scholarly journals STRATEGIE INNOVATIVE PER IL CONTROLLO DI ZANZARE, VETTORI DI ORGANISMI PATOGENI

Author(s):  
Giuliano Gasperi

Mosquitoes are the most dangerous insect species being the vectors of the pathogens causing the most widespread diseases as Malaria, Dengue fever, Chikungunya, West Nile fever, Yellow fever, Zika. Several species of the Anopheles, Aedes and Culex are responsable for millions of human infections causing hundreds of thousands of deaths per year. This causes dramatic socio-economic and health consequences, especially in developing countries. Harmful insects are controlled using chemical insecticides which cause insecticide resistance and environmental pollution, due to long term use. In the second half of the 20th century, new insect environmentally safe control stategies were been developed, based on the insect’s reproductive behaviour. Notably, the Sterile Insect Technique (SIT) has been successfully applied against some dipteran pest species in several regions of the World. It drived several research efforts to increase our knowledge of the biology of the harmful species. SIT improvements have been also achieved with several molecular biology approaches and transgene technologies such as the innovative RIDL, cytoplasmic incompatibility (CI) and gene drive.

2006 ◽  
Vol 33 (6) ◽  
pp. 467 ◽  
Author(s):  
Carlos Calvete ◽  
Enrique Pelayo ◽  
Javier Sampietro

The European wild rabbit (Oryctolagus cuniculus) is an introduced pest species in Australia and New Zealand. Rabbits have a devastating negative impact on agricultural production and biodiversity in these countries, and Rabbit Haemorrhagic Disease (RHD) is currently included in control strategies for rabbit populations. On the other hand, the European wild rabbit is a key native prey species in the Iberian Peninsula. Since the arrival of RHD, however, rabbit populations have undergone dramatic decreases and several predator species at risk of extinction are currently dependent on the rabbit population density. Therefore, from the point of view of biodiversity conservation, evaluating habitat correlates and trends of rabbit populations after the first RHD epizootic is of great interest to improve the long-term control or promotion of wild rabbit populations. We estimated the relationship between habitat factors and long-term population trends as well as the relationships between habitat factors and rabbit abundance 2 and 14 years after the arrival of RHD in several Iberian rabbit populations. We observed that only 26% of surveyed populations seemed to experience an increase in rabbit abundance over the last 12 years and that this increase was higher in the low-rabbit-abundance areas of l992, leading to high rabbit abundance in 2004. Our results suggested that short- and long-term impacts of RHD were related to habitat quality. The initial impact of RHD was higher in more suitable habitats, but increasing long-term population trends were positively related to good habitat quality.


2010 ◽  
Vol 76 (11) ◽  
pp. 3514-3520 ◽  
Author(s):  
Nicolas Radomski ◽  
Emmanuelle Cambau ◽  
Laurent Moulin ◽  
Sophie Haenn ◽  
R�gis Moilleron ◽  
...  

ABSTRACT The environment is the likely source of most nontuberculous mycobacteria (NTM) involved in human infections, especially pulmonary, skin, and soft tissue infections. In order to measure the prevalence of NTM in different aquatic ecosystems, we tried to standardize the culture methods used for surface water testing since many procedures have been described previously. Cultivation of mycobacteria requires long-term incubation in rich media and inactivation of rapidly growing microorganisms whose growth impedes observation of mycobacterial colonies. Consequently, the two criteria used for evaluation of the methods examined were (i) the rate of inhibition of nontarget microorganisms and (ii) the efficiency of recovery of mycobacteria. We compared the competitive growth of Mycobacterium chelonae and M. avium with nontarget microorganisms on rich Middlebrook 7H11-mycobactin medium after treatment by several chemical decontamination methods that included acids, bases, detergent, or cetylpyridinium chloride (CPC) with and without an antibiotic cocktail, either PANTA (40 U/ml polymyxin, 4 μg/ml amphotericin B, 16 μg/ml nalidixic acid, 4 μg/ml trimethoprim, and 4 μg/ml azlocillin) or PANTAV (PANTA plus 10 μg/ml vancomycin). Our results showed that treatment for 30 min with CPC (final concentration, 0.05%) of water concentrated by centrifugation, followed by culture on a rich medium supplemented with PANTA, significantly decreased the growth of nontarget microorganisms (the concentrations were 6.2 � 0.4 log10 CFU/liter on Middlebrook 7H11j medium and 4.2 � 0.2 log10 CFU/liter on Middlebrook 7H11j medium containing PANTA [P < 0.001]), while the effect of this procedure on NTM was not as great (the concentrations of M. chelonae on the two media were 7.0 � 0.0 log10 CFU/liter and 6.9 � 0.0 log10 CFU/liter, respectively, and the concentrations of M. avium were 9.1 � 0.0 log10 CFU/liter and 8.9 � 0.0 log10 CFU/liter, respectively). We propose that this standardized culture procedure could be used for detection of NTM in aquatic samples.


