Figure 2. (a) Illustration of Glaucopsyche lygdamus life cycle (relative timing of adult, larval, and pupal stages) and path model relating change in adult abundance at time t (relative to the previous year) to the following weather variables: winter average daily maximum temperature in year t−1; winter precipitation as well as winter average daily minimum temperature in year t. Adult abundance at t−1 is the count of individuals in each spring, while variation in abundance in year t is expressed as ΔN, or the change in abundance from t−1 to t (see text for more details). Path coefficients are shown with dashed lines for the negative coefficients (*p < 0.05; **p < 0.01). R² for N_t−1 and ΔN in this model are 0.25 and 0.81, respectively. Also, see Table 1 for results from a multiple regression model including the same variables.