Table 1. Generalized linear model testing the effects of insecticide, season, site type (urban or peri-urban) and site (nested within site-type) on bioassay mortality.

Model terms included	χ2	d.f.	P-value
insecticide	35.5	4	3.7 ×10-7
site type	6.5	1	0.011
site(site type)	9.2	4	0.057
insecticide×season	15.7	5	0.008
insecticide × site type	12.1	4	0.016

χ²=Chi-square value

d.f=degree of freedom