International audience | Susceptibility of two French strains of stable flies Stomoxys calcitrans (L.) to six insecticides was assayed, using an exposure technique (1-hour contact) with treated filter papers. Three replicates per insecticide, per concentration (10 concentrations per insecticide), per fly strain (ENVT, Cabanac) and fly category (blood-engorged - non-blood-engorged) were performed using a total of 14,400 adult flies in this trial. The LD50 and LD90 are higher for the blood-engorged flies than the non-blood-engorged flies for both strains of S. calcitrans. The LD90 (mg/m(2)) of the engorged flies for both strains were respectively: cypermethrin (637.9, 54.9), deltamethrin (264.3, 28.1), fenvalerate (2392.5, 125.1), lambda-cyhalothrin (118.2, 41.3), permethrin (353.7, 88.1), and phoxim (194, 226.8). Phoxim, which has not been used in the ENVT for several years, showed the same susceptibility for both strains. The LD90 values obtained for the Cabanac strain (organic farm) were 1 to 4 times lower than the recommended doses of all five pyrethroids. For the ENVT strain (blood-engorged flies), the LD90 was 7.1 and 22.6 times over the recommended doses of both deltamethrin and fenvalerate respectively, which are commonly used insecticides on this site.

Objective: This study aimed to analyze the compound content of the combined extracts of Langusei fruit (Ficus minahassae L.) and papaya latex (Carica papaya L.) and perform bioassays of the combination of extracts on fleas of the genus Ctenocephalides. Materials and Methods: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) determined the chemical composition of the combined extract. The toxicity of the extract combination was evaluated in vivo on cat flea and dog flea imago separately. The combination of phytochemical screening of Langusei extract and papaya latex contained all the main phytochemical compounds. Results: The LCMS/MS analysis results showed that the combination of Langusei extract and papaya latex contained six compounds. Four compounds were identified: 3-butenyl glucosinolate, erythromycin, aluminum palmitate, and henpentakontilbenzene. Four compounds indicate a new compound. The toxicity of the combined extract was highest for both Ctenocephalides felis and Ctenocephalides canis in the P4 treatment (10%), with an average mortality of 100%, the same as the control mortality of the synthetic insecticide deltamethrin. The best LD50 for C. felis was in the F1 formula (4.003 mg/l), while in C. canis it was shown in the F3 (3.733 mg/l). Conclusion: Based on the results obtained, the combination of Langusei fruit extract and papaya latex can be developed as an ectoparasiticide for fleas of the genus Ctenocephalides. [J Adv Vet Anim Res 2024; 11(3.000): 810-818]