Design and Testing of a Boom Sprayer Prototype to Release Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) in Sweet Corn for Biocontrol of Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae)

Abstract

Abstract. Sweet corn requires many insecticide applications to control its main pest: the European corn borer () (Lepidoptera: Crambidae). The use of is an effective biological alternative to control the European corn borer in sweet corn. However, manual introduction at large scale of using Trichocards is time-consuming. Mechanized introduction of using a boom sprayer is an innovative and advantageous solution. The objective of this study was to design and test a boom sprayer to spray (Hymenoptera: Trichogrammatidae) in sweet corn canopy under real field conditions. parasitized eggs were sprayed at a rate of 800,000 individuals ha-1 using a boom sprayer designed at the Department of Soils and Agri-Food Engineering of Université Laval, Québec, Canada. parasitized eggs were also introduced at a rate of 500,000 individuals ha-1 using Trichocards. Overall, eight releases were made during the 2016 season. Field trial results showed a 17.22% emergence rate reduction of in the sprayed plots compared to Trichocards. Total fecundity and longevity of sprayed females were not negatively affected by spraying; indicating that spraying did not have any negative impact on their quality. The parasitism rates observed on natural egg masses of and on sentinel egg masses of were comparable for both methods. At harvest, sprayed and Trichocards treatments resulted in adequate control of the European corn borer. Obtained results also showed that spraying was 1.7 times faster than the manual introduction of Trichocards. Overall, the results indicate that spraying is a promising technique for an efficient and viable introduction of parasitized eggs. However, more research is recommended to further optimize the spraying parameters. The spraying system successfully used in sweet corn could also be used in corn production and adapted to other crops such as pepper, beans, and potatoes to control the European corn borer. Keywords: Biological control, European corn borer, Ostrinia nubilalis, Trichogramma, Trichogramma ostriniae, Sweet corn, Corn production, Spraying, Boom sprayer, Beneficial insects, Trichocards.

Sweet Corn Research around the World 2015–2020

“…Trichogramma is an economically competitive alternative to insecticide applications. Dionne et al [113] developed a mechanized introduction of Trichogramma using a boom sprayer saving time and labor. The applications resulted in high parasitism rates and adequate control of ECB.…”

The Use of UAS to Release the Egg ParasitoidTrichogrammaspp. (Hymenoptera: Trichogrammatidae) Against an Agricultural and a Forest Pest in Canada

“…Although parasitism was detected, parasitism rates of sentinel eggs were below the level considered necessary for suppression of European corn borer populations below relevant economic damage thresholds ( Bigler et al 1994 ). However, a previous study using T. ostriniae against European corn borer showed that the parasitism rates of sentinel E. kuehniella eggs were lower than those of natural European corn borer egg masses ( Dionne et al 2018 ). Another study on the brown marmorated stink bug, Halyomorpha halys , also concluded that sentinel eggs underestimate the parasitism rates on the targeted host ( Jones et al 2014 ).…”

“…In Canada, Trichogramma are mainly deployed manually on Trichocards, which are cardboard cards that have Trichogramma -parasitized eggs glued to their surface. Trichocard installation is particularly time consuming, leading to recent efforts to find more efficient means of deploying Trichogramma under field conditions ( Dionne et al 2018 ).…”

Effectiveness of mass trapping and Trichogramma cacoeciae (Hymenoptera: Trichogrammatidae) releases against Ectomyelois ceratoniae (Lepidoptera: Pyralidae) in Tunisian oases

“…Interestingly, Trichogramma egg parasitoids released would obviously enhance the control performance against many lepidopteran species in Tunisia such as T. absoluta and E. ceratoniae (Ksentini et al 2010;Lebdi-Grissa et al 2010;Abbes et al 2014). This was successfully applied in other countries including, among others, Egypt (Rizk 2016), USA (Salas et al 2019), Pakistan (Hussein et al 2015), and Canada (Dionne et al 2018). Thus, Trichogramma are generally polyphagous parasitoids (Smith 1996).…”