Control of Aphis gossypii in organic citrus orchards (BIOFRUITNET Practice Abstract)

Summary

Beneficial insects and biopesticides are safe for the environment. Pests do not develop resistance, and higher yields may compensate for the increased costs.
Practical recommendations
• Effective beneficial insects include the parasitoid Aphidius colemani and larvae/adults of the predatory coccinellid, Coccinella septempunctata (Picture 1 A and B).
• Low-input management supports the presence of other beneficial insects, such as hoverflies and lacewings.
• Focus on controlling ants to support the establishment of beneficial insects and reduce the movement of aphids within the crop and from surrounding habitats.
• Biopesticides active against aphids are fungal pathogens (Picture 1C), such as Verticillium lecanii (Zimmerman), Bauveria bessiana (Bals.-Criv.) and Paecilomyces fumosoroseus (Wize). Fungi are harmless for beneficial insects and can be used in conjunction, enhancing control efficiency.
• Release beneficial insects and fungal pathogens several times within the growing season, especially in spring and early summer if infestation rates are high.
• Consider that fungal pathogens are more effective when pests are subjected to stress. Higher control rates are expected by applying the pathogens together with low dosages of biopesticides.
• Abamectin and Azadirachtin are efficient biopesticides but could have negative effects on beneficial insects if simultaneously used. Therefore, release beneficial insects 7-10 days after treatment with these biopesticides.