Selectivity of mycoinsecticides and a pyrethroid to the egg parasitoid Cleruchoides noackae (Hymenoptera: Mymaridae)

Abstract

plants of the genus Eucalyptus, cultivated in many countries, have great importance for the world economy. In Brazil, this culture occupies a total of 5.7 million hectares, but native and exotic insect pests can reduce its productivity. Thaumastocoris peregrinus carpintero & Dellapé (Hemiptera: Thaumastocoridae), an exotic Australian pest, damages Eucalyptus plants. Biological control using the egg parasitoid Cleruchoides noackae Lin & Huber (Hymenoptera: Mymaridae), Heteroptera predators and entomopathogenic fungi, such as Beauveria bassiana and Metarhizium anisopliae, have potential for managing T. peregrinus. chemical insecticides, including bifenthrin and acetamiprid + bifenthrin, also control this insect. the compatibility of chemical and biological control methods favors integrated pest management. the objective of this study was to evaluate the selectivity of commercial products based on B. bassiana, M. anisopliae and the chemical bifenthrin on the parasitoid C. noackae and its parasitism on T. peregrinus eggs. the selectivity test followed the standards recommended by the international organization for Biological control (ioBc). Beauveria bassiana has selectivity to parasitism as well as viability, but was slightly harmful to C. noackae adults; M. anisopliae was innocuous to adults and to the viability of the offspring of this parasitoid, but it reduced the parasitism rate; and bifenthrin did not show selectivity to this parasitoid. The area of commercially planted forests in the world increased from 167.5 to 277.9 million hectares from 1990 to 2015 1. Brazil presently has 5.7 million hectares of Eucalyptus plantations with 24%, 17% and 15% of them in the states of Minas Gerais, São Paulo and Mato Grosso do Sul, respectively. The wood from these plantations is mainly destined for the pulp industry, with a production of 21 million tons in 2018 2,3. Insect pests of Australian origin detected in planted forests during the last three decades on a global scale may reduce Eucalyptus productivity 4. The bronze bug, Thaumastocoris peregrinus Carpintero & Dellapé (Hemiptera: Thaumastocoridae), was first detected in Brazil in 2008 in the states of São Paulo and Rio Grande do Sul, and has since dispersed to other Eucalyptus-producing states 5. This insect develops and produces fertile offspring on most Eucalyptus plantations in Brazil 6. Thaumastocoris peregrinus perforates and causes silvering, tanning, drying and defoliation from Eucalyptus plants 7. Biological control is the most widely-used method for managing T. peregrinus 8. This method includes the egg parasitoid Cleruchoides noackae Lin & Huber (Hymenoptera: Mymaridae), imported from Australia 8,9 , the predators Atopozelus opsimus Elkins (Hemiptera: Reduviidae) 10 and Supputius cincticeps Stäl (Heteroptera: Pentatomidae) 11,12 and entomopathogenic fungi 13,14. Beauveria bassiana and Metarhizium anisopliae, registered

Interactions between the Entomopathogenic Fungus Metarhizium anisopliae ICIPE 20 and the Endoparasitoid Dolichogenidea gelechiidivoris, and Implications for Combined Biocontrol of Tuta absoluta

“…On the other hand, spraying eggs of Duponchelia fovealis (Zeller) (Lepidoptera: Crambidae) with commercial M. anisopliae IBCB348 at 1.5 × 105 conidia mL −1 did not affect the choice of Trichogramma atopovirilia Oatman and Platner and T. pretiosum (Hymenoptera: Trichogrammatidae) to parasitise and no effect on the parasitoid emergence, or sex ratio of the progeny was reported [ 59 ]. Furthermore, Domingues et al [ 39 ] reported comparable parasitism rates by the parasitoid Cleruchoides noackae Lin and Huber (Hymenoptera: Mymaridae) between infected and uninfected eggs of Thaumastocoris peregrinus Carpintero and Dellapé (Hemiptera: Thaumastocoridae) treated with M. anisopliae . The simultaneous release of the parasitoid D. gelechiidivoris and the spraying of M. anisopliae will therefore have limited effects on the parasitoid since a choice scenario might be observed in real conditions.…”

“…The combined application of parasitoids and fungal-based biopesticides may enhance the control of T. absoluta and the overall success of IPM programs against this pest. Several findings have demonstrated that entomopathogenic fungi and parasitoids/predators can coexist and manage different insect pest species [ 31 , 32 , 33 , 34 , 35 ]; however, detrimental effects of entomopathogenic fungi on adult or larval survival and other fitness parameters have been reported on some parasitoids [ 31 , 36 , 37 , 38 , 39 ]. The findings by these authors call for a proper understanding of the nature of the interactions between entomopathogenic fungi and other natural enemies before their potential combined use for effective and sustainable control of insect pests.…”

From the dual cyclone harvest performance of single conidium powder to the effect of Metarhizium anisopliae on the management of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae)

“…platyphylla , supported on a 250 ml Erlenmeyer flask with water in a rectangular plastic tray (40 cm long × 35 cm wide × 8 cm high), and were replaced every three to four days, placing the oldest and driest branches next to the new ones to facilitate T . peregrinus migration [ 18 ]. Adults and third instar nymphs were used in the pathogenicity assay.…”

Laboratory evaluation of the compatibility of Beauveria bassiana with the egg parasitoid Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae) for joint application against the oriental fruit moth Grapholita molesta (Lepidoptera: Tortricidae)

“…There also exists the possibility that conidia adhering to G. molesta eggs might reduce their susceptibility to parasitism by the wasp or reduce the fitness of surviving wasp offspring. For these reasons, the potential compatibility of EPFs with egg parasitoids in augmention programs have often been evaluated 33‐36 with a view to optimizing application techniques to avoid any potential adverse effects of the EPF on the parasitoids. An assessment of the potential for intraguild effects and possible antagonistic interactions between B. bassiana and T. dendrolimi is therefore a prerequisite for their joint application in a management program for G. molesta 16,32,37,38 .…”