Impacts of standard wine-making process on the survival of Lobesia botrana larvae (Lepidoptera: Tortricidae) in infested grape clusters.

To determine the risk winery waste poses for the spread of Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) in California, we evaluated the survival of larvae in artificially infested grape clusters (Vitis vinifera L.) processed for wine making. The trial consisted of five treatments: whole cluster pressing to 1 bar (100,000 Pa); whole cluster pressing to 2 bars (200,000 Pa); destemming and berry pressing to 1 bar; destemming and berry pressing to 2 bars; and control. Each treatment was replicated with the following five winegrape varieties: Chardonnay, Sauvignon Blanc, Gewürztraminer, Yellow Muscat, and Cabernet Sauvignon. All winery waste was inspected for larval survival. No live larvae were recovered from any of the treatments in all five varieties; therefore, the hypothesis that green winery waste contributes to the spread of L. botrana was rejected.

Characterization of Bois noir isolates by restriction fragment length polymorphism of a Stolbur-specific putative membrane protein gene.

Bois noir phytoplasma (BNp), widespread in wine-producing areas of Europe and endemic in France and Italy, is classified in the 16SrXII-A subgroup, whose members are referred to as Stolbur phytoplasmas. The 16S rDNA gene of Stolbur phytoplasma shows low variability, and few non-ribosomal genes are available as markers to assess variation among isolates. We used the Stolbur-specific stol-1H10 gene, encoding a putative membrane-exposed protein, to investigate genetic diversity of French and Italian BNp isolates from plants and insects. Amplification of stol-1H10 from infected grapevines, weeds, and Hyalesthes obsoletus produced fragments of three sizes, and restriction fragment length polymorphism analysis divided these amplicons further into 12 profiles (V1 to V12). French BNp isolates were more variable than Italian ones, and different profiles were present in infected grapevines from France and Italy. Isolate V3, most abundant among Italian affected grapes but present among French ones, was found in one Urtica dioica sample and in all H. obsoletus collected on this species. Four Italian-specific profiles were represented among infected Convolvulus arvensis, the most frequent of which (V12) was also detected in H. obsoletus collected on this species. Most of the variability in the stol-1H10 sequence was associated with type II on the tuf gene.

Visual wulst influences on the optic tectum of the pigeon.

The influence of the visual wulst on the optic tectum of Columba livia were studied. Analysis of the surface field potential evoked by optic nerve stimulation showed that it is composed of two presynaptic waves (pr1 and pr2) a negative monosynaptic wave (N) and a late, positive component (P) due to activation of deeply located neurons. Single shock visual wulst stimulation elicited a surface-positive field potential the depth profile of which showed that it is due to the activation of neurons of the deep tectal layers, probably different from those responsible for the P wave. Visual wulst stimulation depresses the positive component of the field potential elicited by optic nerve stimulation. It is suggested that this effect is mediated by intratectal inhibitory interneurons.