THE EFFECTS OF EARLY-LIFE CONDITIONS ON THE DEVELOPMENTAL TIME AND FITNESS OF INVASIVE TURKESTAN COCKROACHES (BLATTA LATERALIS).

Developmental rate is a fundamental axis of life-history variation across taxa. Early-life conditions can influence the development and body condition of individuals and affect long-term reproductive success and longevity. Maternal effects are an important source of variation in offspring fitness and can drive divergent reproductive strategies. In this study, the population density of Turkestan cockroaches (Blatta lateralis) was manipulated during development to measure both the short-term effects on developmental rate and body size at maturity, and the long-term effects on fecundity and survival. Individuals reared at a low density developed faster and females were larger on emergence, suggesting they were able to achieve better condition at maturity than individuals reared at a higher density. Low density females began reproduction earlier, had more reproductive attempts, lived longer, and produced offspring with longer embryonic developmental periods that were larger at hatch than females reared at a high population density, suggesting high quality early developmental conditions broadly lead to higher fitness during adulthood. Intraspecific competition for food resources during development likely constrained the condition and reproductive effort of females reared at a high density. These results highlight the importance of considering early-life conditions in future studies of life-history evolution.