In Vitro Assessment of the Reproductive Biology of Sweet Potato Weevil, Cylas formicarius (Fabricius) (Coleoptera: Brentidae) among Commonly Grown Sweet Potato Cultivars

Authors

• Jerah Mystica Novenario, College of Agriculture Systems and Technology Pampanga State Agricultural University, PAC, Magalang, Pampanga 2011 PhilippinesFollow
• Flor A. Ceballo-Alcantara, Institute of Weed Science, Entomology, and Plant Pathology, College of Agriculture and Food Science, University of the Philippines Los Baños

Publication Date

6-1-2026

Abstract

The sweet potato weevil, Cylas formicarius (Fabricius), is a devastating pest of sweet potato, Ipomoea batatas (L.) Lam., with a specific point of damage at the tuber where eggs are oviposited, and voracious larvae feed. Farmers in Tarlac province in the Philippines claim that a specific cultivar is highly infested by the pest, suggesting that other cultivars may not be susceptible to the pest damage. This study aimed to determine the reproductive biology of the weevil across 3 sweet potato cultivars (Inubi, Super Bureau, and Bureau) frequently grown in Central Luzon. Since the weevils are nocturnal, behavioral observations were conducted at night, starting from 1800H to 0050H. Courtship activities started at 2300H with the males approaching the females. Antennation is initiated by the females, followed by mounting attempts by the males. Mating was observed at 0010H and lasted for an average of 52 min. The average reproductive output per female per day was 1.37 eggs, while the lifetime fecundity was 40.5 eggs, regardless of the sweet potato cultivar. The peak of the oviposition period was observed to be from 1 to 14 d after adult emergence and slowly declined until 26 d. The resulting offspring had a female-biased sex ratio, which ranged from 0.89 to 0.92. Results imply that the reproductive performance of C. formicarius is not affected by the sweet potato cultivar to which they were exposed.

Recommended Citation

Novenario, Jerah Mystica and Ceballo-Alcantara, Flor A. (2026) "In Vitro Assessment of the Reproductive Biology of Sweet Potato Weevil, Cylas formicarius (Fabricius) (Coleoptera: Brentidae) among Commonly Grown Sweet Potato Cultivars," The Philippine Agricultural Scientist: Vol. 109: No. 2, Article 20.
Available at: https://www.ukdr.uplb.edu.ph/pas/vol109/iss2/20