Many foliar endophytic fungi deter herbivores from feeding on their host plants, but a previous study has suggested that their deterrent effect may be reduced in the presence of arbuscular mycorrhizae. In our study, factorial experiments determined the effects of infection of perennial ryegrass, Lolium perenne, by the foliar endophyte Neotyphodium lolii [present (ϩE) or absent (ϪE)] and the mycorrhizal fungus Glomus mosseae [present (ϩM) or absent (ϪM)] on larvae of the noctuid moth Phlogophora meticulosa.When host plants received adequate phosphorus (P), mycorrhizae and the foliar endophyte decreased the survivorship of larvae between their second and fifth instar in an additive manner. Sixth-instar larvae feeding on ϪMϪE plants attained greater mass than those feeding on plants with one or both symbionts. There was an M ϫ E interaction with the total amount of grass consumed per larva. The foliar endophyte increased relative consumption rate and reduced efficiency of conversion of ingested food of larvae, while the mycorrhizal fungus had no effect on insect nutritional indices.Larvae preferred ϪE over ϩE leaf blades regardless of mycorrhizal infection status. They showed no preference with respect to plant mycorrhizal status. When foraging among mixed stands of intact plants, larvae inflicted more damage on ϪE than on ϩE plants. Mycorrhizae reduced feeding damage, but only in ϪE plants and to a lesser extent than the foliar endophyte. The relative difference between ϩE and ϪE plants, in terms of grazing damage, was decreased but not eliminated by mycorrhizae.When P was limiting to plant growth, mycorrhizae still decreased the survivorship of larvae between their second and fifth instar, independently of the foliar endophyte. They accelerated larval development slightly. The foliar endophyte increased the survivorship of fifth-instar larvae, independently of mycorrhizae.We concluded that both foliar endophytes and mycorrhizae affected larval growth and survivorship. Some effects were additive, while others were nonadditive and depended to some extent on host P nutrition. Our findings suggest that the beneficial effect of the foliar endophyte on the host plant, in terms of insect resistance, was reduced but not eliminated by mycorrhizae.

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Animals generate diverse motor behaviors, yet how the same motor neurons generate distinct behaviors remains an open question.Drosophilalarvae have multiple behaviors – e.g. forward crawling, backward crawling, self-righting and escape – and all of the body wall motor neurons (MNs) driving these behaviors have been identified. Despite impressive progress in mapping larval motor circuits, the role of most motor neurons in locomotion remains untested, the majority of premotor neurons (PMNs) remain to be identified, and a full understanding of proprioceptor-PMN-MN connectivity is missing. Here we report a comprehensive larval proprioceptor-PMN-MN connectome; describe individual muscle/MN phase activity during both forward and backward locomotor behaviors; identify PMN-MN connectivity motifs that could generate muscle activity phase relationships, plus selected experimental validation; identify proprioceptor-PMN connectivity that provides an anatomical explanation for the role of proprioception in promoting locomotor velocity; and identify a new candidate escape motor circuit. Finally, we generate a recurrent network model that produces the observed sequence of motor activity, showing that the identified pool of premotor neurons is sufficient to generate two distinct larval behaviors. We conclude that different locomotor behaviors can be generated by a specific group of premotor neurons generating behavior-specific motor rhythms.

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Abstract-We present a distributed, collaborative algorithm to enable opportunistic spectrum access for cognitive radios in the presence of multiple cochannel transmitters. A spectrum hole detection and estimation technique based on received signal strength observations is developed, which allows the coexistence of both licensed and unlicensed transmitters. We address the issues of how to perform collaborative spectrum sensing in the presence of multiple cochannel transmitters and how to determine the maximum transmit power that can be used for a given frequency channel by a cognitive radio while avoiding harmful interference to the licensed network. Simulation results are provided to validate the feasibility and performance of the proposed scheme.

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