Table 2. A geographic cline in ant colony production parameters.

Worker production	P. phylax (F2,65 = 61.46***; adjusted R2 = 0.644)				C. mckeyi (F2,58 = 43.54***; adjusted R2 = 0.586)
Effect	byi±SE	byi′	T	P	byi±SE	byi′	T	P
Size of colony	0.7674±0.0723	0.7755	10.608	<10−3	0.7215±0.0903	0.6694	7.990	<10−3
Distance	0.0013±0.0005	0.1836	2.511	0.015	0.0031±0.0008	0.3105	3.706	<10−3
Intercept	−0.1205±0.2527	–	−0.477	0.635	0.0444±0.2082	–	0.213	0.832

Results of multiple regressions explaining the parameters of productivity of colonies of the mutualist ant Petalomyrmex phylax and the parasitic ant Cataulacus mckeyi for each caste (workers, winged females, males), as a function of the geographic distance (km) to the southern edge of the range of the Leonardoxa system when controlling for colony size (the number of adult workers). b_yi: partial regression coefficient (±Standard Error), b_yi′: standardized partial regression coefficient. N = 68 colonies for P. phylax and 61–74 for C. mckeyi.