Alkaloids provide evidence of intraguild predation on native coccinellids by <Emphasis Type="Italic">Harmonia axyridis</Emphasis> in the field

Over a period of less than 5 years, Belgium was thoroughly invaded by the multicolored Asian coccinellid, Harmonia axyridis. At the same time, a decline of some native coccinellid species was observed in tree habitats. One hypothesis about the cause of this decline was that it might have been due to intraguild predation (IGP) by H. axyridis. In natural conditions, IGP between coccinellids can be tracked by using defensive compounds. Exogenous alkaloids in H. axyridis were therefore examined by gas chromatography-mass spectrometry (GC–MS), using individuals sampled from lime trees that were also occupied by other species of coccinellids. Harmonia axyridis was the dominant species at all life stages, in terms of both numbers of sites occupied and local abundance. The GC–MS analysis of H. axyridis larvae revealed traces of exogenous alkaloids from 19 of the 20 sites and, in nine of those 19 sites, more than 30% of the larvae analyzed contained exogenous alkaloids. Three alkaloids were detected: adaline from Adalia spp., calvine from Calvia spp. and propyleine from Propylea quatuordecimpunctata. Predation by H. axyridis on two different coccinellid species was also detected in the same larva, reinforcing the status of H. axyridis as a top predator. A generalized linear model indicated that IGP frequency was positively influenced by two variables: the abundance of extraguild and intraguild prey; and the interaction between these two variables. Our results therefore support the hypothesis that IGP by H. axyridis on native coccinellids in tree habitats has led to the decline of several of these species.     

Revision of <Emphasis Type="Italic">Heterosavia</Emphasis>, stat. nov., with notes on <Emphasis Type="Italic">Gonatogyne</Emphasis> and <Emphasis Type="Italic">Savia</Emphasis> (Phyllanthaceae)

Heterosavia (Phyllanthaceae) is segregated from Savia (tribe Bridelieae), recognized at generic rank, and placed in tribe Phyllantheae. Floral, fruit, leaf anatomical, leaf venation, and pollen characters of the neotropical taxa previously united as Savia including Gonatogyne are discussed and illustrated. Keys to the three genera and to the species of Heterosavia are presented. Four species (all new combinations), Heterosavia bahamensis, H. erythroxyloides, H. laurifolia, and H. maculata, are recognized. The new combinations Heterosavia laurifolia var. intermedia and H. maculata var. clementis are proposed. The names Heterosavia, H. erythroxyloides, H. laurifolia, Savia clementis, S. clusiifolia, S. clusiifolia var. fallax, and S. longipes are lectotypified. Distribution maps and conservation assessments (IUCN ratings) of Heterosavia species and varieties are provided.     

The <Emphasis Type="Italic">Caenorhabditis</Emphasis><Emphasis Type="Italic">briggsae</Emphasis> genome contains active <Emphasis Type="Italic">CbmaT1</Emphasis> and <Emphasis Type="Italic">Tcb1</Emphasis> transposons

The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.     

New species and a new combination in the <Emphasis Type="Italic">Hyphopichia</Emphasis> and <Emphasis Type="Italic">Yarrowia</Emphasis> yeast clades

Three new species of Candida and a new combination in the genus Hyphopichia are proposed from phylogenetic analysis of nucleotide divergence in domains D1/D2 of the large subunit (26S) rDNA. The new taxa and their type strains are the following: Candida bentonensis sp. nov. (NRRL YB-2364, CBS 9994), Candida hispaniensis sp. nov. (NRRL Y-5580, CBS 9996), Candida pseudorhagii sp. nov. (NRRL YB-2076, CBS 9998) and Hyphopichia heimii comb. nov. (NRRL Y-7502, CBS 6139), basionym Pichia heimii Pignal. Phylogenetic analysis placed C. pseudorhagii and H. heimii in the Hyphopichia clade whereas C. bentonensis and C. hispaniensis are members of the Yarrowia clade.     

<Emphasis Type="Italic">Drosophila</Emphasis><Emphasis Type="Italic">P</Emphasis> transposons of the urochordata <Emphasis Type="Italic">Ciona intestinalis</Emphasis>

P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The ontogenetic basis for floral diversity in <Emphasis Type="Italic">Agonis</Emphasis>, <Emphasis Type="Italic">Leptospermum</Emphasis> and <Emphasis Type="Italic">Kunzea</Emphasis> (Myrtaceae)

Floral development in three species each of Leptospermum and Kunzea, and one species of Agonis, is described and compared. Differences in the number of stamens and their arrangement in the flower at anthesis are determined by the growth dynamics of the bud. In Leptospermum, early expansion of the bud is predominantly in the axial direction and causes the stamen primordia to be initiated in antepetalous chevrons. In Kunzea, early expansion occurs predominantly in the lateral direction and successive iterations of stamen primordia are inserted alternately at more or less the same level. In both genera, further expansion in the lateral plane spreads the stamens into a ring around the hypanthium. Agonis flexuosa is similar to Leptospermum. Other variable factors include the timing at which stamen initiation commences (earlier in Leptospermum than Kunzea), the duration of stamen initiation (hence the total number of stamens produced – varies within genera), and very late differential expansion that forces stamens into secondary antesepalous groups in A. flexuosa and L. myrsinoides.The authors thank Dr H. Toelken for kindly providing some material and the impetus for this project. This research was supported by Australian Research Council grant AS19131815.     

