20种药用植物乙醇提取物对谷蠹的触杀和驱避活性

采用药膜法和滤纸药膜选择法,分别研究了20种药用植物乙醇提取物对谷蠹Rhizopertha dominica (Fab.)成虫的触杀和驱避活性。结果表明：触杀效果以葫芦巴Trigonelia foenum-graecum提取物的活性最强,蛇床子Cnidium monnieri和石菖蒲Acorus gramineus提取物次之。葫芦巴提取物0.39 mg/cm² 浓度处理48 h后对谷蠹的触杀死亡率为100%,处理72 h后对谷蠹的LD₅₀为19.94 μg/cm²。蛇床子和乌头Aconitum carmichaeli提取物对谷蠹成虫具有显著的驱避活性。蛇床子提取物同时具有较好的触杀和驱避活性。     

The specification of metameric order in the insectCallosobruchus maculatus Fabr. (Coleoptera)

Summary Mechanically dividing an insect egg into anterior and posterior fragments results in a segment gap (Sander 1976), a loss of non-terminal segments in the constricted region. By altering the stage and duration of constriction, we produced different types of egg fragments in the pea beetleCallosobruchus. The patterns formed by these fragments suggest the existence of interactions between anterior and posterior egg regions that influence segment patterning and placement. Segments in excess of the numbers expected on the basis of permanent constrictions were produced in fragments when: (1) the constriction was released before cellularization occurred and (2) in addition the complementary fragment degenerated. Apparently the degenerating fragment induced the formation of excess segments in the developing fragment. Differences in the time and extent of excess segment formation in anterior versus posterior fragments suggest an asymmetric distribution of prerequisites for segment formation. This conclusion is consistent with our finding that a partial reversal of segment sequence (double abdomen formation) can be induced only in posterior fragments by a degenerating fragment, but not in anterior fragments (see companion paper).The formation of excess segments shows that the segment gap observed after permanent separation cannot be due to non-specific damage, caused by the process of constriction as such, to the egg or to localized putative segment precursors.     

石菖蒲根茎甲醇提取物对谷蠹的生物活性

采用冷浸法和溶剂萃取法,研究石菖蒲(Acorus gramineus Soland)根茎甲醇提取物对谷蠹Rhizopertha dominica(Fabricius)成虫的生物活性。结果表明,石菖蒲甲醇提取物以石油醚萃取物的生物活性最强,水层次之。石油醚萃取物对谷蠹具有较高的触杀、熏蒸、种群抑制活性和防治效果,并具有一定的驱避活性。药膜法触杀处理72h后对谷蠹的LC50和LC95分别为8.30μg/cm2,51.75μg/cm2。药纸熏蒸法6.25μL/L处理120h后对谷蠹的校正死亡率为94.25%。饲料拌药法250mg/kg处理对谷蠹的防效与5mg/kg马拉硫磷效果相当,且对F1代的种群抑制效果显著高于5mg/kg马拉硫磷处理。     

Genetics of resistance to phosphine in Rhyzopertha dominica (Coleoptera: Bostrichidae)

The inheritance of resistance to phosphine was studied in two strains of the lesser grain borer, Rhyzopertha dominica (F.), labeled 'Weak-R' and 'Strong-R'. These strains were purified versions of field-selected populations collected in Queensland, Australia. Weak-R and Strong-R were, respectively, 23.4 times (20-h exposure) and 600 times (48-h exposure) resistant to phosphine compared with a reference susceptible strain (S-strain). Each -R strain was crossed with the S-strain and the response to phosphine was measured in their respective F1, F2, and F1-backcross (F1-BC) progenies. Data from testing of reciprocal F1 progeny indicated that resistance in Weak-R was autosomal and incompletely recessive with a degree of dominance -0.96. Modified chi-square analysis and contingency analysis of the observed response to phosphine of F1-BC and F2 progenies rejected the hypothesis of single gene inheritance of resistance. Analysis of the response of the F1, F2, and F1-BC progeny from the Strong-R x S-strain cross also rejected the null hypothesis for single gene resistance. Resistance in the Strong-R strain was autosomal and incompletely recessive with a degree of dominance of -0.64. The Weak-R and Strong-R strains were then crossed. Analysis ofthe F1 and F2 progenies of this reciprocal cross revealed that the strong resistance phenotype was coded by a combination of the genes already present in the Weak-R genotype plus an extra major, incompletely recessive gene. There was also evidence of a minor dominant gene present in approximately 5% of Strong-R individuals.     

