Glow in the dark beetles – all eggs, larvae and pupa are bioluminescent. Some adults flash lights at night as part of their mating ritual. The large thorax or pronotum is extended and covers the head. Fireflies can sometimes be mistaken for soldier beetles, which have a somewhat smaller thorax. All fireflies, both male and female have 11 antenna segments. The 2nd segment is quite short. Only one, Pollaclasis bifaria has feathered antenna. The wing-covers or elytra are hard and one of the main ID factors is presence or absence of a golden border around the wings. Where the wings meet down the center of the beetle is called a suture or inside wing border. The abdomen has 7 segments (female) or 8 (male). The male has two light organs or mating flashes on the abdomen underside, usually the last two segments before tip; females have only one.
Phosphaenus hemipterus is odd and stays larvae-like even as an adult with stub-like, non-functioning wings.
All fireflies have ‘reflex bleeding’, where a fluid is released through leg joints and abdominal segments if disturbed.
The female lays eggs during the summer, usually in moist or wet ground, at the base of grasses, or in rotting wood. Larvae hatch and some burrow into the ground during the day. They feed on earthworms, snails, slugs and smaller insects. Larvae usually over-winter and pupate the next spring. Some have a two-year life cycle, and some over-winter as adults.
We have 23 fireflies in Ontario:
Lucidota atra (2 species)
Photinus (11 species)
Pyractomena angulata (4 species)
Pyropyga decipiens (2 species)