109 research outputs found
BACTERIA ASSOCIATED TO RHYNCHOPHORUS FERRUGINEUS (OLIVIER) (COLEOPTERA DRYOPHTHORIDAE) IN ITALY
Thirty-five bacterial strains were selected on the basis of colony morphology from larvae and pupae of Rhynchophorous (Olivier) ferrugineus collected from infested Phoenix canariensis Chabaud trees growing in different Italian locations. 16S rDNA sequencing showed that bacteria isolated from larvae were mostly Gram positive and belonged to Bacillus, Brevibacillus and Paenibacillus genera. Bacteria isolated from pupae were affiliated to Bacillus and five different Gram negative genera (Alcaligenes, Morganella, Myroides, Providencia and Serratia). Some strains produced lytic enzymes like chitinase, lecithinase, lipase and protease in vitro. The enthomopathogenic strains belonging to Bacillus thuringiensis, Providencia rettgeri and Serratia marcescens species may be considered of interest as potential biocontrol agents of R. ferrugineus
First record in Cyprus of Cinara (Cinara) cedri Mimeur (Aphididae Lachninae) on Cedrus brevifolia (Hooker fil.) Henry.
The Authors report on the discovery in South Cyprus of the aphid Cinara (Cinara) cedri Mimeur collected on the endemic cedar, Cedrus brevifolia (Hooker fil.) Henry. This is the first record of the lacnid in Cyprus. The ecological aspects of the cedar and its interaction with the related aphid species are discussed. The Authors suggest the hypothesis that the aphid may be co-endemic with its host conifer since it shows significant morphological differences compared with specimens from other European regions. The question whether the Cyprus cedar aphid can be injurious or not to its host plant is debated as well. The exact taxonomic position of this lacnid is currently under investigation
MANAGEMENT OF THE ROOT-KNOT NEMATODE MELOIDOGYNE INCOGNITAON TOMATO WITH DIFFERENT COMBINATIONS OF NEMATICIDESAND A RESISTANT ROOTSTOCK: PRELIMINARY DATA
In south Italy, tomato growers commonly face severe root-knot nematode infestations. Alternative methods ofcontrol are required because of the high toxicity of current pesticides. Therefore, the potential of an integrated pestmanagement strategy for the control of root-knot nematodes on tomato in greenhouse was investigated. The nematodesusceptible tomato cv. Ikram, non-grafted or grafted onto the tomato rootstock cv. Armstrong, with intermediate resistanceto the nematode, in combination with soil applications of the nematicides fosthiazate, oxamyl, and abamectin were tested.The resistant rootstock significantly reduced nematode soil population levels and root galling index until one month aftertransplanting, when soil temperature was below 28°C, but not by harvest due to increased soil temperature. Fosthiazate,abamectin and oxamyl increased tomato yield and reduced root galling caused by Meloidogyne incognita. The synergisticeffect of the rootstock resistant to root-knot nematodes and soil treatments of fosthiazate in combination with abamectin oroxamyl could successfully be employed in integrated pest management programs to control M. incognita in tomato
Ultrastructure of the anterior alimentary tract of Bursaphelenchus mucronatus Mamiya et Enda (Nematoda Aphelenchoididae)
In view of the phytosanitary importance of nematodes of the genus Bursaphelenchus and the limited information available on their ultrastructure, we carried out a study of the buccal cavity and oesophageal area of Bursaphelenchus mucronatus Mamiya et Enda, 1979. Like the quarantine species Bursaphelenchus xylophilus (Steiner et Bührer) Nickle, its development takes place in the resin canals of conifers. The specimens used in our study were taken from a laboratory population collected on Pinus pinaster Aiton in meso-thermophilic mixed forests of central Italy (Tuscany) and grown on Petri dishes in a climatic chamber for 20 generations. The ultrastructural features of the mouth opening, anterior intestine, labial sensilla, amphidial canals, stylet and metacorpus were investigated with a TEM. The oesophageal glands are also described. The observed structures are discussed and compared with those described for other nematodes
Molecular diagnosis of Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle (Nematoda Aphelenchida Parasitaphelenchidae) in presence of polyphenols and other inhibitory compounds.
