Howell V. Daly

Alarm pheromone production by two honeybee (Apis mellifera) types

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 pheromone levels and defensive behavior, especially numbers of stings, were observed.

Mitochondrial DNA sequence variation in Ixodes pacificus (Acari: Ixodidae)

The western black-legged tick, Ixodes pacificus, is a primary vector of the spirochaete, Borrelia burgdorferi, that causes Lyme disease. We used variation in a 355-bp DNA portion of the mitochondrial cytochrome oxidase III gene to assess the population structure of the tick across its range from British Columbia to southern California and east to Utah. Ixodes pacificus showed considerable haplotype diversity despite low nucleotide diversity. Maximum parsimony and isolation-by-distance analyses revealed little genetic structure except between a geographically isolated Utah locality and all other localities. Loss of mtDNA polymorphism in Utah ticks is consistent with a post-Pleistocene founder event. The pattern of genetic differentiation in the continuous part of the range of Ixodes pacificus reinforces recent recognition of the difficulties involved in using genetic frequency data to infer gene flow and migration.

Morphometric Analysis of the Indian Honeybee in the Northeast Himalayan Region

SummaryAnalyses of 55 morphometric characters were made for collections of Apis cerana from 16 localities in the northeast Himalayan region. Bees from this region have been recognized as distinct from those of the northwest Himalayas and South India. In this region, 3 biometric groups were identified that correspond to geographic distributions in (1) the Naga and Mizo Hills, (2) Brahmaputra valley and Khasi hills, and (3) the foothills of the Himalayas. Discriminant analysis of the samples using all characters and a minimum number of characters are given with appropriate statistics. Correlations of character variation with rainfall and altitude are discussed. Bees from the Himalayan biometric group (3) are generally larger in size than those from the other two groups as well as South India.

Correlations between morphology and colony defence in Apis mellifera L.

SUMMARYSignificant correlations between 25 quantitative characters of worker honey bees used for the morphometric identification of Africanized honey bees (Apis mellifera), seven measures of colony defence and 12 for alarm pheromone production were calculated from data on colonies in Louisiana, USA, and Monagas, Venezuela, two years after the arrival of Africanized honey bees in the eastern portion of Venezuela. The bees in the Venezuela group were identified as European (70%), European with evidence of introgression of Africanized genes (5%), Africanized with evidence of introgression of European genes (7%) and Africanized (18%), indicative of a population undergoing hybridization. For the Venezuelan population alone, the correlations between defensive behaviour and morphometric identification as Africanized were not significant. Therefore, defensive behaviour alone is not an adequate indicator for identification or certification programmes in areas undergoing Africanization.

Effect of Parasitism by Varroa Jacobsoni on Morphometrics of Africanized Worker Honeybees

SummaryAfricanized bees infested with 0–5 Varroa jacobsoni mites per bee were measured for 23 lengths and 25 angles on the forewing and 3 lengths on the hind leg. Bees infested with 1–2 mites exhibited virtually no consequence. For bees infested with up to 4–5 mites, some of the measurements had a simple regression on increased mite infestation in at least one data set, but affected structures often differed in this respect between colonies and on the left and right sides of bees. All such lengths exhibited a negative regression. The net effect of parasitism on the exoskeleton appears minor in contrast to reports of substantial loss of protein, haemolymph volume, weight and reduced longevity suffered by infested bees. This is probably because differentiation of the exoskeleton occurs mainly before the most intense feeding by mites and cuticle development proceeds despite a diminishing protein reserve.

Taxonomy and ecology of Ceratinini of North Africa and the Iberian Peninsula (Hymenoptera: Apoidea)

Abstract A key, synonymy, descriptions and distributions are given for twelve species of Ceratina (Euceratina), including three new species, C.maghrebensis, C.neocallosa, C.saundersi; two species of Ceratina (Ceratina, s.s.); and two species of Pithitis. A neotype is designated for C.callosa and lectotypes for C.callosa algeriensis, C.chalybea, C.cyanea imitatrix, C.decolorans, C.laevifrons moricei, C.mocsaryi and C.nigrolabiata. Ecology of bees in overwintering nests in Tunisia is discussed. Evidence is given for congeneric interference competition for nesting substrates and resource partitioning. C.dallatorreana is shown to reproduces probably entirely by thelytoky and thus is unique among Apoidea.

Honey bee morphometrics: linearity of variables with respect to body size and classification tested with European worker bees reared by varying ratios of nurse bees

SUMMARYThe effects of nutritional stress on body size of worker honey bees and their morphometrics were examined, and morphometrics of stressed bees were compared with the morphometrics of large reference populations of European and Africanized honey bees. Workers from European queens (4 commercial queens from California plus 2 open stock queens and 2 feral queens from Louisiana) were reared with 4 ratios of nurse bees:eggs: 0.5:1,1:1, 5:1, and 100:1. Measurements of 25 morphometric variables were taken from each of 32 samples of usually ten bees per sample. Raw measurements of stressed bees were analysed separately by analysis of variance and multiple range tests. The treatments resulted in different phenotypes irrespective of the queen or her geographic origin. Workers reared at ratios of 0.5:1,1:1 and 5:1 were consistently smaller than workers reared at 100:1. Based on the size of the workers reared at 0.5:1, the initial ratio was apparently altered by the nurse bees, who probably destroyed eggs or lar...