Insecticidal efficacy of three vegetable oils as post-harvest grain protectants of stored wheat against Rhyzopertha dominica （F.） （Coleoptera： Bostrychidae）

The lesser grain borer, Rhyzopertha dominica is a major insect pests of stored grain in the tropics. Vegetable oils （chamomile, sweet almond and coconut） at 2.5, 3.5, 5.0, 7.0 and 10.0 mL/kg were tested against Rhyzopertha dominica （F.） in wheat grain. All bioassays were conductr, d at 30℃ and 65% ＋ 2% RH. Treatments with vegetable oils at high dose （10.0 mL/kg） achieved over 95% control within 24 h of exposure to freshly treated grain, There was little difference between the three oils in their effect. Persistence of oils in grains was tested at short-term storage intervals （48, 72 and 96 h） and intermediate-term intervals （10, 20 and 30 days） after treatments. The activity of all products decreased with storage period. Seed viability was reduced by the high dose rate （10.0 mL/kg） of oil treatments. The potential use of vegetable oils as supplementary or alternative grain protectants against insect damage in traditional grain storage in developing countries is discussed.     

Expression of the Tribolium castaneum （Coleoptera： Tenebrionidae） hsp83 gene and its relation to oogenesis during ovarian maturation

Heat shock proteins (HSP) can protect organisms and cells from thermal damage. In this study, we cloned the full length cDNA encoding the HSP83 protein (the homologue of HSP90) of Tribolium castaneum (red flour beetle). The isolated cDNA contains the full coding sequence, a partial 5′ untranslated region of 55 bp and the complete 3′ untranslated region. We found the hsp83 gene is located on chromosome 5 of the T. castaneum genome. The predicted HSP83 protein sequence has a high similarity (on average 86.77%) with that of other insect species. The expression of the hsp83 gene in the whole body and in the ovary could be induced with heat stress (40°C for 1 h) in newly hatched (within 3 h post emergence) and mature (10 days post emergence) beetles. Under normal conditions, the hsp83 expression in the ovary is about 3-fold higher than in the whole body at both stages. No significant difference in hsp83 expression was observed between the two ovarian developmental stages regardless if the beetles were treated with heat shock or not. The expression of the HSP83 protein in the whole body could also be induced with heat stress in newly hatched and mature beetles. However, in the ovary, HSP83 was only expressed in the follicle cells of mature beetles and not in newly hatched beetles, regardless if the beetles were treated with heat shock or not. Furthermore, the females were not able to produce mature oocytes after knock-down of the hsp83 expression by injecting dsRNA. These results suggest that the HSP83 protein is involved in protection against heat stress and could be involved in oogenesis during ovarian maturation of T. castaneum.     

Influence of growing location and cultivar on Rhyzopertha dominica （Coleoptera： Bostrichidae） and Sitophilus oryzae （Coleoptera： Curculionidae） infestation of rough rice

Long-grain rice cultivars Cocodrie, Wells, and XP 723 grown in three locations （Hazen, MO; Essex and Newport, AR, USA）, and medium-grain rice cultivars Bengal and XP 713 grown in two locations （Jonesboro and Lodge Corner, AR, USA）, were harvested and assayed for susceptibility to Rhyzopertha dominica （F.） （Coleoptera： Bostrichidae）, the lesser grain borer, and Sitophilus oryzae （L.） （Coleoptera： Curculionidae）, the rice weevil, on rice held at 27℃, 57% and 75% relative humidity （RH）. Separate samples from the same harvest lots were also analyzed for the physical characteristics of brown rice yield, percentage whole kernels and kernel thickness. Progeny production and feeding damage of R. dominica were significantly different among long-grain cultivars within two of the three locations （P 〈 0.05）, but not for location or RH （P ≥ 0.05）, while progeny production of S. oryzae was different among cultivars, location, and RH （P 〈 0.05）. On medium-grain rice, both cultivar and location were significant for progeny production of R. dominica, but not RH, while cultivar and RH were significant for progeny production of S. oryzae, but not location. On both rice types, feeding damage of R. dominica followed the same trends and was always strongly positively correlated with progeny production （P 〈 0.05）, but for S. oryzae there were several instances in which progeny production was not correlated with feeding damage （P ≥ 0.05）. Physical characteristics of both rice types were statistically significant （P 〈 0.01） but actual numerical differences were extremely small, and were generally not correlated with progeny production of either species. Results indicate that the location in which a particular rice cultivar is grown, along with its characteristics, could affect susceptibility of the rice to R. dominica and S. oryzae.     

