The death of honey bees, Apis mellifera L., and the consequent colony collapse disorder causes major losses in agriculture and plant pollination worl

The taxonomic identity of the hereditary prokaryotic symbiont of the olive flyBactrocera oleae(Diptera: Tephritidae) was investigated. In order to avoid superficial microbial contaminants and loosely associated saprophytic biota, flies were surface-sterilized at the larval stage and reared under aseptic conditions until adult emergence.B. oleaeflies originating from different geographical locations and collected at different times of the year were tested. Bacterial isolation was undertaken from the cephalic oesophageal bulb, which is known to be a specific site of accumulation for the hosted microsymbionts in the adult insect. Despite evidence of multiplication cycles taking place within the insect, attempts at cultivation of the isolated bacteriaex situwere not productive at any stage, leading to the choice of unculturable status definition. PCR amplification and nucleotide sequencing of the entire 16S rRNA gene consistently yielded a single sequence that displayed marked similarity with enterobacterial lineages, with closest matches (97 %) toErwinia persicinaandErwinia rhapontici. The novel taxon differs from common intestinal bacterial species of fruit flies and from instances of culturable bacteria previously described inB. oleaeraised without sterility precautions, which we also observed as minority occupants or occasional contaminants. The symbiont's identity is also distinct fromPseudomonas savastanoi. In all observations, the numerically dominant inhabitant of the olive fly oesophageal organ was the same unculturable organism, whose presence at later stages was also regularly observed in the midgut. A novel species is proposed, by virtue of its unique properties, under the designation ‘CandidatusErwinia dacicola’.

In the Veneto region (north-eastern Italy) an entomological surveillance system has been implemented since the introduction of the Asian tiger mosquito (Aedes albopictus) in 1991. During the routine monitoring activity in a tiger mosquito-free area, an unexpected mosquito was noticed, which clearly did not belong to the recorded Italian fauna.

A grapevine leafminer Antispila oinophylla van Nieukerken & Wagner, sp. n., is described both from eastern North America (type locality: Georgia) and as a n

The presence of symbiotic bacteria in flies belonging to the subfamily Tephritinae, which predominantly infest the flower heads of composite flowers (Asteraceae), was investigated. Twenty-five species of flies, collected mainly in northern Italy, were examined. The bacteria adhered to the midgut epithelium in a space external to the peritrophic membrane and therefore not in direct contact with the gut contents. Specific, unique and live, but unculturable bacteria were consistently found in the majority of the fly species and their presence was also shown to be persistent in flies reared under microbiologically controlled conditions and devoid of any residual culturable intestinal bacteria. Sequencing of the small subunit rRNA gene from the novel bacteria indicated that they belonged to the family Enterobacteriaceae. Three main strongly supported clades were delineated by phylogenetic trees, the first of which featured a coherent set of sequences displaying gene sequence similarities lower than 96 % compared with recognized taxa. The second and third clades featured cases with higher gene sequence similarities to culturable bacteria, including Erwinia persicina and Ewingella americana, respectively. Relative rate tests were supportive of a fast genetic evolution for the majority of the bacterial symbionts of the subfamily Tephritinae. In agreement with the interpretation suggested in 1929 after pioneering observations made by H. J. Stammer, a symbiotic relationship between the novel bacteria and the tephritid flies is postulated. The origin of this apparently polyphyletic relationship is discussed and a novel candidate organism is proposed for the first clade under the designation ‘Candidatus Stammerula tephritidis’.