二化螟寄主选择行为与种群消长机制的研究进展

二化螟[Chilo suppressalis(Walker)]是一种钻蛀性害虫,具有食性杂、越冬场所多、转株为害等特点,其种群数量近年来呈回升趋势,危害逐年加重。二化螟对寄主存在明显的选择行为,其主要寄主之一水稻由于品种更替、耕作制度变更及气候变化等因素对二化螟种群发生规律产生了一些新的影响,给害虫防治工作带来了许多新问题。研究和了解二化螟的寄主选择规律及其机制,以及影响其种群动态的因素是有效调控二化螟种群的重要前提。本文就二化螟寄主选择行为与机制及其在水稻上种群消长影响因素等的研究概况进行综述报道,旨在更好地为二化螟的综合防治提供指导。     

二化螟种群数量变动规律研究

根据临海市１９７４～１９９８年二化螟发生危害的测报调查资料,分析水稻二化螟的种群数量构成及其变化特点,阐述水稻二化螟种群数量的消长规律及相关特征,明确造成二化螟种群数量上升的主要原因是种群基数增加,越冬场所扩大,耕作制度变化、机械收割推广和冬季气温上升等     

侧多食跗线螨实验种群生命表的研究

侧多食跗线螨是我国蔬菜重要害螨之一。通过对该螨在取食茄子条件下实验种群生命表的研究,结果表明：该螨的内禀增长率（ｒ_ｍ）、周限增长率（λ）、净增殖率（Ｒ_ｏ）、种群世代平均周期（Ｔ）和种群加倍时间（ｔ）分别为０.２５８４、１.２９４８、１９.３９５３、１１.４７２８和２.６８２３。     

二化螟不同年龄段越冬幼虫的耐寒性比较

为比较二化螟越冬幼虫种群内耐寒性的差异,根据体重将二化螟越冬幼虫分为高、中、低三个年龄段,于2008年1月至3月测定了各年龄段越冬幼虫的过冷却点和结冰点,并分析了其耐寒性的生理生化机制.结果表明:在1、2和3月的三次测定中,高龄幼虫的过冷却点在2月最高,为-9.81℃,中龄幼虫的过冷却点逐渐升高,2月份为-13.35 ℃,而低龄幼虫在2月最低,为-15.64℃,且显著低于高龄幼虫;同一月份,低龄越冬幼虫的含水量和甘油含量最高,中龄越冬幼虫次之,而高龄越冬幼虫最低,且差异显著.     

第一代二化螟枯鞘对水稻生长发育影响及药剂防治指标研究

报道了第一代二化螟造成的枯鞘对水稻有效分蘖、水稻根的特性及水稻产量的影响,导出了二化螟造成的枯鞘株率(x)与水稻产量损失率(y)之间的线性回归方程y=1.7506+0.9793x,相关系数为0.9938。根据该方程及湖南省的实际生产情况制定了新的化学防治指标,即枯鞘株率为3.10%。     

水稻及茭白二化螟不同龄期幼虫耐寒性比较

为明确水稻及茭白二化螟种群之间在低温环境下的生理生化差异,将室内饲养获得的1～6龄二化螟幼虫分别置在28、0、-3、-6、-9、-12、-15、-18、-21℃条件下处理24 h,再采用分光光度法测定存活幼虫的超氧化物歧化酶、过氧化物酶及过氧化氢酶活性,并利用隶属函数法对二化螟幼虫的耐寒性进行综合评价。结果表明,随着温度下降,水稻及茭白二化螟各龄幼虫的存活率均呈下降趋势;相同低温下,高龄幼虫的存活率高于低龄幼虫;水稻二化螟各龄幼虫的存活率普遍高于相同低温下的同龄茭白二化螟幼虫。随着温度的下降,3种抗氧化酶的活性均呈现显著上升趋势,高龄幼虫的抗氧化酶活性均高于低龄幼虫,水稻二化螟各龄幼虫的抗氧化酶活性普遍高于相同低温下的同龄茭白二化螟幼虫。根据水稻及茭白各龄二化螟幼虫抗氧化酶活性的平均隶属度,验证了水稻二化螟幼虫对低温的耐受力高于茭白二化螟幼虫。     