The pine wood nematode Bursaphelenchus xylophilus (Aphelenchida Parasitaphelenchidae) infects conifers, in particular pines, causing pine wilt disease. This nematode is considered a quarantine organism according to the EPPO and AQISQ guidelines. For this reason, several procedures for an affordable diagnostic test have been developed based on LAMP technique. In this work we shown how this technique behaved in presence of compounds that exert an inhibitory effect on DNA polymerases, a common problem that could be found in DNA preparations obtained from samples included in plant matrixes  LAMP technique was found able to detect presence of its specific DNA target in almost all cases studied but we found that the addiction of polyphenolic compounds present in some woody matrixes to DNA preparations could affect significantly on the sensibility of diagnostic test, while resinous material had a lesser influence on amplification
Autocontamination trap with entomopathogenic fungi: a possible strategy in the control of Rhynchophorus ferrugineus (Olivier) (Coleoptera Curculionidae)
An experimental autocontamination trap was devised to infect Rhynchophorus ferrugineus (Olivier), the Red Palm Weevil, adults with entomopathogenic fungi. The aim was to develop an autocontamination device to support integrated R. ferrugineus control programs. In laboratory bioassays, the delivery system successfully attracted, infected and released weevil adults after they contacted cereal substrata inoculated with indigenous strains of Beauveria bassiana (Balsamo- Crivelli) Vuillemin and Metarhizium anisopliae (Metchnikoff) Sorokin. Tests carried out with the experimental traps showed that M. anisopliae was the more virulent pathogen, causing 75% cumulative mortality in adults, while B. bassiana gave a 45% cumulative mortality. Infectivity of M. anisopliae was not affected by different cereal substrata, i.e. wheat and rice, since curculionid cumulative mortality (95%) and treatment efficiency (95% Abbott) were very high on both of them and Red Palm Weevil LT50 was reached within the same time (15 days). Conidial persistence and germinability of M. anisopliae grown on the rice substratum were examined in field conditions inside traps located in sunny and shady positions in spring, summer and autumn. The results showed that the traps preserved fungal inoculum stability longer in spring and summer than in autumn. No significant difference in M. anisopliae conidial persistence was found between sunny and shady traps during the various seasons
Metarhizium anisopliae biopesticides and fungus isolates: control efficacy against Rhynchophorus ferrugineus (Olivier) (Coleoptera Dryophthoridae) on different contamination substrata.
The lack of biological insecticides based on Metarhizium anisopliae (Metsch.) Sorokin registered in Italy for the control of the Red Palm Weevil (RPW), Rhynchophorus ferrugineus (Olivier), prompted studies to evaluate the efficacy of two commercial products, Met52® and BioStormTM and of their fungal isolates, M. anisopliae (Man52) and (ManBS) respectively, against the adults. The virulence of the M. anisopliae strains (Man52) and (ManBS) was compared with that of an indigenous M. anisopliae (Man08/I05) strain obtained from R. ferrugineus specimens collected in the wild and that showed to be very virulent against the RPW in previous studies. In both tests the sublethal effects of the treatments on female reproductive potential were examined in relation to the infective substratum. Laboratory results indicated that the commercial formulations mixed directly into the soil were not active in transmitting the infection to RPW adults and in reducing female fecundity and fertility. Diversely the fungal M. anisopliae (ManBS), (Man52) and (Man08/I05) strains inoculated on a rice substratum caused over 80% mortality of the phytophagous. In particular, M. anisopliae (ManBS) and the M. anisopliae (Man08/I05) produced the highest mortality (100%), with LT50 e LT90 reached in 3 and 6 days respectively. M. anisopliae (Met52) strain instead led to 85% mortality of RPW specimens in 28-days but it took longer to reach LT50 (6 days) and LT90 (12 days). The reproductive potential of females infected with the fungal strains was also significantly reduced with respect to the control. This study indicates the possibility of using also M. anisopliae strains in use against other insects of agricultural importance, for the control of R. ferrugineus although their effectiveness is conditioned by the formulations and/or methods employed against the RPW
Inoculation experiments of Bursaphelenchus eremus Rühm (Goodey)(Nematoda Parasitaphelenchidae)on Quercus robur L.
Bursaphelenchus eremus Rühm (Goodey) occurs in declining oak forests of some European countries, althoughdata are lacking on the possibility of the nematode to colonize healthy trees. To evaluate the pathogenicity of thenematode, we carried out an inoculation test in Tuscany (central Italy) in 2007-2008: on May 2007, 32 Quercus robur L.plants (7 years old) were inoculated with an Italian isolate of B. eremus(IT37w) and 16 plants were maintained ascontrols. There were two inoculation sites on each plant: one immediately below the fresh top shoot and another 30 cmbelow the first site. All plants were kept outdoors under a zinc-coated cage covered with a cloth. After four months, 16inoculated plants and eight controls were randomly selected and each stem was cut into three parts, weighed, crushed ina grinder and subjected to Baermann funnel extraction. After 16 months, the remaining 18 inoculated and 6 controlplants were chosen and examined with the same procedure.Bursaphelenchus eremuswas obtained from the stems of all infected oak trees. The difference was in the numberof nematodes/g of fresh wood in the different plant portions both after four (F2,16=86.94) and 16 months (F2,18=400.71).The highest density was always recorded in the fresh top shoot tissue, while no nematode was obtained from the lowerstem portion. The RHS (relative host suitability) index value increased from 0.6 (4 months) to 2.1 (16 months) but itwas still too low to be accompanied by signs of wilting. Because of the resemblance between B. eremusand the PineWood Nematode, we suggest that further experimental studies are needed to evaluate the potential risk of thisnematode for different species of oaks common to the Mediterranean area, where the maximum summer temperaturesreach the optimal temperature range for B. eremusdevelopment
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