Available Pherobank pheromone lure for Cylas puncticollis and Cylas brunneus

Cylas puncticollis and Cylas brunneus
English: Sweetpotato weevils

Cylas puncticollis and Cylas brunneus are two major sweetpotato weevil species causing serious damage to sweetpotato crops in Africa.

C. puncticollis is widespread in East Africa and is considered the more aggressive pest. Adults feed on leaves, stems, and roots, while larvae tunnel inside stems and storage roots. This tunnelling damages the plant's vascular system, reduces root size and quality, and causes bitter terpenoid production in tubers, making them unfit for consumption. Severe infestations can lead to total crop failure and significant yield losses, especially in dry conditions.

C. brunneus, found in West, Central, and parts of East Africa, also damages sweetpotatoes by feeding on leaves and roots. Adult feeding causes punctures on root surfaces, while larvae burrow inside stems and roots causing malformation, thickening, and cracking. Though less aggressive than C. puncticollis, C. brunneus coexists with it in many fields, contributing to overall damage. Larval feeding similarly induces bitter compounds in roots, reducing their quality and marketability.

Both species cause external and internal damage recognizable by holes in vines and tunnels in tubers, which also serve as infection entry points causing rot. They reproduce rapidly, with females laying numerous eggs on vines and roots. Management relies on integrated pest control including resistant varieties, crop rotation, sanitation, and mulching.

Together, these weevils present a major threat to sweet potato production in tropical Africa, impacting farmer livelihoods and food security through direct yield loss and reduced tuber quality.

Both Cylas species share dodecyl (E)-2-butenoate in their pheromone blends, while C. puncticollis also produces the corresponding decyl ester.