Location, reproduction and movement of Neoseiulus californicus (Acari: Phytoseiidae) during the autumn, winter and spring in orchards in the south of France
Field samples and experiments conducted in apple orchards in the south of France showed that Neoseiulus californicus (McGregor) searched for prey on the trees and in the ground cover as late as mid-November 1993, and at least as early in the spring as the end of February 1994. Overwintering females fed, expanded and produced viable eggs within 7.9±0.3 (SE) days given the natural light regime, adequate food and temperatures of 17.0±20.6°C. The first generation of N. californicus developed in the field during March and April 1994. N. californicus nymphs, females and males readily moved over bare ground and through a grass ground cover to trap plants located on stakes 1 m above the ground. In the laboratory, the rate of movement of adult females on 0.5 mm copper wire was a linear function of temperature above a threshold of 11.9±0.9°C. At 25°C they travelled 10 m per h. The migration rate of N. californicus to trap plants on stakes placed in an orchard 13 Apr. increased in 2 weeks from 0.07 to 0.57 predators/trap plant/degree-day, while the migration rate to plants placed directly in the ground cover was 1.45 predators/trap plant/degree-day. The largest population of N. californicus in April occurred on Barley, Hordeum murinum L. This plant produces pollen in April and May, and may be useful in biocontrol programs.
The predatory potential of Phytoseiulus persimilis, Amblyseius californicus, and Metaseiulus occidentalis (Acarina: Phytoseiidae)
Abstract Feeding proto- or deutonymphal stages of Phytoseiulus persimilis killed about 30% more prey/instar h than respective stages of either Amblyseius californicus or Metaseiulus occidentalis. Reproductive females of P. persimilis killed more than 3 times the number of prey eggs killed by A. californicus and more than 5 times the number killed by M. occidentalis. P. persimilis in the presence of excess prey has the shortest developmental time for active stages (69.3 h), the greatest reproductive longevity (482.4 h), kills the most prey as an immature (13.4 eggs) and as a reproductive adult (503.1 eggs), and consistently kills the greatest number of prey/h as post-larval instars or as reproductive females. An index of predator capability estimates that protonymphal P. persimilis can function at 1 tetranychid egg/74.3 cm2 versus 85.6 cm2 and 66.8 cm2 for A. californicus and M. occidentalis, respectively. Similar results were obtained for predator protonymphs searching for tetranychid protonymphs, with A....
Comparison of a Radiometric Procedure with Conventional Methods for Identification of Neisseria
A radiometric procedure was compared with the conventional cystine tryptic agar (CTA) sugar fermentation method for identification of Neisseria species. Four different ATCC cultures of Neisseria were identified by both procedures with identical results. The only difference noted was that the radiometric procedure required 3 h for completion, whereas the conventional CTA sugar method required overnight incubation. The radiometric procedure was also compared with the fluorescent antibody (FA) and CTA methods for identification of Neisseria gonorrhoeae. The organisms examined were gram-negative, oxidase-positive diplococci isolated from 49 clinical specimens sent to the laboratory for bacteriological analysis. Results obtained by both CTA and FA procedures were comparable. However, the radioisotope method appeared to be superior to the other two methods in that only one isolate identified as positive by both the CTA and FA methods was not identified radiometrically, whereas four isolates positive by the radiometric method were not identified by the other two procedures. Thus, a total of seven more positive identifications were made radiometrically than by either of the two other methods. All positive identifications were confirmed by a reference laboratory. These results indicate that the radiometric procedure is more rapid and reliable as compared with both the CTA and direct FA methods and, thus, may serve as a valuable addition to the methodology available for diagnostic microbiology.