Aphelinus abdominalis is a tiny creature that can have a big impact on a farm. The parasitoid wasp, about 1 cm long, attacks aphids in two ways. The wasp simply eats aphid eggs but also lays eggs in aphid eggs or aphid nymphs. The immature wasps later eat the aphid larvae from the inside out.
Researchers studied how these beneficial organisms are affected by thiacloprid, a neonicotinoid that was not included in the recent EU ban on the outdoor use of several related pesticides. They found that, like many wasps and bees, A. abdominalis is highly sensitive to neonicotinoid pesticides. When the pesticide was mixed with a fungicide (using the common practice of tank mixing agrochemicals), the mortality rates were much more significant. Given that most studies examine the effect of only one chemical on an organism at time, the effect of neonictinoids may be underestimated.
Source: Willow J, A Silva E Veromann, G Smagghe. 2019. Acute effect of low-dose thiacloprid exposure synergised by tebuconazole in a parasitoid wasp. PLOS ONE. Volume 14. Issue 2: e0212456.
— Janet Wallace