Magnetic field-induced oxidative stress and DNA damage in Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) larvae

Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) is cosmopolitan pest of stored products. The effect of strong magnetic fields (MFs) on DNA damage and oxidative stress on larvae stage of E. kuehniella was assessed. Antioxidant enzyme systems, which include superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and malondialdehyde (MDA), the end product of lipid peroxidation as a result of strong MF intoxication that might occur in the larvae tissue, were evaluated. A simple technique of single-cell gel electrophoresis (DNA comet assay) enabled a quick detection of MF treatment on larvae. The larvae were exposed in a 1.4-Tesla (T) MF from a DC power supply at 50 Hz for different time periods (3, 6, 12, 24, 48, and 72 h). MFs caused increasing DNA damage and demonstrated using the comet assay with its parameters including tail DNA%, tail length and tail moment. DNA damage at increasing exposure times were significantly larger than the control group (p < 0.05). These parameters were detected using BS 200 ProP with image analysis software. SOD, CAT, GPx, and GST activities decreased and MDA level increased in the MF-treated group in larvae tissue compared to control group for increasing exposure times at 1.4 T (p < 0.05). In our investigation, we showed that MFs caused oxidative stress and proved to be DNA damage as revealed by the comet assay. MFs may be used to determine potential toxic effects as a control agent against E. kuehniella larvae.     

Effects of gamma radiation on life stages of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

We report the results of experiments conducted with Ephestia kuehniella Zeller to determine the effects of gamma radiation on life stages. Eggs, larvae, pupae and adults were irradiated with increasing doses of gamma radiation (seven dose levels between 50 and 400 Gy for eggs and larvae, six dose levels between 50 and 350 Gy for pupae and four dose levels between 250 and 550 Gy for adults). All the experiments were conducted in a growth chamber maintained at 27 ± 1°C, 65 ± 5% r.h., and alternating 14 h light:10 h dark cycles. The number of adults that developed from irradiated eggs and larvae was lower than the untreated control. Doses of 200 Gy and above prevented adult emergence from irradiated eggs. Although a dose of 200 Gy was enough to prevent adult emergence from young larvae, 250 Gy should be used to prevent adult emergence completely from last instar larvae. Delayed developmental periods were observed for the treated eggs and larvae. Fecundity and egg hatchability were decreased depending on the doses applied. Decreased fecundity and egg hatchability were more prevalent when both the male and female pupae were treated compared to the treatment of female pupae only. There was no significant decrease in the fecundity of irradiated adults except 550 Gy, and no eggs hatched at doses of 300 Gy and above.     

The effect of carbon dioxide under pressure against eggs of Ephestia kuehniella Zeller and adults of Stegobium paniceum (L.) and Oryzaephilus surinamensis (L.)

The efficacy of an atmosphere with a high content of carbon dioxide under a pressure of 5 and 10 bar against young eggs of Ephestia kuehniella Zeller (Lep.: Pyralidae) and adults of Stegobium paniceum (L.) (Col.: Anobiidae) and Oryzaephilus surinamensis (L.) (Col.: Cucujidae) was investigated. At a pressure level of 10 bar, a 100?% mortality in eggs of E. kuehniella was obtained after 4 hours. Complete control was not obtained with the adult beetles, except for a 2 hour-treatment at 10 bar with individuals of S. paniceum, which not were offered protection. It is demonstrated that when working with an atmosphere of carbon dioxide under pressure of 10 bar for 2 hours, even a slight protection from food material will influence the mortality. The reason for these findings are discussed.     

Losses and pest infestation in different maize storage systems with particular emphasis onProstephanus truncatus (Horn) (Col., Bostrichidae) in Togo

Three maize storage systems, combined with insecticide treatment, were tested in three trials at the same location in southern Togo. Trials were carried out in the storage season 1989/90, 1990/91 and 1992/93. Maize was stored in traditional granaries as cobs with husks, in cribs as dehusked cobs in bulk and as shelled grain in sacks. After 8 months of storage damage and losses of stored maize and insect infestation were evaluated. Storage of loose grain in sacks gave the best results with lowest insect infestation and smallest damage and losses. Highest damage and losses occurred in cribs, whereas intermediate results were obtained in granaries. The treatment with an insecticide was most effective in traditional granaries. In cribs the insecticide treatment was less effective. No differences were found in treated sack variants because of very low pest infestation.     

