Homing in the Digger Wasp Bembix rostrata (Hymenoptera,Sphecidae) in Relation to Sex and Stage1

In the digger wasp Bembix rostrata in males and females of different stages the homing rates and times after release from different distances were investigated.

• 1 The homing rate decreased with increase of distance (up to 3000 m).
• 2 In females the homing rate increased with progressing stage, from emerging over digging to provisioning.
• 3 Numbers for homing times followed the same order: highest in emerging, medium in digging and lowest in provisioning females.
• 4 Males showed similar homing rates as digging females. No significant differences between age groups could be found.
• 5 The results indicate an effect of sex and stage on the homing capacity. Differences may be traced back to motivation (provisioning females) and lack of experience (emerging females). Landmark orientation, which may include particular search strategies, is a probable orientation mechanism.