Oryx ◽  
2017 ◽  
Vol 52 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Ann K. Sakai ◽  
Stephen G. Weller ◽  
Weigang Yang ◽  
Susan Ching Harbin ◽  
Talia Portner ◽  
...  

AbstractWe report on how a long-term study of the reproductive biology of the Critically Endangered Schiedea adamantis (Caryophyllaceae), one of Hawai‘i's rarest plant species, was leveraged for conservation purposes. Our major goals were to provide seeds with the greatest genetic variation possible for reintroduction and to ensure that both female and hermaphroditic plants of this wind-pollinated species were reintroduced in a manner that maximized both outcrossing and seed production. Schiedea adamantis was one of the first Hawaiian plant species listed under the Endangered Species Act (USA). The species has been studied intensively to test hypotheses addressing the evolution of breeding systems. Information on outcrossing levels and the extent of inbreeding depression was integrated into ongoing reintroduction efforts. Population size peaked in 1994, when 267 flowering individuals were found on Lē‘ahi (Diamond Head Crater). By 2016 only 17 flowering individuals were present, with drought and invasive species being possible causes of this decline. Reintroduction attempts in 1998 using genetically diverse seeds were unsuccessful because of drought and a lack of sufficient supplemental irrigation. Additional reintroduction attempts in 2012 and 2014 were more successful because of increased supplemental irrigation. Plants used in reintroductions represent genotypes long since absent in the natural population, and may contain the genetic variability essential for evolutionary responses to climate change and the spread of invasive species. The destruction of many plants reintroduced in 2015 and 2016 by a fire in March 2016 highlights the need for additional restoration areas at Lē‘ahi and elsewhere, and storage of seeds for future use.


1992 ◽  
Vol 2 (2) ◽  
pp. 123-129 ◽  
Author(s):  
S. M. Evans ◽  
F. J. C. Fletcher ◽  
P. J. Loader ◽  
F. G. Rooksby

SummaryThe avifauna of Western Samoa is dominated by indigenous species, including several endemic ones. They are primarily birds of the rainforest and, since the islands have already suffered severe loss of this habitat and there is likely to be increased pressure on it in the future, their long-term prospects are not good. At present, introduced, non-native birds are not a threat to indigenous species, being confined largely to urban habitats, and there is little interaction with forest species. Several indigenous species exploit manmodified habitats, however, and it is possible that, as has occurred elsewhere, some of them may adapt fully to urban life.


2018 ◽  
Vol 182 (18) ◽  
pp. 516-516 ◽  
Author(s):  
Lena-Mari Tamminen ◽  
Helena Fransson ◽  
Madeleine Tråvén ◽  
Anna Aspán ◽  
Stefan Alenius ◽  
...  

In 2007, human infections with a hypervirulent strain of verocytotoxin-producing Escherichia coli O157:H7 increased in Sweden and especially in the Halland County. A connection between the cases and a local beef cattle farm with an on-farm abattoir and meat processing plant was established. In this observational study the control measures implemented on the infected farm and the dynamics of infection in the herd are described. In May 2008, when measures were initiated and animals put to pasture, the prevalence of positive individuals was 40 per cent and 18 carcasses out of 24 slaughtered animals were contaminated. During summer the monthly prevalence of positive carcasses varied between 8 and 41 per cent and at turning-in 22 out of 258 individually sampled animals were shedding the pathogen. After January 2009 no positive carcasses were found at slaughter and follow-up samplings of environment and individuals remained negative until the study period ended in May 2010. The results indicate that on-farm measures have potential to reduce the prevalence of the pathogen in a long-term perspective. However, as self-clearance cannot be excluded the effectiveness of the suggested measures needs to be confirmed.


