The first gynandromorph of the Neotropical bee Megalopta amoena (Spinola, 1853) (Halictidae) with notes on its circadian rhythm

Abstract

Gynandromorphy is an anomaly that results in an organism phenotypically expressing both male and female characteristics. Here we describe the first gynandromorph of the bee species Megalopta amoena (Spinola, 1853) (Halictidae, Augochlorini) and the second record of this anomaly within the genus Megalopta. Additionally, we analyzed the bee’s circadian rhythm, which has never before been quantified for a gynandromorph. The gynandromorph showed a deviant activity pattern; it was intermediate between that of the male and female M. amoena. Our results imply that the brains of bilateral gynandromorphs may have mixed sex-specific signaling. Based on four days of recording, the gynandromorph circadian rhythm was shifted earlier in the day relative to the male and female M. amoena, and it exhibited intensity similar to the female.

A bilateral gynandromorph of Discoelius dufourii (Hymenoptera, Vespidae, Zethinae): morphology and mating behaviour

“…However, Camargo and Gonçalves (2013) urge caution in predicting the sex-specificity of gynandromorph behaviour in context of scent attraction. Krichilsky et al (2020) have speculated that in a gynandromorphic bee Megalopta amoena, a bilaterally split brain was unable to integrate conflicting sexspecific signalling in relation to the circadian rhythm. In our case of the D. dufourii gynandromorph, the female-like low intensity of substrate antennation, approaching to the female and jumping and, at the same time, the male-like high intensity of female body antennation and the attempt to mount the female may be interpreted as a result of conflicting activities of the female and male parts of the brain.…”