Table 4.

Summary bioassay data on Spodoptera frugiperda populations and Helicoverpa armigera (GR laboratory line) involving topical application to the insect with contact insecticides

Toxin	Population/Species	N	Slope	LC50	95% C.I.	LC99	95%CI	χ2 (Degrees of Freedom)	P	Toxicity ratio (H. armigera = 1)
Alpha cypermethrin µg/larvae	H. armigera	1328	2.849 ± 0.140	0.0036	0.0032–0.0041	0.023	0.018–0.032	109.84 (57)	<0.001	–
	Sf20-1	675	2.399 ± 0.154	0.201	0.171–0.239	1.88	1.31–3.06	43.903 (28)	0.028	56
	Sf20-4	766	2.186 ± 0.132	0.523	0.427–0.641	6.06	3.99–10.85	67.208 (32)	<0.001	145
Methomyl µg/larvae	H. armigera	858	0.809 ± 0.059	0.057	0.031–0.097	43.12	10.27–53.93	135.89 (36)	<0.001	–
	Sf20-1	765	1.064 ± 0.076	0.254	0.177–0.356	39.2	15.81–156.30	72.309 (32)	<0.001	4
	Sf20-4	631	0.874 ± 0.07	2.96	1.87–4.66	1363.7	380.11–10950.47	57.160 (26)	<0.001	52

S. frugiperda from Walkamin Queensland and from Kununurra Western Australia are coded Sf20-1 and Sf20-4, respectively. Helicoverpa armigera laboratory line is coded as ‘GR’. The concentration of each pesticide required to kill 50% and 99% of the test subjects (H. armigera, S. frugiperda) are given as LC₅₀ (50% lethal concentration) and LC₉₉ (99% lethal concentration), respectively. 95% confidence intervals (95% CI) for both LC₅₀ and LC₉₉ are also provided. Sample sizes (N) of H. armigera and S. frugiperda laboratory culture lines used in the bioassay tests are indicated. P-values (P) associated with the χ² tests are also provided.