Anniversary of a beekeeper’s discovery of thelytoky in Cape honey bees

Significance: The laying workers of the Cape honey bee continue to negatively affect the South African beekeeping industry, with more losses suffered in the northern regions of the country. The reproductive parasites enter susceptible host colonies, activate their ovaries, and lay diploid eggs, leading to colony dwindling and collapse. Diploidy in eggs produced by unmated laying workers arises from thelytokous parthenogenesis, first discovered in honey bees by a hobbyist beekeeper. We examine the consequences of thelytokous parthenogenesis and outline what is being done to understand and limit the spread of the laying workers of the Cape honey bee

Sue Nicolson (1950–2023) : internationally recognised insect physiologist and dedicated mentor

No abstract available.http://www.sajs.co.zazkgibs2024Zoology and EntomologyNon

An effective method for maintaining the African termite-raiding ant Pachycondyla analis in the laboratory

Pachycondyla analis Latreille (Hymenoptera: Formicidae) is a common African Ponerine ant that organizes group raids on termites considered a huge burden to agriculture. This ant has been the subject of various entomological and natural history studies aimed at understanding their group raiding behaviour and impact on the ecosystem as well as the roles they play in regulating field termite populations. However, colony maintenance under laboratory conditions for long-termresearch purposes has largely been unsuccessful. Herein,wereport an effective method for maintaining P. analis in the laboratory for long-termstudies that may include behavioural, life history and chemical ecology. Using a simple set-up made up of a Perspex foraging arena and an aluminum nest box in the laboratory, queen right colonies were successfully maintained for an average of 27.0±6.0 weeks and a maximum of 34 weeks before declining. High ant mortality (6–48 %) was observed in the first week of captivity in the laboratory. This declined to a weekly mortality of 4.0 ± 3.6%(24 ± 22.5 ants per colony) after the ants had settled in their new laboratory nest. Therefore, using our laboratory rearing set-up, and keeping laboratory conditions similar to those in the field, as well as feeding P. analis on its usual diet of termites, could increase colony survival time up to 4.5 times longer than previously reported rearing protocols.We acknowledge K.L. Crous and three anonymous reviewers for their comments on an early version of the manuscript, the Mpala Research Centre, Nanyuki, Kenya, for permission to work on their premises, M. Stüben of the University of Würzburg, Germany for confirming the identity of the ants, and P. Malusi of the Animal Rearing and Quarantine Unit at ICIPE for his help with ant rearing. Funding was provided by the Dutch SII project 2004/09 Activity No. 10799 to ICIPE, the University of Pretoria and a DAAD fellowship to A.A.Yusuf."http://www.journals.co.za/ej/ejour_ento.htmlam2013ab2013ab201

Reproductive Biology of the Cape Honeybee: A Critique of Beekman et al: A critique of "Asexually Produced Cape Honeybee Queens (Apis mellifera capensis) Reproduce Sexually,” authors: Madeleine Beekman, Michael H. Allsopp, Julianne Lim, Frances Goudie, and Benjamin P. Oldroyd. Journal of Heredity. 2011:102(5):562-566

Laying workers of the Cape honeybee parthenogenetically produce female offspring, whereas queens typically produce males. Beekman et al. confirm this observation, which has repeatedly been reported over the last 100 years including the notion that natural selection should favor asexual reproduction in Apis mellifera capensis. They attempt to support their arguments with an exceptionally surprising finding that A. m. capensis queens can parthenogenetically produce diploid homozygous queen offspring (homozygous diploid individuals develop into diploid males in the honeybee). Beekman et al. suggest that these homozygous queens are not viable because they did not find any homozygous individuals beyond the third larval instar. Even if this were true, such a lethal trait should be quickly eliminated by natural selection. The identification of sex (both with molecular and morphological markers) is possible but notoriously difficult in honeybees at the early larval stages. Ploidy is however a reliable indicator, and we therefore suggest that these "homozygous” larvae found in queen cells are actually drones reared from unfertilized eggs, a phenomenon well known by honeybee queen breeder

