Male Brooding Behavior of the Water Bug Abedus herberti (Hemiptera: Belostomatidae)

Abstract

Male parental behavior of Abedus herberti Hidalgo is described and its adaptive significance analyzed. Encumbered males provide for the needs of their eggs by keeping them wet, frequently exposing them to atmospheric air, and maintaining an intermittent flow of water over them by brood pumping (rocking up and down on the longitudinal body axis) while below the surface. In addition, males select microhabitats in nature which tend to promote the successful development of embryos and eclosion of nymphs. Eggs removed from the backs of males failed to hatch when covered with water or left in open air. Egg failure was attributable to inadequate gas exchange, desiccation, and nymphal entrapment in the chorion. Eggs left on the backs of healthy males were about 97% successful. Hungry brooding males were inhibited from feeding on 1st instars. Probable costs of brooding to the individual male included reduced predatory efficiency, increased exposure to predation, reduced dispersal options, and upper limits on reproductive potential in addition to direct caloric expenditures. These costs were buffered by the male's ability to abort brooding when conditions were suboptimal. Male fitness is served by brooding in that most of the eggs borne by the individual probably contain his genes. Brood pumping by Abedus herberti has no behavioral antecedent in representatives of 2 subordinate genera.