Determining the sex ratio in the glow-worm Lampyris noctiluca (L.) (Coleoptera: Lampyridae)

By John Tyler

The sex ratio in adult is extremely difficult to determine in the field due to marked differences in the size, mobility and conspicuousness of the two sexes. To overcome this difficulty, eggs and larvae were collected, reared to pupation and the pupae then sexed. The sex ratio established in this way was 1:1 but showed considerable variation between samples. Possible explanations for this apparent variability are discussed.