Effect of Host Plant on the Fecundity of Spittlebug Deois flavopicta Stal (Homoptera: Cercopidae): Implications on Population Dynamics

Abstract

Efeito da Planta Hospedeira na Fecundidade da Cigarrinha-das-pastagens Deois flavopictaStal (Homoptera: Cercopidae): Implicações na Dinâmica Populacional RESUMO -A cigarrinha das pastagens Deois flavopicta Stal (Hom.: Cercopidae) ocorre naturalmente em gramíneas nativas no Brasil Central em baixas densidades populacionais. Após a introdução de gramíneas africanas, principalmente do gênero Brachiaria, D. flavopicta passou a produzir explosões populacionais e tornou-se a principal praga das pastagens na região. Estudos visando comparar os efeitos da planta hospedeira nativa e da exótica sobre a fecundidade do inseto foram desenvolvidos. Fêmeas de D. flavopicta, mantidas durante a fase adulta em Brachiaria ruziziensis, produziram mais ovos e tiveram maior longevidade média que aquelas mantidas em Axonopus marginatus, independente da planta hospedeira em que foram criadas durante a fase ninfal. Devido aos danos causados pelos adultos na planta hospedeira, o efeito da densidade de indivíduos em sua própria fecundidade foi avaliado em gaiolas de oviposição contendo plantas de B. ruziziensis padronizadas no comprimento e quantidade de perfilhos. Densidades de um, dois, três, quatro e seis casais com fêmeas virgens foram avaliadas. A densidade populacional de três casais, equivalente a 150 adultos/m 2 , ou maior que esta, reduziu a fecundidade das fêmeas. Estes estudos contribuíram para o entendimento dos mecanismos que influem para as baixas populações de cigarrinha observadas em gramíneas nativas e que promovem explosões populacionais em pastagens cultivadas com plantas introduzidas. PALAVRAS-CHAVE: Insecta, dinâmica de populações, biologia reprodutiva, interação inseto-planta, surtos populacionais.ABSTRACT -The spittlebug Deois flavopicta Stal (Hom.: Cercopidae) occurs naturally on native grasses in Central Brazil in low population densities. After the introduction of African grasses, mainly of the genus Brachiaria, for cattle raising, D. flavopicta began to produce population outbreaks and became a pest. Two studies were conducted, aiming to estimate the effects of a native and an exotic host plant on the fecundity of this insect. Females of D. flavopicta maintained during the adult stage on Brachiaria ruziziensis produced more eggs and lived longer than those maintained on Axonopus marginatus (a native grass widely distributed in Brazil), independently of the host plant on which the nymphs were reared. Due to the severe damage produced by adult D. flavopicta on the host plant, the effect of insect density on its own reproductive capacity was evaluated in oviposition cages containing plants of B. ruziziensis, standardized in height and stem number. Densities of one, two, three, four and six couples with virgin females were evaluated. Population densities of three couples, equivalent to 150 adults/m 2 , or higher decreased insect's fecundity. These results contributed to the understanding of the mechanisms that determine low levels of spittlebug populations in the native grasses and promote population outbreaks in in...

Effect of host plant on the fitness of the spittlebug Notozulia entreriana: alternative method for rearing

“…According to Sujii et al (2001) the fact that nymphs of spittlebugs are sedentary means that reproduction and fecundity depend on resources acquired by females during adulthood. Females may compensate for low-quality hosts during nymphal instars with different strategies such as polyphagy or plasticity in the preovipositional period.…”

“…As a result, the host plant gets higher-quality nutrients that are essential for xylem-sap feeders such as spittlebugs (Thompson, 1994;Pires et al, 2000;Sujii et al, 2001;Gichangi et al, 2016).…”

Endophytic Capacity of Entomopathogenic Fungi in a Pasture Grass and Their Potential to Control the Spittlebug Mahanarva spectabilis (Hemiptera: Cercopidae)

“…ex A. Rich Stapf]) [13] Agronomy 2024, 14, 943 2 of 18 monocultivation and high temperatures in the country have led to outbreaks of spittlebugs (Hemiptera: Cercopidae), the main pests in pastures in tropical America [14][15][16][17][18]. Nymphs and adults of this insect pest damage host plants by sucking the sap and injecting toxins that induce phototaxis and reduce photosynthetic rates [19][20][21][22][23], leading to a loss of biomass availability for cattle and reducing the support capacity by 60% on average [15,16,19,[24][25][26].…”

Survival and injuries of Deois flavopicta (Stal., 1854) in pastures under seed treatment with insecticides and dry mass yield

“…Extensive culture of Urochloa (syn. Brachiaria) caused outbreaks of spittlebug populations (Hemiptera: Cercopidae), the main pests in the pastures of tropical America (COSENZA, 1981;VALÉRIO;NAKANO, 1988;SUJII et al, 2001). According to AUAD et al (2009), signalgrass (U. decumbens) is more prone to attacks by the spittlebug when compared to other Brachiaria species.…”