Effect of fipronil on the reproduction, feeding, and relative fitness of brown planthopper, Nilaparvata lugens

Abstract

Applications of fipronil (1.25ϫ10Ϫ2 mg) and fipronil (7.50ϫ10 Ϫ3 mg) significantly stimulated the fecundity of Nilaparvata lugens compared with the control. The stimulating effect of fipronil on fecundity was dose-dependent. Fifteen and 30 days after treatment, the quantity of honeydew significantly increased in 1.25ϫ10Ϫ2 mg fipronil treatment. Fifteen days after treatment, the effect of fipronil on the quantity of honeydew was dose-dependent. The results revealed that the fipronil treatment group had developmental advantages. Selection with 25 mg/l fipronil led to a continuous increase in the resistance ratio (from 1.0 to 30.05) in eight generations. The life table indicated that the resistant strain had obvious disadvantages, including decreasing the survival rate from 3rd to 5th instar in G8 generation and decreasing fecundity in G5 generation. Compared with the susceptible strain, resistant insects had a relative fitness of only 0.577 and 0.750. The lower fitness includes a lower larval survival rate from 3rd to 5th instar (in G8 generation), lower adult emergence rate (in G8 generation), lower copulation rate (in G8 generation), lower fecundity (in G5 generation) and fewer offspring. It was concluded that the brown planthopper had the potential to develop high resistance to fipronil but that the lower fitness of resistant hoppers could result in quick recovery of sensitivity when the population did not come into contact with fipronil. This means that a reasonable resistance management program with less fipronil use may efficiently delay or even stop resistance development.

Inheritance and fitness costs of sulfoxaflor resistance in Nilaparvata lugens (Stål)

“…Similar fitness costs have been reported in nitenpyram‐resistant N. lugens , which showed significantly prolonged development times of nymph stages, APOP and TPOP, but significantly decreased longevity, egg survival rate and fecundity . Deleterious effects on some life‐history traits, including the survival rate, adult emergence rate, copulation rate, fecundity and hatchability, have also been observed when N. lugens develop resistance to imidacloprid, fipronil and chlorpyrifos . Decrease in fitness owing to sulfoxaflor resistance development has also been found in a laboratory‐selected strain of M. persicae , which showed a relative fitness of 0.83, with low adult longevity, low oviposition days and low fecundity compared with a susceptible strain .…”

Southern Rice Black-Streaked Dwarf Virus Infection Improves Host Suitability for Its Insect Vector, <I>Sogatella furcifera</I> (Hemiptera: Delphacidae)

“…Sogawa and Pathak (1970) reported a positive relationship between ingestion and honeydew excretion by Nilaparvata lugens Stål (Hemiptera: Delphacidae), and honeydew weights were usually measured to quantify the amount of feeding by planthopper. Thus, feeding rate of S. furcifera was assayed using the honeydew excretion method previously described by Ling et al (2009). After 2 h starvation, a single second nymph stage S. furcifera was placed into a paraÞlm sachet (2.0 by 3.5 cm) and the sachets were hung on the infected or noninfected rice stems (rice plants at tillering stage), which were Ϸ10 cm above the water surface.…”

Insecticide‐contaminated honeydew: risks for beneficial insects

“…Honeydew contaminated with these insecticides harmed the hoverfly Sphaerophoria rueppellii (Wiedemann) (Diptera: Syrphidae). Excretion of contaminated honeydew by resistant hemipteran species has yet to be demonstrated; nevertheless, one study showed that individuals of Nilaparvata lugens Stal (Homoptera: Delphacidae) that were resistant to fipronil excreted honeydew during the 30 days that the experiment lasted (Ling et al ., 2009 ). Even though this study did not measure the concentrations of fipronil in honeydew, it seems likely that honeydew would be contaminated with fipronil.…”