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 852
Author(s):  
Anders Aak ◽  
Morten Hage ◽  
Heidi Heggen Lindstedt ◽  
Bjørn Arne Rukke

Pest management strives to be an efficient, yet healthy and environmentally safe control method, and the use of poisoned bait often fulfils these criteria. In the present study, we show that bait with indoxacarb as the active ingredient is highly efficient for controlling Ctenolepisma longicaudata (Escherich, 1905) and two of its relatives, Lepisma saccharina (Linnaeus, 1758) and Ctenolepisma calva (Ritter, 1910). Applying small bait droplets (size ~10 mg) along the walls of several types of buildings, at no more than 0.5 to 1.0 g bait per 100 m2, was a cost-efficient and safe strategy for the knockdown and eradication of C. longicaudata. During field experiments, the demography changed from an initial mixture of different stages to total dominance of early instars preceding the population collapse. Poisonous bait outcompeted mass-trapping with sticky-traps and conventional insect spray treatment for the efficient control of C. longicaudata in apartments. Different droplet densities (1 vs. 0.5/m2) and active ingredients (indoxacarb vs. clothianidin) did not have different effects in field experiments. These results show that poisoned bait is a highly relevant tool for managing C. longicaudata and potentially against other silverfish infestations.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1692 ◽  
Author(s):  
Paolo Magni ◽  
Serena Como ◽  
Maria Flavia Gravina ◽  
Donghui Guo ◽  
Chao Li ◽  
...  

A comprehensive set of physicochemical variables in near-bottom water and surface sediments, as well as the soft-bottom macrozoobenthic assemblages were investigated at six sites across the Yundang Lagoon (Southeast China) in November 2012. This lagoon was severely damaged in the 1970s due to domestic and industrial pollution and land reclamation and underwent a massive restoration effort over the past 30 years. Our objectives were to: (1) assess the current trophic and environmental condition of the lagoon; (2) investigate the pattern of spatial variation in the macrozoobenthic assemblages; and (3) assess the benthic recovery in relation to the main environmental gradients and the presence of invasive alien species. Nutrient, chlorophyll-a, biological oxygen demand (BOD5), chemical oxygen demand (CODMn), and total organic carbon (TOC) concentrations were lower than those reported in previous decades, yet organically-enriched conditions occurred at an inner site. From azoic conditions in the 1980s and a few benthic species reported prior to this study, we found a significant increase in benthic diversity with 43 species heterogeneously distributed across the lagoon. The invasive bivalve Mytilopsis sallei was the dominant species, which was associated with the richest benthic assemblage. However, M. sallei is a pest species, and its spatiotemporal distribution should be carefully monitored. These results highlight the central role of the macrozoobenthos in providing important ecological information on the current status of the Yundang Lagoon and as an effective biological tool to follow the recovery’s progress and the future evolution of this highly valued ecosystem.


Crop protection materials and techniques can increase productivity by preventing losses of yield or quality due to invading pests and by increasing the efficiency of men and machines. Spectacular advances have been made during the last 40 years in the availability of new highly active and relatively efficient chemicals which are reliable, safe, easy to use and cheap. Consequently, needs and opportunities for further new chemicals have slowed up in the last few years, while the costs of discovering and developing them have soared. Despite this agriculturally favourable situation, losses of productivity due to pests are higher than they need be. This is particularly so in after-harvest losses due to pest attacks which are still much too high in many crops and many countries. Increased productivity by better crop protection in the 1980s will demand better post-harvest protection of crops, more use of chemicals on an area basis, and spray programmes against a wider range of pest species. Early preventive usage should also increase, with less reliance on partial late cures. Most of the changing needs of individual farms in the 1980s can be met by the use of existing or forthcoming chemicals alone or in mixtures, or by special formulations or methods of use. As long as the chemical industry is not unduly hampered by irrational fears concerning the human environment, or long-term survival of agricultural soils, or the human race, it will continue to produce still more chemicals to combat existing and new agricultural problems, and should be encouraged to do so. One must, however, doubt whether non-chemical methods as we now know them will make more than a minor added contribution.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Melanie J. Dixon ◽  
Peter J. Shaw

Watercress releases phenethyl isothiocyanate (PEITC) upon wounding as a defence against herbivores. PEITC levels released from watercress farms are elevated due to cropping, washing, and processing and are thought to lead to adverse effects onGammarus pulexin chalk streams. This study elucidates the sublethal effect of PEITC on reproductive behaviour ofG. pulex, employingex situtests to investigate the disruption of precopular pairing under conditions simulatingin situexposure. Mean time to separation of precopular pairs was 89 ± 6 minutes for watercress wash water (1 g watercress per litre water) and 81 ± 15 minutes for pure PEITC (1 μL/L). Re-exposure to watercress wash water to simulate the pulsed operation at a watercress farm did not alter behavioural response. The repeated interruption of reproductive behaviour underin situconditions would impair long-term reproductive success and could explain in part low abundance ofG. pulexdownstream of watercress farms.


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