Isolation and partial characterization of three isoamylases of Rhyzopertha dominica F. (Coleoptera: Bostrichidae)

Three isoamylases of Rhyzopertha dominica (termed RdA70, RdA79, and RdA90 according to their relative mobility in gel electrophoresis) were isolated by ammonium sulfate fractionation and hydrophobic interaction chromatography. RdA70 and RdA79 showed an optimal pH of 7.0, whereas for RdA90 the optimal pH was 6.5. The three isoamylases remained stable at 50 °C for 1 h, but at 60 °C, all lost 50% of their activity in 20 min and were completely inactivated in 1 h. RdA70 and RdA79 were inhibited by albumin extracts from wheat samples varying widely in amylase inhibitory activity; however, RdA90 was highly resistant to inhibition. β-Mercaptoethanol up to 30 mM increased the activity of the three isoamylases by 2.5-fold. The action pattern of the three isoamylases was typical of endoamylases; however, differences were observed on the hydrolytic efficiency rates measured as V_max/K_m ratio on starch, amylopectin, and amylose. The hydrolyzing action of RdA90 on starch and amylopectin (V_max/K_m = 90.4 ± 2.3 and 78.9 ± 6.6, respectively) was less efficient than that on amylose (V_max/K_m = 214 ± 23.2). RdA79 efficiently hydrolyzed both amylopectin and amylose (V_max/K_m = 260.6 ± 12.9 and 326.5 ± 9.4, respectively). RdA70 hydrolyzed starch and amylose at similar rates (V_max/K_m = 202.9 ± 5.5 and 215.9 ± 6.2, respectively), but amylopectin was a poor substrate (V_max/K_m = 124.2 ± 7.4). The overall results suggest that RdA70 and RdA79 appear to belong to a group of saccharifying isoamylases that breaks down long fragments of oligosaccharide chains produced by the hydrolytic action of RdA90. The simultaneous action of the three isoamylases on starch, aside from the high resistance of RdA90 to wheat amylase inhibitors, might allow R. dominica to feed and reproduce successfully on the wheat kernel.     

Effect of five diatomaceous earth formulations against Tribofium castaneum （Coleoptera： Tenebrionidae）, Oryzaephflus surinamensis （Coleoptera： Silvanidae） and Rhyzopertha dominica （Coleoptera： Bostrychidae）

Laboratory bioassays were conducted to determine the effect of food source on the survival of Tribolium castaneum Herbst, Oryzaephilus surinamensis L. and Rhyzopertha dominica F., after exposure to five diatomaceous earth （DE） formulations： Protect-It, Insecto, Perma-GuardTM, Dryacide and SilicoSec. Adults of these species were exposed to DEs at the rate of 0.5 mg/cm^2 for 1 day on filter paper inside plastic Petri dishes. After exposure, the initial mortality was counted and live individuals of the three species were held for a week in glass vials containing 50 mg wheat flour, rice and whole wheat, respectively. In the second experiment, after 1 day exposure to DEs, beetles were transferred to Petri dishes without food and held for a week to determine if the presence of food source would decrease the mortality of beetles. Experiments were carried out at 27℃ and 55% RH in the dark. The initial mortality in both of the experiments reached 100% for the three species exposed to Protect-It and in the case ofR. dominica and O. surinamensis exposed to Dryacide. In contrast, low level of mortality （〈 10%） was observed for T. castaneum exposed to Perma-GuardTM and Insecto. The mortality after the post-treatment period on food was decreased for the three species exposed to Perma-GuardTM and in the case of T. castaneum and R. dominica exposed to Insecto and SilicoSec. Adults of O. surinamensis were the most susceptible followed by R. dominica and 100% adult mortality was obtained, whereas T. castaneum were the least susceptible beetles to DEs. Protect-It and Dryacide were the most efficient DE formulations and can be used effectively in a stored grain integrated pest management program.     

