Comparison of biological methods to control Aphis fabae Scopoli (Hemiptera: Aphididae) on kalanchoe crops in East Africa

Aphids cause considerable damage to numerous crops all over the world and insecticides are main means of controlling them, despite their detrimental impacts on human environmental health. This study assessed effectiveness parasitoid Aphidius colemani Viereck (Hymenoptera: Braconidae), a mixture predatory ladybird beetles, Hippodamia variegata Goeze, Chilocorus calvus Chiccl, Cheilomenes propinqua Mulsant (Coleoptera: Coccinellidae), an entomopathogenic strain Aspergillus flavus Link (Eurotiales: Trichocomaceae), collected locally in Tanzania, control Aphis fabae Scopoli (Hemiptera: Aphididae). After assessing predation parasitism rates these natural enemies at different aphid densities laboratory experiments, ability aphids kalanchoe was greenhouse experiment two seasons. The largest number A. parasitized or consumed found density 160 per predator, parasitoid. At that density, adult female 114 day, average, adults C. calvus, H. variegata, 75, 72, 85 respectively. spores applied 1 × 107 ml−1 reduced population by 7.9 12.6 times within 10 days first second seasons respectively, as opposed 2.8 2.5 releasing ladybirds rate 5 adults/m2, 3.3 9.5 2 adults/m2. confirmed potential bio-control agents for fabae. However, use isolated undermined its production aflatoxin. Further research is therefore required tap into non-toxic and/or other fungi.