Ontogenetic Patterns in Amounts and Proportions of Dufour's Gland Volatile Secretions in Virgin and Nesting Queens of Lasioglossum malachurum (Hymenoptera: Halictidae)

1990 ◽  
Vol 45 (6) ◽  
pp. 709-714 ◽  
Author(s):  
Manfred Ayasse ◽  
Wolf Engels ◽  
Abraham Hefetz ◽  
Gunther Lübke ◽  
Wittko Francke
Keyword(s):  
Volatile Compounds ◽  
Fat Body ◽  
Dufour's Gland ◽  
Dufour’S Gland ◽  
Sweat Bee ◽  
Nest Recognition ◽  
Lasioglossum Malachurum ◽  
Pheromonal Communication ◽  
Main Component ◽  
Primitively Eusocial

Abstract In the primitively eusocial sweat bee, Lasioglossum malachurum, 66 volatile compounds could be identified from queen Dufour’s gland secretions. The patterns found in gynes and in old nesting queens differed in the absolute amounts of extractable volatiles as well as in the relative proportions. 3-Methyl-3-butenyl octadecanoate is the main component in gynes, while 18-octadecanolide, 20-eicosanolide and 22-docosanolide largely dominate the bouquets of old queens. The probable roles of some specific compounds in pheromonal communication of mates and in nest recognition are discussed. Correlations with the volume of the fat body and the vitellogenic status of the ovary are described.

scholarly journals Dufour’s gland analysis reveals caste and physiology specific signals in Bombus impatiens

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathan T. Derstine ◽  
Gabriel Villar ◽  
Margarita Orlova ◽  
Abraham Hefetz ◽  
Jocelyn Millar ◽  
...  
Keyword(s):  
Age Groups ◽  
Bombus Impatiens ◽  
Reproductive Status ◽  
Dufour's Gland ◽  
Dufour’S Gland ◽  
Insect Societies ◽  
Electroantennogram Recordings ◽  
Reproductive Division Of Labor ◽  
Reproductive Division ◽  
Primitively Eusocial

AbstractReproductive division of labor in insect societies is regulated through multiple concurrent mechanisms, primarily chemical and behavioral. Here, we examined if the Dufour’s gland secretion in the primitively eusocial bumble bee Bombus impatiens signals information about caste, social condition, and reproductive status. We chemically analyzed Dufour’s gland contents across castes, age groups, social and reproductive conditions, and examined worker behavioral and antennal responses to gland extracts. We found that workers and queens each possess caste-specific compounds in their Dufour’s glands. Queens and gynes differed from workers based on the presence of diterpene compounds which were absent in workers, whereas four esters were exclusive to workers. These esters, as well as the total amounts of hydrocarbons in the gland, provided a separation between castes and also between fertile and sterile workers. Olfactometer bioassays demonstrated attraction of workers to Dufour’s gland extracts that did not represent a reproductive conflict, while electroantennogram recordings showed higher overall antennal sensitivity in queenless workers. Our results demonstrate that compounds in the Dufour’s gland act as caste- and physiology-specific signals and are used by workers to discriminate between workers of different social and reproductive status.

scholarly journals Dufour’s gland analysis reveals caste and physiology specific signals in Bombus impatiens

2020 ◽  
Author(s):  
Nathan T. Derstine ◽  
Gabriel Villar ◽  
Margarita Orlova ◽  
Abraham Hefetz ◽  
Jocelyn Millar ◽  
...  
Keyword(s):  
Age Groups ◽  
Bombus Impatiens ◽  
Reproductive Status ◽  
Dufour's Gland ◽  
Dufour’S Gland ◽  
Insect Societies ◽  
Electroantennogram Recordings ◽  
Reproductive Division Of Labor ◽  
Reproductive Division ◽  
Primitively Eusocial

AbstractReproductive division of labor in insect societies is regulated through multiple concurrent mechanisms, primarily chemical and behavioral. Here, we examined if the Dufour’s gland secretion in the primitively eusocial bumble bee Bombus impatiens signals information about caste, social condition, and reproductive status. We chemically analyzed Dufour’s gland contents across castes, age groups, social and reproductive conditions, and examined worker behavioral and antennal responses to gland extracts.We found that workers and queens each possess caste-specific compounds in their Dufour’s glands. Queens and gynes differed from workers based on the presence of diterpene compounds which were absent in workers, whereas four esters were exclusive to workers. These esters, as well as the total amounts of hydrocarbons in the gland, provided a separation between castes and also between fertile and sterile workers. Olfactometer bioassays demonstrated attraction of workers to Dufour’s gland extracts that did not represent a reproductive conflict, while electroantennogram recordings showed higher overall antennal sensitivity in queenless workers. Our results demonstrate that compounds in the Dufour’s gland act as caste- and physiology-specific signals and are used by workers to discriminate between workers of different social and reproductive status.

scholarly journals Split sex ratios and genetic relatedness in a primitively eusocial sweat bee

2020 ◽  
Vol 75 (1) ◽  
Author(s):  
Tanya M Pennell ◽  
Jeremy Field
Keyword(s):  
Genetic Relatedness ◽  
Inclusive Fitness ◽  
Multiple Paternity ◽  
Sweat Bee ◽  
Ecological Benefits ◽  
Investment Ratio ◽  
Lasioglossum Malachurum ◽  
Helping Behaviour ◽  
Primitively Eusocial ◽  
Female Brood

Abstract In eusocial Hymenoptera, queens and their helper offspring should favour different sex investment ratios. Queens should prefer a 1:1 investment ratio, as they are equally related to offspring of both sexes (r = 0.5). In contrast, helpers should favour an investment ratio of 3:1 towards the production of female brood. This conflict arises because helpers are more closely related to full sisters (r = 0.75) than brothers (r = 0.25). However, helpers should invest relatively more in male brood if relatedness asymmetry within their colony is reduced. This can occur due to queen replacement after colony orphaning, multiple paternity and the presence of unrelated alien helpers. We analysed an unprecedentedly large number of colonies (n = 109) from a UK population of Lasioglossum malachurum, an obligate eusocial sweat bee, to tease apart the effects of these factors on colony-level investment ratios. We found that multiple paternity, unrelated alien helpers and colony orphaning were all common. Queen-right colonies invested relatively more in females than did orphaned colonies, producing a split sex ratio. However, investment ratios did not change due to multiple paternity or the presence of alien helpers, reducing inclusive fitness pay-offs for helpers. Queen control may also have been important: helpers rarely laid male eggs, and investment in female brood was lower when queens were large relative to their helpers. Genetic relatedness between helpers and the brood that they rear was 0.43 in one year and 0.37 in another year, suggesting that ecological benefits, as well as relatedness benefits, are necessary for the maintenance of helping behaviour. Significance statement How helping behaviour is maintained in eusocial species is a key topic in evolutionary biology. Colony-level sex investment ratio changes in response to relatedness asymmetries can dramatically influence inclusive fitness benefits for helpers in eusocial Hymenoptera. The extent to which helpers in primitively eusocial colonies can respond adaptively to different sources of variation in relatedness asymmetry is unclear. Using data from 109 colonies of the sweat bee Lasioglossum malachurum, we found that queen loss, but not multiple paternity or the presence of alien helpers, was correlated with colony sex investment ratios. Moreover, we quantified average helper-brood genetic relatedness to test whether it is higher than that predicted under solitary reproduction (r = 0.5). Values equal to and below r = 0.5 suggest that relatedness benefits alone cannot explain the maintenance of helping behaviour. Ecological benefits of group living and/or coercion must also contribute.

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