title: A new biopesticide from a local Bacillus thuringiensis var. tenebrionis (Xd3) against alder leaf beetle (Coleoptera: Chrysomelidae).
abstract: Use of chemical pesticides in agriculture harms humans, non-target organisms and environments, and causes increase resistance against chemicals. In order to develop an effective bio-pesticide against coleopterans, particularly against Agelastica alni (Coleoptera: Chrysomelidae) which is one of the serious pests of alder leaf and hazelnut, we tested the insecticidal effect of 21 Bacillus isolates against the larvae and adults of the pest. Bacillus thuringiensis var. tenebrionis-Xd3 (Btt-Xd3) showed the highest insecticidal effect based on screening tests. For toxin protein production and high sporulation of Xd3, the most suitable medium, pH and temperature conditions were determined as nutrient broth medium enriched with salts, pH 7 and 30 °C, respectively. Sporulated Btt-Xd3 in nutrient broth medium enriched with salts transferred to fermentation medium containing soybean flour, glucose and salts. After fermentation, the mixture was dried in a spray dryer, and spore count of the powder product was determined as 1.6 × 1010c.f.u. g-1. Moisture content, suspensibility and wettability of the formulation were determined as 8.3, 86% and 21 s, respectively. Lethal concentrations (LC50) of formulated Btt-Xd3 were determined as 0.15 × 105c.f.u. ml-1for larvae at laboratory conditions. LC50values were also determined as 0.45 × 106c.f.u. ml-1at the field condition on larval stage. Our results showed that a new bio-pesticide developed from B. thuringiensis tenebrionis (Xd3) (Btt-Xd3) may be valuable as a biological control agent for coleopteran pests.
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080, Trabzon, Turkey.
authors.forename: Ardahan
authors.initials: A
authors.lastname: Eski
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080, Trabzon, Turkey. idemir@ktu.edu.tr.
authors.forename: İsmail
authors.initials: İ
authors.lastname: Demir
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080, Trabzon, Turkey.
authors.forename: Kazım
authors.initials: K
authors.lastname: Sezen
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080, Trabzon, Turkey.
authors.forename: Zihni
authors.initials: Z
authors.lastname: Demirbağ
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000378:metabolism*; D001427:Bacterial Toxins / Q000378:metabolism* / Q000633:toxicity; D061046:Biological Control Agents / Q000378:metabolism* / Q000633:toxicity; D001517:Coleoptera / Q000187:drug effects*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007814:Larva / Q000187:drug effects; D013696:Temperature
chemical_list: D001427:Bacterial Toxins; D061046:Biological Control Agents
keywords: Agelastica alni; Bacillus thuringiensis; Bio-pesticide; Spray drying