Beetles (Scolytinae) form intimate associations with a taxonomically and functionally diverse suite of nematodes that are phytopathogens, fungal feeders, entomoparasites. Despite their ubiquity, the ecological significance in lifecycles economically important bark ambrosia beetle species (Curculionidae: Scolytinae) associated plant diseases remains largely unexplored. Thousand cankers disease (...

Within the past decade an unusual decline of black walnut (Juglans nigra) has been observed in several western states. Initial symptoms involve a yellowing and thinning of the upper crown, which progresses to include death of progressively larger branches (Figure 1). During the final stages large areas of foliage may rapidly wilt. Trees often are killed within three years after initial symptoms...

In this research, the inhibitory effects of silver nanoparticles and zinc oxide nanoparticles,  in vitro, on disease stone fruits bacterial canker caused by Pseudomonas syrigae pv. Syringae and disease bacterial blight caused by Xanthomonas arboricola pv. juglandis, were studied. Different concentrations of nanoparticles were prepared on Mueller Hinton agar medium in two different ways in a com...

1. Reproductive behaviour is routinely studied with a view towards characterizing how an animal responds to variation in resource abundance and quality. This characterization is less commonly made with respect to reproductive physiology. 2. In the Walnut-infesting Fly, Rhagoletis juglandis , ovarian development is cued by the presence of the host fruit resource. In this study, I examined how ov...

For over 30 years, attempts have been made to determine when to begin treating for walnut blight, Xanthomonas campestris pv. juglandis. Past trial results have always indicated that the best time to begin treating was just before significant moisture, usually in the form of rain, occurred. Without some control over the amount of moisture present, the time to begin treating could not be tied to ...