Optimizing application of entomopathogenic nematodes to manage large pine weevil, Hylobius abietis L. (Coleoptera:Curculionidae) populations developing in pine stumps, Pinus sylvestris

Hylobius abietis develops in stumps of recently felled coniferous trees, and adults emerge to feed on and kill young seedlings. Entomopathogenic nematodes applied to stumps containing late instar larvae and pupae can reduce the number of adults emerging. We tested the feasibility of reduced application rate and volume during a broader window of application in field trials in 2004 and 2005. Application at the standard rate of 3.5 million infective juveniles per stump suppressed the number of adults emerging by up to 79–85% relative to controls for Heterorhabditis downesi, 57–64% for Steinernema carpocapsae and 51–56% for S. feltiae. When the application rate was halved, only H. downesi gave a significant reduction in emergence (75–79%). Nematodes applied in April, May or June significantly reduced weevil populations, and application of nematode-killed insects in May was as effective as an aqueous suspension. A fourfold reduction in application volume from 500 to 125 ml per stump did not affect the percentage of weevils parasitized, and stump excavation revealed that even at the reduced volume, both S. carpocapsae (ambusher) and H. downesi (cruiser) parasitized weevils 40–49 cm from the bole and 40–49 cm below soil level. A higher percentage of larvae (60%) were infected than either pupae (36%) or callow adults (18%). Our trials show promise for expanding the use of entomopathogenic nematodes against pine weevil, as the standard application rate can be halved, and the volume reduced to 25% of the standard without significant loss of efficacy, and there is a wide window of opportunity for application, even when soil temperatures are as low as 9 °C

Optimizing application of entomopathogenic nematodes to manage large pine weevil, Hylobius abietis L. (Coleoptera:Curculionidae) populations developing in pine stumps, Pinus sylvestris

Hylobius abietis develops in stumps of recently felled coniferous trees, and adults emerge to feed on and kill young seedlings. Entomopathogenic nematodes applied to stumps containing late instar larvae and pupae can reduce the number of adults emerging. We tested the feasibility of reduced application rate and volume during a broader window of application in field trials in 2004 and 2005. Application at the standard rate of 3.5 million infective juveniles per stump suppressed the number of adults emerging by up to 79–85% relative to controls for Heterorhabditis downesi, 57–64% for Steinernema carpocapsae and 51–56% for S. feltiae. When the application rate was halved, only H. downesi gave a significant reduction in emergence (75–79%). Nematodes applied in April, May or June significantly reduced weevil populations, and application of nematode-killed insects in May was as effective as an aqueous suspension. A fourfold reduction in application volume from 500 to 125 ml per stump did not affect the percentage of weevils parasitized, and stump excavation revealed that even at the reduced volume, both S. carpocapsae (ambusher) and H. downesi (cruiser) parasitized weevils 40–49 cm from the bole and 40–49 cm below soil level. A higher percentage of larvae (60%) were infected than either pupae (36%) or callow adults (18%). Our trials show promise for expanding the use of entomopathogenic nematodes against pine weevil, as the standard application rate can be halved, and the volume reduced to 25% of the standard without significant loss of efficacy, and there is a wide window of opportunity for application, even when soil temperatures are as low as 9 °C

Suppression of the large pine weevil Hylobius abietis (L.) (Coleoptera: Curculionidae) in pine stumps by entomopathogenic nematodes with different foraging strategies