2017—2019年江西省二化螟种群对四种杀虫剂的抗性

为明确近年来江西省二化螟种群对常用杀虫剂的抗性水平,提出合理化用药建议,本研究采用人工饲料浸药法测定2017—2019年江西省13个县（市）二化螟田间种群对氯虫苯甲酰胺、阿维菌素、三唑磷和杀虫单的抗性。结果表明,13个二化螟种群对氯虫苯甲酰胺的抗性水平整体为中等至高水平抗性,其中有11个二化螟种群对氯虫苯甲酰胺的抗性水平整体为上升趋势,在对氯虫苯甲酰胺抗性水平增加的种群中,都昌种群的抗性倍数从2017年的44.1倍上升至2018年的65.1倍,在2019年激增至高水平抗性,抗性倍数为283.5倍,为供试种群的最高抗性倍数。13个二化螟种群对阿维菌素的抗性水平整体为中等偏下,在对阿维菌素抗性水平增加的种群中,南昌种群的抗性倍数最高,2017—2019年分别为74.8倍、108.7倍和80.6倍。13个二化螟种群对三唑磷的抗性水平整体为中等偏下,其中新干、永修、万安、大余、上高和都昌这6个种群对三唑磷的抗性水平呈波动上升的趋势,而其他7个种群对三唑磷的抗性水平为波动性变化,偶有下降。13个二化螟种群对杀虫单的抗性水平整体为中等偏下并且有明显下降趋势,其中大余、永修、泰和、会昌、新干和上高这6个种群对杀虫单的抗性水平呈明显的下降趋势;其他7个种群对杀虫单的抗性水平则为波动性上升趋势。建议限制氯虫苯甲酰胺的使用次数,在抗性水平高、田间防治效果差的地区暂停使用双酰胺类杀虫剂;此外,应减少阿维菌素的用量,轮换使用三唑磷和杀虫单。     

浙江省二化螟不同种群和大螟对三唑磷的敏感性研究

于2004年用点滴法测定了浙江杭州地区(富阳和余杭)和嘉兴地区(平湖、秀城和秀洲)二化螟、杭州富阳大螟等种群4龄幼虫对三唑磷的敏感性,以及各种群体内与抗药性相关酶系(多功能氧化酶、谷胱甘肽S-转移酶、酯酶和乙酰胆碱酯酶等)的比活力。结果证实上述地区二化螟种群对三唑磷产生了21.1~218.8倍的抗性,其中以富阳和平湖种群的抗性水平较高。二化螟体内多功能氧化酶活性与三唑磷抗性水平呈显著正相关,而乙酰胆碱酯酶活性则呈显著负相关,表明二化螟对三唑磷的抗性可能与多功能氧化酶活性增强和乙酰胆碱酯酶敏感性降低有关。大螟富阳种群对三唑磷的敏感性明显高于二化螟富阳种群,其抗性机制还有待研究。     

寄生蜂对水稻二化螟生态控害功能的研究与应用

二化螟是我国水稻的重要钻蛀性害虫,常年发生危害严重,给水稻生产带来巨大产量损失。寄生蜂是二化螟重要的生态调节因子和生物防控天敌资源,对田间二化螟的种群数量具有明显的自然控制作用。本文主要就二化螟寄生蜂多样性及其影响因素、二化螟卵寄生蜂和幼虫寄生蜂生态控害功能及优势种利用、二化螟幼虫越冬滞育期间寄生蜂对越冬幼虫种群基数的控制和寄生蜂生态控害功能的评估等方面的研究与应用进行综述,并探讨寄生蜂对二化螟生态控害功能的评估,尝试提出二化螟寄生蜂生态控害功能研究应在越冬代重视二化螟盘绒茧蜂、稻螟小腹茧蜂和中华钝唇姬蜂对越冬滞育幼虫的生态控害潜力、非越冬世代则重点发掘稻螟赤眼蜂、螟黄赤眼蜂和玉米螟赤眼蜂等卵期优势寄生蜂以降低田间二化螟卵的孵化率、减轻二化螟幼虫为害率,以期为提升寄生蜂的生态控害功能提供参考。     

