不同地区转Bt基因抗虫水稻稻谷对赤拟谷盗生长发育的影响

为了明确来自湖北武穴、孝感、随州3个不同地区的转cry1Ab/cry1Ac、cry2A、cry1C基因明恢63(分别命名为TT51、T2A-1和T1C-19)对赤拟谷盗Tribolium castaneumHerbst生长发育的影响,在室内以不同的转Bt基因稻谷继代饲养赤拟谷盗6代,结果表明:各处理赤拟谷盗的卵期3～4d,卵孵化率85%～100%,幼虫期22～27d,化蛹率85%～97%,蛹期6～7d,百蛹重0.25～0.31g,性比0.8～1.4,羽化率82%～97%,产卵前期5～7d。不同抗虫转基因水稻对赤拟谷盗各发育历期及生命表参数没有显著的影响,同一转基因事件,没有因为种植地区的不同造成对赤拟谷盗生长发育的差异。3种Bt蛋白在继代饲养的赤拟谷盗幼虫体内检测均呈阳性反应,但积累量很小,继代饲养后,没有发现在赤拟谷盗体内明显的累积。     

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。     

1%蛇床子素粉剂对三种储粮害虫的防效

研究1%蛇床子素粉剂在5种处理浓度下对3种储粮害虫谷蠹Rhizopertha dominica Fabricius、玉米象Sitophilus zeamai Motschulsky和赤拟谷盗Tribolium castaneum Herbst的防治效果。室内毒力测定结果表明,按有效成分0.5mg/kg(蛇床子素:粮食)浓度处理粮食,7d后,粮食中谷蠹、玉米象和赤拟谷盗的校正死亡率分别为97.78%、100%、86.70%,防治效果优于对照药剂防虫磷和谷虫净。将药剂处理4个月后的粮食进行接虫试验,15d后谷蠹和玉米象的防治效果仍可达100%,达到储粮害虫防治要求。     

定虫隆对锈赤扁谷盗生长发育影响及其作用机理初探

定虫隆是一种昆虫生长调节抑制剂,研究其对锈赤扁谷盗的控制作用,将为锈赤扁谷盗的综合防治提供理论基础。本研究以锈赤扁谷盗幼虫为研究对象,用定虫隆拌粮进行饲喂,观察定虫隆对锈赤扁谷盗的亚致死效应,并利用实时荧光定量PCR(qPCR)技术,测定经定虫隆处理后锈赤扁谷盗幼虫几丁质合成酶1(CfCHS1)和几丁质合成酶2(CfCHS2)基因表达量的变化。结果表明:定虫隆对锈赤扁谷盗的毒力回归方程为y=7.514+1.81x(r=0.974),LD 10、LD 20、LD 30分别为0.008 mg/kg、0.014 mg/kg、0.021 mg/kg,亚致死剂量定虫隆可使锈赤扁谷盗幼虫发育历期明显延长(P<0.05),体重和几丁质含量明显降低(P<0.05),这说明了定虫隆对锈赤扁谷盗的生长发育有明显的抑制作用,可以有效控制锈赤扁谷盗的为害。qPCR结果显示,与对照组相比,LD 30处理后的锈赤扁谷盗幼虫的CfCHS 1基因表达量提高了74.7%,CfCHS 2基因的表达量提高了27.4%,均差异显著(P<0.05)。CfCHS 1和CfCHS2基因表达量的上调,可能是几丁质合成酶受到了抑制,锈赤扁谷盗为了维持机体的稳定,提高几丁质合成酶基因的表达量,从而形成一种代偿性增加的反馈机制,由此推测定虫隆可能作用于几丁质合成酶。     

球孢白僵菌九个菌株对赤拟谷盗成虫的毒效（英文）

球孢白僵菌Beauveria bassiana (Balsamo) Vuillemin是最重要的昆虫病原真菌, 广泛用于防治世界各地的多种害虫。本研究评价了球孢白僵菌9个菌株对赤拟谷盗Tribolium castaneum (Herbst)成虫的致病性。将15头赤拟谷盗成虫浸入到4个浓度 (1×10⁶, 1×10⁷, 1×10⁸ 和 1×10⁹ 个分生孢子/mL)的白僵菌菌株中 20 s, 14 d内每日记录成虫的死亡率。结果表明： IRAN 440C菌株对赤拟谷盗成虫的LC₅₀最低 (5.04×10⁷ 个分生孢子/mL), IRAN 187C菌株的最高(5.05×10⁸ 个分生孢子/mL); DEBI 005菌株对赤拟谷盗成虫的LT₅₀最短(2.88 d), DEBI 014菌株的最长(4.96 d)。根据LC₅₀, LT₅₀和死亡率结果得出IRAN 440C是防治这一害虫的理想菌株。     

