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Ross Crozier, population geneticist and leader in the study of the evolutionary genetics of social insects, was born on 4 January 1943 in Jodhpur, India. He died of a heart attack in his office at James Cook University in Townsville on 12 November 2009. He is survived by his wife Yuen Ching Kok, who was his inseparable companion and collaborator in life as in the laboratory. Crozier was a pioneer in the application of molecular genetic markers to the analysis of social insect populations, and generated much of the theory that made these analyses possible. Ross and Ching Crozier produced the first sequence of the honey bee mitochondrial genome?the second insect mitochondria to be fully sequenced. From the sequence Crozier produced fundamental insights into the nature of DNA evolution, particularly directional mutation pressure towards particular nucleotides. Crozier contributed massively to the development of kin selection theory, which remains the most potent explanatory theory for the evolution of social behaviour in insects.

Chalkbrood of honey bees (Apis mellifera) is caused by Ascosphaera apis, and is new to Australia. As yet, no treatment or prophylaxis is available for this disease. The best prospects for control are likely to come from the use of 'hygienic' bees, those with a strong genetic tendency to uncap and remove dead pupae, together with good beekeeping practice. Ten strains of Australian commercial honey bee were evaluated for hygienic behaviour. Dead pupae were inserted into the colonies and checked after 3, 5 and 7 days for the number of pupae removed. Most colonies (80%) were non-hygienic and hence likely to be susceptible to chalkbrood. However, 2 strains provided good overall performance in the test and comprised 1 or 2 colonies that were highly hygienic. Colonies were evaluated 3 times, and the good performance of these colonies was repeatable across trials. These data suggest that hygienic behavioural morphs exist in Australia's commercial bee strains, and it is unnecessary to obtain breeding stock from overseas for this reason alone. Selective breeding, with relatively simple techniques which can be used by beekeepers and queen breeders, should produce suitable genotypes.

Honeybee (Apis mellifera) colonies hived in beehive materials that had been sterilised by gamma irradiation had an average weight gain of 29.3 kg while those housed in untreated hives had an average gain of 27.1 kg.Bees sampled from both the treated and untreated colonies were examined for the presence of Nosema apis and virus, causitive organisms of stress related diseases, at the end of the season. No significant differences were found. The slight increase in weight (2.2 kg) of the sterilised colonies was not sufficient to justify the cost of prophylactic sterilisation of beehive equipment.

The pollination requirements of strawberries (Fragaria x ananassa Duchesne cv. Tioga) were examined in a planting in southern Victoria. Plots that were accessible to honeybees (Apis mellifera L.) had 20.8% marketable berries (well shaped, > 10 g fresh weight), whereas plots that were not accessible had only 4.5% marketable berries. The total numbers of fruit (marketable and unmarketable) were not affected by the presence of pollinating insects. Honeybees were considered to be the main pollinators of this crop. They comprised 58.9% of insect visitors to the flowers. The behaviour patterns of other insects were such that they would effect little or no pollination. We conclude that the presence of an adequate population of honeybees increases the proportion of well shaped (marketable) berries.

A partial diallel cross of honeybees (Apis mellifera L.) was formed. Combining ability analysis of variance was used to estimate additive and non-additive genetic variance in seasonal colony weight gain for the artificial 'population' studied. The values determined were: general combining ability variance, 12.14 kg2 (s.e., 11.42); specific combining ability variance, 11 -96 kg2 (s.e., 13.71); environmental variance, 21.65 kg2 (s.e., 8.84); heritability of honey production, 0.42 (s.e., 0.24). The phenotypic standard deviation was 7.6 kg.The results suggest that selection for colony weight gain would be successful.

Heritability of characters (e.g. hamuli number) of honeybee workers can be estimated from data obtained from a random sample of colonies from a single population without the need for controlled matings. Formulae are developed for the estimation of relatedness among workers within colonies as a function of number of drone matings with the queen and the relatedness among these drones. Heritability is then estimated by dividing the intraclass correlation of the character by the relatedness among the workers within colonies. Estimates obtained by this method are shown to be considerably less biased than those obtained by analysing data from single-drone inseminations because of the contribution of dominance variance to the covariance of sib workers.

The brood area and weight gain of colonies headed by hybrid queens were compared with those headed by their inbred parentals. Although the colonies headed by hybrid queens had increased brood production, this did not lead to increased honey production. There was a significant increase in the longevity of hybrid queens compared with inbreds, and this alone may justify their use by apiarists. Additional keywords: Apis melltfera, honey bee.

Twenty honeybee colonies were treated with various oxytetracycline hydrochloride (OTC) preparations at the time of inoculation with Bacillus larvae spores or after American foulbrood (AFB) disease signs had developed.Treatment with 1 g OTC, at the time of inoculation delayed the development of AFB disease signs in four hives for periods between 2 months and 1 year. One colony so treated did not contract the disease.Colonies with a light AFB infection treated with 1 g of OTC recovered from the disease in 3-4 weeks, but AFB disease signs reappeared in three of five colonies the following season. Colonies with a well-established infection showed complete recovery from AFB disease signs after various OTC treatments. However, nearly all of these colonies developed AFB disease signs in the following season.B. larvae was cultured from adult bee samples from colonies that were AFB disease-free at the time of sampling but subsequently developed disease signs, and from colonies that were AFB disease-free at the time of sampling but did not subsequently develop disease signs.The results show that recommended treatments for European foulbrood (EFB) effectively mask AFB disease, making it likely that beekeepers treating EFB also suppress signs of AFB disease if it is present. As it is common practice in Australia to treat EFB prophylactically with OTC, an escalation of AFB in Australian hives is anticipated.