Wingless and intermorphic males in the ant Cardiocondyla venustula

The ant genus Cardiocondyla is characterized by a pronounced male diphenism with wingless fighter males and winged disperser males. Winged males have been lost convergently in at least two species-rich clades. Here, we describe the morphological variability of males of C. venustula from uThukela valley, South Africa. Winged males appear to be absent from this species. However, in addition to wingless (“ergatoid”) males with widely fused thoracic sutures and without ocelli, “intermorphic” males exist that combine the typical morphology of wingless males with characteristics of winged males, e.g., more pronounced thoracic sutures, rudimentary ocelli, and vestigial wings. Similar “intermorphic” males have previously been described from one of several genetically distinct lineages of the Southeast Asian “C. kagutsuchi” complex (Yamauchi et al., 2005). To determine whether male morphology is associated with distinct clades also in C. venustula, we sequenced a 631 bp fragment of mitochondrial DNA of workers from 13 colonies. We found six haplotypes with a sequence variation of up to 5.7%. Intermorphic and wingless males did not appear to be associated with a particular of these lineages and within colonies showed the same sequence. Interestingly, two colonies contained workers with different haplotypes, suggesting the occasional migration of queens and / or workers between colonies.Financial support came from Deutsche Forschungsgemeinschaft (He 1623/32 and He 1623/34).http://www.springerlink.com/content/101198/?p=d05a2cfd29ea4cf1b64b48ed3302b001&pi=906hb2013ab201

Pheromonal predisposition to social parasitism in the honeybee Apis mellifera capensis

In honeybees, worker reproduction is mainly regulated by pheromones produced by the brood and the queen. The source of one of the queen pheromones influencing worker reproduction has been located in the mandibular glands. In nonlaying workers, this gland's profile is dominated by fatty acids that are incorporated into the food given to the brood and to nest mates. After queen loss and onset of reproductive activity, workers are able to synthesize different fatty acids, which are normally only produced by queens and that contribute to their reproductive success. Apis mellifera capensis workers have the ability to rapidly produce queen-like mandibular profiles that could represent an important factor in their ability to behave as facultative intraspecific social parasites. Indeed, A. m. capensis workers can take over reproduction from the host queens in colonies of other subspecies. Here, we show that in the presence of their own queen, the mandibular gland profile of A. m. capensis workers is dominated by the precursor of the major compound of the queen pheromone. This is a unique trait among honeybee workers and suggests that A. m. capensis workers are primed for reproduction and that this phenomenon represents a pheromonal predisposition to social parasitism. We identified geographical variation in the ratio of queen- to worker-specific compounds in the mandibular gland profile of A. m. capensis workers, which corresponds with the introgression with the neighboring subspecies A. m. scutellat

Prey choice and raiding behaviour of the Ponerine ant Pachycondyla analis (Hymenoptera : Formicidae)

Termite raiding behaviour of the African poneromorph ant Pachycondyla analis was studied at Mpala, Kenya. In all, 330 raids were observed with the raiding activity showing peaks in the morning and evening. Time spent at the termite source was positively correlated with the numbers of termites taken. The sizes of foraging parties, number of termites taken, distance travelled and time spent at termite sources also showed a positive correlation. Pachycondyla analis preyed significantly more on Microtermes spp. than they did on Odontotermes spp. but no significant differences were found in terms of predator efficiency even though many ants were injured in raids on Odontotermes spp. compared with those on Microtermes spp. Our results indicate that P. analis seems to forage optimally, balancing the costs of energy with prey reward and prey choices were not only influenced by prey abundance, but also by the costs of foraging, as influenced by prey defences, size and foraging behaviour.AAY acknowledges the German Academic Exchange Programme (DAAD) and Dutch SII funding through project September 2004 Activity No. 10799 to icipe. The University of Pretoria and the National Research Foundation provided financial support to CWWP.http://www.tandfonline.com/loi/tnah202015-08-31hb2014ab201

Reproductive parasitism by worker honey bees suppressed by queens through regulation of worker mandibular secretions