小麦田地下害虫幼虫的空间分布型与抽样技术

为明确山西省南部小麦田地下害虫的空间分布型及抽样技术，采用连片调查法对小麦田地下害虫种群进行系统调查，通过5个聚集度指标、m^*-m回归模型和Taylor幂法则对其不同种群空间分布型进行分析，利用聚集均数分析其聚集原因，确定其理论抽样数和序贯抽样模型。结果表明，小麦田地下害虫混合种群、蛴螬和蝼蛄的聚集度指标扩散系数C>1，丛生指数I>0，负二项分布K值>0，久野指数C_A>1，聚块指数m^*/x>1，空间分布型均表现为聚集分布。金针虫的1组数据所有指标均不符合聚集分布，其余符合聚集分布。由m^*-m回归模型和Taylor幂法则拟合模型得出小麦田地下害虫混合种群、蛴螬和金针虫的空间分布型为聚集分布，聚集度依赖于种群密度，且聚集程度随着种群密度的升高而升高。混合种群、金针虫和蝼蛄的种群个体间相互排斥，基本成分为单个个体（α<0、β>1），而蛴螬种群基本成分是个体群，个体间相互吸引（α>0、β>1）；聚集原因随种群密度而变化。经Iwao方法分析，当允许误差D为0.3，地下害虫混合种群、蛴螬种群和金针虫种群的虫口密度均为4头/m²时，所需的理论抽样数分别为44、26和114 m²。     

杀虫剂对转Bt水稻靶标害虫二化螟和非靶标害虫稻飞虱种群数量的影响

为明确杀虫剂对转Bt水稻品种华恢1号(Huahui 1,HH1)靶标害虫二化螟Chilo suppressalis及其非靶标害虫白背飞虱Sogatella furcifera和褐飞虱Nilaparvata lugens种群数量的影响,于2014—2015年在江西省南昌市南昌县莲塘镇的广福试验基地进行田间试验,种植转Bt水稻和对照亲本水稻,分别对其进行施用杀虫剂和未施用杀虫剂处理,然后对经2种处理后转Bt水稻和对照亲本水稻田中靶标害虫二化螟幼虫数量及非靶标害虫白背飞虱、褐飞虱的若虫数量、成虫数量、总虫量(若虫数量和成虫数量之和)进行调查,并对这3种害虫田间种群数量的年份、水稻品种、杀虫剂影响因子进行方差分析。结果显示,转Bt水稻种植对二化螟幼虫数量影响显著,而施用杀虫剂处理未显著影响二化螟幼虫数量。转Bt水稻种植对白背飞虱和褐飞虱的若虫数量、成虫数量和总虫量无显著影响;而施用杀虫剂处理显著降低转Bt水稻及其对照亲本水稻稻田内白背飞虱和褐飞虱的若虫数量及总虫量,并显著降低白背飞虱成虫数量。2014年和2015年,施用杀虫剂和未施用杀虫剂转Bt水稻田内二化螟幼虫数量极低或未调查到;未施用杀虫剂转Bt水稻上二化螟幼虫数量仅在2014年显著低于未施用杀虫剂对照亲本水稻。2014年,未施用杀虫剂转Bt水稻和对照亲本水稻上白背飞虱总虫量最大值分别为1 037、1 376头/百丛,施用杀虫剂后分别降低至233、253头/百丛;未施用杀虫剂转Bt水稻上和对照亲本水稻上褐飞虱总虫量最大值分别为4 120、2 413头/百丛,施用杀虫剂后降低至367、410头/百丛;2015年白背飞虱和褐飞虱的发生规律与2014年相同。表明转Bt水稻可显著降低二化螟幼虫数量,但褐飞虱及白背飞虱数量没有降低,而施用杀虫剂可有效降低褐飞虱及白背飞虱数量。     

