Larvicidal activity of .ALPHA.-mangostin in the Colorado potato beetle, Leptinotarsa decemlineata

Abstract

a-Mangostin, a major xanthone derivative in mangosteen (Garcinia mangostana), has been proven to have a wide range of biological-activities. In this study, we assessed the larvicidal and antifeeding activities of a-mangostin using larvae and adults of the Colorado potato beetle, Leptinotarsa decemlineata Say. a-Mangostin showed larvicidal activity and growth inhibitory effects under non-choice feeding conditions. The LC 50 values with 7-, 14-and 23-day treatment were 63.66 (13.29-279.79) mM, 8.37 (2.67-20.27) mM and 4.09 (0.89-11.81) mM, respectively. Larval development was significantly delayed 3-8 days with a-mangostin treatment. The antifeeding activity of a-mangostin was also tested by leaf disc non-choice and choice methods against larvae and adults of L. decemlineata. a-Mangostin had stronger antifeeding-activity toward adults than toward larvae, whereas there was low lethality in adults associated with higher antifeeding indexes (AFIs). The larvicidal and antifeeding effects suggest that a-mangostin and related compounds should be explored for their potential as botanical insecticide alternatives for control of the Colorado potato beetle.

Characterization of the sterol carrier protein-x/sterol carrier protein-2 gene in the cotton bollworm, Helicoverpa armigera

“…A similar trend was observed in repeated experiments. The results are consistent with the observations in mangostin-treated Colorado potato beetle larvae in which pupation in treated larvae is delayed by days (Kim and Lan, 2011). On the other hand, the mortality rate on the 18th day in non-treated control, DMSO (Table 2, 0.0006% DMSO), and SCPI-1 treated groups ( (Fig.…”

“…The peaks of mortality in SCPI-treated groups seemed to occur at the time of ecdysis in H. armigera larvae. A similar phenomenon has been observed in mangostin-treated Colorado potato beetle larvae in which increased mortality coincides with larval molting (Kim and Lan, 2011), which suggests that the function of SCP-2 may be important in the molting process, likely related to ecdysteroid biosynthesis. We speculate that HaSCP-x/2 suppression decreased cholesterol accumulation in fat body which may lead to lowered ecdysteroid biosynthesis in larvae, which may finally result in delayed development in larvae.…”

“…Due to the high mortality rate in DMSO controls with the increase of exposure time (S1), estimation of LC 50 values in later larval stages was not attempted. The results were similar to the lethal effect of mangostin in early larvae in Colorado potato beetle with the LC 50 value of 64 lM by the 7th day of mangostin-treatment (Kim and Lan, 2011). Results from toxicity assays starting in newly hatched larvae showed that both SCPI-1 and mangostin had high lethality in H. armigera.…”

“…In the yellow fever mosquito, expression knockdown of SCP-2 throughout larval stages leads to significantly delayed larval development (Blitzer et al, 2005). In the Colorado beetle larvae, mangostintreatments also delay developmental progression (Kim and Lan, 2011). Similarly, delayed developmental progression and lowered body weight were observed in larvae having either HaSCP-2 expression knockdown (Fig.…”

“…SCPIs, sterol carrier protein-2 inhibitors (Kim et al, 2005), are lethal to mosquitoes (Kim et al, 2005;Larson et al, 2008Larson et al, , 2010, M. sexta (Kim et al, 2005), and the Colorado potato beetle larvae (Kim and Lan, 2011). To determine the effects of the lack of functioning HaSCP-2 on H. armigera development and fertility, H. armigera larvae were treated with SCPI-1 (Kim et al, 2005) or mangostin (Larson et al, 2010).…”