Comparison of three Amblydromalus limonicus populations regarding their potential to overcome abiotic resistance of Austrian ecosystems under climate warming scenarios

Abstract: Most introductions of alien species do not result in invasions, which are mainly attributed to the high abiotic resistance of native ecosystems. The use of alien biocontrol agents and climate warming, however, may create ideal thermal conditions to overcome the abiotic resistance of native ecosystems resulting in the establishment and spread of alien species. The alien predatory mite Amblydromalus limonicus might be such a candidate, which can be legally used in Austria as greenhouse biocontrol agent against thrips since 2015. We compared three populations for their potential to overcome the abiotic resistance of native ecosystems: KO = population from the commercial producer Koppert, SP = alien population established in Spain since 2011, NZ = native population collected 2014 in Auckland, New Zealand. Cold-tolerance seemed to be a species-specific trait, so that we used their performance at higher temperatures (survival, juvenile development and oviposition from 15 to 35 °C in 5 °C steps) for population comparison. Irrespective of population, at 35 °C no egg and no female survived. Juvenile survival was high between 30 and 15 °C and was neither affected by temperature nor population. Independent of population, juvenile development was an inverse function of temperature, and female survival over 10 days decreased with increasing temperatures. Egg production increased with increasing temperatures until 25 °C and dropped at 30 °C. Females of SP produced more eggs at 25 and 30 °C than KO and NZ females. Thus, we concluded that the SP population has the best options to invade Austrian predatory mite communities because of its higher reproductive potential at high temperatures compared to the other populations.Abstract only