Warm-Season (C4) Turfgrass Genotypes Resistant to Spittlebugs (Hemiptera: Cercopidae)

Abstract

Screening for resistance to insect pests is one of the early stages of grass breeding programs. Pasture spittlebugs are sap-sucking insects that potentially cause severe damage to turfgrasses, including the loss of functional quality and perenniallity. The Brazilian flora has a large number of grass species with wide morphological variability and adaptability to different soil and climate conditions that can potentially be used as lawns. However, no study has screened turfgrass genotypes for resistance to spittlebug attack. In this study, we evaluated the intra- and interspecific variability of 35 turfgrass genotypes in the genera Paspalum, Axonopus, and Zoysia for resistance to the pasture spittlebugs, Deois flavopicta (Stal) and Notozulia entreriana (Berg) (Hemiptera: Cercopidae), as measured by damage scores, densities of nymphs and adults, and level of antibiosis resistance. Genotypes were grouped into three groups using cluster analysis and principal component analysis: GroupI had genotypes associated with low damage scores and high density of adult spittlebugs; GroupII had genotypes with intermediate damage scores and low density of nymphs and adults; and GroupIII was formed by genotypes with high damage scores and high nymph density. Intra- and interspecific genotypic variability was related to antibiosis resistance and morphological variation among genotypes with some indicating nonpreference resistance and others indicating tolerance resistance. Our results indicate that besides antibiosis resistance studies, it is essential to evaluate the morphological variability of grass genotypes when screening for resistance to insects. Further studies are needed to elucidate the intraspecific variability of Paspalum notatum Flüggé genotypes for resistance to spittlebug attack.

Genetic Mapping With Allele Dosage Information in Tetraploid Urochloa decumbens (Stapf) R. D. Webster Reveals Insights Into Spittlebug (Notozulia entreriana Berg) Resistance

“…This forage grass has relevant agronomic attributes, including exceptional adaptation to poor and acidic soils that are typical of the tropics, leading to good animal performance (Valle et al, 2010). However, the species is susceptible to several types of spittlebug, including Notozulia entreriana Berg (Hemiptera: Cercopidae), which is the most damaging pest for tropical pastures (Gusmão et al, 2016).…”

“…Spittlebugs reduce biomass production, decrease palatability, and reduce the carrying capacity of pastures (Valério and Nakano, 1988). N. entreriana nymphs constantly suck the sap of roots, causing yellowing of the plant, and the saliva of the adults induces phytotoxemia that causes plant death (Valério and Nakano, 1992; Gusmão et al, 2016). Therefore, breeding programs aim to develop new cultivars with reasonable or high resistance to spittlebugs to reduce forage loss.…”

Spittlebug damage on tropical grass and its impact in pasture-based beef production systems

“…The lack of difference on herbage yield in the latter study may be related to short period of infestation. In addition, the magnitude of differences on herbage yield reported in the literature may be due to spittlebug population density, host plant resistance, growth factor availability, and infestation period 20,21,40 .…”

“…In fact, studies about pest science on forage systems are scarce compared to agricultural crops. The little information available has also been focused on plant resistance and genetic traits to support breeding programs 40,44 and there is a knowledge gap on quantifying animal productivity losses caused by spittlebugs. The quantification of damage caused by pests is one of most important aspects to outline strategies of control and there are no fundamentals to define economic threshold levels with no understanding of the relation between number of insects and crop yield 45 .…”

Urochloa spp. multivariate performance: Similarities and divergences among intra‐ and interspecific populations

“…flavopicta (Stal) (Hemiptera: Cercopidae) (Gusmão et al, 2016) and Deois spp. To improve spittlebug resistance, the breeder can either select directly in an intraspecific population or start an interspecific population by performing crosses with resistant cultivars such as U. brizantha cv.…”