种间竞争对四种储粮害虫种群动态的影响

在30 ℃、75 %相对湿度条件下研究种间竞争对玉米象(Sitophilus zeamais)、谷蠹(Rhizopertha domini-ca)、赤拟谷盗(Triboliumcastaneum)和锈赤扁谷盗(Cryptolestes ferrugineus)4种主要储粮害虫种群动态的影响,并对种群动态进行回归分析。结果表明,玉米象与谷蠹、赤拟谷盗与锈赤扁谷盗混合饲养种群增长均受到显著抑制,玉米象和谷蠹对赤拟谷盗和锈赤扁谷盗的种群增长具有明显的促进作用,赤拟谷盗和锈赤扁谷盗对玉米象和谷蠹的种群增长具有一定的抑制作用。回归分析结果表明玉米象种群最大增长潜能最大,锈赤扁谷盗最小,种群增长率变化规律不明显。     

种间竞争对四种储粮害虫种群动态的影响

在30 ℃、75%相对湿度条件下研究种间竞争对玉米象(Sitophilus zeamais)、谷蠹(Rhizopertha dominica)、赤拟谷盗(Tribolium castaneum)和锈赤扁谷盗(Cryptolestes ferrugineus)4种主要储粮害虫种群动态的影响，并对种群动态进行回归分析。结果表明，玉米象与谷蠹、赤拟谷盗与锈赤扁谷盗混合饲养种群增长均受到显著抑制，玉米象和谷蠹对赤拟谷盗和锈赤扁谷盗的种群增长具有明显的促进作用，赤拟谷盗和锈赤扁谷盗对玉米象和谷蠹的种群增长具有一定的抑制作用。回归分析结果表明玉米象种群最大增长潜能最大，锈赤扁谷盗最小，种群增长率变化规律不明显。     

水菖蒲活性物质β-细辛醚对四种储粮害虫的熏蒸活性

植物性次生物质在植物-害虫的关系中起着非常重要的作用, 植物中的一些成分对害虫具有熏蒸、触杀和驱避等作用。水菖蒲Acorus calamus L.是一种常用中药, 它的主要杀虫活性成分为β-细辛醚。本研究通过室内生测试验研究了水菖蒲根茎提取物β-细辛醚对玉米象Sitophilus zeamais Motschulsky、谷蠹Rhyzopertha dominica (Fabricius)、赤拟谷盗Tribolium castaneum (Herbst)和四纹豆象Callosobruchus maculatus (Fabricius) 4种储粮害虫的熏蒸击倒和致死作用。结果表明: β-细辛醚对4种试虫的熏蒸击倒和致死作用明显。以50 μL/L的浓度处理120 h后, 对玉米象、谷蠹和四纹豆象的击倒作用均达到100%, 而对赤拟谷盗击倒率为50%; 玉米象、谷蠹和四纹豆象的死亡率分别为81.23%, 97.78%和100%, 而赤拟谷盗死亡率仅为8.89%。处理24 h, β-细辛醚对玉米象、谷蠹、赤拟谷盗和四纹豆象的KC50分别为49.38, 102.96, 124.04和1.07 μL/L; 处理120 h, β-细辛醚对玉米象、谷蠹、赤拟谷盗和四纹豆象的LC50分别为17.82, 4.42, 116.48和0.73 μL/L。结果显示水菖蒲根茎提取物β-细辛醚对4种储粮害虫均具有明显的熏蒸效果, 具有开发为储粮害虫熏蒸剂的潜力。     

十二种药用植物乙醇提取物对谷蠹和赤拟谷盗成虫的驱避效应

采用滤纸药膜选择法研究了蛇床子、茵陈、萹蓄等12种药用植物乙醇提取物对谷蠹Rhizopertha dominica(Fab.)和赤拟谷盗Tribolium castaneum Herbst成虫的驱避效应。12种药用植物以蛇床子(Cnidium monnieri)提取物对谷蠹成虫的驱避效果最佳,786μg/cm2处理24h对谷蠹的驱避率达93%;茵陈(Artemisia capillaries)提取物对赤拟谷盗成虫的驱避效果最佳,用393μg/cm2处理72h的驱避率为95%,茵陈提取物以262μg/cm2放置7d后对赤拟谷盗成虫的驱避率可达Ⅴ级水平。茵陈提取物对赤拟谷盗的驱避持效期长、效果好,具有一定的开发前景。     

蛇床子提取物对几种储粮害虫的驱避和触杀效应

研究蛇床子(Cnidium monnieri(L.)Cuss.)4种溶剂无水乙醇、丙酮、乙酸乙酯、石油醚提取物对玉米象Sitophilus zeamais(Motschulsky)、谷蠹Rhizopertha dominica(Fabricius)、锯谷盗Oryzaephilus surinamensis(L.)3种储粮害虫的驱避作用和触杀作用。结果表明:蛇床子4种溶剂的提取物对3种试虫具有一定的驱避作用和触杀作用,60 h的平均驱避等级最高达到Ⅴ级,对3种试虫的触杀死亡率最高达到100%。     