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。     

溴氰菊酯亚致死浓度对烟草粉螟生物学特性的影响

为探讨溴氰菊酯对烟草粉螟的亚致死效应,本文采用烟叶浸渍法以溴氰菊酯亚致死浓度(LC 10和LC 25)胁迫烟草粉螟3龄幼虫,并通过年龄-龄期两性生命表的方法探究溴氰菊酯胁迫对烟草粉螟发育和繁殖的影响。结果显示:与对照相比,溴氰菊酯LC 10、LC 25处理F 0代的平均单雌产卵量显著下降;LC 25处理F 0代的产卵前期及总产卵前期明显长于对照;LC 25处理与LC 10处理和对照间,F 0代雌、雄虫寿命均差异显著;LC 10处理和LC 25处理F 1代与对照存活率明显下降,F 1代各处理间的卵、1龄幼虫、3龄幼虫、5龄幼虫、7龄幼虫和蛹的发育历期无显著差异;但LC 25处理组2龄、4龄、6龄幼虫历期比对照延长了且差异显著;LC 25处理组的成虫前期比对照组延长了且差异显著。同时LC 25处理的雌、雄虫寿命最短,但3个处理间差异不显著。研究表明,亚致死浓度的溴氰菊酯能够抑制烟草粉螟的生长发育和繁殖,以上研究结果可为田间用药控制烟草粉螟提供理论参考。     

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。     

营养质量对雄性赤拟谷盗生长发育、抗饥饿和资源再获取能力的影响

昆虫的生长发育、抗饥饿和资源再获取能力对其生存、生殖和性选择非常重要。本文研究了营养质量对赤拟谷盗Tribolium castaneum(Herbst)生长发育、抗饥饿和资源再获取能力的影响。结果表明,三个营养处理下雄性赤拟谷盗的生长发育性状（幼虫重、发育历期、蛹重和成虫重）均存在显著性差异,在高营养质量下生长的雄性赤拟谷盗发育更快,体重更大,且各生长发育性状间存在显著性相关。营养质量对雄性赤拟谷盗成虫的抗饥饿能力没有显著影响,但对其资源再获取能力有显著影响,表现为在高营养质量下生长的雄性赤拟谷盗成虫比在低营养质量下生长的具有更高的资源再获取能力。雄性赤拟谷盗抗饥饿能力和资源再获取能力之间存在显著性相关,但是雄性赤拟谷盗抗饥饿能力和资源再获取能力除了与发育历期存在显著性相关外,与其它生长发育性状不存在显著性相关。本文还对这些实验结果的性选择意义进行了讨论。     

杂拟谷盗体内 Wolbachia 感染密度的时间和空间分布状况

为搞清杂拟谷盗体内沃尔巴克氏体(Wolbachia)感染密度的时间和空间分布状况,本研究采用实时荧光定量PCR方法测定了杂拟谷盗不同发育阶段、不同日龄、不同性别和不同身体部位的Wolbachia感染密度。结果表明,杂拟谷盗在卵和成虫期Wolbachia感染密度高于其幼虫和蛹期,成虫腹部的Wolbachia感染密度高于其头部和胸部,而成虫不同日龄和雌雄之间的Wolbachia感染密度均没有显著性差异。本研究明确了Wolbachia在杂拟谷盗体内的时空分布和动态变化规律,这对于揭示寄主与共生菌之间的互作关系有着重要意义。     

