The Life Cycle of Ctenothrips distinctus (UZEL, 1895) (Insecta: Thysanoptera) and its Influence on the Host Plant Convallaria majalis L

In this paper, we describe the morphological characteristics of the preimaginal stages of Ctenothrips distinctus, as well as its life cycle in temperate climate conditions. We also revise the key characters of the second larval instar of C. distinctus, which were previously confused with those of Taeniothrips picipes (Zetterstedt, 1828). The morphological characteristics of the C. distinctus propupa and pupa represent their adaptations to moulting in the soil, not on the host plant. The study of the biology of C. distinctus is supplemented by an analysis of the impact of the foraging by this insect on its host plant Convallaria majalis. Based on the morphological, anatomical and histological analyses of Lily of the Valley leaves, we show that both adults and larval instars feed on the epidermal cells of both the upper and lower sides of the leaf blade in C. majalis. However, the assimilation parenchyma cells located immediately below the epidermis at the feeding site retain their shape.

Methicillin-resistant Staphylococcus aureus and glycopeptide-resistant enterococci in fecal samples of birds from South-Eastern Poland

Background

The incidence of human infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) has increased in the recent years. Environmental sources, including bird droppings, might play an important role as resistance reservoirs.

Results

Fresh fecal samples were collected from rooks and wild-living birds during the autumn-winter period of 2016/2017, and tested for the presence of bacteria associated with human diseases. Besides bacteria representing the genera Enterococcus, Campylobacter, Escherichia, and Staphylococcus, Enterobacter, Citrobacter, Proteus, Hafnia, and Pseudomonas were also identified. The susceptibility of S. aureus and Enterococcus spp. isolates to methicillin, and vancomycin and teicoplanin, respectively, was analyzed to assess the avian wildlife as a reservoir of MRSA and VRE strains. Twenty-two percent of all S. aureus isolates were methicillin-resistant. These strains were screened by polymerase chain reaction (PCR), using the most widely used primer sets specific for the mecA gene. Twenty percent of all Enterococcus strains were phenotypically vancomycin-resistant. The presence of van resistance genes in these strains was investigated by PCR using vanA and vanB gene-specific primers. A good correlation between mecA gene detection and disc diffusion data was observed, while some discrepancy was noted between the PCR data and the vancomycin/teicoplanin phenotypic resistance pattern. The incidence of strains resistant to methicillin and glycopeptide antibiotics in wild-living birds was twice that in rooks.

Conclusions

The study suggests that rooks from urban areas and passerine birds from the natural habitat carry antibiotic-resistant Enterococcus spp. and S. aureus strains, probably reflecting the presence of such isolates in the environmental food sources.

First insight into microbiome profile of fungivorous thrips Hoplothrips carpathicus (Insecta: Thysanoptera) at different developmental stages: molecular evidence of Wolbachia endosymbiosis

Insects' exoskeleton, gut, hemocoel, and cells are colonized by various microorganisms that often play important roles in their host life. Moreover, insects are frequently infected by vertically transmitted symbionts that can manipulate their reproduction. The aims of this study were the characterization of bacterial communities of four developmental stages of the fungivorous species Hoplothrips carpathicus (Thysanoptera: Phlaeothripidae), verification of the presence of Wolbachia, in silico prediction of metabolic potentials of the microorganisms, and sequencing its mitochondrial COI barcode. Taxonomy-based analysis indicated that the bacterial community of H. carpathicus contained 21 bacterial phyla. The most abundant phyla were Proteobacteria, Actinobacteria, Bacterioidetes and Firmicutes, and the most abundant classes were Alphaproteobacteria, Actinobacteria, Gammaproteobacteria and Betaproteobacteria, with different proportions in the total share. For pupa and imago (adult) the most abundant genus was Wolbachia, which comprised 69.95% and 56.11% of total bacterial population respectively. Moreover, similarity analysis of bacterial communities showed that changes in microbiome composition are congruent with the successive stages of H. carpathicus development. PICRUSt analysis predicted that each bacterial community should be rich in genes involved in membrane transport, amino acid metabolism, carbohydrate metabolism, replication and repair processes.

Insights into the biochemical defence and methylation of the solitary bee Osmia rufa L: A foundation for examining eusociality development

We examined age-related biochemical and histological changes in the fat bodies and hemolymph of Osmia rufa males and females. We analysed solitary bees during diapause, in October and in April; as well as the flying insects following diapause, in May and June. The trophocyte sizes, as well as the numbers of lipid droplets were the greatest at the beginning of diapause. Subsequently, they decreased along with age. Triglyceride and glucose concentrations systematically decreased in fat body cells but increased in the hemolymph from October to June. Concentrations/activities of (enzymatic and non-enzymatic) antioxidant and proteolytic systems, as well as phenoloxidase, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels were constant during the diapause, usually lower in the males than the females. Prior to the diapause/overwintering, the concentrations/activities of all the compounds were higher in the fat bodies than in the hemolymph. Later in the spring and in the summer, they increased in the hemolymph and on the body surfaces, while decreasing in the fat bodies. The global DNA methylation levels increased with age. Higher levels were always observed in the males than in the females. The study will promote better understanding of bee evolution and will be useful for the protection and management of solitary bees, with benefits to the environment and agriculture.

Detection of the quarantine species Thrips palmi by loop-mediated isothermal amplification

Thrips palmi (from the order Thysanoptera) is a serious insect pest of various crops, including vegetables, fruits and ornamental plants, causing significant economic losses. Its presence constitutes a double threat; not only does T. palmi feed on the plants, it is also a vector for several plant viruses. T. palmi originated in Asia, but has spread to North and Central America, Africa, Oceania and the Caribbean in recent decades. This species has been sporadically noted in Europe and is under quarantine regulation in the European Union. For non-specialists its larval stages are indistinguishable morphologically from another widespread and serious insect pest Frankliniella occidentalis (a non-quarantine species in the European Union) as well as other frequently occurring thrips. In this study, we have developed a loop-mediated isothermal amplification protocol to amplify rDNA regions of T. palmi. The results were consistent whether isolated DNA or crushed insects were used as template, indicating that the DNA isolation step could be omitted. The described method is species-specific and sensitive and provides a rapid diagnostic tool to detect T. palmi in the field.