Piyamas Nanork

Social parasitism by workers in queenless and queenright Apis cerana colonies.

We examined worker reproduction in queenless and queenright Apis cerana colonies to determine if they are parasitized by workers from other nests. The results demonstrate that 2–6% of workers in queenright colonies are from another nest (non‐natal), but these workers are not statistically more likely to have activated ovaries than natal workers, and are therefore unlikely to be active parasites. However, in queenless colonies we found a significant difference between the proportion of non‐natal (72.7%) and natal (36.3%) workers with activated ovaries. Non‐natal workers also had significantly higher reproductive success than natal workers: 1.8% of workers were non‐natal, but these laid 5.2% of the eggs and produced 5.5% of the pupae. Unlike A. florea, the proportion of non‐natal workers does not increase in queenless nests.

Conservation of Asian honey bees

East Asia is home to at least 9 indigenous species of honey bee. These bees are extremely valuable because they are key pollinators of about 1/3 of crop species, provide significant income to some of the world’s poorest people, and are prey items for some endemic vertebrates. Furthermore, Southeast Asian Dipterocarp forests appear to be adapted to pollination by honey bees. Thus long-term decline in honey bee populations may lead to significant changes in the pollinator ecology of these forests, exacerbating the more direct effects of deforestation and wood harvesting on forest health. Although complete extinction of any honey bee species is seen as unlikely, local extinction is likely to occur across extensive areas. The most significant threats to local honey bee populations are deforestation and excessive hunting pressure. Conservation of East Asian honey bees requires immediate action to determine what rate of colony harvesting by honey hunters is sustainable. This requires information on the demography of hunted populations, particularly the intrinsic growth rates and the rates of harvest.ZusammenfassungAsien ist eine Region mit hoher Bevölkerungswachstumsrate und zunehmendem Einkommen, in Verbindung mit hohen Entwaldungsraten. Besondere Beachtung für den Schutz der Honigbienen muss dabei auf grossangelegte Umwandlungen von Primärwald in kurzzyklische Waldwirtschaft, in Landwirtschaft und in städtische Gebiete gelegt werden. Nichstdestotrotz sind Honigbienen in ihren ursprünglichen Verbreitungsgebieten nach wie vor mehr oder weniger häufig anzutreffen. Allerdings gibt es inzwischen Anzeichen für lokale Rückgänge, insbesondere von A. koschevnikovi auf der malayischen Halbinsel und von A. andreniformis in den landwirtschaftlich genutzten Gebieten Thailands. Auch die Riesenhonigbienen A. dorsata und A. laboriosa scheinen in Grossteilen der Region unter Druck zu geraten. Diese lokalen Auslöschungen und der generelle Rückgang in der Dichte an Honigbienennestern wird vermutlich Konsequenzen haben, sowohl für die Natur als auch für die Menschen in der Region.An erster Stelle zu nennen wäre, dass ein Drittel unserer Nahrung pflanzlichen Ursprungs ist und dass diese Pflanzen von der Bestäubung insbesondere durch Honigbienen entweder abhängig sind oder davon profitieren. Auch in natürlichen Ökosystemen besteht ein starker Bedarf nach Bestäubern. Aufgrund ihrer Tanzsprache und ihres weiten Sammelradius können Honigbienenvölker kurzfristig verfügbare Trachtquellen schnell erkennen und ausbeuten. Solch schwankende und unvorhersehbare Blühereignisse sind in den Pflanzengemeinschaften der tropischen asiatischen Wälder die Regel. Wir gehen davon aus, dass diese Fortpflanzungsstrategien in der Gegenwart von zwei oder mehr Arten wandernder Honigbienen evoluieren konnten, da diese in der Lage sind ihre lokalen Populationsgrössen schnell zu steigern und somit genügend Bestäuber verfügbar sind. Der Verlust an Honigbienen kann deshalb die bestäubungsabhängige Ökologie der südostasiatischen Wälder stark beeinflussen.An zweiter Stelle steht die Tatsache, dass die asiatischen Honigbienen vielen Insekten, Säugern und Vögeln als Beute dienen. Verschiedene Vogelarten sind sogar auf Honigbienen spezialisiert, wie zum Beispiel der Gelbbürzelhoniganzeiger (Indicator xanthonotus), der Malaienhoniganzeiger (I. archipelagicus), sowie der Schopfwespenbussard (Pernis ptilorhyncus) und der Celebeswespenbussard (P. celebensis). Diese Arten wären entweder bedroht oder würden ganz aussterben, wenn die asiatischen Honigbienen aussterben würden. An dritter Stelle steht, dass Honigbienen bei vielen asiatischen Völkern hohes Ansehen geniessen und dass sie um ihr Wohlbehalten bemüht sind. Honigbienen spielen auch in der Religion in den asiatischen Hauptregionen eine wichtige Rolle.Die hauptsächlichen Ursachen für die Bedrohung der Populationen der Honigbienen stellen die Rodungen, die exzessive Honigjagd, die Ausbreitung von Parasiten und Pathogenen, der imkerliche Transport von Völkern zwischen den Inseln, mögliche Klimaveränderungen und der Verlust an Nistgelegenheiten dar. Letzteres betrifft vor allem die von A. dorsata bevorzugten grossen Bäume.Anstrengungen zum Schutz der Honigbienen sollten die Honigjagd im Auge haben, für die nachhaltige Nutzungskriterien erarbeitet werden sollten. Hierzu müssen dringend Daten erhoben werden zur Abschätzung des Umfangs der ausgebeuteten Völker und deren Überlebensraten. Gleichzeitig müssen Honigerntemethoden entwickelt und propagiert werden, die die Völker nicht vernichten. Wir empfehlen auch ein Moratorium gegen die destruktive Honigernte bei Riesenhonigbienen, dort wo dies rechtlich möglich und durchsetzbar ist, bis wir Daten zur nachhaltig möglichen Honigernte in den betreffenden Gebieten haben.

