Observations made in California over a period of years have disclosed an interesting problenn regarding unproductive cherry trees. An occasional tree, or portion of a tree, has been found that produces practically no fruit, yet branches of the same tree, or other trees of the same variety standing beside it, have been consistently prolific. The behavior of these unproductive trees suggests the ...

toxicities in specific orchards may be different. In addition to testing the pesticides listed in Leaflet 21343, we tested several that were not listed, including some that are not currently registered for use in almonds or are not registered in California at this time. We included those to determine which are most promising for future incorporation into an integrated mite management program fo...

A new species of the family Tydeidae from Iran, Tydeus shabestariensis sp. nov., is described from adult males and females collected from soil in apple orchards. A key to species of Tydeus of Iran, based on females, is provided. The male of Neopronematus sepasgosariani (Tydeoidea: Iolinidae) is also described and illustrated for the first time.

During the past year, we collected walnut aphid parasitoids, !. pallidus, from 8 walnut orchards. Parasites from 2 sites were maintained as individual colonies, those from'the six other sites were pooled into one colony. These colonies and one started in 1985 from three sites were screened with Guthion. We found substantial variability in responses to Guthion by these colonies, which suggests t...

Seven citrus orchards on reduced to no pesticide spray programs were sampled for Thysanoptera in central and south central Florida. Inner and outer canopy leaves, fruits, twigs, trunk scrapings, vines and ground cover plants were sampled monthly between January 1995 and January 1996. Thirty-six species of thrips were identified from 2,979 specimens collected from within citrus tree canopies and...

In California, regulatory agencies are concerned about organophosphate (OP) contamination of surface water. OPs originate in part from applications on dormant almond and stone fruit orchards that are washed off during winter rainstorms. Programs conducted by the University of California Statewide Integrated Pest Management Project, University of California Cooperative Extension, and the Biologi...

Studieswere conducted in apple,MalusdomesticaBorkhausen, orchards to evaluate the attractiveness of the kairomone, ethyl (E, Z)-2,4-decadienoate (pear ester), loaded at various rates into gray halobutyl septa, to adult codling moth, Cydia pomonella L. All studies were conducted in orchards treated with sex pheromone mating disruption. Lure loadings from 0.01 g to 50.0 mg were evaluated in 12 or...

Studies were conducted in commercial apple orchards in British Columbia, Canada, to determine whether lures combining ethyl-(E,Z)-2,4-decadienoate, pear ester (PE), with either acetic acid (AA) or sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone), might improve monitoring of codling moth, Cydia pomonella (L.), in an area-wide programme integrating sterile insect technology (SIT) and mating ...

A severe outbreak of European Stone Fruit Yellows (ESFY) has been reported recently in apricot (Prunus armeniaca) orchards located in the province of Trento (Italy), where partial or total tree dieback caused major economic losses to growers. In order to prevent the disease spreading, the presence of ESFYP-vector, the psyllid Cacopsylla pruni, was monitored together with wild reservoirs of the ...