Preliminary Survey of Parasitism of Leaf Roller, Sylepta derogata (Fabricius) (Lepidoptera: Pyralidae) in Roselle (Hibiscus sabdariffa L. (Malvales: Malvaceae) in Maiduguri, Nigeria

Abstract

This study was carried out in Maiduguri in north eastern Nigeria during the cropping seasons of 2018 and 2019 to determine the seasonal infestation rate, larval abundance and parasitism of Syleptaderogata (Fabricius) (Lepidoptera: Pyralidae) in roselle, Hibiscus sabdariffaL. Data collection was from 30 farmer fields planted with roselle plants. Data on plant infestation, pest abundance and parasitism were analyzed using Kruskal-Wallis test. Mean percent plant infestation by S. derogataper farmers’ field ranged from 84% in 2019 to 88% in 2018, and was not significantly different between years. Mean number of S. derogata larvae per farmers’ field was significantly higher in 2018 (83) than in 2019 (69). In both years, parasitization by microgastrinae was high (97%-98%), whilst that by Bracon sp. was low (2%-3%). Mean total larval parasitism per farmers’ field significantly varied between years, and was particularly higher (18%) in 2018 than in 2019 (5%). In conclusion, results indicate that S. derogata is seasonally responsible for heavy infestation of roselle plants in parts of north eastern Nigeria. Microgastrinae accounts for a high proportion of host parasitization, whilst that by Bracon sp. is negligible. Total larval parasitism is seasonally low, and insufficient to control this pest in roselle grown in this locality.