How Far Can the Red Palm Weevil (Coleoptera: Curculionidae) Fly?: Computerized Flight Mill Studies With Field-Captured Weevils.

Adult Rhynchophorus ferrugineus (Olivier) captured in pheromone-baited traps in commercial date palm orchards in the Al Ahsaa Directorate, Kingdom of Saudi Arabia, were used in computerized flight mill studies to determine the flight characteristics of this highly invasive and destructive palm pest. Flight mill studies were run at three different time periods, winter (December), spring (March), and summer (May). Of the 192 weevils tethered to flight mills ∼30% failed to fly > 1 km. Of those weevils flying > 1 km (n = 139), 55% flew > 10 km, and of these flyers 5% flew > 50 km in 24 h. Flying weevils exhibited an average weight loss of 20-30% and nonflying control weevils lost ∼9-13% body weight in 24 h. Male and female weevils flying in summer (average laboratory temperature was ∼27°C) flew the longest average distances (∼25-35 km), exhibited highest weight reductions (∼30%), and greatest mortality rates (∼80%). Consequently, time of year not weevil sex or color morph had a consistent and significant effect on flight activity, weight loss, and survivorship rates. Flight activity was predominantly diurnal commencing around 5:00 a.m. and peaking between 9-11:00 a.m. before tapering off. The distribution of flight distances combined across season and sex was mesokurtic (i.e., normally distributed).

Prevalence of antibodies to Haemophilus pleuropneumoniae in Iowa swine.

The prevalence of complement-fixing (CF) antibodies to Haemophilus pleuropneumoniae in Iowa swine was determined by testing samples collected randomly from each of 9 crop-reporting areas (9 to 12 counties) in Iowa in approximate proportion to the number of swine marketed annually from each area. For testing, a pooled antigen composed of serotypes 1 to 5 of H pleuropneumoniae was used in a modified direct Microtiter complement-fixation test. Of 7,348 sera tested, 2,362 or 32.1% had CF antibodies (titer greater than or equal to 1:4) to the organism. On a herd basis, 417 of 597 herds or 68.8% had at least 1 animal with CF antibodies (titer greater than or equal to 1:4) to the organism. The clinical problem with H pleuropneumoniae has become significant in recent years, but by no means is the overt disease as prevalent as animals or herds with CF antibodies to the organism.