Quality control of the parasitoid wasp <i>Trichogramma brassicae</i> (Hymenoptera: Trichogrammatidae) over 45 generations of rearing on <i>Sitotroga cerealella</i>

Liu

Pest Management Science

et al. 2023

BACKGROUND Telenomus remus (Nixon) is a dominant natural enemy controlling the invasive pest Spodoptera frugiperda (J. E. Smith). Continuous rearing of egg parasitoids on alternative hosts is crucial for mass production and cost reduction. However, to ensure the effectiveness of natural enemy products against target pests in the field, it is necessary to evaluate the parasitoid quality during the mass‐rearing process. Despite the successful rearing of this parasitoid on the alternative host Spodoptera litura (Fabricius) eggs, less attention has been paid to the quality of parasitoids continuously reared for multiple generations. Therefore, we evaluated the performance of T. remus reared on S. litura eggs for 30 generations via morphological characteristics, flight ability, and life table analysis. RESULTS Wing length, wing width, body length, and right hind tibia length of T. remus did not differ among the different generations. However, the body length of female parasitoids was significantly longer than that of males for any generation. Although the proportion of ‘flyers’ and ‘deformed’ T. remus varied among generations, the flight ability did not decline significantly after rearing on S. litura eggs. Moreover, T. remus continuously reared on S. litura eggs maintained stable parasitism performance and life table parameters on the target host S. frugiperda eggs. CONCLUSION S. litura eggs are suitable hosts for the mass‐rearing of T. remus. This study can be subsequently used to guide the production and facilitate the application of T. remus in the control of S. frugiperda. © 2023 Society of Chemical Industry.

Section: Discussionmentioning

confidence: 55%

“…Numerous studies have demonstrated that long‐term continuous rearing of parasitoids under laboratory conditions leads to poor quality and performance 28,72,73 . Genetic traits of organisms usually change with different rearing environments and conditions, and natural enemy insects are no exception.…”

Section: Discussionmentioning

confidence: 99%

Quality assessment of Telenomus remus successively reared on Spodoptera litura eggs for 30 generations

Liu

Pest Management Science

et al. 2023

“…Rejuvenating the population by regularly collecting more individuals from natural habitats was a remedy (Ghaemmaghami et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, inbreeding depression may contribute to the gradually decreased fitness of decedents. Rejuvenating the population by regularly collecting more individuals from natural habitats was a remedy (Ghaemmaghami et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

Effects of supplementary pollen on the life history traits of predatory mite Euseius nicholsi across generations

Liu

et al. 2022

J Applied Entomology

Pollen as one of the most important supplementary food benefits the generalist predators in many aspects. However, little is known about the performance of generalist predators with type IV lifestyle when they are reared continuously on prey supplemented with pollen for many generations. In this study, the life history traits of the predatory mites Euseius nicholsi (Ehara et Lee) (Acari: Phytoseiidae) were compared when two prey species, Tetranychus urticae Koch (Acari: Tetranychidae) and Eotetranychus kanktus Ehara (Acari: Tetranychidae) were offered with the presence/absence of camellia pollen. The results showed that the mixed diet of prey and pollen significantly improved the fitness of predatory mites. Predatory mites with pollen as supplementary food developed 1 day faster than their counterparts fed only with prey. They survived much longer and produced almost twice as many eggs as their counterparts. Nevertheless, these benefits were only evident in the first few generations and faded away from Generation 5. This study advanced our understanding by indicating that the beneficial effects of supplementary pollen decreased along with generations and clarifying that T. urticae was a more nutritious prey to E. nicholsi.

“…Researchers have demonstrated that the natal rearing experience of parasitoids may affect their behavioral and physiological characteristics [80][81][82][83]. Ghaemmaghami et al [84] found that laboratory mass-reared colonies of T. brassicae (Hymenoptera: Trichogrammatidae) declined in quality after 15 generations. On the other hand, the long-term rearing of predatory mite Neoseiulus californicus (Acari: Phytoseiidae) on almond pollen positively affected its attributes, including in promoting high survivorship, body size, and fecundity [80].…”

Section: Discussionmentioning

confidence: 99%

The Fitness of Mass Rearing Food on the Establishment of Chrysopa pallens in a Banker Plant System under Fluctuating Temperature Conditions

Wang

Yang

et al. 2021

Insects

Banker plant systems can be used to sustain a reproducing population of biological control agents (BCAs) within a crop, thus providing long-term pest suppression. The founder population of natural enemies in banker plant systems is usually mass-reared on factitious hosts. Thus, a better understanding of the population fitness and pest control performance of mass-reared BCAs in the field is crucial when developing integrated pest management (IPM) strategies. In this study, we determined the fitness of the generalist predator, Chrysopa pallens (Hemiptera: Chrysopidae) ever cultured on different food sources (i.e., mass rearing food, Corcyra cephalonica eggs, and aphid food, Megoura japonica) preying on Aphis craccivora in a banker plant system in a greenhouse based on Chi’s age-stage, two-sex life table analysis method. The life tables and predation rate parameters of C. pallens were not significantly different between both treatments under fluctuating temperature conditions. Corcyracephalonica eggs did not significantly weaken the performances of C. pallens in a Vicia faba–A. craccivora banker plant system compared to aphids. In conclusion, C. cephalonica eggs can be used for the mass production of C. pallens as the founder population in a banker plant system. Moreover, linking the life table data with the predation rate is an effective strategy for evaluating mass rearing programs in establishing banker plant systems.