Annual and Social Variation in Foraging Effort of the Obligately Eusocial Sweat Bee, Halictus ligatus (Hymenoptera: Halictidae)

10.2317/e37.1 ◽  
2004 ◽  
Vol 77 (4) ◽  
pp. 484-502 ◽  
Author(s):  
Miriam H. Richards
Keyword(s):  
Sweat Bee ◽  
Foraging Effort ◽  
Social Variation ◽  
Halictus Ligatus

Colony disturbance and solitary nest initiation by workers in the obligately eusocial sweat bee, Halictus ligatus

2013 ◽  
Vol 60 (3) ◽  
pp. 389-392 ◽  
Author(s):  
S. M. Rehan ◽  
A. Rotella ◽  
T. M. Onuferko ◽  
M. H. Richards
Keyword(s):  
Sweat Bee ◽  
Halictus Ligatus ◽  
Nest Initiation

Annual variation in survival and reproduction of the primitively eusocial sweat bee Halictus ligatus (Hymenoptera: Halictidae)

1995 ◽  
Vol 73 (5) ◽  
pp. 933-941 ◽  
Author(s):  
Miriam H. Richards ◽  
Laurence Packer
Keyword(s):  
Survival Rates ◽  
Colony Development ◽  
Sweat Bee ◽  
Geographic Scale ◽  
Brood Production ◽  
Rainy Weather ◽  
Survival And Reproduction ◽  
Halictus Ligatus ◽  
Primitively Eusocial ◽  
Nest Initiation

We studied a nesting aggregation of the primitively eusocial sweat bee Halictus ligatus near Victoria in southern Ontario during the summers of 1984, 1990, and 1991. Differences in local weather patterns from year to year had marked effects on bee demography and behaviour, belying previous conclusions about "typical" social organization in this aggregation. In 1990, comparatively cool, rainy weather resulted in high nest-failure and low brood-survival rates, while in 1984 and 1991, relatively dry, warm weather had the opposite effect. In 1984 and 1990, spring nest initiation was synchronous and the emergence periods of the first (worker) and second (reproductive) broods were temporally distinct. In 1991, exceedingly warm spring weather caused asynchrony in the timing of nest initiation, accelerated brood and colony development, and continuous brood production. In 1984 and 1990, a few males were produced in the first brood but most were produced in the second brood several weeks later. In 1991, continuous brood production meant that production of males represented the transition between production of workers and of gynes (second-brood females). Patterns of demographic and social variation exhibited by H. ligatus at Victoria parallel those observed on a continent-wide geographic scale. This suggests that primitively eusocial sweat bees maintain a variety of reproductive options, adjusting their social behaviour in response to local environmental conditions.

Multiple-foundress associations in a temperate population of Halictus ligatus (Hymenoptera; Halictidae)

1986 ◽  
Vol 64 (10) ◽  
pp. 2325-2332 ◽  
Author(s):  
Laurence Packer
Keyword(s):  
Reproductive Potential ◽  
Sweat Bee ◽  
Reproductive Competition ◽  
Southern Ontario ◽  
Parental Manipulation ◽  
Single Foundress ◽  
Halictus Ligatus ◽  
Reproductive Brood ◽  
Polistine Wasps ◽  
Previous Summer

Thirteen pleometrotic (multiple-foundress) nests of the primitively social sweat bee Halictus ligatus were excavated in the summer of 1984 at Victoria, near Toronto, southern Ontario. Subordinate foundresses were significantly smaller than both dominant females in pleometrotic nests and females that nested solitarily. Most subordinates were smaller than the workers that they helped to raise. These small females could have been surviving workers from the previous summer or the offspring of workers. It seems unlikely that they were malnourished reproductive brood individuals produced as a result of parental manipulation. In successful nests, the number of workers produced was positively correlated with the number of founding females such that productivity per foundress remained fairly constant. Pleometrotic nests also produced more reproductives than haplometrotic (single-foundress) ones. Subordinates may occasionally lay reproductive brood eggs. The increased productivity of multiple-foundress nests was not quite sufficient, by itself, to select for subordinate behaviour. The small subordinates had lower potential productivities in comparison to the larger females. This decreased reproductive potential, when combined with the increased productivity of pleometrotic nests, was sufficient to make subordinate behaviour selectively advantageous. When both factors are taken together, subordinate behaviour is selected for as long as the coefficient of relatedness between dominant and subordinate individuals is greater than 1/4. This indicates that high coefficients of relatedness are not necessary for pleometrosis to be selectively advantageous under the conditions found in this study. Dominant females may suffer increased reproductive competition from their numerous workers. This, plus the difficulty of ensuring association with siblings in spring, may be the reason why multiple-foundress associations were uncommon at this locality. The data presented here are compared with those from other studies of this species. The factors promoting pleometrosis in halictines are compared with those that result in multiple-foundress associations in temperate polistine wasps.

Social variation in size at birth and preterm delivery in the Czech Republic and Sweden, 1989-91

1998 ◽  
Vol 12 (1) ◽  
pp. 7-24 ◽  
Author(s):  
Koupilova ◽  
Vagero ◽  
Leon ◽  
Pikhart ◽  
Prikazsky ◽  
...  
Keyword(s):  
Czech Republic ◽  
Preterm Delivery ◽  
The Czech Republic ◽  
Social Variation ◽  
Size At Birth
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