不同地理种群二化螟对诱集植物香根草的选择趋性比较

为明确不同地理种群二化螟Chilo suppressalis对香根草选择趋性的差异,通过室内盆栽试验测定了3个省份共8个地理种群二化螟成虫对水稻和香根草的选择趋性及产卵选择性。结果表明:8个地理种群中,选择香根草栖息的二化螟雌、雄蛾比例分别为50%~70%和50%~80%。接入二化螟成虫后第1天,除温岭、乐清、萧山种群外,其它种群雌成虫对香根草和水稻的选择性存在显著差异。金华、衡阳、温岭、衢州种群雄成虫对香根草和水稻的选择性存在显著差异。接入二化螟成虫后第2天和第3天,所有种群雌成虫对香根草的选择性均显著高于对水稻的选择性。除乐清和萧山种群外,其它种群雄成虫对香根草的选择性也显著高于对水稻的选择性。8个不同地理种群二化螟在香根草上的产卵量比例为35%~70%,是水稻上产卵量的1.17(温岭)~2.33(衡阳)倍,均显著高于在水稻上的产卵量。结果表明,香根草对不同地理种群二化螟成虫均具有较好的诱集效果。     

Mating and dispersal behaviour of Scirpophaga incertulas and Chilo suppressalis (Lepidoptera; Pyralidae) in relation to resistance management for rice transformed with Bacillus thuringiensis toxin genes

Information on the mating and dispersal behaviour of the rice stem borers Scirpophaga incertulas and Chilo suppressalis is necessary for the design of resistance management strategies for rice varieties genetically engineered with toxin genes from Bacillus thuringiensis (Bt). We investigated whether S. incertulas and C. suppressalis move from the site of adult eclosion before mating to determine the likelihood that random mating will occur between adults eclosing in fields of Bt rice and refuge fields of non-Bt rice. Observations were made under laboratory, screenhouse and field conditions. Almost all S. incertulas males and females flew out of sight after cuticle expansion and hardening, as did most C. suppressalis. Approximately 15% of C. suppressalis females called and mated within 3?m of the site of eclosion, and approximately 5% of C. suppressalis males mated within 5?m of the site of eclosion. These results suggest that random mating is likely to occur between S. incertulas eclosing in Bt rice fields and nearby refuge fields. Although a small proportion of C. suppressalis did not move far before mating, random mating of moths from Bt and nearby refuge fields is also likely to occur in this species if Bt-resistant moths are rare.     

溴虫氟苯双酰胺对水稻主要害虫的毒性及对稻田天敌的影响

为探究新型双酰胺类杀虫剂溴虫氟苯双酰胺对水稻主要害虫的毒性及对稻田天敌的影响,采用点滴法在室内测定了溴虫氟苯双酰胺对水稻主要害虫二化螟Chilo suppressalis、稻纵卷叶螟Cnaphalocrocis medinalis和褐飞虱Nilaparvata lugens的毒力,采用叶面喷雾法在大田测定了溴虫氟苯双酰胺对二化螟和稻纵卷叶螟的防效,对褐飞虱和白背飞虱Sogatella furcifera发生及稻田主要天敌蜘蛛、黑肩绿盲蝽Cyrtorhinus lividipennis消长的影响。结果表明,药后48 h溴虫氟苯双酰胺对二化螟和稻纵卷叶螟的LD_(50)分别为0.88 ng/头和0.31 ng/头,其毒力分别是对照药剂氟苯虫酰胺的1.49倍和1.61倍;而对褐飞虱的毒力较低,其LD_(50)12.50 ng/头。5%溴虫氟苯双酰胺SC对二化螟和稻纵卷叶螟具有较好的田间防效,2016年和2017年经有效成分含量为22.50～30.00 g/hm~2的处理防治二化螟后的保苗效果和杀虫效果均在70.84%以上,经有效成分含量为26.25～30.00 g/hm~2的处理防治稻纵卷叶螟后的保叶效果和杀虫效果均在72.97%以上,高于或显著高于有效成分含量为25.50 g/hm~2的对照药剂20%氟苯虫酰胺WDG。有效成分含量为18.75～30.00 g/hm~2的5%溴虫氟苯双酰胺SC对稻飞虱发生无显著影响,药后3～7 d对稻田天敌蜘蛛消长有一定抑制作用,对黑肩绿盲蝽影响较小,药后14 d不同处理的蜘蛛和黑肩绿盲蝽数量均能恢复到空白对照水平。     

