Influence of different pest control agents on some biological aspects of Chrysoperla carnea (Stephens) [electronic resource]

Includes bibliographic reference

Four different pest control agents (Beauveria bassiana (Balsam), orange oil, neem oil, and pyriproxyfen) were evaluated at 0.5, 1 and 2 of field recommended concentrations (FRC) for their effectiveness on the biological aspects of the 2nd larval instar of Chrysoperla carnea (Stephens) under laboratory conditions of 26 ± 2°C and 65 ± 5% RH. Taking into consideration the relative potency at the LC25 and LC50 levels, the obtained results showed that the neem oil was the highest effective agent against 2nd larval instar of C. carnea, recording the LC50 value of 10.61 4g / ml solvent, while B. bassiana was the lowest effective agent recording the LC50 value of 396.99 4g /ml. The means of larval duration were 6.83, 7.33, 6.50, 5.51 and 6.60 days, for B. bassiana, neem oil, pyriproxyfen, orange oil at 0.5 FRC and control, consecutively. While the means of pupal duration
were 8.33, 7.33, 8.00, 7.00 and 8.50 days, for the same pest control agents and control, respectively.
The maximum percentage of cocooning (100.00%) was recorded when larvae of the predator were fed on treated aphid nymphs with B. bassiana at all tested concentrations, and fed on neem oil and pyriproxyfen at 0.5 and 1 FRC, as well as control larvae. Meanwhile, the minimum value of 75.00 % was noticed when the larvae were fed on treated aphid nymphs with neem oil or orange oil at 2 FRC.
Obtained results cleared that the highest mean of adult emergence of C. carnea (60.00 %) was recorded for larvae fed on treated aphid nymphs with orange oil 0.5 or 1 FRC. Whereas, the lowest one (20.00 %) was noticed in the case of larvae reared on treated aphid nymphs with pyriproxyfen at 2
FRC. Generally, control larvae exceeded other tested pest control agents in adult emergence, showing 70.00%. The maximum of fecundity, fertility, and hatchability percentage (324 eggs, 86.04 and 91.22%, respectively) when the larvae of the predator were fed on untreated aphids. On the contrary,
the 1 RFC pyriproxyfen resulted in the minimum of fecundity and fertility showing 12.00 eggs and 50.00 %, successively. On the basis of the obtained results, it was obvious that the tested pest control agents (B. bassiana, orange oil, neem oil, and pyriproxyfen) at the highest concentrations are not
considered to have an environmental safety profile on C. carnea. We suggest that the use of the tested pest control agents might be useful in combination at the low concentrations with release of C. carnea
larvae in integrated pest management (IPM) programs.

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