Diploid males in the bumble bee Bombus terrestris

Abstract

The frequency of colonies that produce diploid males after brother‐sister (50%) and nephew‐niece (37.5%) matings proves that in B. terrestris the sex is determined by a single multi‐allelic sex locus. The diploid males which develop normally into adults make up 50% of the diploid brood. In the laboratory the growth rate of colonies with diploid males is influenced only slightly. Of 41 colony founding queens caught out of a natural population, all produced a colony without any diploid males. Therefore, the number of sex alleles in this population is estimated to be at least 24. This means that in commercial rearing systems for bumble bees, involving several generations, the occurrence of diploid males can largely be prevented by a good scheme for crossings.

Diploid males sire triploid daughters and sons in the parasitoid wasp Cotesia vestalis

“…In some species, diploid males are larger than haploid males, for example in the sawflies Athalia rosae and Neodiprion nigroscutum (Smith and Wallace, 1971;Naito and Suzuki, 1991). In other species, diploid males may be smaller than haploid males, but this has only been reported for the bumblebee Bombus terrestris (Duchateau and Marien, 1995). Diploid males may have lower survival rates than haploid males and females.…”

Rapid determination of sperm number in ant queens by flow cytometry

“…Logically, precise determination of sperm cell concentration has become a current focus of studies on the evolution of mating systems in social insects. The content of queens spermathecae has been examined for various Hymenoptera to investigate, e.g., the relationship between mating behaviour, sperm number, colony size and queen/colony fitness (yellow jackets: Stein and Fell, 1994;hornets: Stein et al, 1996;ants: Fjerdingstad and Keller, 2004;Reichardt and Wheeler, 1996;Wiernasz et al, 2001), the patterns of sperm transfer and sperm utilization (see review of Page, 1986;ants: Keller and Passera, 1992;Reichardt and Wheeler, 1996;Wiernasz et al, 2001), queen longevity and age from sperm depletion (ants: Tschinkel, 1987), sperm production and sperm competition (bumble bees: Duchateau and Mari n, 1995;honeybees: Moritz, 1986;Woyciechowski and Krol, 1996), or for tests of hypotheses on the evolution of multiple mating (e.g., "multiplemating-for-more-sperm hypothesis"; ants: Fjerdingstad and Boomsma, 1998;Pearcy et al, submitted).…”

“…A usual method consists in dissecting the spermatheca and dispersing sperm cells in a physiological buffer (usually saline) solution, and then counting samples of sperm suspension in aliquots placed in a cell count chamber (e.g., hemacytometers, Makler chamber) under a microscope (Duchateau and Mari n, 1995;Boomsma, 1997, 1998;Fjerdingstad and Keller, 2004;Keller and Passera, 1992;Stein et al, 1996;Tschinkel 1987;Woyciechowski and Krol, 1996). The method can be refined by marking sperm cells with a fluorescent DNA-staining solution (e.g., Hoechst; Sakaluk and O Day, 1984) and counting under a microscope equipped for epifluorescence microscopy, eventually after fixation in glacial acetic acid (Wiernasz et al, 2001).…”

Single-locus complementary sex determination in the inbreeding wasp Euodynerus foraminatus Saussure (Hymenoptera: Vespidae)

“…sl-CSD has been documented in more than 40 species distributed widely over the major taxonomic subgroups of the order Hymenoptera (Smith and Wallace, 1971;Cook, 1993b;Beukeboom, 1995), and is the prevalent system in the clade that includes the Ichneumonoidea (Whiting, 1943;Butcher et al, 2000b) and the aculeate (stinging) Hymenoptera (Mackensen, 1950;Ross and Fletcher, 1985;Duchateau et al, 1994). The wide distribution of sl-CSD across multiple clades suggests that it may be an ancestral character state in Hymenoptera (Cook, 1993b).…”