Phylogenetic analysis based on multiple gene sequences revealing cryptic biodiversity in Simulium multistriatum group (Diptera: Simuliidae) in Thailand

Phylogenetic relationships among four species of the Simulium multistriatum group (Diptera: Simuliidae) in Thailand were examined based on two mitochondrial genes (COI, COII) and one nuclear gene (18S/ITS1). Simulium takense was found to be genetically divergent (>20.3% for COI) from the other species, consistent with their distinctive morphology. Simulium chainarongi and S. chaliowae were monophyletic but were included in paraphyletic S. fenestratum. Simulium fenestratum was divided into three distinct lineages with high levels of genetic divergence. This suggests that S. fenestratum is a species complex. Neither morphological nor cytological examinations revealed evidence of sibling species. The clades derived from phylogenetic analyses were found to be correlated with the ecological conditions of larval habitat. Therefore, ecological adaptation may have played a role in black fly diversification and evolution. These results suggest the use of integrated, multidisciplinary approaches for fully understanding black fly biodiversity and systematics.

The role of genetic diversity in nest cooling in a wild honey bee, Apis florea

Simulation studies of the task threshold model for task allocation in social insect colonies suggest that nest temperature homeostasis is enhanced if workers have slightly different thresholds for engaging in tasks related to nest thermoregulation. Genetic variance in task thresholds is one way a distribution of task thresholds can be generated. Apis mellifera colonies with large genetic diversity are able to maintain more stable brood nest temperatures than colonies that are genetically uniform. If this phenomenon is generalizable to other species, we would predict that patrilines should vary in the threshold in which they engage in thermoregulatory tasks. We exposed A. florea colonies to different temperatures experimentally, and retrieved fanning workers at these different temperatures. In many cases we found statistically significant differences in the proportion of fanning workers of different patrilines at different experimental temperatures. This suggests that genetically different workers have different thresholds for performing the thermoregulatory task of fanning. We suggest, therefore, that genetically based variance in task threshold is a widespread phenomenon in the genus Apis.

Nestmate recognition by guards of the Asian hive bee Apis cerana

Abstract.When a honey bee colony becomes queenless and broodless its only reproductive option is for some of its workers to produce sons before the colony perishes. However, for this to be possible the policing of worker-laid eggs must be curtailed and this provides the opportunity for queenless colonies to be reproductively parasitized by workers from other nests. Such reproductive parasitism is known to occur in Apis florea and A. cerana. Microsatellite analyses of worker samples have demonstrated that the proportion of non-natal workers present in an A. cerana colony declines after a colony is made queenless. This observation suggests that queenless A. cerana colonies may be more vigilant in repelling potentially parasitic non-natal workers than queenright colonies. We compared rates of nestmate and non-nestmate acceptance in both queenright and queenless A. cerana colonies using standard assays and showed that there is no statistical difference between the proportion of non-nestmate workers that are rejected in queenless and queenright colonies. We also show that, contrary to earlier reports, A. cerana guards are able to discriminate nestmate workers from non-nestmates, and that they reject significantly more non-nestmate workers than nestmate workers.

Actual reproductive conflict during emergency queen rearing in Apis florea

Unequal relatedness among workers in polyandrous honey bee colonies provides the potential for reproductive conflict during emergency queen rearing. Adult workers can increase their inclusive fitness by selectively rearing their full-sisters as queens. We investigated the paternity of emergency queens in two colonies of Apis florea using five microsatellite loci. In colony 1 there was no significant difference between the proportions of queens and workers in each patriline (P = 0.48). In contrast, the relative frequency of patrilines in colony 2 differed significantly between queens and workers (P = 0.03). More than a quarter of the queens reared in this colony were of a single patriline, suggesting that larvae were selected for rearing as queens non-randomly.