Towards a better understanding of the dynamics of Aphis spiraecola Patch (Homoptera: Aphididae) populations in commercial alpine yarrow fields

The spatial distribution of Aphis spiraecola Patch was studied in two commercial yarrow fields located in the Swiss and Italian Alps and represented by Taylor’s (1961) power law. The respective parameters indicate a highly aggregated distribution and lead to a high optimum sample size of 400-500 plants in the design of a sampling program. Opportunities for reducing the sampling efforts are discussed. The infestation patterns were studied on the basis of Vansickle’s (1977) time varying distributed delay adequate for modelling the dynamics of age-structured populations. Published literature data were used to parametrize the functions representing the temperature-dependent duration and survival of the nymphal and adult stage. Likewise, literature data were available to obtain reliable estimates for the parameters of the fecundity function comprising the reproductive profile and the number of nymphs produced at different temperatures. The field data were used to parametrize the functions for wing formation and a compound mortality compromising the effects of plant senescence, stem cutting and natural enemies. The model satisfactorily represented the observed infestation patterns. However, there are opportunities for improving parameter estimation and validation. Moreover, the separation of the compound mortality into host plant and natural enemy effects would improve the mechanistic basis of the model and lead towards a tool that could be used to study bottom-up and top-down effects in the yarrow-aphid-natural enemy system

Chemometric analysis of the secondary metabolite profile of Yarrow (Achillea collina Becker ex Rchb.) affected by phloem feeding Myzus persicae Sulzer aphids

Yarrow (Achillea collina Becker ex Rchb.) has a high content of secondary metabolites including phenolic acids. Among them, hydroxycinnamic acid such as chlorogenic acid and its derivatives were found to be the most abundant ones. The phloem feeding Myzus persicae Sulzer was hypothesized to affect the contents of secondary metabolites and change the metabolite profile. A high-performance liquid chromatography technique (HPLC) was used to evaluate whether there is a difference in the phenolic profile between aphid infested and non-infested yarrow leaves. M. persicae colonies composed of between 20 and 30 individuals were allowed to feed for 10 and 20 days. Preprocessing was carried out to standardize the procedures in order to obtain optimal separation of analytes, good chromatographic peak shape and robustness of the results. The methanol extracts of leaves were analyzed by means of HPLC, and the time series of peak areas obtained from each extract were evaluated through chemometric analyses. Results of the phenolic fingerprints showed a specific chromatographic profile with 58 peaks. An autoregression analysis demonstrated the absence of correlation. The discriminant analysis carried out with the data satisfying the assumption of the absence of collinearity showed a significant effect of phloem feeding on soluble phenolic compounds and identified two peaks that separate aphid infested from non-infested plants. The hydroxycinnamic acids widely found in A. collina leaves were not affected by M. persicae feeding. The results are the basis for the current studies aiming at the identification of chemical compounds that correspond to the peaks

Editorial

The Journal of Entomological and Acarological Research (JEAR), formerly the Bollettino di Zoologia Agraria e di Bachicoltura of the Institute of Entomology of the Università degli Studi, Milano, was founded in 1928 by Remo Grandori. Minos Martelli and Luciano Süss were in charge of the journal until December 2011. In January 2012, the Editor came to a big decision and began to explore the possibility of publishing a new online open access version of the JEAR. The aim was to reach out to researchers in the field all over the world, and I was nominated Editor in Chief

Editorial

The Journal of Entomological and Acarological Research (JEAR), formerly the Bollettino di Zoologia Agraria e di Bachicoltura of the Institute of Entomology of the Università degli Studi, Milano, was founded in 1928 by Remo Grandori. Minos Martelli and Luciano Süss were in charge of the journal until December 2011. In January 2012, the Editor came to a big decision and began to explore the possibility of publishing a new online open access version of the JEAR. The aim was to reach out to researchers in the field all over the world, and I was nominated Editor in Chief

The bacterial community associated to an italian population of psacothea hilaris: A preliminary study

