Table 1. Theoretical expectation of th locus genotypes carried by the queens and drones and their worker offspring in each F₁ or BC colony.

Colony	Cross type	Cross direction (queen x drone)	Expected th genotype queen	Expected th genotype drone	Expected th genotype workers	Thelytoky expected	Arrhenotoky expected	Thelytokous offspring	Arrhenotokous offspring	Origin of HB-THE alleles carried by thelytokous offspring
3	F1	SxC	Th,Th	th	Th,th	No	Yes	0	47	—
4	F1	SxC	Th,Th	th	Th,th	No	Yes	0	31	—
7	F1	CxS	th,th	Th	Th,th	No	Yes	0	20	—
9	F1	CxS	th,th	Th	Th,th	No	Yes	1	16	1 C
11	F1	CxS	th,th	Th	Th,th	No	Yes	1	15	1 S
14	F1	CxS	th,th	Th	Th,th	No	Yes	0	58	—
10	BC	(SxC)xS	Th,th	Th	Th,Th or Th,th	No	Yes	0	8	—
15	BC	(SxC)xC	Th,th	th	Th,th or th,th	Yes	Yes	20	8	1 S,C and 18 C,C
16	BC	(SxC)xC	Th,th	th	Th,th or th,th	Yes	Yes	26	1	6 S,C and 19 C,C
21	BC	(SxC)xC	Th,th	th	Th,th or th,th	Yes	Yes	2	0	2 C,C
19	BC	(CxS)xS	Th,th	Th	Th,Th or Th,th	No	Yes	0	6	—
20	BC	(CxS)xS	Th,th	Th	Th,Th or Th,th	No	Yes	21	0	11 S,S and 9 S,C
22	BC	(CxS)xC	Th,th	th	Th,th or th,th	Yes	Yes	23	0	9 S,C and 14 C,C
26	BC	(CxS)xC	Th,th	th	Th,th or th,th	Yes	Yes	14	21	14 C,C

Abbreviation: BC, backcross.

Th is the putative arrhenotoky allele derived from the Scutellata parent (S), while th is the recessive thelytoky-determining allele derived from the Capensis (C) parent. Based on the expected genotype the expected mode of reproduction in workers is presented, followed by the observed number of thelytokous and arrhenotokous offspring (eggs, larvae and pupae) of workers. The empirically determined origin of the linked HB-THE alleles in thelytokously produced offspring is given in the last column. Queens heading colonies 10, 15, 16 and 21 were offspring of colony 3. Queens heading colonies 19, 20, 22 and 26 were offspring of colony 6. All the worker-produced offspring collected from colony 6 at the time of sampling were non-natal.