Do male golden egg bugs carry eggs they have fertilized? A microsatellite analysis

In the golden egg bug, Phyllomorpha laciniata (Heteroptera, Coreidae), both males and females carry eggs on their back. Although females cannot carry their own eggs, males may carry eggs that they have fertilized. If males carry eggs they have fertilized, their behavior may be interpreted as paternal care. In this article, we provide genetic data for paternity assignment of eggs carried by 40 males collected from the field. The males and the eggs were typed by using four highly polymorphic microsatellite DNA markers. Out of the 247 eggs typed, 87% were excluded from the father-offspring relationship based on single-locus (least conservative exclusion) mismatches. Under the more conservative (exclusion by at least two single locus mismatches) method, 78% of the eggs were nonpaternal. Relatedness estimates further supported our paternity analyses. The average relatedness of the eggs to the carrying males was low (b-sub-em = - 0.052 ± 0.024 SE). Within the population, males were unrelated to each other (b-sub-mm = - 0.004 ± 0.0002 SE), as were the eggs carried by individual males (b-sub-eggs = - 0.004 ± 0.0001 SE). This first genetic study on the breeding system of the golden egg bugs did not find any support for the claim that egg carrying functioned as paternal care, nor did it support kin selection as explanation for conspecific egg carrying. Copyright 2003.