described. The diagnostic characters for the tribe Charipini are discussed and a key to the Charipini genera is provided.     

Biology and host specificity of Mecinus Janthinus Germar (col.: Curculionidae), a candidate for the biological control of yellow and dalmatian toadflax,Linaria Vulgaris (l.) mill,and Linaria Dalmatica (l.) mill. (scrophulariaceae) in North America

The biology and host specificity of Mecinus janthinus Germar, an oligophagous, univoltine stem‐borer of Linaria spp. are discussed. The results of feeding and oviposition tests with 38 species in 13 families and of larval transfer tests with four plant species are presented. They show that M. janthinus is restricted to the genus Linaria and does not develop on snapdragon Antirrhinum majus, an important ornamental in North America. The weevil is widely distributed in Europe. It accepts and develops normally on plants from the target North American toadflax populations. Therefore, it should be relatively easy to establish M. janthinus where the control of L. dalmatica and L. vulgaris is required. The release of M. janthinus in Canada and the USA is recommended.     

Historical divergence vs. contemporary gene flow: evolutionary history of the calcicole Ranunculus alpestris group (Ranunculaceae) in the European Alps and the Carpathians

Although many species have similar total distributional ranges, they might be restricted to very different habitats and might have different phylogeographical histories. In the European Alps, our excellent knowledge of the evolutionary history of silicate‐dwelling (silicicole) plants is contrasted by a virtual lack of data from limestone‐dwelling (calcicole) plants. These two categories exhibit fundamentally different distribution patterns within the Alps and are expected to differ strongly with respect to their glacial history. The calcicole Ranunculus alpestris group comprises three diploid species of alpine habitats. Ranunculus alpestris s. str. is distributed over the southern European mountain system, while R. bilobus and R. traunfellneri are southern Alpine narrow endemics. To explore their phylogenetic relationships and phylogeographical history, we investigated the correlation between information given by nuclear and chloroplast DNA data. Analyses of amplified fragment length polymorphism fingerprints and matK sequences gave incongruent results, indicative for reticulate evolution. Our data highlight historical episodes of range fragmentation and expansion, occasional long‐distance dispersal and on‐going gene flow as important processes shaping the genetic structure of the group. Genetic divergence, expressed as a rarity index (‘frequency‐down‐weighted marker values’) seems a better indicator of historical processes than patterns of genetic diversity, which rather mirror contemporary processes as connectivity of populations and population sizes. Three phylogeographical subgroups have been found within the R. alpestris group, neither following taxonomy nor geography. Genetic heterogeneity in the Southern Alps contrasts with Northern Alpine uniformity. The Carpathians have been stepwise‐colonised from the Eastern Alpine lineage, resulting in a marked diversity loss in the Southern Carpathians. The main divergence within the group, separating the ancestor of the two endemic species from R. alpestris s. str., predates the Quaternary. Therefore, range shifts produced by palaeoclimatic oscillations seem to have acted on the genetic structure of R. alpestris group on a more regional level, e.g. triggering an allopatric separation of R. traunfellneri from R. bilobus.     

Cryptic species complexes,widespread species and conservation: lessons from Amazonian frogs of the Leptodactylus marmoratus group (Anura: Leptodactylidae)

Morphologically cryptic species act as a wild card when it comes to biodiversity assessments and conservation, with the capacity to dramatically alter our understanding of the biological landscape at the taxonomic, ecological, biogeographic, evolutionary, and conservation levels. We discuss the potential effects that cryptic species may have on biodiversity assessments and conservation, as well as some of the current issues involving the treatment of cryptic species both at taxonomic and conservation levels. In addition, using a combination of advertisement call and morphological data, we describe a new species of the Leptodactylus marmoratus group from the upper Amazon basin, and we assess how cryptic species can affect conservation assessments of species in the Leptodactylus marmoratus group by examining how recent findings affect our understanding of the distribution of what is assumed to be a widespread Amazonian species, Leptodactylus andreae.     