Effect of cold storage and different diets on <Emphasis Type="Italic">Ephestia kuehniella</Emphasis> Zeller (Lep:Pyralidae)

Ephestia kuehniella adults were stored at 10°C for 1–10 weeks. Reproductive ability and number of living adults decreased depending on the length of the storage period. Long-term exposure to cold lengthened the life of the adults and 50% mortality was reached after 6 weeks. To obtain complete mortality and sterility 10 weeks of storage was needed. The larvae reared on corn flour diet developed to the adult stage more rapidly than that of the other treatments. The adults reared on oat flour produced significantly more eggs than the other diets. There was no difference among diets with regard to emergence rate, longevity or sex ration of E. kuehniella adults. Trichogramma evanescens did not differentiate among hosts from different food sources with respect to parasitization, adult emergence and sex ratio. The suitability of the eggs from cold-exposed adults with respect to parasitization was found to be the same as the control during the first 3 weeks.     

In vitro growth of Gremmeniella abietina isolates (European race) at different temperatures

The mycelial growth of 24 isolates of types A and B of Gremmeniella abietina (Lagerb.) Morelet, collected in northern Finland and the Kola peninsula, Russia, was studied on malt agar plus pine needle extract at 18°C and 5°C. Great variation occurred within both types, and the results suggest that several isolates per stand are needed to represent one local isolate, if responses of G. abietina mycelia are studied on artificial media.     

Biological characteristics and life tables of Neoseiulus umbraticus Chant (Acari, Phytoseiidae) at three constant temperatures

The development time, survival and fecundity of the generalist predatory mite, Neoseiulus umbraticus Chant, were determined at 20, 25, and 30?°C and 65?±?10?% RH. N. umbraticus females completed development in 9.7, 8.0 and 5.9 days, respectively, using a diet of all life stages of Tetranychus cinnabarinus Boisduval. Total developmental times of males were relatively shorter at 25 and 30?°C than at 20?°C. In general, preoviposition, oviposition, and postoviposition periods of N. umbraticus shortened as temperature increased. The longest survival rate of N. umbraticus of 80.5 days occurred at 20?°C, followed by 67.0 and 57.6 days at 25 and 30?°C, respectively. Mated females laid an average 0.9, 1.3 and 1.4 eggs per female per day and 33.1, 44.0 and 43.6 eggs over their entire lives at 20, 25 and 30?°C, respectively. The sex ratios of this species were 0.57, 0.57 and 0.54 female (female+male) at 20, 25 and 30?°C, respectively. The intrinsic rate of increase (r_m) became greater with rising temperatures from 0.123 at 20?°C to 0.180 at 30?°C. The net reproduction rate (R_o) was highest at 25?°C (25.0 females/female) and lowest at 20?°C (18.8 females/female), while T_o decreased with increasing temperatures, from 23.8 days at 20?°C to 17.5 days at 30?°C.     

Reproductive traits and diel activity of adultMonochamus saltuarius (Coleoptera: Cerambycidae) at two different temperatures

To investigate the reproductive traits and diel activity ofMonochamus saltuarius, 14 pairs of the adults were reared and observed at each of 20°C and 25°C. Both sexes were more active at 25°C than at 20°C irrespective of the presence or absence of light. A diel change in behavior during 24 h was found on 33% of a total of 48 observations of three age classes of both sexes. No significant difference was found in the mean longevity between sexes or between the two temperature conditions. The time required for reproductive maturation showed no significant difference within the same sex when reared at 20°C and 25°C. The mean oviposition period was significantly longer at 25°C (28.8 days) than at 20°C (12.2 days). The mean lifetime fecundity was significantly greater at 25°C than at 20°C. There was no significant difference in the oviposition ratio (number of eggs deposited/number of oviposition wounds excavated), oviposition rate or hatchability for females between the two temperature conditions.     

Laboratory evaluation of five novel pyrrole derivatives as grain protectants against <Emphasis Type="Italic">Tribolium confusum</Emphasis> and <Emphasis Type="Italic">Ephestia kuehniella</Emphasis> larvae