Differential susceptibilities to pyrethroids in field populations of Chilo suppressalis (Lepidoptera: Pyralidae)

To assess the feasibility of pyrethroids for rice insect control, we examined susceptibilities of six field populations of rice stem borer Chilo suppressalis (Walker) to 10 pyrethroids using the topical application method in laboratory in 2004 and 2005. Our results showed that the seven pyrethroids with high fish-toxicity (i.e., β-cyfluthrin, λ-cyhalothrin, β-cypermethrin, deltamethrin, S-fenvalerate, α-cypermethrin, and fenpropathrin) were more effective against C. suppressalis than the three compounds with low fish-toxicity (i.e., cycloprothrin, etofenprox, and silafluofen). The results also showed that all 10 of the pyrethroids were much more effective than methamidophos and monosultap for C. suppressalis control. In addition, we found that susceptibilities of some field populations of C. suppressalis to some high fish-toxicity pyrethroids were significantly reduced, and our results indicated that a Ruian (RA) field population showed a year-to-year variation in susceptibility to most tested pyrethroids between 2004 and 2005. Our data indicated that the tolerance levels increased dramatically in RA population, especially to β-cyfluthrin and deltamethrin. This study provided the first assessment of resistance to pyrethroids in field populations of C. suppressalis. In addition, a close correlation between resistance ratios to the 10 compounds and differences of the structures of these compounds was established in the RA05 population, which was resistant to most of the pyrethroids tested while it was still very susceptible to fenvalerate with no cross resistance. Finally, the feasibility and precaution were discussed in selecting pyrethroids as alternatives to replace high toxicity organophosphates for C. suppressalis control and insecticide resistance management.     

Fipronil resistance mechanisms in the rice stem borer,Chilo suppressalis Walker

Fipronil resistance mechanisms were studied between the laboratory susceptible strain and the selective field population of rice stem borer, Chilo suppressalis Walker in the laboratory. The borer population was collected from Wenzhou county, Zhejiang province. After five generations of selection, fipronil resistance ratio was 45.3-fold compared to the susceptible strain. Synergism experiments showed that the synergistic ratios of PBO, TPP and DEF on fipronil in susceptible and resistant strains of C. suppressalis were 7.55-, 1.93- and 2.91-fold, respectively, and DEM showed no obvious synergistic action on fipronil. Activities of carboxylesterase and microsomal-O-demethylase in the resistant strain were 1.89- and 1.36-fold higher that in susceptible strain, and no significant difference of glutathione-S-transferase activity was found between the resistant and susceptible strains. The K_m and V_max experiments also demonstrated that fipronil resistance of C. suppressalis was closely relative to the enhanced activities of carboxylesterase and microsomal-O-demethylase. Moreover, cross-resistance between fipronil and other conventional insecticides and the multiple resistant properties of the original Wenzhou’s population were also discussed.     

