Field evaluation of indigenous predacious insect, Chrysoperla carnea (Steph.) (Neuroptera: Chrysopidae), fitness in controlling aphids and whiteflies in two vegetable crops

Egyptian Journal of Biological Pest Control

Table 2 Population densities and reduction (%) of the whitefly, B. tabaci, on squash plants received two releasing rates of the second larval instar of C. carnea

	28 Jul.	7 Aug.		17 Aug.		27 Aug.		6 Sep.		16 Sep.		26 Sep.
Releasing rate per plant	Infestation	Infestation	Reduction	Infestation	Reduction	Infestation	Reduction	Infestation	Reduction	Infestation	Reduction	Infestation	Reduction
Control (untreated plants)	6.13 ± 4.1^A	14.60 ± 6.6^A	–	21.13 ± 7.6^A	–	26.33 ± 8.5^A	–	24.73 ± 7.8^A	–	15.93 ± 6.6^A	–	10.67 ± 4.5^A	–
5	5.60 ± 3.4^A	10.87 ± 3.5^B	25.62 ± 12.9	14.00 ± 6.0^B	33.68 ± 5.4	15.27 ± 6.5^B	41.22 ± 16.0	12.60 ± 7.0^B	49.00 ± 27.2	7.73 ± 5.5^B	51.54 ± 11.8	3.87 ± 3.3^B	63.76 ± 19.2
10	6.33 ± 3.1^A	6.20 ± 4.5^C	57.54 ± 17.9	4.13 ± 3.0^C	80.50 ± 10.3	1.40 ± 1.5^C	90.98 ± 4.7	0.87 ± 1.1^C	93.32 ± 4.3	0.27 ± 0.8^C	96.62 ± 5.6	0.00 ^C	100
F values (with df = 2.42)	0.173	10.451	–	31.849	–	60.179	–	58.327	–	37.313	–	43.018	–
T values (with df = 1.8)	–	–	3.237	–	9.001	–	6.658	–	3.600	–	7.72	–	4.215
P	0.842	< 0.001	0.012	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	0.007	< 0.001	< 0.001	< 0.001	0.003

Means within each column bearing different superscript letters are significantly different according to Duncan test (P = 0.05). Infestation = no. of whitefly nymphs per leaf (mean ± SD). Reduction = percentage (%) of reduction comparing to control (mean ± SD)