Table 4.

General linear models testing simultaneously the effects of environmental factors on ovipositor length and morphological clustering membership coefficients for crickets from the Pennsylvania hybrid zone. Shorter ovipositors and lower morphological clustering membership coefficients represent Gryllus pennsylvanicus crickets. VIF = Variance inflation factor

Term	Beta	Std Beta	SE	t-Ratio	VIF	P
Ovipositor length
Intercept	186.183	0.000	26.779	6.95	–	<.0001
Latitude	−4.181	−0.546	0.670	−6.24	1.277	<.0001
Vegetation density	−0.013	−0.249	0.005	−2.66	1.466	0.010
Natural vegetation	−0.016	−0.213	0.007	−2.16	1.622	0.034
Latitude × natural vegetation	0.050	0.215	0.021	2.45	1.287	0.017
Vegetation density × natural vegetation	−0.001	−0.272	0.000	−3.11	1.282	0.003
Morphological clustering membership coefficient
Intercept	29.478	0.000	4.171	7.07	–	<.0001
Latitude	−0.717	−0.592	0.104	−6.89	1.276	<.0001
Organic matter	−0.042	−0.180	0.018	−2.32	1.046	0.022
Natural vegetation	−0.004	−0.363	0.001	−4.59	1.079	<.0001
Latitude × natural vegetation	0.012	0.331	0.003	3.900	1.244	0.0002
Organic matter × natural vegetation	0.001	0.238	0.001	3.000	1.089	0.003

Whole model statistics: ovipositor length (F_[5,73] = 18.861; R² = 0.563; P < 0.0001); morphological clustering membership coefficients (F_[5,82] = 18.084; R² = 0.524; P < 0.0001).