Biological Natural Role of Major Parasitoids and Predatory Species Associated with Common Insects’ Pests, in Cowpea Fields

Ali, Mohamed A.; Bahy El-Din, Ismaeil A.; Abazaid, Mohamad A. A.; EL-Khawas, Mostafa A. M.

doi:10.21608/eajbsa.2025.461618

Biological Natural Role of Major Parasitoids and Predatory Species Associated with Common Insects’ Pests, in Cowpea Fields

Document Type : Original Article

Authors

Biological Control Research Department, Plant Protection Research Institute, Agriculture Research Centre.

10.21608/eajbsa.2025.461618

Abstract

Cowpea is an important strategic vegetable, representing a part of traditional cropping systems. Several insects’ pests attack cowpea during its field development stage (from germination to maturity) and also in stores. In cowpea field, results recoded occurrence of following insects’ pests: the leafminer, Liriomyza trifolii Burgess (which had highest recorded total numbers of infested leaflets, pest mines and pest larvae during second week of May, 2024), the cowpea aphid, Aphis craccivora Koch. (which had highest recorded total number of pest individuals during second week of April, 2024), the leafhopper, Empoasca sp. and the green bug Nezara viridula L., were also recorded. Two parasitoids’ species; Diglyphus isaea (Walker) (a larval ectoparasitoid of the leafminer, L. trifolii, that was recorded with a maximum parasitism percentage (34.81%) during third week of April, 2024) and Diaeretiella rapae (M’Intosh) (a primary endoparasitoid of the cowpea aphid, A. craccivora, that was recorded with a maximum parasitism percentage (39.83%) during last week of April, 2024). Two common predatory species were also recorded in cowpea field; including Chrysoperla carnea (Steph.) (Neuroptera: Chrysopidae) and Coccinellidae (Coleoptera) predators (which mainly included Hippodamia convergens (Geur.) and Coccinella undecimpunctata L.), (where, maximum total number of all recorded predatory species individuals (108 individuals) was during second half of April 2024). Means calculations of resulted cowpea green pods yield weight and length after 117days post cowpea grains sowing were evaluated. Generally, occurrence of major natural enemies was directly related with that of recorded pests' species populations. Natural role of two recorded parasitoids species (D. isaea and D. rapae), besides predatory species (Ch. carnea and Coccinellidae), must be continuously protected and they can be used by their mass rearing and releasing against pests' species attacking cowpea fields or other related fields that suffer from common pests' attacks when planning I.P.M. programs.

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