Effects of Pirimiphos-Methyl on Non-Target Invertebrates

The effects of pirimiphos-methyl have previously been assessed on blood-sucking insect species, pollinating insects, and target crop pest species. The sensitivity of non-target zoophagous and saprophage species to this insecticide remains largely unstudied. In laboratory conditions, we assessed the susceptibility of 43 species of invertebrates to pirimiphos-methyl. The most tolerant species to this insecticide were <i>Pyrrhocoris apterus</i> (LC₅₀ measured over 60 mg/m²), <i>Cylindroiulus truncorum</i>, <i>Pterostichus niger</i>, <i>Harpalus rufipes</i>, <i>Lithobius forficatus</i>, and <i>Carabus hortensis</i> (LC₅₀ ranged from 25 to 50 mg/m²). Average tolerance to pirimiphos-methyl was displayed by <i>Ophonus rufibarbis</i>, <i>Teuchestes fossor</i>, <i>Silpha carinata</i>, <i>Badister sodalis</i>, <i>Rugilus rufipes</i>, <i>Phosphuga atrata</i>, <i>Porcellio laevis</i>, <i>Pterostichus oblongopunctatus</i>, <i>Aphodius foetens</i>, <i>Lasius fuliginosus</i>, <i>Oxypselaphus obscurus</i>, <i>Platydracus fulvipes</i>, <i>Myrmica ruginodis</i>, <i>Xantholinus tricolor</i>, and <i>Megaphyllum</i> sp. (LC₅₀ for those species ranged from 12 to 24 mg/m²). Higher sensitivity to this insecticide was seen for <i>Amara nitida</i>, <i>Leistus ferrugineus</i>, <i>Harpalus xanthopus winkleri</i>, <i>Philonthus nitidus</i>, <i>Pterostichus melanarius</i>, <i>Harpalus latus</i>, <i>Limodromus assimilis</i>, <i>Philonthus decorus</i>, <i>Tachinus signatus</i>, <i>Ponera coarctata</i>, <i>Carabus convexus</i>, <i>Philonthus coprophilus</i>, <i>Philonthus laevicollis</i>, <i>Platydracus latebricola</i>, <i>Labia minor</i>, and <i>Carabus granulatus</i> (LC₅₀ for those species ranged from 6 to 12 mg/m²). The greatest sensitivity to pirimiphos-methyl was observed in <i>Hister fenestus</i>, <i>Drusilla canaliculata</i>, <i>Bisnius fimetarius</i>, <i>Oxytelus sculptus</i>, <i>Lasius niger</i>, and <i>Lasius flavus</i> (LC₅₀ ranged from 0.4 to 6 mg/m²). We found a relationship between the parameters of bodies of invertebrates (the average body length and dry body mass) and sensitivity to pirimiphos-methyl. With an increase in body sizes of invertebrates, the tolerance to the insecticide increased (per each mm of body length, LC₅₀ increased by 0.82 mg/m² on average). We identified no relationship between the trophic specialization and sensitivity to the insecticide.