Several naturally discovered or laboratory-synthesized pyrrole compounds have insecticidal, acaricidal and microbial properties. The novel sulfanyl 5H-dihydro-pyrrole derivatives exhibit certain antioxidant activities. However, there is a knowledge gap whether these substances are potent grain protectants against stored-product insect pest species. In this context, we evaluated the insecticidal activity of five novel pyrrole derivatives (under the trivial names 3a, 3g, 3l, 3m, 3h), against larvae of Tribolium confusum Jaquelin du Val and Ephestia kuehniella Zeller at different doses (0.1, 1 and 10 ppm), exposure intervals (7, 14 and 21 days or 1, 2, 7, 14, 21 days), temperatures (20, 25 and 30 °C), relative humidity (RH) (55 and 75 %) levels and commodities (wheat, maize, barley). The pyrrole derivative 3a exhibited the highest insecticidal activity, while 3g, 3l, 3m and 3h caused similar mortality against larvae of T. confusum. Apart of the level of efficacy, all tested pyrrole derivatives performed similarly according temperature. We found that increase in temperature increased mortality in the majority of the tested combinations. Generally, the pyrrole derivatives caused the highest mortality levels at 30 °C. The pyrrole derivatives 3a, 3g, 3l and 3m were affected by relative humidity at almost all combinations tested. The 75 % level of RH moderated the efficacy of the pyrrole derivatives, while the 55 % enhanced it. Mortality of T. confusum and E. kuehniella on maize was much lower on treated maize than barley or wheat. However, 100 % control of both species was recorded only on treated barley. The results of the present study indicate that the pyrrole derivatives tested could serve as grain protectants against noxious stored-product insects under certain biotic and abiotic conditions.     

Examination of efficacy of magnesium phosphide (Detiaphos R) against the cigarette beetleLasioderma serricorne (Fabr.) (Col., Anobiidae) at low temperatures

Tobacco was fumigated to control the cigarette beetleLasioderma serricorne (Fabr.) with a fumigant based on magnesium phosphide (Detiaphos R) in hogsheads and cartons at temperatures almost constantly below freezing point and alternatively at temperatures which increased or decreased very slowly in the course of the fumigation. The dosage was 1 g PH₃ per m³ and the fumigation lasted 96 h in all cases. Gas concentration measurements in the tobacco and under sheeting showed that PH₃ developed rapidly in lethal concentrations from magnesium phosphide at low temperatures. Complete mortality of the inserred test insects was registered after the 96 h fumigation period. With magnesium phosphide, a fumigant is available which can be used for fumigating tobacco even at low temperatures.     

Root water flow and growth of aspen (Populus tremuloides) at low root temperatures

Effects of root zone temperature on growth, shoot water relations, and root water flow were studied in 1-year-old aspen (Populus tremuloides Michx.) seedlings. Seedlings were grown in solution culture and exposed to day/night air temperatures of 22/16 degrees C and solution culture temperatures of 5, 10, or 20 degrees C for 28 days after bud flush. Compared with root growth at 20 degrees C, root growth was completely inhibited at 5 degrees C and inhibited by 97% at 10 degrees C. The 5 and 10 degrees C treatments severely reduced shoot growth, leaf size, and total leaf area. Root water flow was inhibited by the 5 and 10 degrees C treatments. However, when seedlings were grown for 28 days at 5 degrees C and root water flow was measured at 20 degrees C, there was an increase in flow rate. This increase in root water flow was similar in magnitude to the decrease in root water flow observed when seedlings were grown for 28 days at 20 degrees C and root water flow was measured at 5 degrees C. Reduced root water flow of seedlings grown at 5 and 10 degrees C resulted in decreased stomatal conductance, net assimilation, and shoot water potentials. Root water flow was positively correlated with leaf size, total leaf area, shoot length, and new root growth. Transferring seedlings from 5 to 20 degrees C for 24 h significantly increased root water flow, shoot water potential, and net photosynthesis, whereas transferring seedlings from 10 to 20 degrees C resulted in only a slightly increased shoot water potential. Transferring seedlings from 20 to 5 degrees C greatly reduced root water flow, stomatal conductance, and net photosynthesis, whereas shoot water potential decreased only slightly.     

Chemical composition and bioactivities of three Chrysanthemum essential oils against Tribolium confusum (du Val) (Coleoptera: Tenebrionidae)

Essential oils from three species of Chrysanthemum growing in Tunisia (C. coronarium, C. fuscatum, and C. grandiflorum) were first analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) and then evaluated for toxicity and antifeeding action against Tribolium confusum. The essential oils obtained from leaves and flowers shared a similar qualitative composition, but the relative proportions of the constituents were quite different. The essential oil of C. grandiflorum was rich in sesquiterpenoids, while those of C. fuscatum and C. coronarium were rich in monoterpenoids. The main common constituents of all the essential oils were ??-pinene, myrcene, ??-humulene, ??-caryophylene, spathulenol, and caryophyllene oxide. The most effective essential oil was obtained from the leaves of C. grandiflorum, that inhibited the relative growth rate (?0.03?mg/mg/d), efficiency of conversion of ingested food (?50.69%), relative consumption rate, caused an antifeeding effect (66.43%) and a high mortality (80%) of T. confusum larvae. Topical application C. grandiflorum essential oil caused a significant insect mortality that attends 27% after 7?days of treatment. While essential oil from C. coronarium flowers has contact and fumigant toxicity with a mortality of 9 and 13%, respectively. Results analysis highlights a relationship between essential oils composition and insecticidal activity against T. confusum. The study showed that each essential oil has specific chemical composition and act differently according to the nature of attributed test. The use of essential oils from different Chrysanthemum species with different methods helps poor farmers who store small amounts of grains to preserve it against pest infestation.     