Population development of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) on different stored products

The lesser grain borer, Rhyzopertha dominica, is an important pest of various stored products around the world. In this study, the development, survival, reproduction, and life table parameters of R. dominica were investigated on six stored products (angelica, jujube, maize, rice, soybean, and wheat). The developmental time of the immature stage of R. dominica was shortest on wheat (40.20 days) and longest on angelica (67.04 days). The survival rate of the immature stage was highest on wheat (76.33%) and lowest on angelica (41.00%). The fecundity level of R. dominica was highest on wheat (246.05 eggs/female) and lowest on angelica (69.38 eggs/female). The net reproductive rate (R₀) and intrinsic rate of increase (r_m) of R. dominica differed significantly among the six stored products. The highest R₀ of R. dominica was on wheat (68.50), followed by rice (41.28), maize (32.32), soybean (27.17), jujube (23.16), and angelica (20.18); the r_m values showed a similar trend, with values of 0.059, 0.046, 0.042, 0.039, 0.036, and 0.033, respectively. Our results indicate that wheat was the most suitable stored product, whereas angelica was the least suitable, for the feeding, development, and population increase of R. dominica. These findings provide basic information about the occurrence trends and characteristics of R. dominica that will be useful for the control of this pest on different stored products. The physicochemical properties of angelica should be further explored for potential application in the control or integrated management of R. dominica.     

Efficacy of Probe Traps Supplemented with an Attractant and Repellent for the Control of Rhizopertha dominica

Rhizopertha dominica is a serious pest of stored commodities. The population shows its peak during the monsoon season. The use of chemicals has resulted in resistance. Therefore, some substitutes need to be identified; the probe traps are one of such techniques. The laboratory-reared 50,000 adults of both sexes were used for present investigation. The response of this insect was tested against empty probe traps and those filled with tobacco and neem dried leaves and mustard oil as repellents and attractant, respectively. It has been observed that probe traps have the ability to provide aggregating places for Rhizopertha dominica, while the performance of these traps could further be enhanced with tobacco leaves, as these helped to trap more individuals after 72 hr.     

Immediate and delayed mortality of Rhyzopertha dominica (Coleoptera: Bostrichidae) and Sitophilus oryzae (Coleoptera: Curculionidae) adults exposed to spinosad-treated commodities

A series of tests was conducted to characterize differences in the mortality of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), and rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), exposed to three commodities treated with a liquid and dry spinosad formulation. In laboratory bioassays, adults of the two insect species were exposed to untreated wheat, Triticum aestivum L., corn, Zea mays L., and sorghum, Sorghum bicolor (L.) Moench., and to commodities treated with 1 mg (AI)/kg of liquid and dry spinosad formulations. Mortality was assessed from independent samples examined at specific time intervals to determine immediate mortality and after 24 h of recovery on untreated grain at 28 degrees C and 65% RH to determine delayed mortality. Comparison of the time required for 50% (LT50) and 95% (LT95) mortality indicated that R. dominica adults were consistently and significantly more susceptible (died quickly) than S. oryzae adults when exposed to spinosad-treated commodities. In general, the toxicity of liquid and dry spinosad formulations was similar against R. dominica or S. oryzae. The toxicity of spinosad to each species varied slightly among the three commodities, and there were no consistent trends to suggest that spinosad was more effective on one commodity versus another. LT50 values based on immediate mortality for R. dominica on all commodities ranged from 0.45 to 0.74 d; corresponding values based on delayed mortality ranged from 0.04 to 0.23 d, suggesting delayed toxic action of spinosad in R. dominica. LT50 values based on immediate and delayed mortality for S. oryzae on all three commodities treated with the two spinosad formulations were essentially similar and ranged from 2.75 to 4.56 d. LT95 values for R. dominica based on immediate mortality on spinosad-treated commodities ranged from 1.75 to 3.36 d, and those based on delayed mortality ranged from 0.49 to 1.88 d. There were no significant differences in LT95 values based on immediate and delayed mortality for S. oryzae on spinosad-treated commodities, and the LT95 values ranged from 7.62 to 18.87 d. The toxicity of spinosad was enhanced during a 24-h holding period after removal from spinosad-treated commodities only against R. dominica adults, and possible reasons for increased postexposure mortality of R. dominica adults after brief exposures to spinosad warrant further study.     

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.     

Efficacy of Bacillus thuringiensis against Lesser Grain Borer, Rhyzopertha dominica (Coleoptera: Bostrichidae)

Toxins from 36 isolates, representative of all available subspecies of Bacillus thuringiensis, were tested against larvae and adults of the lesser grain borer, Rhyzopertha dominica. beta -Exotoxin was effective against both larvae and adults. Spore-crystal complexes of subspecies darmstadiensis isolates from Germany were effective against larvae. Isolates of subspecies darmstadiensis from the US and Japan were not effective. The degree of control achieved by even the best isolate was not economically satisfactory.     

