Efficacy of fipronil, amitraz and (S)-methoprene combination spot-on for dogs against adult dog fleas (Ctenocephalides canis, Curtis, 1826)

A novel spot-on formulation combining fipronil, amitraz and (S)-methoprene (CERTIFECT?, Merial Limited, GA, USA) was evaluated in adult Beagle dogs in a study to determine its adulticidal efficacy against the dog flea (Ctenocephalides canis, Curtis, 1826). Sixteen dogs were randomly allocated to treatment groups: 8 dogs served as untreated controls, and 8 dogs were treated once. Treatment consisted of applying a new combination formulation to deliver at least 6.7mg fipronil/kg body weight (bw), 8.0mg amitraz/kg bw, and 6.0mg (S)-methoprene/kg bw. The combination was designed to enhance the efficacy against ticks of the original fipronil/(S)-methoprene combination. Each dog was infested with 100 adult unfed dog fleas within 24h prior to treatment and then at weekly intervals for 8 weeks after treatment. At 24h after treatment or after each subsequent infestation, each dog was combed thoroughly to remove live fleas to be counted. A single treatment with CERTIFECT provided excellent knock-down of fleas within 24h after treatment and controlled re-infestations for up to 7 weeks (efficacy ≥96.5%, p<0.05).     

Activity of a deltamethrin shampoo against Ctenocephalides felis and Rhipicephalus sanguineus in dogs

A controlled clinical trial was undertaken to assess the efficacy of an application of a 0.07% deltamethrin shampoo against fleas and ticks in dogs. Twenty beagles, housed in separate cages, were randomly allocated into two groups of 10. The dogs were infested with 50 Ctenocephalides felis and 50 Rhipicephalus sanguineus each, and parasites were counted 24 h (fleas) and 72 h (ticks) later (Day 0). Dogs, when state, were then treated with 25 ml of a shampoo containing 0.07% deltamethrin (Group 1). Dogs in Group 2 were the controls. Fleas and ticks were counted 24 h (Day 1) and 48 h (Day 2) after the shampoo was applied, and the parasites were then removed. All the dogs were reinfested with fleas and ticks on Days 2, 7, 9, 14, 16 and 20. Parasites were counted 24 and 48 h after each reinfestation. Effectiveness against fleas was calculated 24 h after infestation, and against ticks 48 h after infestation. This study showed that the application of 25 ml of shampoo containing 0.07% deltamethrin to beagle dogs weighing between 10.2 and 12 kg was very well tolerated. It controlled the parasites present on the animals at the time of application: with an efficacy of 100% against fleas 24 h after treatment and an efficacy of 95% against ticks 48 h after treatment. The treatment protected against flea reinfestations with an efficacy of 100% during the first week, >98% in the second week and >95% in the third week. It also gave >99% protection against tick reinfestations in the first week and >96% in the second week.     

Translocation and mechanical spread of a Minnesota isolate of potato virus S in potatoes

Potato cultivars Norland, Kennebec, and Russet Burbank were inoculated with a Minnesota isolate of potato virus S (PVS) in the field. The incidence of secondary infection, measured by enzyme-linked immunosorbent assay (ELISA), indicated that significantly more PVS infection occurred in Russet Burbank than Norland or Kennebec, and that Norland had significantly more infection than Kennebec (P≤ 0.01). Mature plant resistance was not observed. Rapid reinfection of PVS-free seedlots resulted from inoculum point-sources when routine cultivation practices were followed. Reinfection rates were significantly greater for seedlots grown at Grand Forks, ND, when compared with seedlots grown at Becker, MN, during both years of the study (P≤ 0.01). After two years in the field, reinfection rates for Norland (71.8%) and Russet Burbank (73.0%) did not differ significantly, but were significantly greater than the reinfection rate for Kennebec (29.5%) (P≤ 0.01). In greenhouse-grown plants, PVS moved out of rub-inoculated leaves within 24 hr, however, 13 and 20 days were required before PVS was detected with ELISA in foliage above and below the inoculated leaf, respectively. The frequency of PVS detection was significantly greater in foliage above the inoculated leaf compared to foliage below the inoculated leaf (P≤ 0.05). Translocation of PVS from inoculated leaves to daughter tubers occurred within 13 days for Russet Burbank and Norland and within 20 days for Kennebec.     