Expression of an endoglucanase from Tribolium castaneum （TcEG 1 ） in Saccharomyces cerevisiae

Insects are a largely unexploited resource in prospecting for novel cellulolytic enzymes to improve the production of ethanol fuel from lignocellulosic biomass. The cost of lignocellulosic ethanol production is expected to decrease by the combination of cellulose degradation （saccharification） and fermentation of the resulting glucose to ethanol in a single process, catalyzed by the yeast Saccharomyces cerevisiae transformed to express efficient cellulases. While S. cerevisiae is an established heterologous expression system, there are no available data on the functional expression of insect cellulolytic enzymes for this species. To address this knowledge gap, S. cerevisiae was transformed to express the full-length cDNA encoding an endoglucanase from the red flour beetle, Tribolium castaneum （TcEG 1）, and evaluated the activity of the transgenic product （rTcEG 1）. Expression of the TcEG1 cDNA in S. cerevisiae was under control of the strong glyceraldehyde-3 phosphate dehydrogenase promoter. Cultured transformed yeast secreted rTcEG1 protein as a functional β-1,4-endoglucanase, which allowed transformants to survive on selective media containing cellulose as the only available carbon source. Evaluation of substrate specificity for secreted rTcEG1 demonstrated endoglucanase activity, although some activity was also detected against complex cellulose substrates. Potentially relevant to uses in biofuel production rTcEG1 activity increased with pH conditions, with the highest activity detected at pH 12. Our results demonstrate the potential for functional production of an insect cellulase in S. cerevisiae and confirm the stability of rTcEG1 activity in strong alkaline environments.     

Demographic parameters of cotton aphid, Aphis gossypii Glover （Homoptera： Aphididae） on five cotton cultivars

Life table parameters of the cotton aphid, Aphis gossypii Glover, were estimated on five cotton cultivars （‘ Sealand＇ ,‘Siokra＇ ,＇ Vararnin＇ ,‘ Bakhtegan＇ and ‘ Sahel＇ ）. Demographic parameters of the cotton aphid were assessed at 27.5 ± 1 ℃, 65% ＋ 10% RH and a photoperiod of 14：10 （L： D）h. The shortest developmental time for the nymphal stages was 5.5 days on ‘Siokra＇ and the longest was 6.1 days on‘ Sealand＇. The highest offspring per female was 29.6 on ‘Sahel＇ and the lowest was 15.3 on ‘Sealand＇. The rm values varied from 0.272 on ‘Sealand＇ to 0.382 （day^-1） on ‘Varamin＇. Jackknife estimates of the A. gossypii parameters on these cultivars indicated the greatest developmental rate and fecundity on ‘ Varamin＇ and the poorest on ‘ Sealand＇ cultivar.     

Life history and life table analysis of the whitefly predator Delphastus catalinae （Coleoptera： Coccinellidae） on collards

Abstract The ladybeetle, Delphastus catalinae (Horn), is one of the most commonly used predacious natural enemies being commercially reared for controlling whiteflies, including Bemisia tabaci (Gennadius) biotype B (= B. argentifolii Bellows & Perring), on various ornamental and vegetable crops under greenhouse conditions. The development, survivorship, and fecundity of D. catalinae feeding on B. tabaci biotype B on collard plants were determined in the laboratory, and the age-specific life table parameters were analyzed based on the life history data. Developmental time was 4.0, 1.9, 1.1, 1.4, 5.2, and 5.3 days for eggs, first, second, third, fourth instars, and pupae, respectively, with an average of 18.9 days from oviposition to adult emergence for both sexes, 19.0 days for females, and 18.8 days for males. Adult longevities averaged 146.6 days for both sexes, 122.6 days for females, and 170.5 days for males. After an average 4.9 days preoviposition period, females laid a mean of 5.6 eggs per day over a 97.0-day period. Net reproductive rate ( R ₀) and gross reproductive rate (ΣM m_x ) were estimated by life table analysis at 276.8 and 325.1, respectively. Generation time (T) and doubling time (DT) were 35.6 and 4.8 days respectively, and the intrinsic rate of natural population increase ( r_m ) was estimated at 0.158, or l = 1.171 for the finite rate of increase. The r_m value of D. catalinae is similar to or higher than those of the whitefly feeding on most vegetable and ornamental crops, indicating that the ladybeetle is capable of regulating populations of B. tabaci biotype B and other whiteflies under greenhouse conditions.     

