3 years ago

Synergism to acaricides in resistant Neoseiulus californicus (Acari: Phytoseiidae), a predator of Tetranychus urticae (Acari: Tetranychidae)

Tetranychus urticae Koch is one of the most important phytophagous mite species worldwide, and Neoseiulus californicus (McGregor) is the main predatory mite species marketed for control of this pest in Brazil. The present study aimed to evaluate the toxicity of acaricides on both prey and predator mites and to assess mechanisms of resistance to acaricides in the predator. Concentration-response curves for the mite populations were established using the acaricides abamectin, chlorfenapyr, diafenthiuron, spiromesifen and fenpyroximate. Acaricide field dose effect on predator survival was also assessed. Additionally, synergism of PBO, TPP and DEM to fenpyroximate and chlorfenapyr was performed on the predator to preliminarily assess the involvement of detoxification enzymes on their toxicities. Ovicidal effects of acaricides were also evaluated on N. californicus eggs. Abamectin was the most toxic acaricide for both T. urticae (LC50 varying from 0.02 to 0.24 mg/L) and N. californicus (LC50 varying from 3.92 to 4.94 mg/L). Chlorfenapyr, diafenthiuron, fenpyroximate and spiromesifen are promising acaricides for the integrated management of T. urticae in combination with N. californicus. However, spiromesifen efficacy is stage dependent. Resistance of N. californicus to chlorfenapyr (RR50 = 14.69-times) and fenpyroximate (RR50 = 113.96-times) was observed for Bonito and Brejão populations, respectively. Synergism of chlorfenapyr toxicity in both N. californicus populations suggested an involvement of CYP450-dependent monooxygenases in the resistance, while these and esterases seem to be involved in the resistance to fenpyroximate. Survival of N. californicus was reduced to zero in a maximum of 12 h, to abamectin only. Excepting abamectin, the other acaricides must have their use encouraged regarding chemical-biological control association.

Publisher URL: www.sciencedirect.com/science

DOI: S0261219417303812

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.