Improved control of Frankliniella occidentalis on greenhouse pepper through the integration of Orius sauteri and neonicotinoid insecticides

Frankliniella occidentalis (Thysanoptera: Thripidae) is a notorious pest of horticultural crops, against which the predator Orius sauteri or neonicotinoid insecticides are commonly used in control programmes. Here, we carried out a series of indoor acute toxicity tests and a risk assessment of eight neonicotinoid insecticides (imidacloprid, nitenpyram, acetamiprid, thiacloprid, thiamethoxam, clothianidin, dinotefuran and flupyradifurone) for O. sauteri and F. occidentalis. For O. sauteri, the LC50 values of acetamiprid and flupyradifurone were 12.75 and 9.24 mg a.i. L-1, respectively, and their hazard quotients were <= 2. Their toxicities to F. occidentalis were in a similar range. When LC20 of acetamiprid or flupyradifurone was applied to the pest, predator or both, predation ability was slightly reduced with flupyradifurone (37, 59 and 18, respectively) having less impact compared to acetamiprid (18, 21 and 10, respectively). Furthermore, we performed a greenhouse efficacy trial which involved the selected neonicotinoids acetamiprid and flupyradifurone as well as O. sauteri. Our results showed that integrated pest management, i.e. the application of half the amount of O. sauteri together with low doses (LC20) of acetamiprid or flupyradifurone, significantly reduced the pest with 76% and 75%, respectively, during the trial time, similar to the biocontrol treatment and significantly better than for chemical control alone. The cost of the integrated pest control strategy was similar to chemical control alone and lower than for biocontrol, indicating its potential as an economically feasible thrips control strategy, with reduced environmental risks compared to using chemicals only.

Automated summary

This study showed that integrated pest management using neonicotinoid insecticides and the predator Orius sauteri effectively reduced the population of the thrips pest on horticultural crops. The cost of this integrated strategy was similar to chemical control alone and lower than biocontrol, indicating its potential as an economically feasible and environmentally friendly pest control method.