Abstract
Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a polyphagous pest with a wide geographic distribution. This pest first arrived in Brazil in 2013, and since then studies on possible control methods for it have been necessary. A possible method for the control of H. armigera is using the egg parasitoid Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). Therefore, the objective of this study was to evaluate the performance of T. pretiosum on H. armigera eggs, which are known to represent suitable hosts for the development of this parasitoid species in the laboratory. Parasitism and emergence rates and the duration of the egg-to-adult period of T. pretiosum were investigated following 24- and 48-h exposures of this parasitoid to H. armigera and Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) eggs. The longevity of offspring after the 24-h exposure was studied, as well as the frequency of parasitism and emergence, host preference, and the emergence of offspring from eggs of different ages or oviposited by lepidopterans on different days. Parasitism was 14.4 and 34.9% more frequent on C. cephalonica than on H. armigera after 24 and 48 h of exposure, respectively. In C. cephalonica, parasitism was 27.2% higher after 48 h. Parasitism was more frequent on C. cephalonica eggs collected on the second day of oviposition (76.2%), and on H. armigera on the third day of oviposition (71.1%). Parasitism frequency was lower on 2-day-old C. cephalonica eggs (63.3%) and on 3-day-old H. armigera eggs (41.3%). When tested with a chance of choice between hosts, T. pretiosum preferred H. armigera, while in the test with no chance of choice there was no difference in preference. Thus, T. pretiosum may be considered a tool for the Integrated Pest Management (IPM) of H. armigera.
Highlights
Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a polyphagous pest with a wide geographic distribution
Comparing parasitism on the same host over time, an increase of 27.2% was observed when the female T. pretiosum was exposed to eggs of C. cephalonica for 48 h compared to that after 24 h (t = −4.90, df = 43, p < 0.0001)
The present study contributes basic information useful for studies aiming to achieve the management of an introduced pest in Brazil, H. armigera, using the egg parasitoid T. pretiosum, which is efficient at controlling some lepidopteran pests in several crops of economic importance[16,27]
Summary
Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a polyphagous pest with a wide geographic distribution. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is an important agricultural pest worldwide because it is highly polyphagous and damages several crops of economic importance, such as tomato, cotton, soybean, corn, and sunflower[1,2,3,4]. This species was first reported in Brazil in 2013 at high population sizes on soybean, corn, and cotton crops[5,6]. Among the species in the genus Trichogramma, T. pretiosum Riley (Hymenoptera: Trichogrammatidae) has been commercialized for the control of lepidopteran eggs[13,14,15], and has been reported in approximately 18 different hosts and in 13 crops[16]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
