Impact of sulfur dust application on the abundance of two important coccinellid predators in marrow fields

Bulletin of the National Research Centre

Table 1 Population densities of Coccinella undecimpunctata adults in untreated and sulfur-treated marrow cultivations

Inspection periods (hours)	First area		Second area	F value (1)
	Average number of adults/50 plants/plot ± SE
	Treated plot	Untreated plot	Untreated area
(−) 0	16.20 ± 0.86 aAB	18.20 ± 0.86 aC	17.00 ± 0.71 aB	1.535^NS
(+) 2	6.80 ± 1.07 bD	29.60 ± 1.50 aAB	27.80 ± 1.85 aA	70.474**
(+) 12	8.40 ± 1.36 cD	32.80 ± 0.86 aA	29.20 ± 1.16 bA	132.102**
(+) 24	9.20 ± 1.16 bCD	31.00 ± 2.92 aA	30.80 ± 1.50 aA	38.983**
(+) 48	13.80 ± 2.69 bBC	25.20 ± 1.66 aB	18.60 ± 1.21 bB	8.591**
(+) 72	17.20 ± 1.56 aAB	18.40 ± 1.03 aC	15.80 ± 1.69 aB	0.801^NS
(+) 7 days	20.40 ± 1.72 aA	14.00 ± 2.35 aC	10.80 ± 1.50 bC	6.699*
F value (2)	10.348**	17.551**	29.961**

Before application (−), after application (+), df 1 = 2, 9, df 2 = 6, 21. Data in rows with the same small letters are not significantly different (P value at 5%). Data in columns with the same capital letters are not significantly different (P value at 5%). *Significant, **highly significant, and NS insignificant