Characterisation of Aceria massalongoi and a histopathological study of the leaf galls induced on chaste trees.

The eriophyoid mite Aceria massalongoi (Canestrini) was collected from globoid leaf galls on severely injured chaste trees, Vitex agnus-castus L. (Lamiaceae), in Bari and Bernalda (southern Italy), and on the Ionian island Leukade (Greece). Female, male and nymph were described in detail, following the current morphometric descriptive scheme, supplementing older and incomplete descriptions. Molecular characterization of A. massalongoi from Italy and Greece was conducted by amplifying and sequencing the ribosomal ITS, the D2-D3 expansion domains of the 28S rRNA gene and the mitochondrial COI, for the first time. Phylogenetic trees based on the three molecular markers showed congruent results, confirming that Italian and Greek A. massalongoi populations are the same species that cluster together with some intraspecific variability. Galls, ranging from 0.5 to 2.8 mm in diameter, were randomly distributed on both leaf surfaces, and protruded ca. 1 mm from the leaf surface. Sometimes they were closely aggregated on midrib and leaves, which, consequently, appeared strongly deformed. Close-up observations revealed that gall induction causes hyperplastic proliferation of leaf tissues around the gall chamber hosting mites. The uniserial cell lining inside this chamber provides the nutritional tissue for the mites. All feeding cells contained one or more (frequently 2-3) hypertrophied nuclei and dense granular cytoplasm.

Ultralow oxygen treatment for control of Planococcus ficus (Hemiptera: Pseudococcidae) on grape benchgrafts.

Controlled atmosphere treatments with ultralow oxygen (ULO treatments) were developed successfully for control of vine mealybug, Planococcusflcus Signoret (Hemiptera: Pseudococcidae), on dormant grape (Vitis spp.) benchgrafts. At 30 ppm oxygen, 3-d ULO treatment at 25 degrees C and 4-d ULO treatment at 150C achieved complete control of all life stages of P. ficus. At a much lower oxygen level (<1 ppm), the two ULO treatments with the same exposure periods of 3 d at 25 degrees C and 4 d at 15 degrees C were tested on six table and wine grape cultivars grafted on rootstocks along with P. ficus. The benchgrafts were then potted in a greenhouse, together with untreated controls, to determine treatment effects on rootstock viability. Both ULO treatments achieved complete control of P. ficus and did not have any negative effects on vine growth, compared with the control. Results indicate that ULO treatments can be used to control P. ficus on dormant grape benchgrafts. The advantages of the ULO treatments are also discussed with respect to hot water treatments.