3.1.3.1. Sex determination of adults

The easiest approach for adults has been developed by Schmolke (1974; Fig. 9).

  1. Grasp the adult beetle so that the ventral side of the tip of the abdomen can be viewed.
  2. Gently squeeze the beetle abdomen.
  3. Squeezing the abdomen will cause the female to extend her ovipositor and the male to protrude his 8th tergite (Fig. 9).

Females readily extend their ovipositor without much squeezing. If you are squeezing “hard” with little result, the beetle likely is a male. It is more difficult to cause male beetles to protrude their 8th tergite so care must be taken to avoid harming the beetle.

If done gently, the sexed adults will not be affected adversely.

Note: When sexing many adult beetles (Ellis et al., 2002b; Spiewok and Neumann, 2012), it is recommended to slow them down by placing them in a fridge or in a vial on ice for at least 5 min (up to 10 min).

Fig. 9. Sexing of adult small hive beetles. Squeezing the abdomen will cause the female to extend her ovipositor (arrowed in a.) and the male to protrude his 8th tergite (arrowed in b.). The line sketches inset in both pictures are redrawn from Schmolke, 1974 and show the female ovipositor and male 8th tergite in detail. Sketches: Kay Weigel (University of Florida); photos: Marc Schäfer.

12106VD revised Fig9