Evaluation of the effectiveness of insecticide trunk injections for control of Latoia lepida (Cramer) in the sweet olive tree Osmanthus fragrans

Jun Huang; Juan Zhang; Yan Li; Jun Li; Xiao-Hua Shi

doi:10.7717/peerj.2480

Evaluation of the effectiveness of insecticide trunk injections for control of Latoia lepida (Cramer) in the sweet olive tree Osmanthus fragrans

PeerJ. 2016 Sep 21:4:e2480. doi: 10.7717/peerj.2480. eCollection 2016.

Authors

Jun Huang^#¹, Juan Zhang^#¹, Yan Li², Jun Li³, Xiao-Hua Shi¹

Affiliations

¹ Flower Research and Development Centre, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, China.
² The Key Laboratory of Chemistry for Natural Products of the Guizhou Province, Chinese Academy of Sciences, Guizhou, Guiyang Province, China.
³ Guangdong Key Laboratory of IPM in Agriculture and Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, Guangdong Province, China.

^# Contributed equally.

Abstract

The screening of suitable insecticides is a key factor in successfully applying trunk injection technology to ornamental plants. In this study, six chemical pesticides were selected and injected into the trunks of Osmanthus fragrans to control the nettle caterpillar, Latoia lepida (Lepidoptera: Limacodidae), using a no-pressure injection system. The absorption rate of the insecticides, the leaf loss due to insect damage, and the mortality and frass amount of L. lepida larvae were evaluated after 77 and 429 days. The results showed that 4% imidacloprid + carbosulfan and 21% abamectin + imidacloprid + omethoate had the fastest conductivity and were completely absorbed into the trunkswithin14 days; however, the efficiencies of these insecticides in controlling L. lepidawere extremely low. Additionally, the treatment 10% emamectin benzoate + clothianidin and 2.5% emamectin benzoate was almost completely absorbed within 30 days and exhibited a longer duration of insecticide efficiency (>80% mortality) in the upper and lower leaves of the canopy. Treatment with these insecticides also resulted in significantly lower leaf loss and frass amounts. We conclude that emamectin benzoate and emamectin benzoate + clothianidin have a rapid uptake into O. fragrans, and are effective as insecticides over long durations. Hence, they may be a suitable control option for L. lepida in O. fragrans plants.

Keywords: Frass; Latoia lepida; Leaf loss; Mortality; Osmamthus fragrans; Trunk injection.

Grants and funding

This work was supported in part by the National Key Research and Development Program (2016YFC1201100, 2016YFC1201104), Key Programs of Agricultural Science and Technology of Xiaoshan (grant number, 2013203, 2015210) and the Funds for Environment Construction and Capacity Building of GDAS’ Research Platform (2016GDASPT-0305, 2016GDASPT-0215). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.