Erratum to “Conformations of NhaA, the Na/H Exchanger from Escherichia coli, in the pH-Activated and Ion-Translocating States” [J. Mol. Biol. 386 (2009) 351-385]: Conformations of NhaA, the Na/H Exchanger from Escherichia coli, in the pH-Activated and Ion-Translocating States

NhaA, the main sodium-proton exchanger in the inner membrane of Escherichia coli, regulates the cytosolic concentrations of H⁺ and Na⁺. It is inactive at acidic pH, becomes active between pH 6 and pH 7, and reaches maximum activity at pH 8. By cryo-electron microscopy of two-dimensional crystals grown at pH 4 and incubated at higher pH, we identified two sequential conformational changes in the protein in response to pH or substrate ions. The first change is induced by a rise in pH from 6 to 7 and marks the transition from the inactive state to the pH-activated state. pH activation, which precedes the ion-induced conformational change, is accompanied by an overall expansion of the NhaA monomer and a local ordering of the N-terminus. The second conformational change is induced by the substrate ions Na⁺ and Li⁺ at pH above 7 and involves a 7-Å displacement of helix IVp. This movement would cause a charge imbalance at the ion-binding site that may trigger the release of the substrate ion and open a periplasmic exit channel.     

Emendation of the Genus Paurodontella Husain &Khan, 1968 and Description of P. auriculata n. sp. from Western Canada (Nematoda: Paurodontidae)

Males and females of Paurodontella auriculata n. sp. are described and illustrated and the genus emended. The species is characterized by a short, robust body of 355-525 μm, a stylet length of 7-8 μm, lateral field with 5-6 incisures, and a conoid, attenuated tail 1.5 times the vulva-anus distance. Primary characters used in emending the genus are asymmetrical stylet knobs, absence of lateral lips, a deep slit-like amphid dividing the submedian lips to base of head, where open lateral sides are covered by a large auriform cuticular flap, and variable length of the basal esophageal bulb stem and male bursa.     

The integripennis species group of Geocharidius Jeannel, 1963 (Carabidae,Bembidiini, Anillina) from Nuclear Central America: a taxonomic review with notes about biogeography and speciation

Our review recognizes 15 species of the integripennis species group of Geocharidius from Nuclear Central America, include three species previously described (Geocharidius gimlii Erwin, Geocharidius integripennis (Bates) and Geocharidius zullinii Vigna Taglianti) and 12 described here as new. They are: Geocharidius andersoni sp. n. (type locality: Chiapas, Chiapas Highlands, Cerro Huitepec) and Geocharidius vignatagliantii sp. n. (type locality: Chiapas, Motozintla, Sierra Madre de Chiapas, Benito Juárez) from Mexico; Geocharidius antigua sp. n. (type locality: Sacatepéquez, 5 km SE of Antigua), Geocharidius balini sp. n. (type locality: Suchitepéquez, 4 km S of Volcan Atitlán), Geocharidius erwini sp. n. (type locality: Quiché Department, 7 km NE of Los Encuentros), Geocharidius jalapensis sp. n. (type locality: Jalapa Department, 4 km E of Mataquescuintla), Geocharidius longinoi, sp. n. (type locality: El Progreso Department, Cerro Pinalón), and Geocharidius minimus sp. n. (type locality: Sacatepéquez Department, 5 km SE of Antigua) from Guatemala; and Geocharidius celaquensis sp. n. (type locality: Lempira Department, Celaque National Park), Geocharidius comayaguanus sp. n. (type locality: Comayagua Department, 18 km ENE of Comayagua), Geocharidius disjunctus sp. n. (type locality: Francisco Morazán, La Tigra National Park), and Geocharidius lencanus sp. n. (type locality: Lempira Department, Celaque National Park) from Honduras. For all members of the group, adult structural characters, including male and female genitalia, are described, and a taxonomic key for all members of the integripennis species group is presented based on these characters. Behavioral and biogeographical aspects of speciation in the group are discussed, based on the morphological analysis. In all cases of sympatry, pairs of closely related species show greater differences in sizes than pairs of more remotely related species. Integripennis group species occupy six different montane areas at elevations above 1300m, with no species shared among them. Major faunal barriers in the region limiting present species distributions include the Motagua Fault Zone and a gap between the Guatemalan Cordillera volcanic chain and the Honduran Interior Highlands no higher than 900m in elevation. Highest species diversity is in the Guatematan Cordillera (six species), second highest in the Honduran Interior Highlands area (four species).     

