Comprehensive DescriptionRead full entry
General DescriptionGomphus adelphus is similar in appearance to its close relatives, having greenish yellow and black bodies, and a stocky abdomen with segments 7, 8, and 9 enlarged. It is distinguished from other species by black borders completely surrounding a wide yellow frons and a black inverted triangle dividing the labrum. The eyes are separated dorsally on the head. Thin yellow stripe partially divides black lateral thoracic stripe along the carina. Majority of the abdomen is black, with a pale dorsal line narrowing on the middle segments and terminating somewhere on the distal three segments. Spotted lateral abdominal lines are also narrow, but widen on the enlarged segments. Males have black claspers on terminal segment. Females generally exhibit more yellow colour on the end of the abdomen and erect spines on the head behind the ocelli. Adults are usually no more than 46mm in length (Needham et. al. 2000).