Passos D A, Silva-Torres C S A, Siqueira H A A
Departamento de Agronomia - Entomologia, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos 52171-900, Recife - PE, Brazil.
Bull Entomol Res. 2020 Feb;110(1):96-105. doi: 10.1017/S0007485319000300. Epub 2019 Jun 13.
Diamides have been used worldwide to manage the diamondback moth (DBM), Plutella xylostella L. (Lepidoptera: Plutellidae), however some strains showed resistance to these molecules. Also, pheromone traps could be used to manage this pest, hence reducing the use of insecticides in the field. Resistant DBM strains may have biological disadvantages in comparison to susceptible strains in areas without sprays, including reduction in fitness or behavioral changes. Therefore, the aim of this study was to investigate whether DBM strains resistant to chlorantraniliprole showed adaptive costs that could alter male attraction to the sex pheromone, in comparison to susceptible strains in the laboratory and semi-field conditions. First, the LC1, LC10, LC25, and LC50 of DBM to chlorantraniliprole were established, which were 0.003, 0.005, 0.007, and 0.011 mg a.i. liter-1, and 5.88, 24.80, 57.22, and 144.87 mg a.i. liter-1 for the susceptible and resistant strains, respectively. Development and reproduction of DBM strains subjected to those concentrations were compared. Later, male response to the sex pheromone was investigated in a Y-tube in the laboratory and in a greenhouse to pheromone traps. Resistant DBM strain showed an adaptive cost in comparison to the susceptible strain that can result in a delay in population growth in the field when selection pressure is absent. Conversely, resistant males have no olfactory response alteration in comparison to susceptible males, consistently at 3 (P = 0.6848) and 7 days (P = 0.9140) after release, suggesting that pheromone traps continue to be a viable alternative to manage DBM in an IPM system.
双酰胺类药剂已在全球范围内用于防治小菜蛾，小菜蛾学名Plutella xylostella L.（鳞翅目：菜蛾科），然而一些品系对这些药剂表现出抗性。此外，性诱捕器可用于防治这种害虫，从而减少田间杀虫剂的使用。与未施药地区的敏感品系相比，抗性小菜蛾品系可能具有生物学劣势，包括适应性降低或行为改变。因此，本研究的目的是调查与实验室和半田间条件下的敏感品系相比，对氯虫苯甲酰胺具有抗性的小菜蛾品系是否表现出适应性代价，从而改变雄蛾对性信息素的吸引力。首先，确定了小菜蛾对氯虫苯甲酰胺的LC1、LC10、LC25和LC50，敏感品系分别为0.003、0.005、0.007和0.011毫克有效成分/升，抗性品系分别为5.88、24.80、57.22和144.87毫克有效成分/升。比较了经受这些浓度处理的小菜蛾品系的发育和繁殖情况。随后，在实验室的Y型管中和温室中对性诱捕器，研究了雄蛾对性信息素的反应。与敏感品系相比，抗性小菜蛾品系表现出适应性代价，在没有选择压力的情况下，这可能导致田间种群增长延迟。相反，与敏感雄蛾相比，抗性雄蛾在释放后3天（P = 0.6848）和7天（P = 0.9140）时嗅觉反应没有改变，这表明在综合防治系统中，性诱捕器仍然是防治小菜蛾的可行选择。
