Effect of predators and host phenology on the maternal and reproductive behaviors ofGargaphia lace bugs (Hemiptera: Tingidae)

Lace bugs of the genus Gargaphia specialize on taxonomically and ecologically diverse host plants. To examine the impact of predation pressure and host phenology on Gargaphia subsocial and reproductive behavior, we compared G. tiliae, a woodland species restricted to riparian trees in the genus Tilia, and G. solani, a specialist on Solanum in early successional habitats. Both lace bug species exhibit maternal care of eggs and nymphs. Predator densities associated with Solanum were higher than those associated with Tilia and were correlated with higher levels of maternal aggression exhibited by G. solani. In both habitats, artificial exclusion of predators significantly increased nymphal survivorship over maternally guarded broods. Both species reduced the costs associated with maternal care by ovipositing into the egg masses of conspecifics. Gargaphia solani and G. tiliae differed most strikingly in voltinism and thus the potential for iteroparity. Leaf age determined the reproductive future of G. tiliae nymphs independent of photoperiod or temperature. Feeding on plants with young foliage was sufficient to trigger oviposition. Constraints imposed by host plants on life-history patterns and maternal options are discussed.