Drosophila suzukii Matsumura (Diptera: Drosophilidae) is an agricultural pest with a wide host range. It is known to infest fruit that are still ripening on the plant, as well as rotting and damaged fruit. Our study sought to determine whether D. suzukii use mulberries (Morus spp.) and figs (Ficus carica (L.)) as hosts, as their host status was ambiguous. Accordingly, we collected 25 field-infested fruit and counted the numbers of D. suzukii emerging from them. We also sought to determine whether female D. suzukii would respond to olfactory cues from ripe figs and mulberries. As the host population has been known to impact host odor response, flies from mulberry, fig, and cherry origins were tested in "one-choice" olfactometry studies. Our results show that mulberries and figs can serve as hosts for D. suzukii and that female flies will respond to their odors. The host population did affect response to fruit odors, although further studies are necessary to determine habitat fidelity. This has implications for management of this pest, especially in backyard and mixed fruit orchard situations, which commonly occur in the current range of D. suzukii, and fig and mulberry may serve as a pest reservoir for other hosts and cultivated crops.

We investigated the effect of explant origin on survival and adventitious shoot production from field-grown shoot tips of 8 Vitis vinifera L. cultivars. Survival and shoot production were greater in explants from axillary shoot tips than those from terminal positions. Similarly, explants from shaded shoot tips exceeded those that had grown in full sun. Explants from weak shoot tips had a higher survival rate than those from vigorous shoot tips. The effects of position, light, and vigor were independent. There was a strong negative correlation between survival in vitro and the preexisting phenolic content of the explants. Similar effects were observed with greenhouse-grown explants. Our findings may be applicable to other woody species with high phenolic contents.