Susceptibility of Cypriot Tuta absoluta populations to four targeted insecticides and control failure likelihood

Abstract

Tuta absoluta, known as the South American tomato pinworm, is one of the most disastrous pests of tomato cultivations, presently menacing tomato cultivations worldwide. In 2006, T. absoluta invaded Spain from South America. Since then, it was rapidly spread to most European, African and Asian countries. Such alien invasive species can minimize crop production, whereas the increasing use of insecticides raises various environmental concerns as well as on control costs, control failure and the toxicity to non‐target organisms. The S. American tomato pinworm is mostly controlled by chemical insecticides, and failure to control it is not a rare phenomenon. Resistance to numerous insecticides has been reported and is mainly due to the fact that farmers do not follow a sustainable resistance management scheme. Several examples have been reported from several countries where the tomato pinworm is present. In order to develop a successful insecticide resistance management (IRM) strategy for any major pest, one needs to identify the baseline toxicity to insecticides and then monitor susceptibility levels. In Cyprus, the current status of susceptibility levels to the main insecticides that are used to control T. absoluta has never been studied before. Herein, nine Cypriot populations of the pest were subjected to laboratory bioassays between 2016 and 2018 using the main insecticides applied against it. We found that the insecticides chlorantraniliprole and indoxacarb could not control the Cypriot T. absoluta populations anymore, with a resistance ratio (RR) >28 and 3–23, respectively. Furthermore, mortality achieved by those two insecticides was 20.6%–72% for chlorantraniliprole and 27.5%–78% for indoxacarb. However, the insecticides emamectin benzoate and spinosad are very effective, since mortality to both of them ranged between 99.5% and 100%.

Nesidiocoris tenuis in Burkina Faso: Distribution, predatory capacity and insecticide sensibility

“…Abamectin, emamectin benzoate, spinosad and spinetoram are effective against T. absoluta , confirming previous results (Bala et al, 2019; Michaelides et al, 2019), including those performed in the country (Sawadogo et al, 2020b). To preserve the efficacy of these active ingredients, appropriate resistance management systems must be set up, including rotation of molecules with different modes of action and implementation of alternative means of control (IRAC, 2011).…”

Insecticide susceptibility level and control failure likelihood estimation of Sub‐Saharan African populations of tomato leafminer: Evidence from Burkina Faso

“…Leaflets were then placed in a Petri dish containing moisten filter paper and sealed with parafilm. Five or six larvae were introduced in each Petri dish, stored at a temperature of 28 ± 3 °C and a relative humidity of 50 ± 15%, as described in Roditakis et al (2013a, b) and Michaelides et al (2019). A total of 32 larvae per insecticide concentration were tested: three Petri dishes containing five larvae and two Petri dishes containing six larvae were used.…”

Population structure and insecticide resistance status of Tuta absoluta populations from Turkey

“…Considering the high efficiency and very low frequency of the G275E mutation, spinosad seems to offer a good alternative for chemical control of T. absoluta in Turkey. Similarly, spinosad showed excellent efficacy against Cypriot populations of T. absoluta 75 . In addition, since spinosad showed no cross‐resistance to other widely used insecticides registered in T. absoluta control and resistance to spinosad has been known to decrease in the absence of selection pressure indicating the fitness cost of resistance development, 76 it should be implemented in resistance management programs.…”