Ultrastructural dynamics of the corpus allatum of Choleva angustata Fab. (Coleoptera,Catopidae)

Summary The ultrastructure of the corpora allata (CA) during postembryonic stages of Choleva angustata Fab. shows cyclic changes, in particular regarding the endoplasmic reticulum and the mitochondria. During the last larval instar, at the short transitory period which follows the cessation of alimentation, we observed a highly unusual appearance of the CA, characterized by intensive vacuolization. After this transitory period, the smooth endoplasmic reticulum (ser) disappears until the imago emerges. These observations along with our experimental data permit a physiological interpretation.We thank Departments of Electron Microscopy and Photography of the Institute of Neurophysiology and Psychophysiology, C.N.R.S., Marseille, France     

Relation between corpus allatum and haemolymph proteins in Sphaerodema rusticum Fabr.

The active and inactive stages of the corpora allata have been described on the basis of size and nucleo-cytoplasmic ratio. The polyacrylamide gel disc electrophoresis of the haemolymph has been done in the males and different stages of reproducing females. A protein fraction with a value 14 less than or equal to Rm less than 16 has been observed only in females. Out of 8 protein fractions, 5 showed oscillations in their concentration at the time of vitellogenesis. Finally active stages in the corpora allata are correlated with the fluctuations in haemolymph protein concentration.     

Effect of temperature and commodity on insecticidal efficacy of spinosad dust against Sitophilus oryzae (Coleoptera: Curculionidae) and Rhyzopertha dominica (Coleoptera: Bostrychidae)

The insecticidal effect of spinosad dust, a formulation that contains 0.125% spinosad, was evaluated against adults of Sitophilus oryzae (L.) and Rhyzopertha dominica (F.) at three temperature levels (20, 25, and 30 degrees C) and four commodities (wheat, Triticum aestivum L.; barley, Hordeum vulgare L.; rice, Oryza sativa L.; and maize, Zea mays L.). For this purpose, quantities of the above-mentioned grains were treated with spinosad at two dose rates (20 and 50 ppm of the formulation, corresponding to 0.025 and 0.06 ppm AI, respectively), and mortality of the exposed adults in the treated grains was measured after 7 and 14 d, whereas progeny production was assessed 65 d later. Generally, for both species, mortality increased with dose, exposure interval, and temperature. For S. oryzae, adult survival and progeny production were lower on wheat than the other grains. After 14 d of exposure, mortality of S. oryzae adults on wheat treated with 50 ppm ranged between 61 and 98%, whereas in the other three commodities it did not exceed 42%. Mortality of R. dominica after 14 d on grains treated 50 ppm ranged between 91 and 100%. For this species, progeny production from exposed parental adults was low in all commodities regardless of temperature. Results indicate that spinosad dust can be used as an alternative to traditional grain protectants, but its effectiveness is highly determined by the target species, commodity, dose, and temperature.     

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.     

Effects of pyrimidine-2-thiol on the ovarian histology of Epilachna vigintioctopunctata (Fabr.) (Coleoptera: Coccinellidae)

The telotrophic ovary of Epilachna vigintioctopunctata is composed of 32-40 ovarioles, each with an apical germarium and a basal vitellarium. The germarium encloses mononucleate and binucleate trophocytes, prefollicular tissue and oogonia, while the vitellarium contains 2-5 oocytes arranged in order of maturity. Definite nutritive cords are absent. When females are exposed to 75 mg 4,4,6-trimethyl-1h, 4H-pyrimidine-2-thiol by contact, the trophocytes and the follicular epithelial cells disintegrate to form dark-staining clumps and thus fail to supply nourishment to the developing oocytes, which consequently remain yolk-less and are ultimately reduced to shrunken masses.     

Histological studies of the neurosecretory and retrocerebral complex of the water beetle,Hydrophilus olivaceus Fabr. (Insecta,Coleoptera)

The neurosecretory cells (NSC) in the breeding phases show gigantic sized droplets. NSC show two peaks of activity in females at midnight and at 9 A.M., while a single peak occurs in males between midnight and 3 A.M. Light has a triggering effect on the neurosecretory release. The corpus cardiacum is the main neurohaemal organ. It has a nerve core formed by the nervi corpus cardiacum I and II, which is surrounded by the glandular region. Intrinsic secretory chromophilic cells and chromophobic cells occur randomly. Aorta is probably not a storage-release centre. The corpora allata are lobulated structures, showing cyclical activity which is correlated with egg-maturation. No neurosecretory material occurs in allatum.     

