Pesticidal agents such as entomopathogenic fungi and medicinal plant extracts can be used as a component of integrated pest management. Biocontrol agents such as fungal isolates can be used as a component of integrated pest management. An evaluation of plant extracts from Azadirachta indica and Justicia schimperiana and two strains of entomopathogenic fungi were carried out on Ethiopian rape (Brassica carinata) against two stages (adult and nymph) of cabbage insect pests (aphids) in the laboratory and greenhouse condition. The efficacies of different treatments were examined, and results were recorded for plant extracts and entomopathogenic fungi on cabbage aphids. A significant difference was observed in the mortality of aphid insect pests recorded at different intervals of days. The adult aphid was reduced gradually from 8.65/plant to 2.77/plant after six days of spraying with A. indica indicating the highest efficacy. Moreover, the adult aphids after spraying of entomopathogenic fungi (BEI1) reduced from 11.2/plant to 6.5/plant after six days of spraying at 1 × 108 conidia/mL, showing the highest efficacy. The present results suggest the possibility of using a combination of entomopathogenic fungi and plant extracts to manage Brevicoryne brassicae (aphids). It revealed that a given combination displayed considerable efficacy to reduce B. brassicae (aphids) infestation. From the result, the adult aphids sprayed with A. indica + BEI1 reduced from 7.01/plant to 1.74/plant after six days of spraying with the highest efficacy. Generally, maximum percent of mortality was identified in plant extract treatment next to coapplication against adult aphids on sixth day of application. Similarly, conidial suspension of entomopathogenic fungi was found to have high activities for adult aphids. Therefore, based on the present result, products of fungal isolates and plant extracts should be used for further tests against other insect pests.

Cabbage aphid (Brevicoryne brassicae L.) is an important sucking insect pest of cabbage and other vegetables. It can be controlled using continuous chemical insecticides that cause human health and environmental problems. The present study was, therefore, designed to evaluate antagonistic activities of indigenous entomopathogenic fungi together with selective insecticides within the context of integrated pest management (ipm). To this effect, four strains of entomopathogenic fungi from Beauveria bassiana and Metarhizium anisopliae were tested for their antagonistic activities against the cabbage aphid. The result showed that microbial inoculums of 1×107 and 1×108 conidia mL-1 showed high mortality (66.7-100%) of aphids after 6 days of incubation under laboratory condition. Among them, bei1 (B. bassiana) isolate was the most virulent strain on adult aphids and nymphs showing 67 to 100% and 39-72% mortality after 4th-5th days of treatments. The data also indicated that the fungal isolates were compatible to the three insecticides with 70% - 91% conidial germination by M. anisopliae and 68%-98% conidial germination by B. bassiana after 24 hours of treatment of which Karate was the most compatible insecticide to the isolates. The single treatment with the entomopathogens gave a substantial percentage mortality of insect pests after 11 days compared to (80-100%) mortality obtained from a combined treatment with half recommended dose of Karate in seven days, which was similar to the treatment with full dose of the insecticide control. The treatments were slightly more effective on adults than they were on aphid larvae.  It is interesting to note that the combination of bei1 + Ka induced 100% mortality of adult aphids after seven days of incubation compared to the 11 day incubation required to kill the nymphs. Given that the full dose of karate killed the adult aphids in five days, the 100% mortality of the half dose of karate with bei1 within seven days was a good indication that the ipm could reduce pollution problem. Thus, B. bassiana and M. anisopliae with Karate could be further tested in the field to realize their potential as bioinsecticides for integrated pest management to control mustard aphids.