Entomopathogenic Fungi against Cabbage Aphids, Brevicoryne brassica L.

Abstract

The present investigation was carried out during two successive Cabbage seasons (2016-2017 and 2017- 2018), to study the impact of entomopathogenic fungi on Brevicoryne brassica L. The aphid Populations were evaluated in the field early in the season in December 2016 which began to appear on cabbage plants. Thereafter number of aphids increased gradually to reach a peak of abundance during December 2016 & 2017 and January 2017 & 2018). Three concentrations were used (1 x105, 1 x 106 and 1 x 107 spores/ ml.). Under laboratory conditions, the results showed that V. lecanii, M. anisopliae, and B. bassiana have high toxicity and mortality rates occurred after 3rd day from treatment. The maximum percent of mortality (100 %) occurred after the 10th day from treatment with the 3rd concentration in V. lecanii. The 3rd concentration (1 x 107spores/ ml.) was highly toxic in V. lecanii, B. bassiana, and M. anisopliae to the adult of Brevicoryne brassica L. compared with the other two concentrations.Under field conditions, the third concentration (1 x 107) also, was the best concentration against Brevicoryne brassica L. after the third application in V. lecanii, B. bassiana, and M. anisopliae. The percent of reduction was ranged between 93.3 to 99.2% and 92.0 to 97.7 in the high concentrations, in the two seasons, respectively. V. lecanii and B. bassiana were highly effective than M. anisopliae against Brevicoryne brassica L. These results confirmed that V. lecanii, B. bassiana, and M. anisopliae isolates are promising agents for Brevicoryne brassica L. control in the field.

Keywords

• entomopathogenic fungi; brevicoryne brassica l; control