Localized treatments using commercial dust and liquid formulations of fipronil against Coptotermes formosanus （Isoptera： Rhinotermitidae） in the laboratory

Use of proper application methods and formulations of termiticides are im- portant to reduce their negative impact to the environment. In this study, we conducted laboratory experiments to determine the effect of localized treatments with commercial dust and liquid formulations of fipronil against Formosan subterranean termites, Coptoter- mes formosanus Shiraki. The test arena consisted of a specially designed 16-chambered structure with a center chamber connected to 5 foraging chambers that themselves were connected to 10 additional foraging chambers. One peripheral chamber received a liquid or dust treatment and termites were released in the center chamber. Results showed that 〉 91% of the termites were dead within the 9-d test period despite the localized treatment of only 1 foraging chamber. Termites that were still alive after 9 d were transferred to an untreated dish and held for 10 more days. The majority of those termites were dead and the rest were moribund on day 19. Regardless of the specific dish treated, both formulations of fipronil were found to be highly efficacious. Termites did not exhibit repellency to either formulation. Our results suggest that localized （or spot） treatment with either commer- cially available dust or liquid formulations of fipronil can be a viable option for control of a termite infestation where complete soil drenching is not desirable.     

Effect of Verticillium lecanfi on biological characteristics and life table of Serangium japonicum （Coleoptera： Coccinellidae）, a predator of whiteflies under laboratory conditions

Effects of entomopathogenic fungus Verticillium lecanii on biological characteristics and life table of Serangiumjaponicum, a predator of whiteflies against five different conidial concentrations （1 × 10^4, 1 × 10^5, 1 × 10^6, 1 × 10^7, and 1 × 10^8 conidia/mL） were studied under laboratory conditions. The developmental periods for all immature stages （from eggs, 1 st, 2nd, 3rd, 4th instar nymph and pupae up to emergence） among the treatments were significantly different when compared to that of control, and the longest development period was observed as treated with 1 × 10^8 spore/mL. However, no significant difference on the percent survival of all immature stages was observed among the treatments and control. Also, there were no significantly different effects of V. lecanii on mean generation time, intrinsic rate, the finite rate of increase and longevity of S. japonicum among the treatments and control.     

Accumulation of cadmium and its effects on growth, development and hemolymph biochemical compositions in Boettcherisca peregrina larvae （Diptera： Sarcophagidae）

Newly emerged larvae of the fleshfly, Boettcherisca peregrina were exposed to two different CdCl2 concentrations of 100μg/g and 400 mg/g diet fresh weight （DFW）. They were administered in the diets until the end of larval stage. Cd-exposed larvae accumulated significant amounts of Cd and this accumulation increased with the exposure dose and time. The body weights were lightened and lengths of larvae were shortened considerably after Cd exposure, especially at the higher Cd concentration. The total larval duration was also extremely affected due to Cd exposure. The average duration was prolonged significantly by 14 h at the lower Cd concentration, while it was increased by 33.7 h over controls at the higher Cd concentration. A significant decrease in contents of either soluble proteins, total lipids or caloric values in the hemolymph occurred due to Cd exposure throughout the entire tested period but after 120 h of Cd exposure. In contrast, when exposed to Cd with its higher concentration, total sugar contents in the hemolymph were increased strikingly over the whole tested time, except after 96 h of Cd exposure, while they were not apparently altered except after 24 h of Cd exposure at the lower concentration. Thus, it is suggested that Cd exposure shows significant adverse impact on the growth and development, as well as metabolism, in larvae of this fleshfly, depending on its exposure time and dose.     

