Trichogramma galloi and Trichogramma pretiosum for the management of Duponchelia fovealis (Lepidoptera: Crambidae) in strawberry plants

Abstract

-The objective of this work was to determine the ideal number for field release of Trichogramma galloi and T. pretiosum for controlling Duponchelia fovealis (Lepidoptera: Crambidae) in strawberry (Fragaria x ananassa). The experiment was carried out in a greenhouse, where the strawberry cultivar 'Oso Grande' was infected with 100 eggs of D. fovealis distributed on the leaf surface area of each plant. A total of 1, 2, 4, 8, 16, 32, 64, and 128 female parasitoids were released per egg of D. fovealis. The greatest level of egg parasitism, with no differences for the species of Trichogramma, was observed at the densities of four and eight parasitoids per egg of D. fovealis, considered ideal for field release. Duponchelia fovealis Zeller (Lepidoptera: Crambidae), popularly known in Brazil as the strawberry caterpillar (Paes et al., 2015), is a polyphagous pest with several reported botanical species as hosts (Bonsignore & Vacante, 2010;Franco & Baptista, 2010). Recently introduced in Brazil, D. fovealis has been establishing itself in strawberry fields (Fragaria x ananassa), causing large losses (Zawadneak et al., 2016).Biological control by the release of parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae) has shown promise for controlling agriculture and forestry insect pests before they damage the crop (Pratissoli et al., 2007). Moreover, this control is favored because of Trichogramma parasitism on many lepidopteran species (Pizzol et al., 2010). For strawberry cultivation, this type of control is critical because D. fovealis caterpillars can damage the fruit, reducing its value, or preventing its commercialization.The objective of this work was to determine the ideal number for field release of Trichogramma galloi and T. pretiosum for controlling D. fovealis in strawberry.The experiment was performed in a greenhouse of the Universidade Federal do Espírito Santo, in Alegre, ES, Brazil. Duponchelia fovealis caterpillars were collected from a strawberry crop in Espírito Santo state, and transported to laboratory, where they were kept at 25±1°C, 70±10% relative humidity (RH), and 14-hour photophase, for the establishment of rearing stock. Eggs were distributed onto four cards (2.5×8 cm), with 25 eggs per card. Newly emerged adults were transferred to 20×20 cm cages made with PVC pipe and lined with sulfite paper. To prevent insect escape, the cage bottoms were closed with Styrofoam lined with sulfite paper, and the cage tops were closed with voile cloth. A 10% honey solution (v/v) embedded in cotton was offered as feed to the adults. Egg-laid papers were collected daily from the cages and immediately stored in acrylic gerbox-type boxes (11×11×3.5 cm). The sheets containing eggs were immersed for 10 seconds in 1% formaldehyde solution (v/v) and, subsequently, in 17% copper sulfate solution (m/v) in an aseptic environment, where they remained until dry. Next, the paper portions containing eggs were cut and transferred to flat-bottomed glass tubes (8.5×2.5 cm) containing an artificial diet ...

Toxicity of Insecticides in Duponchelia fovealis Zeller (Lepidoptera: Crambidae), a New Strawberry Pest in Brazil under Laboratory Conditions

“…They were kept in a controlled environment at 25±1ºC, 70±10% relative humidity (RH) and 14 hours of photophase (14L: 10D). Rearing of the juvenile and adult insects followed the methodology described by Pirovani et al [8].…”

“…In Brazil, the occurrence was reported in 2008 [1,2,[5][6][7]. In the country, the pest was established in strawberry (Fragaria x ananassa) crops in the metropolitan regions of Curitiba -PR and Mountainous state of Espírito Santo, where it has caused losses of up to 100% in production [2,8,9]. For this reason, the pest was known as a strawberry caterpillar or crown caterpillar [1,5,9].…”

Chemical and biological products used in sugarcane and their effect on Trichogramma galloi

“…Egg parasitoids of the genus Trichogramma are effective agents to control lepidopteran pests in several crops (Liu &Zhang, 2012; Pirovani et al, 2017; Cherif et al, 2019; Basso et al, 2020; Ruhela & Kumar, 2020; Jin et al, 2021). In sugarcane fields, the use of egg parasitoids has increased in control programs for Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), one of the main and most harmful pests of the crop (Valente et al, 2016; Parra & Coelho Jr., 2019).…”

Compatibility between Entomopathogenic Fungi and Egg Parasitoids (Trichogrammatidae): A Laboratory Study for Their Combined Use to Control Duponchelia fovealis

“…Trials involving Trichogramma species on D. fovealis eggs indicated that Trichogramma galloi Zucchi and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) are promising at controlling the pest's eggs [9]. Studies have also determined the ideal number of such biological agents to be released in strawberry fields [25]. Other species from the Trichogrammatidae family have been reported as effective biological agents against D. fovealis, including Trichogramma exiguum Pinto and Platner, Trichogramma atopovirilia Oatman and Platner [10], Trichogramma cacoeciae Marchal, and Trichogramma brassicae Bezdenko [26].…”