Systemic grass-endophytes of the genus Epichloë symbiotically
infect the above-ground plant parts of many grass species, where they
produce alkaloids in a grass- and endophyte-specific manner that are
toxic or deterrent to herbivores. An increasing number of studies show
cascading negative effects of endophyte-derived alkaloids that extend to
higher trophic levels, harming beneficial insects, including those that
control aphid populations. Lacewings are one of the major biological
aphid controls, and are especially resistant to insecticides and
pollutants, but their susceptibility to endophyte infection in the food
chain has never been studied. Our study found variability in aphid
population growth depending on the endophyte-grass chemotype, where
aphid population growth was lowest on chemotypes known for producing
high amounts of loline alkaloids. We also showed that larval and pupal
development and mortality of the Common Green Lacewing (Chrysoperla carnea)
was, in a non-choice experiment, not affected by endophyte infection in
the food chain. This is a first indication that lacewings might be
resistant to endophyte-derived alkaloids and could be robust biocontrol
agents when applied together with endophyte-infected grass, possibly
replacing chemical pesticides.