Mixing of Isaria fumosorosea with enhanced diatomaceous earth and bitterbarkomycin for control of Rhyzopertha dominica

The virulence of Isaria fumosorosea alone and integrated with an enhanced formulation of diatomaceous earth (diatomaceous earth + bitterbarkomycin, DEBBM) was tested against the lesser grain borer Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) under laboratory conditions on stored wheat. The fungus was applied to wheat grains at various concentrations of 3.60 × 10⁶, 3.60 × 10⁸, and 3.60 × 10¹⁰ conidia/kg alone, or in combination with 15 and 30 ppm of DEBBM. R. dominica was held at 20, 25 and 30°C and two RH regimes (56 and 75%) and mortality was registered after 5, 10 and 15 d. Generally, I. fumosorosea was most effective at 25°C caused the highest mortality of R. dominica at 56% RH. The increase of temperature, concentration and exposure interval increased the insecticidal effect of DEBBM at low RH level. The DE alone suppressed the progeny emergence at higher dose rate as compared I. fumosorosea alone, but their simultaneous use further reduced the progeny production of R. dominica. The integrated use of both tested bio control agents synergized the effect of each other and caused the highest mortality at 25°C and 56% RH. The results clearly demonstrated that I. fumosorosea and new enhanced DEBBM can be integrated to be an effective control measure for R. dominica in stored wheat.     

Entomopathogenic fungus as a biological control agent against Rhyzopertha dominica F. (Coleoptera: Bostrychidae) on stored wheat

To evaluate the pathogenicity of Metarhizium anisopliae (Metschinkoff) Sorokin (Deuteromycotina: Hyphomycetes) a bioassay was designed under laboratory conditions against Rhyzopertha dominica F. (Coleoptera: Bostrychidae) on stored wheat. The fungus was applied at the dose rates of 8 × 10³, 8 × 10⁵, 8 × 10⁷ and 8 × 10⁹ conidia/kg of wheat and the bioassay was conducted at 25°C with 60% relative humidity. The data regarding the mortality was recorded after 7 and 14 days exposure intervals. All the treatments gave the significant mortality of R. dominica and M. anisopliae of 8 × 10⁹ conidia/kg was found to be the most effective after a 14-day exposure interval. There was greater production of progeny when the low rate of M. anisopliae was applied to wheat. Overall, our study showed that M. anisopliae is vigorous when applied at a high dose rate which revealed an effective control of R. dominica and also played a pivotal role in the integrated pest management program (IPM) of stored wheat insect pests.     

七种糕点对赤拟谷盗(鞘翅目：拟步甲科)感染的抗性（英文）

Biscuits are flour-based products,which areconsumed by majority of people,both old and young,throughout the world and most especially by children,teenagers and mid-adults(Majumder,1970).It can beserved as a desert or snacks and as a breakfast foodwhentaken with beverages.Its ready-to-serve state andlong shelf life contribute to its acceptability by themasses.Wheat as humanfoodis used principallyintheformof flour for baked products such as bread,bis-cuits,pastries and crackers(Kent,1983).In th…     

球孢白僵菌九个菌株对赤拟谷盗成虫的毒效

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,l×107,l×lo8和l×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 ×l07个分生孢子/mL),IRAN187C菌株的最高(5.05 ×lo8个分生孢子/mL);DEBI 005菌株对赤拟谷盗成虫的LT5o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.     

Electroantennographic responses of red flour beetle Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) to volatile organic compounds

The red flour beetle Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) is the most encountered and destructive stored product insect pest of cereal grains and seeds. Although this beetle has been used as a model organism for many decades, there is no systematic knowledge about antennal detection of host and non‐host volatiles. Electroantennogram responses to 94 selected volatile organic compounds including alkanes, alkenes, alcohols, aldehydes, ketones, carboxylic acids, esters, terpenoids and aromatic compounds were recorded from both sexes of T. castaneum. Overall, female and male T. castaneum exhibited similar electroantennography (EAG) responses. Compounds eliciting the strongest EAG responses within compound groups of chemical similarity were undecane, 1‐hexen‐3‐ol, octanal, 2‐heptanone, hexanoic acid and ethyl hexanoate. Comparison of vapour pressure and EAG amplitudes within homologous series of compounds revealed responses to undecane, octadecane, octanal, nonanal, 2‐heptanone, hexanoic acid and octanoic acid as outstanding. Given that systematic EAG screenings have not been conducted before, these are the best candidates for evaluation in future behavioural studies to unravel their potential for application in integrated pest management strategies of T. castaneum.     