Ni2+胁迫对斜纹夜蛾幼虫血淋巴中能量物质水平的适应性调节

为明确食物中重金属胁迫对昆虫血淋巴能量物质和生长的影响,本研究测定了饲料中不同浓度的Ni²⁺ （1~40 mg/kg）对连续3个世代斜纹夜蛾Spodoptera litura Fabricius 5龄始龄（0 h）至6龄末幼虫（分别记为0,24,48,72,96和120 h幼虫）血淋巴中能量物质总糖、蛋白质和脂肪含量,血淋巴中热量值及5龄和6龄幼虫体重的影响。结果表明：第1和2代48 h和96 h幼虫血淋巴的总糖含量均低于对照;而连续3代其他处理幼虫血淋巴中的总糖含量均在低浓度Ni²⁺（1~5 mg/kg）胁迫下增高,在高浓度Ni²⁺ （20~40 mg/kg）胁迫下降低。连续3个世代的Ni²⁺胁迫均显著降低了0~48 h幼虫血淋巴中的蛋白含量;低浓度Ni²⁺（1~5 mg/kg）胁迫增加了连续3代72~120 h幼虫血淋巴中的蛋白含量,而高浓度Ni²⁺（20~40 mg/kg）胁迫只降低了第1代72~120 h幼虫以及第2代72 h幼虫血淋巴中的蛋白含量。第1代0 h,48~72 h和120 h幼虫血淋巴中的脂肪含量在1~20 mg/kg Ni²⁺胁迫下均高于对照,但24 h和96 h幼虫血淋巴中的脂肪含量均低于对照中的含量。连续3代0~48 h幼虫血淋巴中的热量值均随饲料中Ni²⁺浓度的增加而降低;低浓度Ni²⁺胁迫（1~5 mg/kg）增加,而高浓度Ni²⁺（20~40 mg/kg）的胁迫降低第2和3代72 ~120 h幼虫血淋巴中热量值。同时,低浓度Ni2+胁迫增加而高浓度Ni²⁺胁迫降低了第3代5龄和6龄幼虫的体重。因此推测,Ni²⁺胁迫对S. litura幼虫血淋巴的能源物质含量以及热量值的影响与能量物质的种类、虫体的发育阶段和Ni²⁺的胁迫世代等都有一定的联系。     

虫酰肼对甜菜夜蛾汰选种群生长发育及生殖的影响

研究虫酰肼对甜菜夜蛾汰选种群生长发育及生殖的影响。结果显示:经虫酰肼处理后,甜菜夜蛾SS种群和RR种群卵的孵化抑制中浓度分别为179.38和160.71mg/kg,孵化幼虫的存活抑制中浓度分别为18.64和30.53mg/kg,虫酰肼对甜菜夜蛾卵的孵化率影响较小,而对孵化后幼虫的存活率影响较大。处理初孵幼虫6d后,2种群幼虫存活率及化蛹率随处理浓度的增加而降低,幼虫历期最高饲毒浓度与最低饲毒浓度相比分别延长了2.71d和6.19d,同一浓度下,RR种群幼虫历期比SS种群缩短了0.94～2.59d。处理甜菜夜蛾3龄幼虫12h后,随虫酰肼浓度的增加,2种群化蛹率逐渐降低,雌雄蛹重均有递减的趋势,雌蛹比例随浓度的增加变化较小,但SS种群雌蛹比例≤50.00%,而RR种群雌蛹比例≥50.00%,雌雄成虫羽化率总体上依次递减,处理浓度大于1.00mg/kg时虫酰肼对甜菜夜蛾成虫羽化的影响较大。     

Bioactivities of methyl allyl disulfide and diallyl trisulfide from essential oil of garlic to two species of stored-product pests, Sitophilus zeamais (Coleoptera: Curculionidae) and Tribolium castaneum (Coleoptera: Tenebrionidae)

