Browsing by Author "Baum, Kristen A."
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- Africanization of a feral honey bee (Apis mellifera) population in South Texas: does a decade make a difference?Publication . Rangel, Juliana; Giresi, Melissa; Pinto, M. Alice; Baum, Kristen A.; Rubink, William L.; Coulson, Robert N.; Johnston, J. SpencerThe arrival to the United States of the Africanized honey bee, a hybrid between European subspecies and the African subspecies Apis mellifera scutellata, is a remarkable model for the study of biological invasions. This immigration has created an opportunity to study the dynamics of secondary contact of honey bee subspecies from African and European lineages in a feral population in South Texas. An 11-year survey of this population (1991-2001) showed that mitochondrial haplotype frequencies changed drastically over time from a resident population of eastern and western European maternal ancestry, to a population dominated by the African haplotype. A subsequent study of the nuclear genome showed that the Africanization process included bidirectional gene flow between European and Africanized honey bees, giving rise to a new panmictic mixture of A. m. scutellata- and European-derived genes. In this study, we examined gene flow patterns in the same population 23 years after the first hybridization event occurred. We found 28 active colonies inhabiting 92 tree cavities surveyed in a 5.14 km(2) area, resulting in a colony density of 5.4 colonies/km(2). Of these 28 colonies, 25 were of A. m. scutellata maternal ancestry, and three were of western European maternal ancestry. No colonies of eastern European maternal ancestry were detected, although they were present in the earlier samples. Nuclear DNA revealed little change in the introgression of A. m. scutellata-derived genes into the population compared to previous surveys. Our results suggest this feral population remains an admixed swarm with continued low levels of European ancestry and a greater presence of African-derived mitochondrial genetic composition.
- Feral honey bees in pine forest landscapes of East TexasPublication . Coulson, Robert N.; Pinto, M. Alice; Tchakerian, Maria D.; Baum, Kristen A.; Rubink, William L.; Johnston, J. SpencerThe goal of this study was to investigate the diversity of feral honey bee races in pine forest landscapes of east Texas, subsequent to immigration of Africanized honey bees, Apis mellifera scutellata. The specific objectives were (i) to assess the immigration of A. m. scutellata into east Texas pine forest landscapes and (ii) to evaluate the suitability of the pine forest landscape to feral honey bees. This mesoscale landscape study was conducted on the Sam Houston National Forest in east Texas. Swarm traps and aerial pitfall traps were used to monitor feral honey bees. Spatial databases were used to evaluate suitability of the pine forest landscape for honey bees. Scoring mitochondrial DNA type (mitotypes), we found representatives of A. mellifera scutellata, eastern European, western European, and A. mellifera lamarckii races in pine forest landscapes of east Texas. The significant conclusions that follow from this evaluation are (i) honey bees are a ubiquitous component of the pine forest landscape in east Texas, (ii) mitotype diversity persists in the presence of significant immigration of A. m. scutellata, and (iii) A. m. scutellata, is an added element of the mitotype diversity in the landscape. The landscape structure in 1256 ha units surrounding 6 swarms of honey bees captured in swarm traps was examined. The metrics used to characterize the kind, number, size, shape, and configuration of elements forming the landscape, defined a heterogeneous environment for honey bees that included food and habitat resources needed for survival, growth, and reproduction.
