Fungal endophytes of grasses and their effects on an insect herbivore

Abstract

The effects of endophytic fungi (Tribe Balansiae, Clavicipitaceae, Ascomycetes) of grasses on an insect herbivore were studied by feeding paired groups of larvae of the fall armyworm (Spodoptera frugiperda, Noctuidae, Lepidoptera) leaves from either infected or uninfected individuals. Perennial ryegrass infected by "the Lolium endophyte", tall fescue infected by Epichloe typhina, dallisgrass infected by Myriogenospora atramentosa, Texas wintergrass infected by Atkinsonella hypoxylon, and sandbur infected by Balansia obtecta were utilized. The endophytes of ryegrass and fescue previously have been shown to be toxic to mammalian herbivores and to deter feeding of some insect herbivores. In this study we extend the antiherbivore properties of those endophytes to the fall armyworm and demonstrate that fungal endophytes in three other genera have similar antiherbivore properties. For most grasses, survival and weights of fall armyworm larvae fed infected leaves were significantly lower and larval duration was significantly longer compared to larvae fed uninfected leaves. Resistance to herbivores may provide a selective advantage to endophyte-infected grasses in natural populations.

The Influence of Non-Host Predators on Parasite-Induced Behavioral Changes in a Freshwater Snail

“…Parasites and pathogens have been demonstrated to increase unpalatability in their hosts in some cases (e.g. Clay et al 1985). An increase in distastefulness could be advantageous for the parasite if it decreases the probability of predation by non-host predators.…”

Endophytic microorganisms: a review on insect control and recent advances on tropical plants

“…In addition to the reports mentioned above (Webber, 1981;Funk et al, 1983;Gaynor and Hunt, 1983;Lasota et al, 1983;Barker et al, 1984;Prestidge et al, 1984;Ahmad et al, 1985;Clay et al, 1985a;Claydon et al, 1985;Hardy et al, 1985;Latch et al, 1985a;Johnson et al, 1985), that correlate endophytic fungi with negative effects towards insects, other reports kept accumulating in the following years. Some of them will be presented here but we should keep in mind that most of them refer to the host F. arundinacea and L. perenne.…”

“…Lasota et al (1983) had also correlated in the white spruce Picea glauca, death rate of the Homoptera Adelges abietis when galls are infected with the endophytic fungus Cladosporium sphaerosperum. In L. perenne and members of the genus Cyperus, weight gain and survival of the insect-pest, Spodoptera frugiperda, were affected by endophytic fungi like Balansia cyperi (Clay et al, 1985a;Hardy et al, 1985). Studies related to this insectpest affecting different species of Lolium were also conduced by Larch et al (1985b) with two endophytic fungi, Acremonium lolii and a member of the genus Gliocadium.…”

The endophytic fungal community in leaves of a coastal redwood population diversity and spatial patterns

“…The ecological roles of fungi with endopbytic stages are varied. They may be dormant saprobes (Chapela & Boddy, 1988), latent pathogens (Verhoeff, 1974;Carroll, 1986) or mutualists, either antagonizing plant enemies (Clay, Hardy & Hammond, 1985;Latch, Christensen & Gaynor, 1985;Bacon et al, 1986;Carroll, 1986) or stimulating growth and competitive ability (Bose, 1956;Bradshaw, 1959;Clay, 1986). Although tbe ecological roles played by individual endopbytes are important ^er se, the importance of entire endopbytic communities for plant ecology has yet to be assessed.…”