Two of the major constituents of the essential oil of garlic, Allium sativum L., methyl allyl disulfide and diallyl trisulfide, were tested against Sitophilus zeamais Motschulsky and Tribolium castaneum (Herbst) for contact toxicity, fumigant toxicity, and antifeedant activity. The contact and fumigant toxicities of diallyl trisulfide were greater than that of methyl allyl disulfide to the adults of these two species of insects. These two compounds were also more toxic to T. castaneum adults than to S. zeamais adults. Older T. castaneum larvae were more susceptible to the contact toxicity of the two compound, whereas younger larvae were more susceptible to the fumigant toxicity of these compounds. Both compounds reduced egg hatching of T. castaneum and subsequent emergence of progeny. Diallyl trisulfide totally suppressed egg hatching at 0.32 mg/cm2, and larval and adult emergence at 0.08 mg/cm2. Methyl allyl disulfide significantly decreased the growth rate, food consumption, and food utilization of adults of both insect species, with feeding deterrence indices of 44% at 6.08 mg/g food for S. zeamais and 1.52 mg/g food for T. castaneum. However, it did not affect any nutritional indices of T. castaneum larvae. Diallyl trisulfide significantly reduced all of the nutritional indices in all of the insects tested. Feeding deterrence indices of 27 and 51% were obtained in S. zeamais adults and T. castaneum larvae, respectively, at the concentration of 2.98 mg/g food, whereas feeding deterrence of 85% was achieved in T. castaneum adults at a much lower concentration of 0.75 mg/g food. Hence, diallyl trisulfide is a more potent contact toxicant, fumigant and feeding deterrent than methyl allyl disulfide.     

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.     

Toxicity, feeding deterrence, and effect of activity of 1,8-cineole from Artemisia annua on progeny production of Tribolium castanaeum (Coleoptera: Tenebrionidae)

1,8-Cineole isolated from Artemisia annua was tested against Tribolium castaneum (Herbst) for contact toxicity, fumigant toxicity, and antifeedant activity. The adults of T. castaneum were more susceptible than larvae to both contact and fumigant toxicity of 1,8-cineole, and LD50 and LC50 values of 108.4 microg/mg body weight of adult insect and 1.52 mg/liter air were found, respectively. Furthermore, 14-d-old T. castaneum larvae were more tolerant than 16- and 18-d-old larvae and adults to the contact toxicity of 1,8-cineole, but the 16- and 18-d-old larvae have similar susceptibility. In contrast, all the larvae (14-18 d old) of T. castaneum were much more tolerant than the adults to the fumigant action, but larvae of different ages had similar susceptibility. The compound 1,8-ciineole applied to filter paper at a concentration of 3.22-16.10 mg/cm2 significantly (P < 0.05) reduced the hatching of T. castaneum eggs and the subsequent survival rate of the larvae. Adult emergence was also reduced by 1,8-cineole. Feeding deterrence of 81.9% was achieved in T. castateum adults by using a concentration of 121.9 mg/g food, whereas larvae showed 68.8% at the same concentration.     

麻疯树蛀梢斑螟生物学特性观察及其防治药剂筛选

本文对攀西地区麻疯树(Jatropha curcasL.)人工林中的麻疯树蛀梢斑螟Oncocera faecella Zeller进行了生物学特性观察及其防治药剂筛选的研究。结果表明:该虫在攀西地区1年发生5代,每雌产卵量为(29±17.05)个,卵期(7±1)d,孵化率93.23%;幼虫共4龄,1、2龄取食量小,占整个幼虫生长阶段的10.6%,3、4龄幼虫取食量大,占整个幼虫生长阶段的89.4%;蛹期(13.11±1.05)d,雌雄比为1.04(F)∶1(M),羽化率88.96%。成虫寿命为6～8d。初孵幼虫仅取食叶肉,后缀嫩叶为害梢头,老熟幼虫在叶片上或枯枝落叶中织茧化蛹;以老熟幼虫越冬。对2龄和3龄幼虫进行防治药剂筛选,表明4.5%高效氯氰菊酯1.0×103mg·L-1和0.5×103mg·L-1、30%乙酰甲胺磷乳油0.5×103mg·L-1和0.25×103mg·L-1有很好的防治效果。     

