Entomofauna e parassiti del mirto

Myrtle pests are mainly represented by Rhinchota homoptera and Thisanoptera. In particular, Saissetia oleae, Partenolecanium corni e Ceroplastes rusci are the most frequent species reported in Sardinia whereas Heliothrips haemorroidalis is a harmful pest in other Italian regions. Pest control in myrtle cultivations is possible only following the plant protection regulation of European organic agriculture. In fact, in Italy there currently are no conventional insecticides authorized for myrtle destined to liquor or essential oil production

La Lotta microbiologica a difesa delle sugherete. Risultati ottenuti in Sardegna

Si riporta una sintesi delle indagini condotte in sugherete della Sardegna sui principali lepidotteri defogliatori. Le specie che causano danni di un certo rilievo sono Lymantria dispar L. e Malacosoma neustria (L.), con infestazioni di tipo periodico, e Tortrix viridana L., con fluttuazioni di tipo temporaneo. La periodicità delle gradazioni di L. dispar, studiata con il conteggio delle ovature, ha avuto un’ampiezza variabile fra 11 e 5-6 anni nei diversi comprensori subericoli dell’Isola, probabilmente per le differenti condizione di conservazione degli equilibri naturali nei singoli ambienti indagati. Sono inoltre illustrati i risultati di prove di lotta microbiologica condotte contro questo defogliatore con preparati a base di Bacillus thuringiensis kurstaki. Dosi superiori a 30 miliardi di U.I. per ettaro hanno determinato elevate mortalità larvali (anche superiori all’80%) mentre la distribuzione di soli 16 miliardi di U.I./ha non ha garantito un’efficace protezione della vegetazione. I preparati microbiologici saggiati nel corso di 5 anni di sperimentazione non hanno avuto nessun effetto negativo diretto sull’entomofauna utile

Biological studies on Tomicus destruens (Wollaston) (Coleoptera Curculionidae Scolytinae): phenology, voltinism and sister broods.

Biology and behaviour of Tomicus destruens were investigated in Sardinian pine forest in order to define the seasonal pattern of trunk attacks by breeding adults, the number of annual generations, and the number of sister broods produced per female. The counting of maternal galleries made each month in trap trees shows that T. destruens colonizes the pine trunk in all the months between October and May with the highest infestation intensity in autumn followed by decreasing values. Female laid ca. 80 to 95 eggs per gallery in October-November and ca. 70 in the following months. Although the bark beetle’s reproductive activity extended for a period of 7-8 months, the flight of new adults was concentrated in a much shorter time period between May and June, when ca. 95% of the emergences occurred. The experiments have ruled out the possibility of a second annual generation. Even the earliest emerging adults, originating from eggs laid in October, were unable to mature their gonads and oviposit before the summer stasis. Tomicus destruens females can make up to four sister broods and lay a total of ca. 170 eggs throughout their life, without regeneration feeding in the shoots. The new knowledge provides information useful to calibrate well-timed interventions to control this dangerous pest by means of the trap tree technique

COMBINING TRANSLATION READTHROUGH INDUCING DRUGS AND NONSENSE MEDIATED DECAY PATWHAY INHIBITION TO THE CFTR RESCUE IN CYSTIC FIBROSIS CELL MODEL SYSTEM

Nonsense mutations affect 10% of patients with cystic fibrosis and produce a premature termination codon in CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) mRNA causing early termination of translation and leading to lack of CFTR function. A potential therapy for nonsense mutations provides the use of small molecules able to overcome the premature stop codon (PTC) by a readthrough mechanism that lead to synthesis a complete CFTR protein. Despite the good results obtained from this approach, TRIDs efficiency is considerably reduced by the poor amount of target transcript, that is the mRNA containing the PTC. The readthrough, indeed, does not occur on the totality of target transcripts because of their degradation due to the nonsense mediated decay pathway (NMD). This pathway provides the degradation of mRNA harboring premature stop codon to prevent the production of altered polypeptides. In contrast, the activity of this pathway interferes with the effectiveness of the readthrough drugs, limiting the mRNA concentration of the target protein. Thus, a promising strategy for nonsense mutation treatment is a combined use of readthrough agents and factors that attenuate the nonsense mRNA decay. By silencing the UPF1 mRNA/protein, the activity of the NMD pathway was reduced, in FRT cells CFTR W1282X. Alternatively, caffeine was used as specific inhibitor of the UPF1 activity, to increase the efficiency of readthrough molecules (NV848 and NV914) in FRT cells CFTRW1282X cells. In both cases, the combined treatment: NV848 or NV914/caffeine and NV848 or NV914/UPF1siRNA caused an increase of CFTRW1282X mRNA level followed by the rescue of the CFTR expression and functionality. However, unexpectedly, despite the higher CFTRW1282X mRNA level in caffeine treated samples, both expression and functionality CFTR rescue resulted slightly lower than the recovery achieved by UPF1 silencing. Our results indicate that modulation of NMD pathway, although still to be optimized, could be a promising approach in order to increase TRIDs effects in presence of stop mutations

Impiego del <i>Bacillus thuringiensis</i> Berl. nella lotta alla <i>Lymantria dispar</i> L. in boschi di<i>Quercus suber</i> L. 3: risultati della sperimentazione condotta nel 1992.

