Abedus

Several Abedus herberti, including both males with eggs on their back and individuals without eggs

Giant water bugs exhibit male parental care. In Abedus and other species in the subfamily Belostomatinae (but not subfamily Lethocerinae), the female glues the eggs onto the male's back and the male tends them until the eggs hatch.[4][10] The eggs are initially yellow-white but gradually change to gray-brown.[4][11] They can be quite large compared to the size of the adult; in the up to 4 cm-long (1.6 in) A. herberti of streams in southwestern United States and northwestern Mexico each egg can measure as much as 6 mm × 2 mm (0.24 in × 0.08 in) when fully developed.[4][12] After hatching, the nymphs go through five instar stages before adulthood.[11]

Because of the unusual breeding behavior, especially A. herberti is often displayed in zoos, sometimes together with the sunburst diving beetle.[13] These two species also occur together in the wild.[14]

Abedus are sit-and-wait predators that catch small animals, especially invertebrates such as other aquatic insects and snails, but also small vertebrates such as young fish and tadpoles.[3][14] Small and medium-sized prey items are caught with their strong front legs and stabbed with the proboscis, which injects a saliva that both incapacitates the prey and dissolves it.[14] The largest food category (in A. herberti, animals 1.2 cm (0.5 in) or more in length) are mostly scavenged. The only prey they regularly catch alive (not just scavenge) in the largest category is nymphs of their own species.[14] Adults are generally highly cannibalistic towards their nymphs and older nymphs often eat younger; adults however only rarely cannibalize other adults.[11][14]