Evaluation of the bioequivalence of two formulations of deltamethrin for treatment of sheep with psoroptic mange

OBJECTIVE: To evaluate efficacy of 2 deltamethrin emulsifiable concentrates that differed on the basis of vehicle (methyl glycol acetate [AMG] or 2-propylene glycol 1-methyl ether acetate [AMP]) for the treatment of sheep with mange. ANIMALS: 30 ewes between 11 months and 7 years old that weighed 16 to 71 kg and were naturally infested with Psoroptes ovis. PROCEDURE: Sheep were randomly allocated into 3 groups (13 sheep in group AMP, 13 sheep in group AMG, and 4 negative-control sheep). Each sheep was dipped twice (10-day interval between dippings) in the assigned formulation. Assessment of efficacy was performed on days 3, 7, 14, 21, 28, 35, 42, 49, 56, and 63 after the first dipping. Efficacy was assessed by determining the number of eggs or live mites on those days, as well as regrowth of wool at the end of the study. RESULTS: Psoroptic mange infestation was maintained in the 4 control sheep throughout the study. We did not detect live Psoroptes mites in scrapings after day 7 (AMP group) or after day 14 (AMG group). No parasites were seen after day 14 in either treatment group. Therefore, efficacy was 100% for both treatment groups from days 14 to 63. CONCLUSIONS AND CLINICAL RELEVANCE: The 2 formulations of deltamethrin were equally able to eradicate Psoroptes infestation of sheep after 2 dippings performed in accordance with the label recommendations.     

Historical Changes in Levels of Organic Pollutants in Sediment Cores from Brno Reservoir, Czech Republic

Results of a comprehensive study are presented on the spatial and depth-related distribution of persistent organic pollutants (POPs) in sediments of the Brno reservoir, Czech Republic. Based on sedimentological observations, three major historic phases were identified related to the evolution of the depositional environment, flow rate, and material input. Data on organic carbon, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides showed specific distribution patterns in a 3-m-deep core. The analysis of the depth trends of the geochemical data combined with sedimentology made it possible to distinguish between remote sources of the pollutants, early weathering alterations of POPs, transport by river associated with organic matter as sorbent on one hand, and local sources weakly related to lithology on the other hand. The integrated sedimentological and environmental geochemical archive provided an improved dynamic view of the pollution in historical terms.     

Mortality,progeny production and preference of Sitophilus zeamais adults to wheat from integrated and alternative production systems

The objectives of this study were to assess the effects of the production systems of wheat from different production systems on the mortality, progeny production and preference of Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). The factors tested were production system (integrated [INT], organic [ORG], biodynamic [BD] and control), which differed in plant protection and fertiliser procedures during plant growth and development; exposure interval (7, 14 and 21 d); relative humidity (r.h.) (55% and 75%) and temperature (20°C, 25°C and 30°C). Mortality after 7 d increased with the temperature increase and decreased with the increase in r.h. in most of the tested combinations. The mortality of weevils was higher in ORG compared to INT-produced wheat after 7 d. Progeny production was recorded 56 d after removal of parental adults and was higher at 75% r.h. in comparison to 55% r.h. At 55% r.h. and 20°C, progeny was 60.8% higher when S. zeamais were exposed to ORG in comparison to INT-produced wheat. Wheat from different production systems influenced mortality rates which were higher in alternative compared to INT production systems under optimal conditions for wheat storage (low temperature and r.h.). The reverse was recorded for temperature and r.h. increase. Progeny was not affected by wheat from various production systems. Significantly more S. zeamais adults were found in traps containing wheat from BD and control in comparison to INT. An understanding of the agricultural processes, biotic and abiotic factors which alter the post-harvest response of storage pests could be useful for the development of efficient post-harvest strategies for ORG and BD farms and the processing industry.