The native thelytokous(TH)and arrhenotokous(AR)strains of Neochrysocharis formosa(Westwood)(Hymenoptera:Eulophidae)are promising biocontrol agents against the invasive tomato pest Tuta absoluta(Meyrick)(Lepidoptera:Ge...The native thelytokous(TH)and arrhenotokous(AR)strains of Neochrysocharis formosa(Westwood)(Hymenoptera:Eulophidae)are promising biocontrol agents against the invasive tomato pest Tuta absoluta(Meyrick)(Lepidoptera:Gelechiidae).This study assessed the performance and preferences of these strains in choice experiments involving five host instar ratios and evaluated their functional responses to seven densities of 1st instar larvae(5 to 40 hosts).In host-attacking behavior assays,an increasing proportion of 1st instar larvae led to a significant rise in host mortality rates for both strains.Both strains exhibited strong preferences for parasitizing and attacking 1st instar larvae over later instars,with the TH strain demonstrating significantly greater host-killing efficacy than the AR strain.Functional response experiments revealed that the attack rates of both strains were positively correlated with host density.Parasitism by both strains and host-stinging behavior by the TH strain showed type Ⅲ functional responses,while host-feeding by both strains and host-stinging by the AR strain followed type Ⅱ functional responses.Early establishment of the TH strain in tomato agroecosystems could enhance the management of T.absoluta.These findings provide critical insights into the functional dynamics of the TH and AR strains of N.formosa that can inform the development of effective biocontrol programs for this globally significant pest.展开更多
文摘通过传统形态分类结合DNA条形码方法对寄生性天敌伲姬小蜂属Necremnus Thomson(姬小蜂科Eulophidae)进行整合分类研究,查明东帕米尔高原伲姬小蜂属资源状况,为该属物种的快速准确鉴定以及生物学、系统发育等研究奠定基础。于2021-2023年以网扫和黄盘诱集为主要采集方法获得东帕米尔高原的伲姬小蜂属标本;在数码体视显微镜下观察测量标本的形态特征,进行形态分类学研究;在传统形态鉴定的基础上,利用无损伤提取法提取物种基因组DNA,获得COI序列,并与数据库中该属物种COI序列比对,分析其碱基组成和遗传距离,基于最大似然法构建系统发育树,进行系统发育分析。本研究发现东帕米尔高原伲姬小蜂属5种,其中一个新种—暗黑伲姬小蜂Necremnus nigra Xi&Hu, sp.nov.,对该新种进行了形态描述,并提供了形态特征图。DNA条形码分析结果表明,暗黑伲姬小蜂与潜叶蛾伲姬小蜂亲缘关系更近。
基金supported by the National Key Research and Development Project of China(2021YFD1400200 and 2017YFC1200600)the Yunnan Biodiversity Conservation Foundation Program,China(202301AT070485)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(caascx-2021-2025-IAS and caas-zdrw202203)。
文摘The native thelytokous(TH)and arrhenotokous(AR)strains of Neochrysocharis formosa(Westwood)(Hymenoptera:Eulophidae)are promising biocontrol agents against the invasive tomato pest Tuta absoluta(Meyrick)(Lepidoptera:Gelechiidae).This study assessed the performance and preferences of these strains in choice experiments involving five host instar ratios and evaluated their functional responses to seven densities of 1st instar larvae(5 to 40 hosts).In host-attacking behavior assays,an increasing proportion of 1st instar larvae led to a significant rise in host mortality rates for both strains.Both strains exhibited strong preferences for parasitizing and attacking 1st instar larvae over later instars,with the TH strain demonstrating significantly greater host-killing efficacy than the AR strain.Functional response experiments revealed that the attack rates of both strains were positively correlated with host density.Parasitism by both strains and host-stinging behavior by the TH strain showed type Ⅲ functional responses,while host-feeding by both strains and host-stinging by the AR strain followed type Ⅱ functional responses.Early establishment of the TH strain in tomato agroecosystems could enhance the management of T.absoluta.These findings provide critical insights into the functional dynamics of the TH and AR strains of N.formosa that can inform the development of effective biocontrol programs for this globally significant pest.
