Comparative reproduction and nonparasitic development of Boophilus microplus and hybridized Boophilus ticks (Acari: Ixodidae) under natural field conditions in subtropical South Texas

Abstract

The reproductive biology and nonparasitic development of Boophilus microplus (Canestrini) and hybridized Boophilus ticks (B. annulatus (Say) male x B. microplus female) held under natural field conditions in south Texas throughout the year were compared. Comparisons between the two types of ticks indicated that the ovipositional biology (percentage of ovipositing females and number of eggs laid) of the females favored hybrid ticks during some months and B. microplus ticks during other months. However, on a year long basis, there was virtually no difference in the percentage of ovipositing females or in the number of eggs deposited by hybrid females as compared to B. microplus. The duration of each nonparasitic development period (preoviposition period, incubation period of eggs, and larval longevity) showed that both types of ticks had very similar developmental and survival rates during the year. Generally the difference in duration of each of the nonparasitic parameters was < 8 days, leading to a high degree of synchrony of the nonparasitic developmental rates between the two types of ticks. On the other hand, egg hatchability of hybrid ticks was consistently lower than pure-strain B. microplus throughout the year with significantly lower hatch rates occurring in April, July, August, October, and November. Thus, results obtained on percentage of ovipositing females, number of eggs laid, preoviposition period, incubation period of eggs, and larval longevity provide encouragement for the possible use of sterile hybrid males as a means of eliminating a native B. microplus population. In contrast, results of the egg hatchability of the two types of ticks indicate that the selective advantage afforded to B. microplus could have an adverse affect on the success of a sterile hybrid male program by making the number of hybrid ticks necessary to eliminate a native population prohibitively high.

Comparison of efficiency and reproductive aptitude indexes between a reference and field strains of the cattle tick Rhipicephalus (Boophilus) microplus, in Sinaloa, Mexico

“…Climatic conditions would favor the development of adult ticks during autumn and winter (DAVEY et al, 1980a, b;DAVEY;COOKSEY;DESPINS, 1991;DAVEY, 1988;BARRIGA;DA SILVA;AZEVEDO, 1995). Davey, Pound and Cooskey (1994) found more eggs laid in spring and autumn and the egg hatchability were essentially equal during the study. Furthermore, when the relative humidity (RH) is equal or above 75%, temperature becomes the main factor that determines larvae survival; in contrast, when RH is equal or less than 63%, it becomes the main factor substituting temperature (DAVEY; COOKSEY; DESPINS, 1991).…”

Development of a Spatially Targeted Field Sampling Technique for the Southern Cattle Tick,Rhipicephalus microplus, by Mapping Whitetailed Deer,Odocoileus virginianus, Habitat in South Texas

“…This is in agreement with Teel et al (1996), who characterized South Texas habitats of canopied mesquite and mixed-brush vegetation as more favorable for higher numbers and longer survival of cattle ticks than grass and grass-mixed brush. Davey et al (1994) also found whether or not an area was favorable to R. microplus larvae survival was determined by temperature and humidity requirements, and these varied by season. In their study, they separated bufflegrass, Cenchurus ciliarus L., with no overstory (grass habitat) from bufflegrass with a mesquite, Prosopis glandulosa Torrey, overstory (shade habitat).…”

“…The type of vegetation affects the microenvironment, making a site favorable or unfavorable for larval survival (Fleetwood and Teel 1983;Sutherst 1983;Teel 1984;Garris and Popham 1990). Teel et al (1997) and Davey et al (1994) characterized South Texas habitats of canopied mesquite and mixedbrush vegetation as more favorable for higher numbers and longer survival of cattle fever ticks than grass and grass-mixed brush. The dynamics of tick infestation and occurrence is a complex function of many factors, which may include the degree of contact between cattle and white-tailed deer, climatic variables, and geographic locations to habitat and water.…”

Analysis of doramectin in the serum of repeatedly treated pastured cattle used to predict the probability of cattle fever ticks (Acari: Ixodidae) feeding to repletion

“…Temperatures recorded in September through mid November and mid February through May were similar. Temperatures recorded during this study compared favorably with historical records for the region (National Oceanic and Atmospheric Administration 1983), as well as those recorded during a previous 2-year study conducted at the same site (Davey et al 1994).…”