Resistance to the rice leaf bug,Trigonotylus caelestialium, is conferred byNeotyphodiumendophyte infection of perennial ryegrass,Lolium perenne.

Neotyphodiumfungal endophytes form mutualistic symbiotic associations with many grasses of the subfamily Pooideae, including important forage and turfgrass species. This relationship provides a competitive advantage to the host plant by increasing abiotic/biotic stress tolerance, such as its resistance to drought, diseases, and insect pests. The insect deterrent effects of endophytes are now receiving attention in Japan, as insect pests growing in meadows are causing problems in adjacent rice paddies. One of the most serious problems is the kernel spotting of rice grains caused by the rice leaf bug,Trigonotylus caelestialiumKirkaldy (Heteroptera: Miridae), which reproduces onLoliumspecies grown as forage. To determine the potential ofNeotyphodiumendophytes to reduce the invasion of rice crops byT. caelestialiumfrom adjacentLoliumcrops, we carried out choice and no-choice feeding tests using endophyte-infected and endophyte-free clonal perennial ryegrass (Lolium perenneL.) (Poaceae). Our experiments revealed that the presence of theNeotyphodiumendophyte strongly deterred the feeding of both first-instar larvae and adults ofT. caelestialium. These results show the potential ofNeotyphodiumendophytes to reduce the number ofT. caelestialiumin forage fields and grasslands, and thus to reduce the damage to rice grains caused by this insect pest. [ABSTRACT FROM AUTHOR]