Interspecific interaction between Telenomus remus (Hymenoptera: Platygastridae) and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) on Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs

Abstract

This work aimes to evaluate the interspecific interaction between Trichogramma pretiosum and Telenomus remus, two biological control agents of fall armyworm (Spodoptera frugiperda) eggs. Eggs of Spodoptera frugiperda previously parasitized by Telenomus remus were offered to Trichogramma pretiosum, and those parasitized by Trichogramma pretiosum were offered to Telenomus remus. The previously parasitized eggs were tested at different embryonic development stages for each parasitoid. In addition, to evaluate the competition between species, Spodoptera frugiperda eggs were offered to the parasitoids simultaneously. The behavior of the insects was recorded under a stereomicroscope. When Spodoptera frugiperda eggs were previously exposed to either parasitoid, there was no emergence of the other parasitoid. When the Telenomus remus and Trichogramma pretiosum females were placed together with Spodoptera frugiperda eggs, Telenomus remus had a greater parasitism rate. Except searching time, all Trichogramma pretiosum behaviors took a longer time than Telenomus remus behaviors. Thus, despite belonging to different families, each of these parasitoids is able to recognize host eggs previously parasitized by the other. So, this suggests that the recognition mechanism involved is not exclusively specific.

Parasitism of Locally Recruited Egg Parasitoids of the Fall Armyworm in Africa

“…This reflects a competitive dominance of T. remus over Trichogrammatoidea sp. Similar findings have been reported for T. remus over Trichogramma atoporivilia and Trichogramma pretiosum [34,47], and for related Telenomus ullyetti Nixon over Trichogrammatoidea lutea Girault [64].…”

“…is very low compared to Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae), a parasitoid used in the biological control of FAW in Nicaragua [21]. In fact, T. pretiosum also avoids egg masses with too many scales, parasitizing only the upper layer of egg masses and those found on the edge of the egg masses, which can be easily reached from the side [47]. The poor performance of Trichogrammatoidea sp.…”

“…This could be due to exploitative competition toward eggs of FAW and/or interference competition, as observed between Trichogramma pretiosum Riley, Trichogramma atopovirilia Oatman & Platner and T. remus [34]. In fact, by being quicker in ovipositing and searching for FAW eggs, T. remus likely parasitized a larger number of eggs within a shorter period of time than its competitor [47], and thus subjected itself to superparasitism by Trichogrammatoidea sp., as suggested by previous studies [34]. Similar findings were observed for T. pretiosum on the related Telenomus heliothidis Ashmead species [63].…”

Efficacy of the parasitoid, Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) on the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) egg masses

“…Numbers in parentheses represent the range Occasionally, T. bactrae parasitoid tried to remove the scales by moving on the egg mass and passing the front legs over the antennae, also rubbing the hind legs with each other's, cleaning the scales adhered to the body. Similar behavior was observed by the egg parasitoid, Telenomus remus Nixon females on S. frugiperda egg masses (Carneiro and Fernandes 2012).…”

Global Habitat Suitability of Spodoptera frugiperda (JE Smith) (Lepidoptera, Noctuidae): Key Parasitoids Considered for Its Biological Control

“…pretiosum are estimated to be less than that of Te. remus [12,[48][49][50]. Hence further assessment, including biological parameters of these two egg parasitoids, using tools such as Insect Life Cycle Modeling (ILCYM) or CLIMEX can highlight their potential for FAW management.…”