25 research outputs found
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A new method to assess the acute toxicity toward honeybees of the abrasion particles generated from seeds coated with insecticides
Abstract
Background: Large amounts of insecticide-containing dusts produced from abrasion of the seed dressing can be
released into the atmosphere during sowing operations. Neonicotinoid pesticides, introduced in the 1990s for several
crops, are the leading products for seed-coating treatments in many countries. Neonicotinoid containing dusts can
be efectively intercepted by bees in fight over the sowing feld, inducing lethal acute efects, so that restrictions in
the use of the main neonicotinoids have been adopted in the European Union. This led to the consequent introduction of replacement insecticides for seed-coating, i.e. methiocarb and thiacloprid, despite the lack of information on
both the toxicity and the exposure scenarios for honeybees.
Results: In this study, a laboratory apparatus was developed in order to quantify the toxicity of the dusts produced
from the abrasion of the seed coating. This quantifcation is based on (i) an airstream transporting coating particles
into an exposure chamber; (ii) exposure of bees to reproducible and measurable concentrations of insecticide, and
(iii) direct measurement of the exposure dose on single bees. The method allowed us to perform in vivo experiments
of honeybee exposure to provide toxicity data in more realistic exposure conditions. In fact, the formulation rather
than the active principle alone can be tested, and the exposure is through dusts rather than a solution so that specifc
absorption behavior can be studied in representative environmental conditions. The method was used to quantify
the acute toxicity (LD50) of dusts obtained from the abrasion of corn seeds coated with clothianidin, thiacloprid and
methiocarb.
Conclusions: Our results show that, surprisingly, the replacement insecticide methiocarb has a toxicity (LD50=421–
693 ng/bee) in the same order of magnitude as clothianidin (LD50=113–451 ng/bee) through this specifc exposure
route, while thiacloprid (LD50=16.9·103 ng/bee) has a signifcantly lower acute toxicity. Moreover, dusts containing
methiocarb and clothianidin show a signifcant increase in toxicity when, after exposure, bees are kept under high
humidity conditions. This suggests that the method here presented can be used to obtain complementary toxicity
data in the risk assessment procedure for the authorization of new seed-coating insecticides or new formulations.
Keywords: Systemic insecticides, Neonicotinoids, Methiocarb, Seed coating, Abrasion dusts, Honeybees, Pollinator
insects, Acute toxicity, Exposure measuremen
Improving the early detection of alien wood-boring beetles in ports and surrounding forests
International ports are generally considered the most likely points of entry for alien wood-boring beetles. A better understanding of the factors affecting their arrival and establishment at ports and their surrounding areas is of utmost importance to improve the efficacy and the cost-effectiveness of early detection programmes. Our work aimed at understanding how port size and the characteristics of the landscape surrounding the port, in terms of forest cover and forest composition, influence the occurrence of alien wood-boring beetles.
From May to September 2012, 15 Italian international ports and the surrounding forests were monitored with multi-funnel traps baited with a multi-lure blend (\u3b1-pinene, ethanol, ipsdienol, ipsenol, methyl-butenol), three in each port and three in forests located 3\u20135 km away from the port. We identified both alien and native Scolytinae, Cerambycidae and Buprestidae beetles.
Fourteen alien species, among which four are new to Italy, were trapped. Alien species richness was positively related to the amount of imported commodities at the port scale. Broadleaf forests surrounding ports received larger number of alien species than conifer forests. By contrast, total forest cover in the landscape surrounding ports was positively related to the occurrence of native but not alien species. The alien and native species richness was higher in the surrounding forests than in the ports.
Synthesis and applications. The simultaneous use of traps in ports with large volume of imported commodities and in their surrounding broadleaf forests can strongly increase the probability of alien wood-boring beetle interceptions. The identification of sites where the arrival and establishment of alien species is more probable, combined with an efficient trapping protocol, can substantially improve the efficacy of early detection. Similar approaches may be used in other countries as early warning systems to implement timely measures to eradicate or contain alien invasions at the European scale
Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes
Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening
Monitoring of the pine sawyer beetle Monochamus galloprovincialis (Olivier) (Coleoptera Cerambycidae) by pheromone traps
The pine sawyer beetle Monochamus galloprovincialis
(Olivier) (Coleoptera Cerambycidae)
gained importance as a pest in Europe after the introduction
in Portugal of the pine wood nematode Bursaphelenchus
xylophilus, the agent of pine wilt
disease. As the nematode is transmitted by the adult
beetles during both maturation feeding and oviposition,
effective methods of monitoring of the longhorn
beetle populations are needed for the surveillance of
the disease spread in Europe. Although in the last
years many studies focused on the efficacy of different
trapping methods, the general results are still controversial.
In this study, we compared the efficiency of
two trap types, cross-vane and multi-funnel, and two
attractive blends, a kairomonal lure (\u3b1-pinene, ipsenol
and methyl-butenol) and a commercial kit specific for
M. galloprovincialis (pheromone plus kairomonal
lure), in order to identify the trap/blend combination
more appropriate for the surveillance of the M.
galloprovincialis populations. Moreover, the trap efficiency
was tested also in a pine stand colonized by M.
galloprovincialis after a hailstorm and in a control
stand. The results showed that the multi-funnel traps
baited with the specific commercial kit was the most
effective combination. Interestingly, trap catch was
similar in the two pine stands, despite a different
density of the target species. As the trapping method
was effective also at low population density of M.
galloprovincialis, it may be adopted as a general tool
for beetle surveillance in the forest and at ports of
entry