Social cohesion in social insect colonies can be achieved through the use of chemical signals whose production is caste-specific and regulated by social contexts. In honey bees, queen mandibular gland pheromones (QMP) maintain reproductive dominance by inhibiting ovary activation and production of queen-like mandibular gland signals in workers. We investigated whether honey bee queens can control reproductively active workers of the intraspecific social parasite Apis mellifera capensis, parasitising A. m. scutellata host colonies. Our results show that the queen’s QMP suppresses ovarian activation and inhibits the production of QMP pheromone signals by the parasitic workers, achieved through differential expression of enzymes involved in the biosynthesis of these pheromones at two points in the biosynthetic pathway. This is the first report showing that honey bee queens can regulate reproduction in intraspecific social parasites and deepens our understanding of the molecular mechanisms involved in the regulation of worker reproduction in social insects.The South African National Research Foundation (NRF) Thuthuka Grant No. TTK150703123061 to AAY, NRF Incentive funding and Competitive Research grant for rated scientists (CPR) to CWWP and RMC and an OWSD postgraduate bursary awarded to FNM.http://www.nature.com/srephj2018Zoology and Entomolog

Effects of age and reproductive status on tergal gland secretions in queenless honey bee workers, Apis mellifera scutellata and A. m. capensis

Secretions from tergal glands are part of a queen’s pheromonal control of worker reproduction in honey bees. However, in queenless honey bee colonies, workers compete to gain pheromonal, and hence reproductive dominance, over nestmates with ontogenetic changes in their glandular secretions that affect the behavioral or physiological responses of other individuals. Using gas chromatography/mass spectrometry, we investigated for the first time the age-dependent changes in tergal gland secretions of queenless workers of the clonal lineage of Apis mellifera capensis and workers of A. m. scutellata. The reproductive status of honey bee workers was determined by recording the presence of spermathecae and the level of ovarian activation. The tergal gland chemicals identified in both A. m. scutellata workers and A. m. capensis clone workers were oleic acid, n-tricosene, n-pentacosene, and n-heptacosene, with three additional compounds, palmitic acid, n-heneicosene, and n-nonacosene, in A. m. capensis clones.We report ethyl esters as new compounds from honey bee worker tergal gland profiles; these compounds increased in amount with age. All A. m. capensis clone workers dissected had spermathecae and showed ovarian activation from day 4, while ovarian activation only started on day 7 for A. m. scutellata workers that had no spermathecae. Tergal gland secretions were present in higher quantities in bees with activated, rather than inactive ovaries. This suggests that tergal gland secretions from reproductive workers could act as releaser and primer pheromones in synergy with other glandular compounds to achieve pheromonal and reproductive dominance.A University of Pretoria postgraduate research bursary (Okosun), by the Competitive Programme for Rated Researcher of the National Research Foundation (NRF) South Africa (Pirk), incentive funding of the NRF (Crewe, Pirk), and the DST/NRF SARChI Chair in Mathematical Models and Methods in Bioengineering and Biosciences (M3B2) at the University of Pretoria (Yusuf).http://link.springer.com/journal/108862016-10-31hb2016Zoology and Entomolog

Tergal gland components of reproductively dominant honey bee workers have both primer and releaser effects on subordinate workers

The primer and releaser effects of dominant honey bee workers’ tergal gland pheromones are not known under queenless conditions. The Cape honey bee, Apis mellifera capensis, is the ideal model to investigate such question since workers normally reproductively dominate workers of all other subspecies. We determined the effects that short- and long-term exposure to pheromone blends from dominant A. m. capensis workers had on subordinate workers of A. m. scutellata. Three putative pheromonal blends, 1 (palmitic acid, oleic acid, n-heneicosene and n-tricosene), 2 (ethyl palmitate, ethyl oleate and ethyl stearate) and 3 (mixture of blends 1 + 2), were tested. All the three putative pheromonal blends elicited releaser effects in the form of retinue formation and primer effects by suppressing ovarian activation in workers. The resultant effects indicated that these pheromonal blends appear to play a role in establishing dominance among workers and hence regulating opportunities to reproduce.The National Research Foundation (NRF) of South Africa’s Competitive Programme for rated researchers and incentive funding to CWWP, RMC and AAY (grant numbers 90579, 111683, 103710 and 109380), NRF Research Career Advance-ment Fellowship (grant number 91419) to AAY, NRF Scarce Skills Postdoctoral Fellowship to OOO (Grant number 108019) and University of Pretoria, South Africa.http://link.springer.com/journal/13592hj2020Zoology and Entomolog