Survival of stored-product insect natural enemies in spinosad-treated wheat

The survival of stored product insect natural enemies in wheat treated with spinosad was investigated in laboratory and pilot scale experiments. The predator Xylocoris flavipes (Reuter), the warehouse pirate bug, and the parasitoids Habrobracon hebetor (Say), Theocolax elegans (Westwood), and Anisopteromalus calandrae (Howard) were exposed to wheat treated with aliquots of water or spinosad at 0.05-1 mg ([AI])/kg. X. flavipes was the only species that survived (92% survival) in spinosad-treated wheat at 1 mg/kg. X. flavipes suppressed populations of immature Tribolium castaneum (Herbst), the red flour beetle, by nearly 90% compared with a water-treated control, but 100% suppression of immatures was achieved in wheat receiving spinosad or spinosad + X. flavipes treatments. A 3-mo pilot scale experiment to evaluate T. castaneum suppression in drums holding 163.3 kg of wheat showed that the pest populations increased throughout the study in the control treatment, but peaked after 1 mo in the X. flavipes-treated drums. By comparison, better T. castaneum population suppression was achieved in spinosad or spinosad + X. flavipes treatments. Although X. flavipes can survive and reproduce in spinosad-treated wheat, under our test conditions spinosad alone provided adequate suppression of T. castaneum populations in stored wheat.     

Persistence and efficacy of spinosad residues in farm stored wheat

Degradation and insecticidal effectiveness of spinosad residues were evaluated in Kansas during November 2000 to November 2001 in farm bins holding wheat (34-metric ton capacity). About 50 kg of hard red winter wheat from each of three bins were brought to the laboratory and treated separately with 1-ml aqueous suspensions of spinosad to provide rates of 0.1, 0.5,1, 3, 6 mg (AI)/kg of wheat. Wheat treated with distilled water served as the control treatment. Untreated and spinosad-treated wheat samples (250 g each) were placed in three plastic pouches of two different mesh sizes, and buried 2.5 cm below the grain surface. Pouches with large mesh openings were used to monitor insect infestations and kernel damage in untreated and spinosad-treated samples. Pouches with small mesh were used for extracting spinosad residues and for conducting laboratory bioassays with adults of the lesser grain borer, Rhyzopertha dominica (F.) and red flour beetle, Tribolium castaneum (Herbst) at 28 degrees C and 65% RH. Wheat temperature and relative humidity near the pouches during the 1 yr of storage ranged from -10 to 32 degrees C and 50 to 70%, respectively. Moisture of wheat samples varied from 12.4 to 13%. Observed spinosad residues on wheat samples were 25% less than the calculated rates of 0.1 to 6 mg/kg. However, these residues were stable during the 1 yr of storage, and killed all R. dominica adults exposed for 14 d in the laboratory. Mortality of T. castaneum adults increased with an increase in spinosad rate. The linear regression slope of LD50s (0.3-2.7 mg/kg) against storage time was not significantly different from zero, indicating no loss in spinosad toxicity to T. castaneum adults. Insect species, insect numbers, and kernel damage over time in wheat samples inside pouches with large mesh openings were highly inconsistent, and failed to accurately characterize spinosad performance. Laboratory bioassays with R. dominica and T castaneum adults using grain from pouches with small mesh openings accurately gauged spinosad persistence and insecticidal activity under the field conditions.     

Bioactivities of l-carvone, d-carvone, and dihydrocarvone toward three stored product beetles

The rice weevil, Sitophilus oryzae L., adults were highly susceptible by contact to l-carvone, d-carvone, and dihydrocarvone when compared with the lesser grain borer, Rhyzopertha dominica F., adults and red flour beetle, Tribolium castaneum (Herbst.). Adults of R. dominica were more susceptible than the other species to fumigant vapors of l-carvone, d-carvone, and dihydrocarvone. The three larval stages (14-, 16-, and 18-d-old) of T. castaneum progressively became more susceptible with age toward contact toxicity of three test compounds but in fumigant toxicity, 16-d-old larvae of T. castaneum were more susceptible to the three compounds. Comparison of contact and fumigant toxicity of the test compounds indicates that l-carvone and d-carvone possess 24 times more fumigant toxicity toward adults of R. dominica than its contact toxicity. Overall order of toxicity was l-carvone > d-carvone > dihydrocarvone. Egg hatching and subsequent larval and adult survival of T. castaneum were significantly reduced when the eggs of T. castaneum were treated with l-carvone, d-carvone, and dihydrocarvone. l-Carvone completely suppressed egg hatching at the concentration of 7.72 mg/cm2. Data on feeding-deterrent indices indicate the high potency of l-carvone as feeding-deterrent in order of S. oryzae adults > T. castaneum adults > R. dominica adults > T. castaneum larvae.