Evaluation of forage grass resistance to Mahanarva fimbriolata (Stål)

Eliane Grisoto,José Djair Vendramim,André Luiz Lourenção,José Alfredo Usberti,Ricardo Alves De Olinda

doi:10.1590/1678-4499.2016280

Eliane Grisoto, José Djair Vendramim + Show 3 more

Open Access

https://doi.org/10.1590/1678-4499.2016280

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Abstract

ABSTRACT The aim of this study was to select forage grasses with potential resistance to Mahanarva fimbriolata by assessing effects on insect. No-choice assays were conducted with 12 genotypes and laboratory-reared insects. The following parameters were assessed: mortality and duration of the nymphal stage; adult weight and longevity; pre-oviposition period; number of eggs/female; viability and duration of the embryonic period. As main result it was verified that the mortality of nymphs reared on Panicum maximum cv. Paredao is almost complete and that this forage grass may be characterized as resistant to this insect by antibiosis. Further, the grasses can be divided into three groups following a cluster analysis: P. maximum cv. Aries, Setaria sphacelata cv. Kazungula, Brachiaria humidicola, A. gayanus and P. maximum cv. Aruana, which are insect-resistant grasses; Brachiaria decumbens cv. Basilisk, B. dictyoneura, B. brizantha cv. MG-4 and B. ruziziensis, which are moderately resistant grasses; and B. brizantha MG-5 and B. brizantha ecotype BB185, which are susceptible grasses.

Highlights

The spittlebug Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) is currently a major pest of mechanically harvested sugar cane, i.e., which is harvested without burning (Dinardo-Miranda 1999; Dinardo-Miranda et al 2001; Dinardo-Miranda et al 2004; Ravaneli et al 2011)
One of the few studies of this effect was conducted by Holmann and Peck (2002), who, using a simulation model and analyzing two different ecosystems in Colombia, found that spittlebugs caused economic losses of US$ 228-273 million/year and 39-47 million/year in the dry and humid tropics, respectively
Rearing of M. fimbriolata started in February 2011 after collection in the field, and the spittlebugs were maintained in the laboratory according to the technique described by Garcia et al (2006), with some modifications: after infestation with newly hatched nymphs, the plants were packed in PVC tubes (10 cm diameter × 25 cm height) placed in a phytotron

Summary

Introduction

The spittlebug Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) is currently a major pest of mechanically harvested sugar cane, i.e., which is harvested without burning (Dinardo-Miranda 1999; Dinardo-Miranda et al 2001; Dinardo-Miranda et al 2004; Ravaneli et al 2011). The treatments consisted of 12 grasses, and the variables analyzed were the duration and viability of the nymph stage, adult weight and longevity, pre-oviposition period, number of eggs/ female and duration and viability of the embryonic stage. The survival of the nymphal stage of M. fimbriolata was affected by the genotypes, and all treatments differed from the reference of susceptibility, Brachiaria brizantha ecotype Considering the other treatments, when analyzing males and females together, the longer duration of this phase was found in A. gayanus (54.1 days) and P. maximum cv.

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