Herbicide toxicity, selectivity and hormesis of nicosulfuron on 10 Trichogrammatidae (Hymenoptera) species parasitizing Anagasta ( = Ephestia) kuehniella (Lepidoptera: Pyralidae) eggs

ABSTRACTSelective agrochemicals including herbicides that do not affect non-target organisms such as natural enemies are important in the integrated pest management (IPM) programs. The aim of this study was to evaluate the herbicide toxicity, selectivity and hormesis of nicosulfuron, recommended for the corn Zea mays L. (Poaceae) crop, on 10 Trichogrammatidae (Hymenoptera) species. A female of each Trichogramma spp. or Trichogrammatoidea annulata De Santis, 1972 was individually placed in plastic test tubes (no choice) with a cardboard containing 45 flour moth Anagasta ( = Ephestia) kuehniella Zeller, 1879 (Lepidoptera: Pyralidae) eggs. Parasitism by these natural enemies was allowed for 48 h and the cardboards were sprayed with the herbicide nicosulfuron at 1.50 L.ha−1, along with the control (only distilled water). Nicosulfuron reduced the emergence rate of Trichogramma bruni Nagaraja, 1983 females, but increased that of Trichogramma pretiosum Riley, 1879, Trichogramma acacioi Brun, Moraes and Smith, 19...