Hylobius abietis is the most important pest of reforestation in Northern Europe. Weevils develop in stumps of felled conifers and emerging adults feed on and kill young trees. In trials conducted in each of 3 years, entomopathogenic nematodes were applied around pine stumps containing late instar weevils. Since these immature weevils are sedentary and occur within stumps at varying depths in soil, it is predicted that nematodes with a cruise foraging strategy, such as Heterorhabditis spp., should be most effective. The three commercially available species used in our trials, H. megidis, Steinernema feltiae, and S. carpocapsae, have cruise, intermediate and ambush strategies, respectively. We also included the indigenous species H. downesi and a strain of S. feltiae isolated from an Irish coniferous forest. Heterorhabditis downesi suppressed emergence of adult weevils in 2 of 3 trials; and commercial S. feltiae and H. megidis NLH85 in 1 trial each. Stump excavation showed that H. downesi parasitized 55â63% of developing weevils; this was matched by H. megidis NLH85 and S. carpocapsae in 2 and 1 years, respectively. A higher proportion of larvae (46%) than of pupae (32%) or callow adults (30%) were parasitized by nematodes. All nematodes, including S. carpocapsae, parasitized weevils 40â49 cm from the bole of the stump and 30â39 cm below soil level. We conclude that heterorhabditids, particularly H. downesi, have greatest potential against pine weevils in stumps, but that a reputation as an ambush forager should not exclude a species such as S. carpocapsae from trials against sedentary subterranean insect pests

Environmental safety of entomopathogenic nematodes – Effects on abundance, diversity and community structure of non-target beetles in a forest ecosystem

The large pine weevil, Hylobius abietis, is a serious threat to reforestation in Europe that necessitates routine use of chemical insecticides. Application of entomopathogenic nematodes (EPN) to the coniferous tree stumps in which weevils breed has the potential to reduce the use of chemical pesticides. During field trials to assess the efficacy of nematodes against pine weevil, non-target beetles were also identified and quantified on 10 sites (14 trials). Nematodes were applied to stumps between June and July. Emergence traps captured beetles exiting from nematode-treated and untreated control stumps. Four trials were monitored in the months immediately following nematode application and ten were monitored the year after nematode application. A total of 65 species of non-target beetles were recovered, including 11 saproxylic species. We found no evidence of an effect of applied EPN on non-target beetle species richness, abundance, species richness per individual collected, or Shannon’s entropy (H’) either immediately or a year after nematode application, when more wood-specialists were recorded. As expected, there were marked differences between sites and/or tree species in the populations of non-target beetles recovered. These results indicate that when EPN are applied in a forest ecosystem to suppress H. abietis populations, the risk to non-target coleopteran populations must be considered negligible

Inundative pest control: How risky is it? A case study using entomopathogenic nematodes in a forest ecosystem

Entomopathogenic nematodes (EPN) are globally important inundative biological control agents. Their widespread use makes environmental risk assessment important, but very few comprehensive post-application risk assessments have been conducted for EPN. We apply a rigorous risk analysis procedure to the use of EPN applied in a forest ecosystem to suppress the large pine weevil (Hylobius abietis). In this synthesis, we provide a quantitative evaluation of five risk categories: (a) establishment, (b) dispersal, (c) host range, (d) direct non-target effects and (e) indirect non-target effects. A low level of risk was identified (35–51 out of a possible total of 125). Species exotic to the clear-fell forest ecosystem (Steinernema carpocapsae and Heterorhabditis downesi) were accorded a lower overall risk status than native species and strains (Steinernema feltiae), largely as a result of their shorter persistence in the target environment. We conclude that EPN are a low risk viable alternative control for pine weevil compared to the higher risk conventional control using pyrethroid or neonicotinoid insecticides

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

Pine weevils modulate defensive behaviour in response to parasites of differing virulence

Grooming and avoidance of contaminated areas are among the behavioural defences employed by animals against parasites. Antiparasite defence behaviour is costly in terms of time, energy and/or food foregone and therefore animals are expected to modulate their defences depending on the risk of attack and/or the severity of the symptoms caused.We tested the hypothesis that an insect host invests more in defence against more virulent (more likely to cause death) than less virulent parasites. We tested avoidance and grooming of adult pine weevils, Hylobius abietis, in response to infective juveniles of two species of entomopathogenic nematodes, the more virulent Steinernema carpocapsae and less virulent Heterorhabditis downesi. Weevils avoided feeding on a substrate contaminated with S. carpocapsae but not H. downesi. Weevils also groomed more when their bodies were contaminated with S. carpocapsae than either H. downesi or water. We also made direct observations of nematodes on weevils. When equal numbers of nematodes were applied to weevils more S. carpocapsae than H. downesi moved actively on the weevil’s cuticle. Thus, the differential response of weevils to the two nematode species can be explained by the weevils detecting the more aggressive behaviour of S. carpocapsae than H. downesi, which corresponds to a higher probability of death

