John R. Harbo

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Africanized and European honey bee (Apis mellifera) populations showed quantitative differences in colony defensive behavior. Africanized bees responded faster and in much larger numbers than European honey bees and produced 8.2 and 5.9 times as many stings during two different experiments. Times to react to alarming stimuli were negatively correlated with(More)
Honeybees have evolved a social immunity consisting of the cooperation of individuals to decrease disease in the hive. We identified a set of genes involved in this social immunity by analysing the brain transcriptome of highly varroa-hygienic bees, who efficiently detect and remove brood infected with the Varroa destructor mite. The function of these(More)
This study demonstrated (1) that honey bees, Apis mellifera L, can express a high level of resistance to Varroa destructor Anderson & Trueman when bees were selected for only one resistant trait (suppression of mite reproduction); and (2) that a significant level of mite-resistance was retained when these queens were free-mated with unselected drones. The(More)
Honey bee (Apis mellifera) semen was treated as follows: diluted in saline with 10 percent dimethyl sulfoxide (DMSO) and stored at -196 degrees C; same treatment but stored at 12 degrees C; diluted in saline and stored at 12 degrees C; and undiluted, unstored semen. Daughters (queens) produced from the treated spermatozoa were evaluated for total sterility.(More)
We measured signiÞcant variation in the instantaneous growth rates for varroa mites, Varroa destructor (Anderson & Trueman) from 1993 to 2002 in Baton Rouge, LA. Mite population growth was monitored in colonies of honey bees, Apis mellifera L., with queens from miscellaneous U.S. sources that had not been selectively bred for varroa resistance.Mite(More)
Screen instead of wood on the floor of a bee hive has been tested over the years for various reasons. Most recently, screen floors have been employed to monitor populations of Varroa destructor (PAM, 1993) or reduce varroa populations (Pettis & Shimanuki, 1999; Ostiguy et al., 2000; Ellis et al., 2001; Sammataro et al., 2004). Others have tested the effects(More)
Of 12 alarm pheromones assayed in European and Africanized honeybees, nine were found in larger quantities in the Africanized population. Isopentyl and 2-heptanone levels were similar in both; 2-methylbutanol-1 was greater in European workers. These differences were not due to age or geographical location. Significant positive correlations between alarm(More)
The inheritance of a group character, the alarm behaviour of honey bee workers (Apis mellifera L.), was analyzed using a metabolic bio-assay. In a diallel test cross of preselected queens and drones, genetic variance and maternal effects on this behaviour were estimated. Crossfostering experiments showed that the hive environment during larval and pupal(More)
The effects of queenlessness on worker honeybees (Apis mellifera) were tested with 50 colonies in groups of 10 (five treatments and two replicates) in August, October and December, 1984 and February and April, 1985 in Baton Rouge, Louisiana. The 10 colonies in each group were all from a single heterogeneous mixture of bees, and each colony began with about(More)
Mosaic male honey bees were found as the progeny of queens that had been inseminated with spermatozoa stored in liquid nitrogen. The origins of these mosaics and the genotype of their gametes were determined by using mutant markers. The mosaics probably developed from an egg pronucleus and a sperm pronucleus that did not unite after the latter had entered(More)