Sammanfattning

BACKGROUND The pine weevil (Hylobius abietis) is a major forest regeneration pest causing high levels of seedling mortality and economic losses. Current management relies on silviculture, stem coatings and insecticides. Here we evaluated for the first time the effects of Bacillus thuringiensis (Bt) strains on H. abietis adults: two producing the Coleoptera-targeted toxins Cry3Aa (Bt tenebrionis NB-176) and Cry8Da (Bt galleriae SDS-502), and one producing the Diptera-targeted Cry10A (Bt israelensis AM65-52). Choice and nonchoice assays using individual and mixtures of Bt formulations, containing these strains respectively, were conducted.RESULTS We found that Bt had toxic and lethal effects on H. abietis, but effects varied with strain and formulation concentration. The Diptera-targeted Bt israelensis had the most negative effects on weevil weight, feeding and mortality (70-82% feeding reduction, 65-82% greater mortality than control), whereas the effect was lower for the Coleoptera-specific Bt tenebrionis (38-42%; 37-42%) and Bt galleriae (11-30%; 15-32%). Reduced weevil feeding was observed after 3 days, and the highest mortality occurred 7-14 days following Bt exposure. However, we found no synergistic toxic effects, and no formulation combination was better than Bt israelensis alone at reducing consumption and survival. Also, pine weevils were not deterred by Bt, feeding equally on Bt-treated and non-Bt treated food.CONCLUSION There is potential to develop forest pest management measures against H. abietis that include Bt, but only the Diptera-targeted Bt israelensis would provide effective seedling protection. Its Diptera-specificity may need reconsideration, and evaluation of other Bt strains/toxins against H. abietis would be of interest.

Nyckelord

biopesticides; forest pest; forest regeneration; insecticidal toxins; pest management; plant protection

Publicerad i

Pest Management Science
2021, Volym: 77, nummer: 3, sidor: 1303-1315
Utgivare: JOHN WILEY AND SONS LTD

SLU författare

• Tudoran, Amelia

  • Institutionen för ekologi, Sveriges lantbruksuniversitet
    
  • Universitatea de Ştiinţe Agricole şi Medicină Veterinară Cluj-Napoca

• Nordlander, Göran

  • Institutionen för ekologi, Sveriges lantbruksuniversitet
    

• Puentes, Adriana

  • Institutionen för ekologi, Sveriges lantbruksuniversitet
    

Associerade SLU-program

SLU Nätverk växtskydd


UKÄ forskningsämne

Skogsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1002/ps.6144

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/109024