Trampa de fondo como una alternativa en el control integrado del ácaro Varroa destructor en colmenas de abejas africanizadas

The effectiveness of the bottom board trap to control the mite Varroa destructor in Africanized honey bee colonies was evaluated from June to September 2017 in Atenas, Alajuela. Naturally fallen mites were collected during a 30-day period with a bottom board trap, which consisted of a wooden bottom (50 x 42 cm) modified with a metal lattice and a screen of six holes per cm2. A white piece of cardboard previously gridded and coated with a thin layer of Vaseline to help count the number of fallen mites was placed inside the trap. The cardboard was replaced every seven days. After 30 days, the remaining mites were eliminated, and the effectiveness of the method was determined by applying four strips of flumethrin to each hive for six weeks. Furthermore, the mortality of the different Varroa stages in a sealed (operculated) worker brood was evaluated. Naturally fallen Varroa mites were 715 ± 531 (n= 5) during a 30-day period. Mite mortality occurred mainly during day 22 with 335 ± 285, whereas the lowest number was collected on day one with 30 ± 13 mites. After applying flumethrin, mite mortality was 2072 ± 1874. The above allows us to establish that the number of mites that fell naturally and those eliminated from the hive by means of the bottom trap corresponded to 25.7%. In addition, it was determined that Varroa mortality in capped worker brood cells was less than 10.0%. In conclusion, the bottom board trap eliminated more than a quarter of the mites in the beehives; consequently, this method may be considered as an alternative in the integrated Varroa management in Africanized honey bees. Se midió la efectividad de la trampa de fondo en el control del ácaro Varroa destructor en colmenas de abejas africanizadas, de junio a setiembre 2017, en Atenas, Alajuela. Se registró la caída natural de ácaros durante un período de 30 días en la trampa, la cual consistió en un fondo de madera (50 x 42 cm), cubierto con cedazo metálico en la parte superior, con un tamaño de tamiz de seis agujeros por cm2. En el interior de la trampa, se colocó una lámina de cartulina blanca, impregnada con vaselina, previamente cuadriculada, para facilitar el conteo de los ácaros, la cual se reemplazó cada siete días. Luego del día 30, los ácaros remantes se eliminaron. Se determinó la efectividad del método, para lo cual se aplicó cuatro tiras de flumetrina a cada colmena, durante seis semanas. Adicionalmente, se evaluó la mortalidad de los diferentes estadios de varroa en la cría sell