The Sublethal Effects of β-Ecdysterone, a Highly Active Compound from Achyranthes bidentata Blume, on Grape Phylloxera, Daktulosphaira vitifoliae Fitch.

Yongqiang Liu,Hongtie Pu,Junping Su,Zongjiang Liu,Khalid Hussain Dhiloo,Fuqian Yang,Zhongyue Wang,Raul Narciso Carvalho Guedes

doi:10.1371/journal.pone.0165860

Abstract

Grape phylloxera, Daktulosphaira vitifoliae (Fitch) (Hemiptera, Phylloxeridae), is a very destructive insect pest of grapevines. Intercropping of Achyranthes bidentata Blume (f. Amaranthaceae) and Vitis spp. grapevines can be useful to control this pest. In the present study, the toxicity of 22 compounds, known to be present in A. bidentata, to grape phylloxera was evaluated. All treatments were toxic towards grape phylloxera but the degree of toxicity differed between treatments. Among the 22 tested compounds, several of which proved toxic towards grape phylloxera. However β-ecdysterone had higher toxic effects against grape phylloxera, with LC50 values of 175.73 mg a.i. liter-1. In addition, we assessed the sublethal effects of LC10, LC20 and LC40 of β-ecdysterone on grape phylloxera. The fourth instar and adult developmental periods and total life span were significantly prolonged by LC40 of β-ecdysterone. Fecundity decreased when grape phylloxera were exposed to LC20 and LC40 of β-ecdysterone. In addition, LC40 of β-ecdysterone decreased the intrinsic rate of increase (rm) and the finite rate of increase (λ) and prolonged the population doubling time (DT). The net reproductive rate (R0) was significantly reduced by both the LC20 and LC40 β-ecdysterone treatments. Our results demonstrated that β-ecdysterone had higher toxic effects and significant sublethal effects on grape phylloxera, and showed potential control of grape phylloxera.

Highlights

Grape phylloxera (Daktulosphaira vitifoliae Fitch) is an aphid-like insect pests, native to North America [1,2], which was accidentally imported into Europe in the mid 19th century [3] and nowadays is regarded as the most destructive insect pest of commercial grapevines Vitis spp
Mortality of grape phylloxera nymphs was significantly different after treatment for fifteen days (F = 23.60, d.f. = 22, 46, P < 0.001)
Achyranthes bidentata is widely distributed in China, Korea, and Vietnam [13]

Summary

Introduction

Grape phylloxera (Daktulosphaira vitifoliae Fitch) is an aphid-like insect pests, native to North America [1,2], which was accidentally imported into Europe in the mid 19th century [3] and nowadays is regarded as the most destructive insect pest of commercial grapevines Vitis spp. Grape phylloxera is an obligate parasite of grapevines Vitis spp., it PLOS ONE | DOI:10.1371/journal.pone.0165860. The Sublethal Effects of β-Ecdysterone to Grape Phylloxera reproduce parthenogenetically during spring and summer on leaves and roots of susceptible vines, towards the end of the season, sexual reproduction take place due to the populations increase and the nutrient status of vines changes [5]. The galls on roots split and crack and feeding sites leave entry points, which allows entry of soil-borne pathogens and this can cause death of the vine [5]. Its worth noting that grapevines do not always die this is dependent on the host genotype and the insect genotype

Methods

Results

Conclusion