The seed gall nematode, Anguina agrostis, feeds and reproduces within the developing ovaries of bentgrass seeds and overwinters in seed galls as anhydrobiotic juveniles. These dormant juveniles can survive within the seed gall for many years. In this dehydrated state, they are more tolerant to extreme environmental conditions than are their hydrated counterparts. Nematodes in seed galls were ex...

Galls induced by Meloidogyne spp. in plant roots are a complex organ formed by heterogeneous tissues; within them there are 5-8 giant cells (GCs) that root-knot nematodes use for their own nurturing. Subtle regulatory mechanisms likely mediate the massive gene repression described at early infection stages in galls, particularly in giant cells. Some of these mechanisms are mediated by microRNAs...

Six different strains of crown gall bacteria were tested to determine whether the commonly used biocontrol strain, K-84, would present them from infecting the paradox hybrid. Previous research showed that K-84 was highly effective in preventing crown gall infections of English root stock. There was considerable variability among the six strains in ability to cause disease. One of the strains di...

Ecosystem engineers, organisms that modify the physical environment, are generally thought to increase diversity by facilitating species that benefit from engineered habitats. Recent theoretical work, however, suggests that ecosystem engineering could initiate cascades of trophic interactions that shape community structure in unexpected ways, potentially having negative indirect effects on abun...

The Plant Vigor Hypothesis (PVH) predicts an oviposition preference of females and higher offspring performance for insect herbivores on longer and fast-growing plant modules. We tested the PVH predictions by investigating the effects of leaf size of Miconia prasina (Sw.) DC. (Melastomataceae) on the oviposition preference and on the offspring survival of the gall-inducing weevil Prospoliata bi...

Plants associate with a wide range of mutualistic and parasitic biotrophic organisms. Here, we investigated whether beneficial plant symbionts and biotrophic pathogens induce distinct or overlapping regulatory pathways in Medicago truncatula. The symbiosis between Sinorhizobium meliloti and this plant results in the formation of nitrogen-fixing root nodules requiring the activation of specific ...

At least two species of aphid, Tamalia coweni and Tamalia dicksoni (Hemiptera: Aphididae) induce galls on the leaves of Arctostaphylos spp. shrubs (Ericaceae). These galls are frequently inhabited by at least one species of congeneric inquiline. The inquiline clade has branched off from the gall-inducing clade and appears to be radiating rapidly on different host-plants, in contrast to the gall...

The new Tremella umbilicariae, lichenicolous on Umbilicaria, is described from Peru. It is characterized by large, dark brown, convex basidiomatal galls, long and narrow basidia, and relatively large basidiospores.