Aleiodes ceres Shimbori, 2023 (Hymenoptera: Braconidae), potential biological control agent of three species of the Spodoptera complex in Brazil

Author(s)

Jailma Rodrigues dos Santos

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2025-04-28

Examining board members

José Roberto Postali Parra; Geraldo Andrade de Carvalho; Dori Edson Nava

• Advisor: José Roberto Postali Parra

Abstract

Aleiodes Wesmael, 1838 is a widely distributed koinobiont endoparasitoid genus of Lepidoptera, with numerous described species. Recently, the species Aleiodes ceres Shimbori, 2023, was collected in São José dos Pinhais, Paraná, Brazil, parasitizing species of the Spodoptera complex. This species has demonstrated significant potential as a biological control agent against Spodoptera cosmioides (Walker, 1858), Spodoptera eridania (Stoll, 1782), and Spodoptera frugiperda (J.E. Smith, 1797), pests that cause severe damage to soybean and corn crops. This study investigated the potential of A. ceres as a biological control agent against these three species, including different host instars (1st, 2nd, 3rd, and 4th instars) and diets (artificial and natural). Biological and behavioral parameters were evaluated, such as parasitism rate, acceptance rate, foraging time, parasitism time, egg-to-pupa, pupa-to-adult, and egg-to-adult durations, emergence rate, sex ratio, functional response, parasitism rhythm, longevity, and consumption of artificial diet and foliar area by parasitized larvae. Parasitism was highest when it occurred in the second instar of all three host species, being substantially enhanced by the use of natural diets (60.00 ± 0.04% to 84.30 ± 2.95%) compared to the artificial diet (18.10 ± 2.89% to 26.30 ± 1.90%). Spodoptera eridania and S. cosmioides exhibited the highest parasitism rates when fed on soybean leaves (84.30 ± 2.95% and 79.70 ± 2.84%, respectively), while for S. frugiperda, parasitism rates were 60.00 ± 0.04% on soybean and 65.30 ± 3.86% on corn. Diet influenced the behavior and development of A. ceres. Natural diets promoted higher acceptance rates, enhanced foraging behavior, and reduced parasitism time, suggesting a possible allelochemical interaction. Hosts fed on soybean leaves supported faster development of A. ceres than those fed on artificial diet. The egg-to-adult period for S. cosmioides and S. eridania on soybean leaves was 13.60 ± 0.21 days and 14.00 ± 0.27 days, respectively, while for S. frugiperda on corn leaves, it was 13.00 ± 0.10 days. Despite this, the artificial diet supported an emergence viability of over 75% and a comparable sex ratio (0.30 ± 0.10), indicating its suitability for rearing. Aleiodes ceres exhibited a type II functional response, reaching a saturation plateau at 15 larvae for both S. eridania and S. frugiperda. The parasitism rhythm showed that 80% of A. ceres\' parasitism capacity was reached by the 20th day for S. eridania and by the 25th day for S. frugiperda. The average longevity of A. ceres ranged from 32.80 ± 2.09 to 35.40 ± 3.39 days for females, and from 32.60 ± 3.61 to 36.00 ± 4.37 days for males. Parasitism reduced larval feeding by more than 90.00%, highlighting its potential to reduce field damage. Cluster analysis demonstrated that A. ceres is a suitable parasitoid for rearing on the three studied species, confirming its effectiveness as a promising biological control agent against S. eridania, S. frugiperda, and S. cosmioides. (AU)

• FAPESP's process: 22/06321-2 - Aleiodes sp. nov. Wesmael, 1838 (Hymenoptera: Braconidae), potential biological control agent for species of the Spodoptera complex
• Grantee: Jailma Rodrigues dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate