Oviposition in Boophilus microplus infected artificially with Babesia bovis and naturally with B. bovis and Babesia bigemina

Abstract

Ten Boophilus microplus engorged females (GI) (average weight 327.7 mg), with induced Babesia bovis infection (0.2 to 20.5 kinetes per microscope field of haemolymph on day 5 from detachment) were monitored for egg production. Egg output was also measured in 20 engorged females ticks (GII) (average weight 327.2 mg) free of B. bovis and in 11 B. microplus (GIII) (average weight 211.5 mg) found naturally infected with B. bovis and Babesia bigemina (0.1 to 14.9 kinetes per microscope field of haemolymph) on day 5 from collection. All ticks were held in darkness at 27 +/- 1 degrees C, 83-86 % relative humidity. The pre-oviposition period in GI was 2.4 +/- 0.52 days and 3.1 +/- 0.37 days in GII (P < 0.01, <<t>> test). The Reproductive Efficiency Index (REI) (number of eggs laid/tick weight) was 5.75 +/- 2.239 and 12.86 +/- 1.340 for GI and GII, respectively (P < 0.01). No evident harmful effects of babesial infection on egg output of ticks from GIII were found; pre-oviposition period and REI were 2.8 +/- 0.40 days and 11.05 +/- 1,521, respectively. The correlation coefficient between REI and number of kinetes per microscope field of haemolymph was -0.3669 in GI (P > 0.05) and -0.0855 (P > 0.05) in GIII. Adaptive tolerance between B. microplus and Babesia, probably occurs under natural conditions.