Competencias en argumentación y uso de pruebas : 10 ideas clave

Incluye glosarioEl libro trata en las 5 primeras ideas la caracterización y elementos de los argumentos y el uso de las pruebas. En las 5 siguientes la argumentación en diferentes contextos: explicaciones causales, cuestiones sociocientíficas, argumentación oral y escrita y cómo promoverla y evaluarla en el aula. El libro esta dirigido al profesorado que se centra en que los alumnos razonen las respuestas.CataluñaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

Suppression of the large pine weevil Hylobius abietis (L.) (Coleoptera: Curculionidae) in pine stumps by entomopathogenic nematodes with different foraging strategies

Hylobius abietis is the most important pest of reforestation in Northern Europe. Weevils develop in stumps of felled conifers and emerging adults feed on and kill young trees. In trials conducted in each of 3 years, entomopathogenic nematodes were applied around pine stumps containing late instar weevils. Since these immature weevils are sedentary and occur within stumps at varying depths in soil, it is predicted that nematodes with a cruise foraging strategy, such as Heterorhabditis spp., should be most effective. The three commercially available species used in our trials, H. megidis, Steinernema feltiae, and S. carpocapsae, have cruise, intermediate and ambush strategies, respectively. We also included the indigenous species H. downesi and a strain of S. feltiae isolated from an Irish coniferous forest. Heterorhabditis downesi suppressed emergence of adult weevils in 2 of 3 trials; and commercial S. feltiae and H. megidis NLH85 in 1 trial each. Stump excavation showed that H. downesi parasitized 55â63% of developing weevils; this was matched by H. megidis NLH85 and S. carpocapsae in 2 and 1 years, respectively. A higher proportion of larvae (46%) than of pupae (32%) or callow adults (30%) were parasitized by nematodes. All nematodes, including S. carpocapsae, parasitized weevils 40â49 cm from the bole of the stump and 30â39 cm below soil level. We conclude that heterorhabditids, particularly H. downesi, have greatest potential against pine weevils in stumps, but that a reputation as an ambush forager should not exclude a species such as S. carpocapsae from trials against sedentary subterranean insect pests

Optimizing application of entomopathogenic nematodes to manage large pine weevil, Hylobius abietis L. (Coleoptera:Curculionidae) populations developing in pine stumps, Pinus sylvestris

Hylobius abietis develops in stumps of recently felled coniferous trees, and adults emerge to feed on and kill young seedlings. Entomopathogenic nematodes applied to stumps containing late instar larvae and pupae can reduce the number of adults emerging. We tested the feasibility of reduced application rate and volume during a broader window of application in field trials in 2004 and 2005. Application at the standard rate of 3.5 million infective juveniles per stump suppressed the number of adults emerging by up to 79–85% relative to controls for Heterorhabditis downesi, 57–64% for Steinernema carpocapsae and 51–56% for S. feltiae. When the application rate was halved, only H. downesi gave a significant reduction in emergence (75–79%). Nematodes applied in April, May or June significantly reduced weevil populations, and application of nematode-killed insects in May was as effective as an aqueous suspension. A fourfold reduction in application volume from 500 to 125 ml per stump did not affect the percentage of weevils parasitized, and stump excavation revealed that even at the reduced volume, both S. carpocapsae (ambusher) and H. downesi (cruiser) parasitized weevils 40–49 cm from the bole and 40–49 cm below soil level. A higher percentage of larvae (60%) were infected than either pupae (36%) or callow adults (18%). Our trials show promise for expanding the use of entomopathogenic nematodes against pine weevil, as the standard application rate can be halved, and the volume reduced to 25% of the standard without significant loss of efficacy, and there is a wide window of opportunity for application, even when soil temperatures are as low as 9 °C