Progeny production by Tribolium castaneum (Coleoptera: Tenebrionidae) and Oryzaephilus surinamensis (Coleoptera: Silvanidae) on maize previously infested by Sitotroga cerealella (Lepidoptera: Gelechiidae)

A laboratory experiment was conducted to quantify the effects of infestation of maize by Sitotroga cerealella (Olivier) on progeny production by two common secondary colonizers of grain, Tribolium castaneum (Herbst) and Oryzaephilus surinamensis (L.). Adults of both secondary pest species were allowed to oviposit for 3 wk on intact kernels of 'DeKalb 689', mechanically split kernels, kernels that had been infested for 3 mo by S. cerealella, and kernels that had been infested for 6 mo. Progeny of both species reached highest numbers on 6-mo infested maize. Prior infestation for 6 mo by S. cerealella makes maize a more suitable medium for reproduction by T. castaneum and O. surinamensis, much more than can be accounted for by mere disruption of kernel integrity resulting from larval feeding. The results highlight the importance of limiting establishment by S. cerealella on maize in storage.     

Effects of heat shock on ovary development and hsp83 expression in Tribolium castaneum (Coleoptera: Tenebrionidae)

Heat shock affects reproductive performance in insects including Tribolium castaneum. In this study, the effects of heat shock on ovary development and hsp83 expression in T. castaneum were investigated. Two lines of T. castaneum, H line and C line, from the same base population were established and maintained for five successive generations. In each generation, the newly hatched beetles (within 3 h after eclosion) in the H line were treated with a heat shock at 40°C for 1 h, and those in the C line were raised at normal temperature (30°C) as control treatment. Four traits related to ovary development were measured for the beetles of the fifth generation: days from eclosion to laying the first eggs (T_o), days from eclosion to laying the first hatchable eggs (T_h), ovariole size on the third day after eclosion, and pupal mass of their offspring. The results showed that the beetles of the H line had a significantly longer pre‐oviposition period (0.6 more days) and smaller ovariole size than those of the C line. No significant difference in pupal mass was observed. Applying heat shock to the offspring of the fifth generation of both lines led to significantly higher hsp83 expression in offspring of the C line than in offspring of the H line. Within each line, the hsp83 expression level in offspring with heat shock was significantly higher than that of offspring without heat shock, but the difference in the C line was much larger than that in the H line. We infer from these results that a tradeoff between heat resistance, registered as hsp83 expression, and ovarian development operates under heat stress in T. castaneum. 2009 Wiley Periodicals, Inc.     

赤拟谷盗HSP70基因克隆和竞争定量PCR检测

为研究赤拟谷盗Tribolium castaneum受到热胁迫后高度保守的热激蛋白70（heat shock protein 70,HSP70）基因的表达变化,本研究扩增了681 bp的赤拟谷盗hsp70片段,编码227个氨基酸残基,GenBank登录号为HM345948。同源性分析表明：赤拟谷盗hsp70核苷酸序列与马铃薯甲虫Leptinotarsa decemlineata的hsp70（GenBank登录号：AF322911.1）同源性最高,为97%;其推测的蛋白序列与马铃薯甲虫、甘蓝夜蛾Mamestra brassicae、黑腹果蝇Drosophila melanogaster和美洲斑潜蝇Liriomyza sativae的HSP70蛋白均有94%以上的同源性。利用RT-PCR技术得到与赤拟谷盗hsp70进行竞争定量的内部竞争物, 以等量的目标cDNA和一系列稀释的竞争模板进行竞争PCR扩增,构建了hsp70的竞争定量PCR检测体系, 该体系标准曲线的线性方程为Y=1.032X-1.618 (r²=0.975)。这些结果为赤拟谷盗的hsp70定量检测提供了方便,并为热控技术防治害虫提供了基础资料。