Varietal Resistance and Chemical Ecology of the Rice Stink Bug, Oebalus pugnax, on Rice, Oryza sativa

Abstract

The rice stink bug, Oebalus pugnax F. (Hemiptera: Pentatomidae), is a key pest of heading rice in the southern United States. Chemical insecticide application is currently the primary method of control of O. pugnax, warranting an improved management program for this species. The potential other management tactics for O. pugnax include eco-friendly measures such as host-plant resistance, silicon application, and the use of semiochemicals. In this study, the feeding preference and performance of O. puganx on cultivated and non-cultivated rice varieties were examined. Choice tests showed that the rice varieties Cheniere and Kaybonnet were most and least preferred by O. pugnax for feeding, respectively. The results of a no-choice experiment showed that the number of nymphs surviving to the adult stage did not differ among rice varieties, although the percent survival was low on the varieties Kaybonnet and Jazzman. Here, we also showed for the first time that silicon application had a significant negative impact on O. pugnax performance, increasing the nymph development time and reducing survival by almost 40% relative to the control. Based on these results, it could be suggested that silicon amendment is a promising management strategy for this pest. Further research is needed to examine whether silicon application also reduces the feeding damage caused by O. puganx. In addition, the chemical compositions of the metathoracic gland and dorsal abdominal gland extracts were also characterized for the first time in this study, and their biological roles and potential use in pest management are discussed.

Keywords: dorsal abdominal glands; host-plant resistance; metathoracic glands; silicon.

Figure 1

Mean (±SE) number of adult rice stink bugs, Oebalus pugnax, observed on different varieties of rice at 2, 4, 6, and 20 h post-adult release in (A) first group and (B) second group of varieties. In each figure, bars with different lowercase letters indicate significant differences among means (p < 0.05).

Figure 2

Means (±SE) of (A) nymph development time (days), (B) survival to adult stage (%), and adult weights (mg) of 1 d-old (C) male and (D) female Oebalus pugnax reared on panicles taken from rice (Oryza sativa) plants treated with silicon (@ 1120 kg/ha) provided in the form of slag, wollastonite, or untreated control in the laboratory at 27 ± 1 °C and 14:10 h L:D photoperiod.