Table 3. Virulence bioassay: Accumulated mortalities and Tukey test.

Treatment	IO-20	IO-23	IO-27	IO-28	Control
Supernatant (24h)	60 ± 20 Aa	100 ± 0 Aa	73.33 ± 23.09 Aab	80 ± 20 Aa	20 ± 0 B	df = 4; F = 10,000; P = 0.002.
Bacterial cells (24h)	80 ± 20 Aa	33.33 ± 23.09 Bb	100 ± 0 Aa	100 ± 0 Aa	20 ± 0 B	df = 4; F = 22,857; P = 0.0001.
Supernatant (48h)	100 ± 0 Aa	93.33 ± 11.55 Aa	73.33 ± 11.55 Aab	73.33 ± 23.09 Aa	20 ± 0 B	df = 4; F = 18,500; P = 0.0001.
Bacterial cells (48h)	86.66 ± 23.09 Aa	93.33 ± 11.55 Aa	53.33 ± 11.55 ABb	53.33 ± 23.09 ABa	20 ± 0 B	df = 4; F = 9,850; P = 0.002.
	df = 3; F = 1.212; P = 0.374.	df = 3; F = 9.848; P = 0.005.	df = 3; F = 4.934; P = 0.032.	df = 3; F = 3.094; P = 0.090.	*

Mortality rates (in %) determined for Providencia isolates assayed against adults of the olive fly. Values followed by the same letter are not statistically different using mean comparisons (Tukey test; P<0.05) angular transformed data. Capital letters represent comparisons within a row and lower case letters comparisons within a column. The asterisk “*” indicates that statistical analysis is not feasible (due to equal percentages for all data).