Self-, Intra-, and Interspecific Host Discrimination in Telenomus busseolae Gahan and T. isis Polaszek (Hymenoptera: Scelionidae), Sympatric Egg Parasitoids of the African Cereal Stem Borer Sesamia calamistis Hampson (Lepidoptera: Noctuidae)

Oviposition behavior, intra- and interspecific host discrimination, and super- and multiparasitism by the scelionids Telenomus busseolae and T. isis were studied using batches of eggs of the noctuid stalk borer Sesamia calamistis as the host. Both Telenomus species were able to discern eggs already parasitized. As a result, self-superparasitism was only 4.0% for T. busseolae and 5.8% for T. isis. Likewise, intraspecific superparasitism was avoided by both species and was significantly higher for T. busseolae than T. isis, and higher when parasitized eggs were offered immediately (0 h) and after 48 h than after 24 h; apparently, the recognition of parasitized eggs at 24 and 48 h was based on the presence of parasitoid larvae rather than a specific marking substance. Multiparasitism was avoided if the female had a choice between unparasitized and parasitized eggs. In a choice experiment, it was 10.2 and 2.5% for T. busseolae and T. isis, respectively. In a nonchoice experiment, multiparasitism did not vary between species and time treatment; it was low, varying between 9.6 and 24.1%. In the 0-h treatment, T. busseolae always outcompeted T. isis, accounting for 63.4 or 91.7% of the offspring, when T. isis or T. busseolae, respectively, was the first species. In the 24-h treatment, the first species emerged more often than the second did but the host egg mortality, i.e., eggs from which neither borer larvae nor parasitoid emerged, was >40%. Whereas T. busseolae is ubiquitous in Africa, T. isis has never been reported from eastern Africa, and it has been proposed for introduction against the prevailing noctuid pest Bussoela fusca. Based on earlier life table and host suitability studies and on the present findings, it is concluded that T. isis would establish in the midaltitudes but not the highlands of eastern Africa.     

Characterization of New Entomopathogenic Nematodes from Thailand: Foraging Behavior and Virulence to the Greater Wax Moth, Galleria mellonella L. (Lepidoptera: Pyralidae)

Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis and their associated bacteria (Xenorhabdus spp. and Photorhabdus spp., respectively) are lethal parasites of soil dwelling insects. We collected 168 soil samples from five provinces, all located in southern Thailand. Eight strains of EPNs were isolated and identified to species using restriction profiles and sequence analysis. Five of the isolates were identified as Heterorhabditis indica, and one as Heterorhabditis baujardi. Two undescribed Steinernema spp. were also discovered which matched no published sequences and grouped separately from the other DNA restriction profiles. Behavioral tests showed that all Heterorhabditis spp. were cruise foragers, based on their attraction to volatile cues and lack of body-waving and standing behaviors, while the Steinernema isolates were more intermediate in foraging behavior. The infectivity of Thai EPN strains against Galleria mellonella larvae was investigated using sand column bioassays and the LC(50) was calculated based on exposures to nematodes in 24-well plates. The LC(50) results ranged from 1.99-6.95 IJs/insect. Nine centimeter columns of either sandy loam or sandy clay loam were used to determine the nematodes' ability to locate and infect subterranean insects in different soil types. The undescribed Steinernema sp. had the greatest infection rate in both soil types compared to the other Thai isolates and three commercial EPNs (Heterorhabditis bacteriophora, Steinernema glaseri and Steinernema riobrave).     

Rhipicephalus (Boophilus) microplus: distinct acute phase proteins vary during infestations according to the genetic composition of the bovine hosts, Bos taurus and Bos indicus

Tick bites may trigger acute phase responses. Positive and negative acute phase proteins were measured in infested cattle genetically resistant and susceptible to ticks. During heavier infestations levels of haptoglobin increased significantly in susceptible bovines; levels of serum amyloid A increased in resistant bovines; levels of alpha-1-acid glycoprotein decreased significantly in resistant bovines; levels of transferrin decreased significantly in susceptible bovines. In conclusion, tick infestations trigger acute phase responses and enhancement of specific acute phase proteins differs according to the genetic composition of hosts. Acute phase proteins may constitute useful biological signatures for monitoring the stress induced by tick infestations.