Acceptability of different sugars and oils to three tropical ant species (Hymen., Formicidae)

Baits are generally more effective than insecticidal sprays and dusts for controlling ant infestations. It is important to use a highly acceptable food attractant in order for baits to be effective. We examined the acceptability of 6 sugars and oils to 3 ant species,Pheidole megacephala (Fab.),Ochetellus glaber (Mayr), andParatrechina longicornis (Latr.). One of these sugars, melezitose, is a trisaccharide found only in the honeydew of homopterous insects.P. megacephala showed a significant preference for melezitose over maltose and trehalose, but not over fructose and surcose. O.glaber significantly preferred sucrose over maltose andP. longicornis did not show any significant preferences for the different sugars.P. megacephala showed a significant preference for olive oil. NeitherO. glaber norP. longicornis showed a preference for the different oils and there were very low numbers ofO. glaber andP. longicornis workers attracted to oiltreated disks. Hence, oil-based baits would probably not be effective for controlling either of these latter two ant species.With one table     

四川大渡河流域不同地点铁杉林瓢虫科多样性比较

文章首次报道了四川大渡河流域的铁杉林瓢虫科种类、数量及发生时间.在3个地点的铁杉林中,共采集到瓢虫48种.对斑小瓢虫Scymnus geminus、华山松小瓢虫S.huashansong、马蹄毛瓢虫S.lycotropus、宁陕毛瓢虫S.ningshanensis为首次在四川报道.3月到11月均可采集到瓢虫成虫,以5月(22种)、6月(25种)和7月(24种)为最多.幼虫出现主要集中在5月.羊厂沟铁杉林是以阔叶为主的针阔混交林,其瓢虫的物种丰富度指数、多样性指数、均匀度指数均远远高于泥巴沟和驷马桥.泥巴沟和驷马桥同属于针叶树占优势的针阔混交林,林内瓢虫科物种丰富度指数较低,但种类优势度高.三地瓢虫组成相似性均处于较低水平.     

Functional responses of the parasitoid,Ertmocerus longipes Compere (Hym., Aphelinidae) to densities of the whitefly,Aleurotuberculatus takahashi David et Subramaniam (Hom., Aleyrodidae) at different temperatures

The present study dealt with the functional responses of the parasitoid,Eretmocerus longipes Compere (Hym., Aphelinidae) to the densities of the whitefly,Aleurotuberculatus takahashi David et Subramaniam (Hom., Aleurodidae) at different temperatures under the laboratory conditions. The results showed that when the initial densities ofA. takahashi-3rd instar were raised from 10 to 320 ind./leaf, the numbers of parasitized nymphs increased as well, ranging from 7.0 to 23.1 at 20°C, 9.8 to 42.9 at 25°C, 6.7 to 39.9 at 30°C, and 1.8 to 8.3 ind./leaf at 35°C, respectively. The Holling Disk Equation was introduced to build up the models of functional responses. The response curves remained type II, although the numbers of parasitized nymphs were significantly different under different temperatures. The suitable initial densities of the host whitefly for parasitization were about 80 individuals per leaf. A negative relation was observed between the initial densities of the whitefly and the parasitization rates by the parasitoid. An increase in the initial densities ofA. takahashi-3rd instars ranging from 10 to 320 ind./leaf resulted in a decrease in the parasitization rate byE. longipes ranging from 70.0% to 7.2% at 20°C, 98.0% to 13.4% at 25°C, 67.0% to 12.5% at 30°C and 18.0% to 2.6% at 35°C with a value of 0.2877 was significantly smaller than that at 20°C with a vlaue of 1.3354, that at 25°C with a value of 1.6465 and that at 30°C with a value of 1.1199, respectively (p<0.01). The handling time (Th) forE. longipes was 0.1521 at 35°C, significantly longer than 0.0510 at 20°C, 0.0289 at 25°C and 0.0320 at 30°C, respectively (p<0.01). The maximum loading number (K) of the parasitized nymphs with a value of 34.5 ind./leaf at 25°C was similar to that with a value of 31.2 ind./leaf at 30°C, about 1.8 times as high as that with a value of 19.6 ind./leaf at 20°C and 4 times more than that with a value of 6.6 ind./leaf at 35°C. It was suggested that temperature affected the functional response by balancing searching rate and handling time. The optimal temperature range for the functional responses ofE. longipes to the densities ofA. takahashi-3rd instar was 25° to 30°C.     