The yellow-spotted longicorn beetle, Psacothea hilaris (Pascoe) (Coleoptera Cerambycidae), native to eastern Asia, is an invasive species for Europe, where it is present since 2005 as a pest of Morus and Ficus spp. Up to date, no study on the bacterial community associated with P. hilaris has been carried out. The aim of the present work is to characterize the bacterial community associated to an Italian population of P. hilaris collected on F. carica L. through a culture-independent method (i.e., 454 pyrosequenc-ing) targeting the 16S rRNA gene. The DNA used for bacterial characterization has been extracted from the whole abdomen of 15 adults (seven males and eight females) sampled on the host plant immediately after their emergence in Alserio (Como, Italy) between August and September 2012. The sequencing strategy led to a total of ≈ 2,350 bacterial 16S rRNA gene sequences that have been clustered into 141 bacterial operational taxonomic units. Results shown that the bacterial community was dominated by Proteobacteria (86%) belonging to Oxalobacteraceae and Enterobacteriaceae (respectively 36.4% and 34.8%). Pantoea resulted the most abundant genus (28.4%), and the other relevant bacterial genera associated with P. hilaris are Ralstonia (18.6%), Methy-lobacterium (3%), Lactococcus (2%) and Propionibacterium (1.4%)

The Beetle (Coleoptera) and True bug (Heteroptera) species pool of the alpine “Pian di Gembro” wetland (Villa di Tirano, Italy) and its conservation

he C oleoptera and Heteroptera species pool was investigated in the “Pian di Gembro” wetland (Villa di T irano, Sondrio, Italy). T he wetland consists of a bog and its surroundings, referred to as wetland components, that are both subjected to a diversified intermediate management regime (DIMR). T he application of the DIMR for plant species conservation resulted in the establishment of 11 wetland zones with a characteristic vegetation. In a three year sampling program, 997 C oleoptera and Heteroptera representing 141 species from 14 families were collected. Among these species, 64 species share both wetland components, 11 are restricted to the bog and 63 were found in the surroundings only. Among the species pool there were 23 tyrphophile taxa and only one tyrphobiont. With the exception of one zone, all zones are inhabited by zone-specific species. By taking into account both the general species pool and the pool of species of particular interest to conservationists, only one zone can be considered as redundant since it is inhabited by species that occur also in other zones. Hence, all the zones, with one exception, are effective for species pool conservation. The existing DIMR implemented for plant species conservation is also effective for conserving the species pool of C oleoptera and Heteroptera

A new strain of wolbachia in an alpine population of the viviparous oreina cacaliae (Coleoptera: Chrysomelidae)

Microbial symbionts played a central role in insect evolution. Oreina cacaliae (Schrank, 1785) (Coleoptera: Chrysomelidae) is a rare example of a viviparous insect, able to feed on toxic plants and sequester toxic compounds. In the current study, the microbiota associated with O. cacaliae was characterized using a culture-independent approach, targeting the 16S rRNA bacterial gene. The obtained 16S rRNA gene sequences were analyzed and identified at different taxonomic levels. Wolbachia was the dominant bacterium, both in male and female (100 and 91.9%, respectively) individuals; the detected Wolbachia was described as a new sequence type based on multilocus sequence typing (Wolbachia ST375 Ocac-A-wVdO). After phylogenetic analyses, Wolbachia ST375 Ocac-A-wVdO was attributed to the supergroup A. Immunofluorescence assays and electron microscopy confirmed the presence of Wolbachia within O. cacaliae oocytes, confirming its transovarial transmission in this species. Representatives of six species of Oreina were tested for the presence of Wolbachia through specific polymerase chain reaction, and a dendrogram was generated for these species based on coxI gene sequences. The Wolbachia harbored by different species of Oreina were characterized by multilocus sequence typing. Five out of the six examined Oreina species were positive for Wolbachia, with four of these harboring the same sequence type. © 2014 Entomological Society of America

Operational taxonomic units shared by the three groups of weevils.

<p>Venn diagram showing the shared bacterial OTUs (at 97% similarity) between all studied weevils groups.</p