Morphological characterization and development of the immature stages of the parasitoid Zaeucoila unicarinata Ashmead (Hymenoptera: Figitidae)

Abstract Zaeucoila unicarinata Ashmead (Hymenoptera: Figitidae) is an endoparasitoid of the leafminer Liriomyza sativae Blanchard (Diptera: Agromyzidae), a significant pest in agricultural systems. Despite its ecological importance, limited information is available on this parasitoid species. Understanding its bioecological characteristics is crucial for advancing biological control strategies. This study aimed to elucidate the developmental process and provide a detailed morphological characterization of the immature stages of Z. unicarinata . To investigate the development of Z. unicarinata and characterize its immature stages, 50 parasitized larvae or pupae were dissected every 24 h under a stereoscopic microscope throughout the parasitoid developmental period. The complete development of the immature stages required approximately 22 days. Morphological Characteristics: The eggs were elongated with a subtle stalk-like structure. The first and second instar larvae exhibited a eucoiliform shape with average lengths ranging from 0.62 mm to 1.14 mm. The third and fourth instar larvae transitioned to a hymenopteriform shape, measuring approximately 1.54 mm and 1.56 mm in average length, respectively. Pupae displayed a clearly defined head, thorax, and abdomen, with an average length of 1.46 mm. These findings provide valuable insights into the developmental biology of this parasitoid, thus contributing to its identification during the immature stages and expanding foundational knowledge essential for its potential application in biological control programs. Moreover, understanding its developmental traits may facilitate mass-rearing protocols and improve the use of biological control in integrated leafminer management systems.