Three new species of <Emphasis Type="Italic">Luetzelburgia</Emphasis> (<Emphasis Type="Italic">Leguminosae</Emphasis>, <Emphasis Type="Italic">Papilionoideae</Emphasis>) from the caatinga of Bahia,Brazil and an identification key to all species of the genus

Three new species of the Brazilian genus Luetzelburgia Harms (Leguminosae, Papilionoideae, Sophoreae sensu lato (Vataireoid clade)) are described and illustrated under the names Luetzelburgia harleyi D. Cardoso, L. P. Queiroz &; H. C. Lima, L. neurocarpa D. Cardoso, L. P. Queiroz &; H. C. Lima and L. purpurea D. Cardoso, L. P. Queiroz &; H. C. Lima. All three occur in the caatinga vegetation of the State of Bahia, Eastern Brazil. A discussion of the morphological characters distinguishing the new species from their close relatives, as well as an identification key to all known species of Luetzelburgia, are presented.     

Detection of <Emphasis Type="Italic">Candida</Emphasis><Emphasis Type="Italic">dubliniensis</Emphasis> in Venezuela

Over the past decades there has been a significant increase in fungal infections caused by Candida species, and continues to be common in immunocompromised individuals infected with the human immunodeficiency virus (HIV). Although Candida albicans remains the fungal species most frequently isolated as an opportunistic oral pathogen, other non-albicans are often identified in this cohort of patients, including C. dubliniensis. This yeast is closely related to and shares many phenotypic characteristics with C. albicans. Colonies of these two species appear morphologically identical when not grown on special media. The shared phenotypic characteristics of C. dubliniensis and C. albicans suggest that many C. dubliniensis isolates may have been misidentified as C. albicans in the past. The present studies aim is to recover and identify C. dubliniensis, and presumptive clinical C. albicans, from the oral cavities of HIV-seropositive individuals, comparing conventional media to obtain a simple, low-cost and reliable identification system for C. dubliniensis. A total of 16 isolates (3,98%) had been obtained from 402 HIV infected individuals with recurrent oropharyngitis and were identified as C. dubliniensis. Out of these C. dubliniensis isolates 19% were resistant, with MICs above 64 μg/ml to fluconazole. This constitutes, to the authors knowledge the first recovery of this organism in Venezuela.     

Fecundity and feeding of <Emphasis Type="Italic">Galerucella calmariensis</Emphasis> and <Emphasis Type="Italic">G. pusilla</Emphasis> on <Emphasis Type="Italic">Lythrum salicaria</Emphasis>

Fecundity and feeding of two introduced sibling biological control species, Galerucella calmariensis and G. pusilla (Coleoptera: Chrysomelidae) on purple loosestrife, Lythrum salicaria L. (Lythraceae) were compared at constant temperatures of 12.5, 15, 20, 25, and 27.5 °C. Larval feeding was also carried out at 30 °C, but at this temperature, larvae developed only to the L2 stage and none pupated. Thus, data for this temperature were not used in the analysis. There were significant species × temperature interactions in fecundity. Of the two species, Galerucella pusilla laid more eggs. Although egg production of both species was lowest at 12.5 °C and increased to 20 °C, at higher temperatures, the two species reacted differently. From 25 to 27.5 °C, egg production decreased for G. pusilla, but G. calmariensis fecundity peaked at 27.5 °C. Significant temperature × species × life-stage interactions were also observed in feeding. For each species, the amount of feeding varied with temperature and stage of development. Galerucella pusilla adults consumed more foliage at 15, 20, and 27.5 °C. However, at 12.5 °C G. calmariensis adults fed more than G. pusilla. G. pusilla larvae consumed an average of 25% less foliage than G. calmariensis. The lower larval consumption of G. pusilla suggests that when food is limited, G. pusilla larvae may have a higher survival rate because of its ability to complete larval development with less food and produce more progeny due to its greater fecundity. When food is not limited neither species would have a competitive advantage and both species could coexist temporally and spatially. However, since G. calmariensis larvae consumed more leaf material, the larval stage of this species would have a greater impact on purple loosestrife than G. pusilla.