Resistance of Sugarcane Cultivars to Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae)

Abstract

The spittlebug Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) is one of the most important pests of the sugarcane crop in Brazil. Despite of its importance, there is currently a lack of information regarding sugarcane cultivars' resistance to the spittlebug. Therefore, our objective was to evaluate the response of sugarcane genotypes to this species. Two experiments were carried out under laboratory conditions using a random block design with treatments in a factorial arrangement of 2 × 13 (experiment 1) and 2 × 12 (experiment 2), with six replicates. The first factor included two levels of infestation (infested and noninfested plants with spittlebugs), while the second consisted of the cultivars. Nymph survival varied from 47.9 to 84.5%, indicating that there are different levels of antibiosis to M. fimbriolata among the tested cultivars. The highest degree of antibiosis was found in cultivars IACSP96-7586 and IACSP96-2008, in which nymph survival was close to 48%. IACSP96-7586 also presented some degree of tolerance, but IACSP96-7569 and IACSP97-6682 stood out as the most tolerant cultivars to the pest, showing the lowest reduction in weight of aboveground biomass. On average, spittlebug infestations caused a significant reduction in relative leaf chlorophyll content and aboveground biomass weight.

Resistance of sugarcane cultivars to Mahanarva fimbriolata

“…The author recorded that spittlebug nymph attacks on sugarcane reduce leaf chlorophyll content and, consequently, the photosynthetic rate, with a decrease in plant production. These facts were observed in the present work and by Dinardo-Miranda et al (2014) Table 5. Multiplication rate of Mahanarva fimbriolata each 39 days for each cultivar.…”

“…The degree of susceptibility, however, varied among cultivars: RB966928 was the less susceptible, presenting 19.0% of aboveground biomass reduction, while RB935744 was one of the most susceptible, showing 70.4% of aboveground biomass reduction due to pest attack (Table 7). Dinardo-Miranda et al (2014; also found different tolerance degrees among sugarcane cultivars, some of them could be considered tolerant, as IACSP96-7569, for example.…”

“…For cultivars SP80-1816, SP80-1842 and SP81-3250, those authors reported nymph survival and nymph stage duration values similar to those in this study (76% and 35.2 days for SP80-1816, 78% and 35.2 days for SP80-1842 and 78% and 37.6 days for SP81-3250). Dinardo-Miranda et al (2014) also reported different antibiosis levels for M. fimbriolata in sugarcane cultivars, in which nymph survival varied from 47.9% for IACSP97-7569 to 84.5% for IACSP97-2098. Latter, Dinardo-Miranda et al (2016), working with 12 sugarcane cultivars, also observed different antibiosis levels for M. fimbriolata: nymph survival varied from 20% in IAC91-1099 to 83% in IACSP94-2101.…”

“…In those works, even the least effected cultivars showed significant reductions in yield due to spittlebug infestation. Subsequently, Garcia et al (2011) and Dinardo-Miranda et al (2014; carried on studies in laboratory conditions and recorded differences among cultivars in relation to spittlebug populations and damage, although few of then could be considered resistant to the pest.…”

Resistance mechanisms of sugarcane cultivars to spittlebug Mahanarva fimbriolata

“…Cultivar SP81-3250 was chosen as a susceptible reference cultivar (Dinardo-Miranda et al, 2001) that is widely cultivated in São Paulo State, Brazil, and the others were chosen…”