石菖蒲提取物对四种储粮害虫的生物活性研究

研究了石菖蒲4种溶剂无水乙醇、丙酮、乙酸乙酯、石油醚提取物对玉米象、谷蠹、长角扁谷盗和锯谷盗4种储粮害虫的驱避作用和触杀作用。结果表明：石菖蒲4种溶剂提取物对4种试虫均有明显的驱避作用和触杀作用,处理60 h的平均驱避等级均达到Ⅲ级以上,对4种试虫的触杀死亡率均达到41.11%以上。     

一种新杀虫剂对储粮害虫和作物害虫的杀虫效果

测定以植物提取物异硫氰酸酯为主要成分而复配的宏劲杀虫剂对玉米象Sitophilus zeamais(Motschulsky)、赤拟谷盗Tribolium castaneum(Herbst)和谷蠹Rhizopertha dominica(Fabricius)3种重要储粮害虫的熏蒸效果及其对菜青虫Pieris rapae(L.)、红蜘蛛Tetranychus cinnabarinus(Boisduval)的杀虫效果。结果表明,宏劲杀虫剂48h对玉米象、赤拟谷盗和谷蠹的LC50分别是0.016,0.009和0.009μL/mL,均明显低于常规熏蒸剂磷化铝的要求处理剂量;对菜青虫和红蜘蛛的LC50分别是0.0159和1.3738mg/mL,其防效均优于对照药剂3%阿菊乳油和3%新型水分散性颗粒剂。     

赤拟谷盗和杂拟谷盗的生殖隔离研究

赤拟谷盗和杂拟谷盗是两个同域发生的近缘储粮害虫。为明确它们的生殖隔离程度和机制,本研究比较分析了赤拟谷盗和杂拟谷盗雄虫对同种和异种雌虫的交配选择;赤拟谷盗与杂拟谷盗交配后,测定了精子在异种雌体内的存活情况;将赤拟谷盗和杂拟谷盗进行正反杂交,研究其F1代、F2代和回交代杂种是否产生及其雌雄比。结果显示,赤拟谷盗和杂拟谷盗雄虫对同种雌虫的爬跨率和交配率高于其对异种雌虫的爬跨率和交配率,表明赤拟谷盗和杂拟谷盗种间性隔离不完全;赤拟谷盗和杂拟谷盗交配后精子在异种雌体内是存活的,杂交所产的F1代卵为受精卵,说明交配后完成了精子传送和受精过程,表明种间机械隔离和配子隔离不完全;赤拟谷盗和杂拟谷盗的杂种F1代自交和回交产生了F2代和回交代,表明种间不存在杂种不育;一些杂交组合产生的F2代和回交代数量少且存在雌雄性比偏离,表明种间存在部分杂种不活和杂种衰败。本研究明确了赤拟谷盗和杂拟谷盗的生殖隔离机制,这对于揭示它们的物种进化关系有着重要意义。     

储粮环境挥发性化合物与储粮害虫的关系研究进展

每种粮食的储粮环境中都存在有其特征性挥发物,储粮害虫的发生对储粮环境中挥发物具有重要影响。本文简述了顶空式固相微萃取法、浸入式固相微萃取法、电子鼻检测法等储粮挥发物的提取方法及其优缺点,对小麦 Triticum aestivum L.、稻谷 Olyza sativa L.、玉米 Zea mays L.和燕麦 Avena sativa L.等主要储藏粮食种类的挥发性化合物成分、粮食挥发物对昆虫行为反应的影响、主要储粮害虫(赤拟谷盗 Tribolium castaneum、锈赤扁谷盗 Cryptolestes ferrugineus 和象虫 Sitophilus spp.)发生与粮食挥发物的关系等研究进展进行综述,探讨了储粮环境挥发性化合物与储粮害虫关系未来的研究方向,以期对今后储粮害虫生态防治研究与应用提供参考信息。     

