Preference and Performance of Anagrus nilaparvatae (Hymenoptera: Mymaridae): Effect of Infestation Duration and Density by Nilaparvata lugens (Homoptera: Delphacidae)

Abstract

The effect of Nilaparvata lugens (Stål) infestation duration and density on the host preference and performance of Anagrus nilaparvatae Pang et Wang, an egg parasitoid of rice planthoppers, was determined. The results showed that the parasitoid preferred N. lugens eggs on the plants infested with 10 gravid N. lugens females for 1 d to those plants infested with 10 gravid females for 2 or 3 d. It was also found to prefer N. lugens eggs on plants infested with 10 or 20 adult females after 24 h of infestation to those plants infested with 5 or 80 females. The parasitoid's offsprings had lower survival rates, fecundities, female ratios, indexes of capacity for population increase, and longer developmental durations on plants when they were infested with high N. lugens density (80 adult females per plant). However, the performance of the parasitoid on plants infested with low N. lugens density (5 female adults per plant) was similar to those on plants with intermediate N. lugens density (10 or 20 adult females per plant). Low preference of the parasitoid for N. lugens eggs on plants with heavy or light infestation levels may be correlated with low host suitability and detectability, respectively. The result implies an important role of herbivore-induced rice volatiles in the host preference of the parasitoid A. nilaparvatae, by which the parasitoid perceives the host and its suitability.

Specific herbivore‐induced volatiles defend plants and determine insect community composition in the field

“…To measure the abundance and parasitism of BPH eggs, 20 plants per plot were randomly sampled, and the total and parasitised N. lugens eggs on each plant were recorded using the method described in Xiang et al . (). For collection of other data, 10 hills of plants in each plot were investigated and the number of insects and spiders was recorded.…”

Silencing OsSLR1 enhances the resistance of rice to the brown planthopper Nilaparvata lugens

“…As the population density of SSB was very low, we did not investigate this pest. To determine the parasitism of BPH and WBPH eggs by the parasitoid Anugrus nilaparvatae, we randomly sampled 20 plants per plot at each time interval and counted the total and the number of parasitized eggs on each plant using the method described by Xiang et al (2008).…”

The broad‐leaf herbicide 2,4‐dichlorophenoxyacetic acid turns rice into a living trap for a major insect pest and a parasitic wasp

“…The numbers of parasitized and nonparasitized BPH eggs were counted at 0 and 10 d after the treatments. To do so, 20 plants from each block were cut off at the base and dissected under a microscope using the method described by Xiang et al (2008). Based on these data, the relative changes in abundance of parasitized and nonparasitized BPH eggs, nymphs, adults and predatory spiders were calculated for the buffer and 2,4-D-treated plots relative to the control plots.…”