Insecticidal Activity of Camptothecin Against <I>Nilaparvata lugens</I>, <I>Brevicoryne brassicae</I>, and <I>Chilo suppressalis</I>

Abstract

Greenhouse tests showed that 0.2% camptothecin emulsifiable concentrate (EC) has strong contact toxicity to three agricultural pests, with LC50 and LC90 values of 0.1-0.6 and 0.4-5.0 mg liter(-1), respectively. The descending order of susceptibility was Nilaparvata lugens (Ståhl) > Brevicoryne brassicae (L.) > Chilo suppressalis (Walker). Field tests showed that the corrected mortality of B. brassicae and N. lugens was 94.6 and 69.1%, respectively, which was not significantly different from that with 10% imidacloprid WP at 98.4 and 63.4%, respectively. The corrected mortality of C. suppressalis was 85.8%, which was not significantly different from that with 5% Regent SC at 93.0%. Camptothecin EC showed no acute oral toxicity to the mouse (LD50 > 5000 mg/kg) nor acute dermal toxicity (LD50 > 2000 mg/kg).

Camptothecin‐induced expression of programmed cell death gene 11 in Spodoptera litura

“…5 Experimentally determined LC 50 and LC 90 values of 0.6 and 5.0 µg mL −1 , respectively, indicate that 0.2% camptothecin EC (emulsifiable concentrate) exhibits a strong oral toxic effect against Nilaparvata lugens, Brevicoryne brassicae and Chilo suppressalis. 6 The oral toxic effect of CPT towards S. litura has also been observed in the present authors' laboratory (see supporting information). However, the mechanism of action of CPT as a botanical pesticide is still unknown.…”

Perspectives on Biologically Active Camptothecin Derivatives

“…[105][106][107][108] Additionally, a recent study showed that CPT could cause visible changes in the midguts from the lepidopteran pests Trichoplusia ni and Spodoptera exigua, such as losing the single layer of epithelial cells and disrupting the peritrophicmembrane. 109 Investigations by Zhong et al 110 also demonstrated that CPT-induced apoptosis in SL-1 cells and midgut cells of S. litura. Consistent with these results, Zhang et al 111 recently revealed that CPT caused Sf21 and IOZCAS-Spex-II cell apoptosis via a mitochondrial-dependent apoptosis signal transduction pathway, suggesting that its mode of action may be related to apoptosis.…”

Laboratory and field evaluations of camptothecin sodium salt against phytophagous mites

“…This application rate is economically feasible for practical mite control, based on the current price of ∼ $US 4320 kg −1 CPT as a raw material in China and a low‐cost technology for the production of CPT‐Na + AS with CPT. More importantly, 0.5% CPT‐Na + AS controlled different mite pests as effectively as 0.2% CPT EC controlled different insect pests in a previous study . Compared with the mite control efficacies achieved by aramite, we recommend the median and high rates of the CPT sodium salt for use in mite pest management.…”

“…Compared with CPT, first of all, the CPT sodium salt developed in this study is completely soluble in water, forming an aqueous solution that can be easily applied without any other additive and that reduces environmental risk. Previously, the LC 50 values of the formulation 0.2% CPT EC against B. brassicae , N. lugens and C. suppressalis under greenhouse conditions were 0.37, 0.14 and 0.54 mg L −1 respectively, but the time lengths associated with the estimates were not disclosed. In this study, the LC 50 and LT 50 values estimated from the fitted cumulative TCM relationships, incorporating not only the effects of concentration and post‐spray time but also an interaction of both variables, decreased with post‐spray time and sprayed CPT‐Na + concentration respectively.…”

“…6,7 An emulsifiable concentrate (EC) of natural CPT extract (0.2% CPT EC) has shown insecticidal activity towards the cabbage aphid Brevicoryne brassicae (L.), the brown rice planthopper Nilaparvata lugens (Stål) and the Asiatic rice striped borer Chilo suppressalis (Walker). 8 Moreover, natural or artificial CPT analogues or derivatives have also been investigated for their activity to kill the palm leaf beetle Brontispa longissima Gestro and the beet armyworm Spodoptera exigua (Hübner). 9 -11 Additionally, CPT has also proved to be a synergist of the microbial pesticides of Bacillus thuringiensis var.…”