Myllocerus undecimpustulatus undatus Marshall (Coleoptera: Curculionidae), also known as the Sri Lankan weevil, is becoming a major pest of ornamentals and tropical fruit trees in the southern states of United States, especially in Florida. Recent findings of this species in Florida citrus groves justify research into their biology and ecology. Identification of semiochemicals involved in their behavioral and chemical communication will help to develop insect control strategies. We studied morphological and sexually dimorphic characters of this species as an aid to rapid separation of sexes for studies aiming to identify semiochemicals that may be of value in management. Female weevils collected from the field in southeastern Florida were significantly larger than males in length of head, abdomen, and overall length. Females weight was approximately twice that of males. No significant differences in the distance between procoxal or mesocoxal articulations observed between males and females. But the distance between the metacoxal articulations was significantly higher for females than males. All measures of female elytra were significantly greater than those of male elytra. Females, but not males, have a characteristic black—gray marking extending from the ventral mesosternum to the second abdominal segment. Scanning electron microscopic images revealed that females had fewer ovate-to-obovate scales in this region of characteristic black—gray marking and more plumose scales compared with males. Deposition of white cuticular hydrocarbons in this region was less dense on females compared with males. These characters proved sufficient to separate sexes 100% of the time in a blind test and should allow researchers to develop an accurate gestalt to separate males and females of the Sri Lankan weevil.