两种防护剂和磷化氢联用对储粮书虱和 锈赤扁谷盗的实仓防治效果

储粮书虱Liposcelis spp.和锈赤扁谷盗Cryptolestes ferrugineus(Stephens)由于对磷化氢具有较高的抗性而成为目前粮食储藏过程最难防治的两类害虫,研究储粮防护剂和磷化氢联用对储粮书虱和锈赤扁谷盗的防治效果,对于缓解其对磷化氢的抗性以及其在实仓中综合防治具有重要的经济意义。本文用55%甲基嘧啶磷乳油和2%溴氰·甲嘧磷粉剂分别和磷化氢联用对广东、广西、安徽和河南4个不同气候条件的粮库中的书虱和锈赤扁谷盗进行防治效果的研究。结果表明,在磷化氢熏蒸粮食之前用55%甲基嘧啶磷乳油或2%溴氰·甲嘧磷粉剂处理粮面表层的粮食,在4个粮库的试验粮仓内书虱和锈赤扁谷盗的防治效果有显著差异:在北方干燥少雨的河南汤阴库防治效果最好,可达100%,其次是安徽舒城库、广西柳州库,防治效果分别为71.8%和71.9%。效果最差的是高温高湿的是广东湛江库,防治效果为50.4%。用55%甲基嘧啶磷乳油或2%溴氰·甲嘧磷粉剂和磷化氢联用对书虱和锈赤扁谷盗具有很好的防治效果,说明储粮防护剂和磷化氢联用对于储粮书虱和锈赤扁谷盗具有更好的防治效果。     

Effectiveness of spinosad against seven major stored-grain insects on corn

In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum （Jacquelin duVal）; rusty grain beetle, Cryptolestesferrugineus （Stephens）; lesser grain borer, Rhyzopertha dominica （F.）; sawtoothed grain beetle, Oryzaephilus surinamensis （L.）; rice weevil, Sitophilus oryzae （L.）; maize weevil, Sitophilus zeamais （Motschulsky）; and Indian meal moth, Plodia interpunctella （Htibner）. Corn kernels were treated with spinosad at 0, 0. 1, 0.5, 1, and 2 active ingredient （a.i.） mg/kg for controlling the seven species. Beetle adults or P. interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, 0. surinamensis, S. oryzae, and S. zeamais was 〉 98% at 1 and 2 mg/kg after 12 days. Spinosad at≥ 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.     

Phosphine resistance in Tribolium castaneum and Rhyzopertha dominica from stored wheat in Oklahoma

Phosphine gas, or hydrogen phosphide (PH3), is the most common insecticide applied to durable stored products worldwide and is routinely used in the United States for treatment of bulk-stored cereal grains and other durable stored products. Research from the late 1980s revealed low frequencies of resistance to various residual grain protectant insecticides and to phosphine in grain insect species collected in Oklahoma. The present work, which used the same previously established discriminating dose bioassays for phosphine toxicity as in the earlier study, evaluated adults of nine different populations of red flour beetle, Tribolium castaneum (Herbst), and five populations of lesser grain borer, Rhyzopertha dominica (F.) collected from different geographic locations in Oklahoma. One additional population for each species was a laboratory susceptible strain. Discriminating dose assays determined eight out of the nine T. castaneum populations, and all five populations of R. dominica, contained phosphine-resistant individuals, and highest resistance frequencies were 94 and 98%, respectively. Dose-response bioassays and logit analyses determined that LC99 values were approximately 3 ppm for susceptible and 377 ppm for resistant T. castaneum, and approximately 2 ppm for susceptible and 3,430 ppm for resistant R. dominica. The most resistant T. castaneum population was 119-fold more resistant than the susceptible strain and the most resistant R. dominica population was over 1,500-fold more resistant. Results suggest a substantial increase in phosphine resistance in these major stored-wheat pests in the past 21 yr, and these levels of resistance to phosphine approach those reported for other stored-grain pest species in other countries.     

Bioactivities of the leaf essential oil of Curcuma longa (var. ch-66) on three species of stored-product beetles (Coleoptera)

Essential oil extracted from the leaves of turmeric, Curcuma longa L., was investigated for contact and fumigant toxicity and its effect on progeny production in three stored-product beetles, Rhyzopertha dominica F. (lesser grain borer), Sitophilus oryzae L. (rice weevil), and Tribolium castaneum Herbst (red flour beetle). Oviposition-deterrent and ovicidal actions of C. longa leaf oil were also evaluated against T. castaneum. The oil was insecticidal in both contact and fumigant toxicity assays. The adults of R. dominica were highly susceptible to contact action of C. longa leaf oil, with LD50 value of 36.71 microg/mg weight of insect, whereas in the fumigant assay, adults of S. oryzae were highly susceptible with LC50 value of 11.36 mg/liter air. Further, in T. castaneum, the C. longa oil reduced oviposition and egg hatching by 72 and 80%, respectively at the concentration of 5.2 mg/cm2. At the concentration of 40.5 mg/g food, the oil totally suppressed progeny production of all the three test insects. Nutritional indices indicate >81% antifeedant action of the oil against R. dominica, S. oryzae and T castaneum at the highest concentration tested.     