Contact and fumigant toxicities of calamusenone isolated from Acorus gramineus rhizome against adults of Sitophilus zeamais and Rhizopertha dominica

Abstract Calamusenone [3,8‐dimethyl‐5‐(1‐methylethylidene)‐1,2,3,4,5,6,7,8‐octahydroazulene‐6‐one, C₁₅H₂₂O] from Acorus gramineus Soland rhizome was tested in the laboratory for its insecticidal activities against adults of Sitophilus zeamais Motsch. and Rhizopertha dominica (Fab.), using dry film contact and fumigation methods. Responses varied with insect species, dosage and exposure time. In the dry film contact experiment, the highest insecticidal effects of calamusenone against S. zeamais and R. dominica adults were produced at 170.32 μg/cm² after treatment for 72 h, with 96.2% and 98.7% mortalities, respectively. The median lethal concentration (LC₅₀) (72 h) values of calamusenone against S. zeamais and R. dominica adults were 67.00 μg/cm² and 77.30 μg/cm², respectively. As a potential fumigant, calamusenone showed moderate insecticidal effect on the adults of S. zeamais and R. dominica in fumigation experiment, with their LC₅₀ (120 h) values of 125.71 μL/L and 93.64 μL/L respectively. Calamusenone isolated from A. gramineus rhizome showed promise as a novel pesticide candidate for stored‐product pest control.     

The investigation of the combined effects of gamma irradiation and environmental manipulation on mortality and sterility of Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae)

With respect to the limitations use of methyl bromide and phosphine, employing ionizing radiation to control stored product pests has attracted great attention. The aim of this study is the investigation of the combined effects of gamma irradiation as viable alternatives to synthetic insecticides and environmental management on mortality and sterility of Rhyzopertha dominica (Fabricius) in a wheat cultivar (Gascogen). The effect of doses range from 30 to 2000?Gy gamma irradiation in combination with manipulation of temperature (15, 21, 27 and 32?°C) and relative humidity (20%, 50%, 65% and 85%) on 5–10?days old adults of R. dominica in Gascogen cultivar of wheat were explored. The experiments were repeated three times and conducted in The Nuclear Agriculture Research School in Karaj and laboratory of shahid steki silo in shahre-kord. Probit analysis revealed that both temperature and relative humidity had combined effects when used with gamma irradiation. The lowest doses of gamma ray required to kill 25% (14.2?Gy) and 50% (610.8?Gy) of the population (LD₂₅ and LD₅₀) were recorded at 21?°C and 85% relative humidity respectively. The low dose for 99% mortality (LD₉₉; 2386.7?Gy) was recorded for beetles maintained at 21?°C and 50% relative humidity. The effect of temperature (15, 21, 27 and 32?°C) on sterility caused by gamma irradiation was also investigated. The results showed that the F₁ generation emerged only when the beetles were treated with doses of 0–100?Gy at 32?°C and 0–70?Gy at 27?°C. These results indicate that temperature and relative humidity play an important role in the susceptibility of the lesser grain beetle to gamma irradiation. The results suggest that controlling the efficiency of gamma radiation through environmental control allows the use of low doses of gamma radiation that have a less harmful effect on human health, non-target organisms and seed agronomic features.     

Morphology of antennal sensilla of the brown spruce longhorn beetle,Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae)

The antennal sensilla of the brown spruce longhorn beetle, Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae) were examined with particular focus on the sensilla present on the apical flagellomere. T. fuscum antennae are composed of 11 segments, namely the scape, pedicel, and nine flagellomeres. Nine types of sensilla were observed: three types of sensilla chaetica, sensilla trichodea, two types of sensilla basiconica, grooved peg sensilla, thick-walled sensilla, and Böhm bristles. Seven of these types were present on the apical flagellomere, the exceptions were sensilla chaetica type 3 and Böhm bristles. There were no significant differences in the distribution or density of sensilla present on the ninth flagellomere of males and females, except that males had significantly more sensilla chaetica type 1, which are put forward as the putative contact chemoreceptors for T. fuscum.