- Feral honey bees in pine forest landscapes of East TexasPublication . Coulson, Robert N.; Pinto, M. Alice; Tchakerian, Maria D.; Baum, Kristen A.; Rubink, William L.; Johnston, J. SpencerIn 1990 the Africanized honey bee, a descendent of Apis mellifera scutellata, was identified in south Texas [Hunter, L.A., Jackman, J.A., Sugden,E.A., 1992.Detection records of Africanized honey bees inTexas during 1990, 1991 and 1992. Southwestern Entomol. 18, 79–89]. The potential impact of this immigrant on feral and managed colonies was the subject of considerable speculation. The goal of this study was to investigate the diversity of feral honey bee races in pine forest landscapes of east Texas, subsequent to immigration of A. m. scutellata. The specific objectives were (i) to assess the immigration of A. m. scutellata into east Texas pine forest landscapes and (ii) to evaluate the suitability of the pine forest landscape to feral honey bees. This mesoscale landscape study was conducted on the SamHouston National Forest in east Texas. Swarm traps and aerial pitfall traps were used to monitor feral honey bees. Spatial databases were used to evaluate suitability of the pine forest landscape for honey bees. Scoring mitochondrial DNA type (mitotypes), we found representatives of A. mellifera scutellata, eastern European, western European, and A. mellifera lamarckii races in pine forest landscapes of east Texas. The conclusions that follow from this aspect of the investigation are (i) honey bees are a ubiquitous component of the pine forest landscape in east Texas, (ii) mitotype diversity persists subsequent to the immigration of A. m. scutellata, and (iii) A. m. scutellata is an added element of the mitotype diversity in the landscape. To evaluate quantitatively the suitability of the pine forest to feral honey bees, we used a spatial database for the study area and FRAGSTATS. The landscape structure in 1256 ha units surrounding six swarms of honey bees captured in the swarm traps was examined. The metrics used to characterize the kind, number, size, shape, and configuration of elements forming the landscape, defined a heterogeneous environment for honey bees that included sufficient food and habitat resources needed for survival, growth, and reproduction. The conclusions that follow from this aspect of the investigation are (1) although classified as a pine forest, management practices and other human activities have altered the landscape and thereby created food and habitat resources suitable for honey bees, (2) the forestry practices associated specifically with road corridor maintenance, stream side corridor protection, RCW management, and Wilderness Area management introduce structural heterogeneity to the forest landscape which enriches the diversity and abundance of early successional flowering plants and provides cavity sites needed by honey bees, (3) ranching, farming, and urbanization within the study area also create these conditions, and (4) based on inferences from melissopalynology, honey bees provide pollination services for a broad representation of native and introduced flowering plant species of the pineywoods ecoregion.
- Long term preservation of DNA from honey bees (Apis mellifera) collected in aerial pitfall trapsPublication . Rubink, William L.; Murray, K.D.; Baum, Kristen A.; Pinto, M. AliceThis study examines the preservation of nuclear and mitochondrial DNA from honey bee (Apis mellifera L.) specimens which were first kept in propylene glycol-based antifreeze under various conditions, and then stored long-term, refrigerated in 95% ethanol. Two sets of bees were subjected to the propylene glycol treatment, then ethanol storage. One set consisted of bees captured in the field in propylene glycol-containing "aerial pitfall traps", where they remained for up to 21 days. A second set consisted of bees taken from a hive and kept in propylene glycol under various temperature and lighting conditions for up to 90 days. Both the field bees and laboratory bees were then stored long-term in ethanol before evaluation of the persistence of nuclear and mitochondrial DNA using the polymerase chain reaction. DNA integrity was preserved for both field and laboratory specimens. The results demonstrate that propylene glycol-captured, ethanol-preserved honey bees retain both nuclear and mitochondrial DNA after capture and long tern preservation. It is suggested that with little or no modification, the techniques described here might he applied to other studies involving trap-collected arthropod specimens.
- Spatial and temporal distribution and nest site characteristics of feral honey bee (Hymenoptera: apidae) colonies in a coastal prairie landscapePublication . Baum, Kristen A.; Rubink, William L.; Pinto, M. Alice; Coulson, Robert N.We evaluated the distribution and abundance of feral honey bee, Apis mellifera L., colonies in a coastal prairie landscape by examining nest site characteristics, population trends, and spatial and temporal patterns in cavity use. The colony densities of up to 12.5 colonies per km2 were the highest reported in the literature for an area including both suitable and unsuitable patches of nesting habitat. The measured cavity attributes were similar to those reported from other areas. The time occupied and turnover indices provided useful information about cavity quality, although none of the measured cavity attributes were correlated with these indices. Unmeasurable cavity characteristics, such as cavity volume, may provide a better estimate of cavity quality. Spatial patterns existed in cavity use by the feral colonies, with the colonies showing an aggregated pattern of distribution throughout the study. Colony aggregations probably resulted from the distribution of resources, especially cavities. Two years after the arrival of Africanized honey bees, cavities used by Africanized and European colonies were aggregated in distribution. During what seemed to be a transition period, both Africanized and European colonies were randomly distributed. After that time, European colonies remained randomly distributed, whereas Africanized colonies were aggregated. Therefore, the invasion of Africanized honey bees seemed to fragment the existing European population, corresponding to a decrease in the overall number of European colonies in the study area.