The study was carried out in a North Sardinian cork oak forest in 1992. To control the gypsy moth population three commercial preparations of B. thuringiensis subsp. kurstaki were applied by helicopter: Activator THK and Bactospeine at low volume and Foray 48B at ultra low volume, when 80-90% of the gypsy moth larvae were in 1st and 2nd instars. At 14d after treatment, Activator (applied at 5 l/ha) did not cause significant population reductions, while Bactospeine (applied at 32 B.I.U./ha) and Foray 48B (applied at 31.75 B.I.U./ha) caused average mortalities respectively of 40 and 53%. All preparations showed a good compatibility with the activity of the gypsy moth natural enemies. Smaller mortalities, compared with previous tests, seem to be related with the low average temperatures, between 13.9 and 16.8°C, of the post-treatment week which slowed down both feeding and metabolism of the larvae just when there was the largest amount of spores on the foliage

An Identification Method for Orifice-Type Restrictors Based on the Closed-Form Solution of Reynolds Equation

Even though the behavior of aerostatic bearings has for long been the topic of extensive research, there are still many aspects that require further investigation. Among these, the identification of the discharge coefficients is one the most crucial. This paper presents a hybrid method to identify the discharge coefficients of aerostatic bearing orifices. The method is termed as hybrid since it exploits experimental data and the equations of the analytical model of a circular and centrally fed aerostatic pad. The obtained results demonstrate the accuracy of the method. The proposed method further offers practical advantages compared to the conventional methods

When a threatened species becomes a threat: a key to reading the Habitats Directive based on occurrence and distribution of Cerambyx cerdo L. in Mediterranean urban and peri-urban areas

Abstract Cerambyx cerdo is a large saproxylic species included in the Annex IV of the European Habitats Directive as a 'priority species'. Although C. cerdo populations have shown a significant decline in size and distribution in central and northern European forests, in the Mediterranean basin it is often considered as a pest in urban and peri‐urban areas. Based on European legislations currently in use, we propose a simplified decision‐making flowchart that should be followed regarding the adoption of different control measures against severe C. cerdo infestations

Design and Analysis of an Aerostatic Pad Controlled by a Diaphragm Valve

Because of their distinctive characteristics, aerostatic bearings are particularly suitable for high-precision applications. However, because of the compressibility of the lubricant, this kind of bearing is characterized by low relative stiffness and poor damping. Compensation methods represent a valuable solution to these limitations. This paper presents a design procedure for passively compensated bearings controlled by diaphragm valves. Given a desired air gap height at which the system should work, the procedure makes it possible to maximize the stiffness of the bearing around this value. The designed bearings exhibit a quasi-static infinite stiffness for load variation ranging from 20% to almost 50% of the maximum load capacity of the bearing. Moreover, the influence of different parameters on the performance of the compensated pad is evaluated through a sensitivity analysi

Sustainable management of the vine mealybug in organic vineyards

The vine mealybug (VMB), Planococcus ficus, is a major grapevine pest worldwide, whose chemical control is often unsatisfactory due to its cryptic behavior, insecticide resistance and high fecundity rate. Recently, increasing restrictions have been applied to insecticides used for managing VMB. This review discusses sustainable VMB management strategies in organic viticulture. Pheromone-mediated mating disruption has been proved to be effective in both organic wine and table-grape vineyards. Biocontrol projects carried out through the release of parasitoids and/or predators have often provided inconclusive results, ranging from effective reduction of mealybug infestation to a marginal impact of parasitoids on VMB density. The latter outcome is likely due to constraints affecting the parasitoid activity, such as the disrupting activity of mealybug-tending ants and broad-spectrum insecticides, or untimely release of parasitoids. Ant suppression should be associated with the release of beneficial organisms, as mealybug-tending ants can severely affect the parasitoid activity. Cultural and physical control and the employment of entomopathogens and natural products mitigate the buildup of VMB populations, but they are not widely applied. VMB control in organic viticulture requires the integration of different strategies, as application of single control tools as a stand-alone treatment may not be effective, especially for high pest infestation. Future research to determine the density action threshold below which sustainable methods are effective and calibrate efforts in relation with pest infestation is needed. A multi-disciplinary approach is required to define the most appropriate sustainable control protocols in different environmental conditions and promote a further spread of organic viticulture