Adaptation without Specialization Early in a Host Shift.

AbstractStudents of speciation debate the role of performance trade-offs across different environments early in speciation. We tested for early performance trade-offs with a host shift experiment using a member of the species complex of treehoppers (Hemiptera: Membracidae). In this clade of plant-feeding insects, different species live on different host plants and exhibit strong behavioral and physiological host specialization.