转cry1Ab/cry1Ac基因水稻赣绿1号对田间稻纵卷叶螟和二化螟及其捕食性天敌的影响

为研究转cry1Ab/cry1Ac基因水稻赣绿1号对稻纵卷叶螟Cnaphalocrocis medinalis和二化螟Chilo suppressalis及其捕食性天敌的影响,采用剥查法和吸虫法,于2012—2013年在江西省南昌县调查了赣绿1号田间稻纵卷叶螟与二化螟的发生为害情况及其捕食性天敌拟环纹豹蛛Pardosa pseudoannulata和拟水狼蛛Pirata subpiraricus的种群动态。结果表明,与非转基因亲本9311水稻相比,在2012和2013年螟虫为害高峰期,赣绿1号田间稻纵卷叶螟百株虫量分别减少57.78头和27.78头,卷叶率分别降低20.46%和6.50%;二化螟百株虫量分别减少24.44头和152.22头,枯心/白穗率分别降低13.02%和14.20%。此外,赣绿1号与9311水稻田间拟环纹豹蛛和拟水狼蛛的种群动态趋势基本一致。研究表明,转cry1Ab/cry1Ac基因水稻赣绿1号能有效控制稻纵卷叶螟和二化螟,而对其捕食性天敌拟环纹豹蛛和拟水狼蛛无显著影响。     

Fipronil resistance mechanisms in the rice stem borer, Chilo suppressalis Walker

Fipronil resistance mechanisms were studied between the laboratory susceptible strain and the selective field population of rice stem borer, Chilo suppressalis Walker in the laboratory. The borer population was collected from Wenzhou county, Zhejiang province. After five generations of selection, fipronil resistance ratio was 45.3-fold compared to the susceptible strain. Synergism experiments showed that the synergistic ratios of PBO, TPP and DEF on fipronil in susceptible and resistant strains of C. suppressalis were 7.55-, 1.93- and 2.91-fold, respectively, and DEM showed no obvious synergistic action on fipronil. Activities of carboxylesterase and microsomal-O-demethylase in the resistant strain were 1.89- and 1.36-fold higher that in susceptible strain, and no significant difference of glutathione-S-transferase activity was found between the resistant and susceptible strains. The K_m and V_max experiments also demonstrated that fipronil resistance of C. suppressalis was closely relative to the enhanced activities of carboxylesterase and microsomal-O-demethylase. Moreover, cross-resistance between fipronil and other conventional insecticides and the multiple resistant properties of the original Wenzhou’s population were also discussed.     

高幼虫密度胁迫对二化螟生长发育的影响

为明确二化螟幼虫群集密度对种群增长的影响,在室内用人工饲料饲养比较了不同幼虫密度对二化螟生长发育的影响。结果表明,高幼虫密度800头/盒胁迫下,二化螟雌、雄幼虫和蛹的发育更快,其幼虫+蛹历期分别比低密度100头/盒处理要快8.0 d和6.0 d;化蛹率和羽化率较100头/盒处理分别显著下降了25.7和25.0个百分点,且雌、雄蛹重分别减少了9.4 mg和4.8 mg;但对二化螟成虫性比、寿命、产卵量和卵孵化率无显著影响。低密度100头/盒处理下二化螟幼虫发育最好,其种群增长指数为56.9,化蛹率达61.4%,羽化率达57.7%,雌、雄蛹重分别为58.3 mg和43.0 mg,但其幼虫+蛹历期较长,雌虫为58.5 d,雄虫为53.9 d。高密度800头/盒胁迫下二化螟幼虫发育最差,其种群增长指数仅为24.1,化蛹率仅为35.7%,羽化率为32.7%,雌、雄蛹重分别为48.9 mg和38.2 mg,但其幼虫+蛹历期较短,雌虫为50.5 d,雄虫为47.9 d。表明在恒定的空间和有限的食物中,幼虫密度过大会导致种内竞争加剧,使得幼虫可能倾向以更快的速度化蛹,确保其存活率以更好地繁殖后代。