Biological activity of two juvenoids and two ecdysteroids against three stored product insects

The insecticidal activity of juvenile hormone agonists methoprene and pyriproxyfen, and the ecdysone agonists RH-5849 and tebufenozide was evaluated against susceptible and actellic-resistant strains of Tribolium castaneum and susceptible strains of Rhyzopertha dominica and Sitophilus oryzae. Concentrations ranging from 0.1 to 20 ppm of the analogues were mixed in the food medium to which the tested insects were exposed. The results showed that all these compounds could affect the development of the tested species to differing extents but had no effect on the mortality of parental adults. The two JH analogues did not prolong the life span of R. dominica and S. oryzae, but very greatly extended that of T. castaneum. The extension led to the production of giant larvae and failure to pupate. Actellic-resistant strain of T. castaneum showed some cross-resistance to methoprene and pyriproxyfen, but not to RH-5849 and tebufenozide. Pyriproxyfen was the most effective compound among the four IGRs; a concentration of 0.1 ppm could completely inhibit the F(1) adult occurrence of both S- and R-strains of T. castaneum and its LC(90)s for controlling R. dominica and S. oryzae were 0.1 and 1.2 ppm, respectively. Methoprene was highly effective against R. dominica, but less active on S. oryzae. RH-5849 could achieve almost complete control of F(1) adults of T. castaneum and R. dominica at 10 ppm, but was less potent on S. oryzae. Tebufenozide appeared to be much less active on these three species compared with the other three compounds. The percentage reductions of F(1) adults for S- and R-strains of T. castaneum at a concentration of 20 ppm were 80 and 99%, respectively.     

Susceptibility of laboratory and field strains of four stored-product insect species to spinosad

Two field strains of the Indianmeal moth, Plodia interpunctella (Hübner); red flour beetle, Tribolium castaneum (Herbst); and lesser grain borer, Rhyzopertha dominica (F.), and one field strain of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), were collected from hard red winter wheat stored on farms in northeastern Kansas. Fifty eggs of P. interpunctella and 25 beetle adults of each species were exposed to 100 g of untreated wheat or wheat treated with various rates of spinosad, to determine susceptibility of the field and corresponding insecticide-susceptible laboratory strains. Mortality of beetle adults and P. interpunctella larvae was assessed after 7 and 21 d postinfestation, respectively. Field strains of P. interpunctella, C. ferrugineus, and T. castaneum were less susceptible to spinosad than the corresponding laboratory strains. The LD50 and LD95 values for P. interpunctella and C. ferrugineus field strains were 1.7-2.5 times greater than values for corresponding laboratory strains. Adults of both laboratory and field strains of T. castaneum were tolerant to spinosad, resulting in <88% mortality at 8 mg/kg. The LD50 and LD95 values for the field strains of T. castaneum were 2.0-7.5 times greater compared with similar values for the laboratory strain. The field and laboratory strains of R. dominica were highly susceptible to spinosad, and one of the field strains was relatively less susceptible to spinosad than the laboratory strain. Our results confirm a range of biological variability in field populations, which is consistent with findings for other compounds, and underscores the need to adopt resistance management programs with stored grain insect pests. The baseline data generated on the susceptibility of the four insect species to spinosad will be useful for monitoring resistance development and for setting field rates.     

Effectiveness of spinosad on four classes of wheat against five stored-product insects

Spinosad is a commercial reduced-risk pesticide that is naturally derived. Spinosad's performance was evaluated on four classes of wheat (hard red winter, hard red spring, soft red winter, and durum wheats) against adults of the lesser grain borer, Rhyzopertha dominica (F.); rice weevil, Sitophilus oryzae (L.); sawtoothed grain beetle, Oryzaephilus surinamensis (L.); red flour beetle, Tribolium castaneum (Herbst); and larvae of the Indianmeal moth, Plodia interpunctella (Hübner). Beetle adults (25) or P. interpunctella eggs (50) were exposed to untreated wheat and wheat treated with spinosad at 0.1 and 1 mg (AI)/kg of grain. On all untreated wheat classes, adult beetle mortality ranged from 0 to 6%, and P. interpunctella larval mortality ranged from 10 to 19%. The effects of spinosad on R. dominica and P. interpunctella were consistent across all wheat classes. Spinosad killed all exposed R. dominica adults and significantly suppressed progeny production (84-100%) and kernel damage (66-100%) at both rates compared with untreated wheat. Spinosad was extremely effective against P. interpunctella on all wheat classes at 1 mg/kg, based on larval mortality (97.6-99.6%), suppression of egg-to-adult emergence (93-100%), and kernel damage (95-100%), relative to similar effects on untreated wheats. The effects of spinosad on S. oryzae varied among wheat classes and between spinosad rates. Spinosad was effective against S. oryzae, O. surinamensis and T. castaneun only on durum wheat at 1 mg/kg. Our results suggest spinosad to be a potential grain protectant for R. dominica and P. interpunctella management in stored wheat.