Observations on a Unique Monster Embryo of Wyeomyia Smithii (Coquillett) (Diptera: Culicidae)1

Abstract

This monster was found in 15 out of 1,570 fertile eggs inspected during the colonization of the pitcher plant mosquito. Each consisted only of two apparently complete abdomens fused in the region of the first abdominal segment of each. The “anterior” abdomen was doubled back and occupied the anterior one-third of the egg; the “posterior” abdomen was straight and occupied the posterior two-thirds of the egg. A living embryo exhibiting duplication in the longitudinal axis with complete absence of head and thorax is believed to represent a hitherto unreported type of teratological phenomenon.