Transgenic expression of Pinellia ternata agglutinin (PTA) and Arisaema heterophyllum agglutinin (AHA) in wheat confers resistance against the grain aphid,Sitobion miscanthi

Journal of Pest Science - The present study investigated the feeding behaviour and life-table parameters of the grain aphid Sitobion miscanthi in response to being fed on transgenic wheat lines...     

不同品种(系)李果实外观和内在品质的比较

为了筛选出适合河南及周边地区推广的新优李品种,选取生产中主栽的8个李品种(紫琥珀、青脆李、法国李、公主李、黑宝石、济源的黄甘李、黄桔李和平顶山的黑宝石)及5个新选育的李优良品系(7-15、4-12、1-24、3-11、4-22)作为材料,测定并比较果实主要外观指标、营养成分、功能性成分和提取液抗氧化活性。结果表明:不同地区的同一李品种(系)果形指数一致,但是果形大小、营养成分、功能性成分及抗氧化活性均存在显著差异。不同品种(系)李果实中总糖含量与还原糖含量、维生素C含量均呈极显著正相关,相关系数分别为0.926、0.708。大果型的4-12、7-15和小果型的青脆李、公主李,表现为糖酸比高,分别为14.92、10.01、16.54、14.86;维生素C含量高,分别为0.098 9、0.063 2、0.069 2、0.078 3 mg/g。不同品种(系)李果实中类黄酮含量与总酚含量呈极显著正相关,相关系数为0.979。类黄酮、总酚含量与李果实提取物清除·OH的能力呈显著正相关,相关系数分别为0.664、0.650。公主李和法国李具有较高的类黄酮、总酚含量和清除·OH的能力,4-12具有较高的三萜酸含量和清除DPPH·的能力,黄甘李具有较高的三萜酸含量和清除·O_2-的能力,均适合在河南及周边地区进行推广栽培。     

COMPARISON OF DIFFERENT STAINING METHODS FOR ANALYSING ESTERASE (EST) ISOZYME OF FUNGI AND PLANTS

INTRODUCTIONAPOenZyl11evanahon(lsoZyl11evanahOI1),asoneof111oIecu1argel1ehcai111arkers.l1asbeenwidelyapplledtothefieldofgenehcs'pll}'slologyandsyste111aticaltaxono111yofpla11ta11danl111alsincel97O's,andalsoapplledtoful1gisnldies111orea11dl11ore111recentyears.Dlerearemal1y'el1Zy1l1esthatareisoZyl11es-alnongthe111Esterasel1asbeen111ore-wideIyappliedtothestudyofftl1Wrece11tly.Tl1estaini11gn1etl1odstoEstisocyl11earefew.a11donlyoneortwol11ethodswererecorded.T11eyarelnIhallyappIledtohlghe…     

Bioactivities of <Emphasis Type="Italic">Cocos nucifera</Emphasis> L. (Arecales: Arecaceae) and <Emphasis Type="Italic">Terminalia catappa</Emphasis> L. (Myrtales: Combretaceae) leaf extracts as post-harvest grain protectants against four major stored product pests

Compounds extracted from the leaves of coconut palm, Cocos nucifera L. (Arecales: Arecaceae) and the Indian almond, Terminalia catappa L. (Myrtales: Combretaceae) were assessed as potential grain protectants against four major pests of stored grains, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), and Callosobruchus chinensis (L.) (Coleoptera: Bruchidae). The crude leaf extracts and their fractions were obtained by solvent elution and bioassayed in the laboratory, focusing on (a) the duration of protection and (b) their effects on progeny production. Results showed that adults of C. chinensis, S. oryzae, and T. castaneum were equally susceptible to the fumigant toxicity of C. nucifera and T. catappa crude extracts as well as their column eluted fractions. On the contrary, adults of R. dominica showed tolerance to all the extracts tested in both fumigation and contact mode bioassays. Cocos nucifera crude extracts were highly effective in offering long-term protection in residual toxicity trials and along with the crude extracts of T. catappa showed strong repellent properties against the tested species except for R. dominica in a Y-tube olfactometer. Generally, the chromatographic fractions of crude leaf extracts eluted with ethyl acetate were significantly more effective than methanol, chloroform or hexane-eluted fractions. Further, all the tested plant extracts demonstrated a negative impact on several biological parameters such as feeding activity and progeny production of the tested species. These results highlight the potential of C. nucifera and T. catapa extracts as potent insecticides, feeding deterrents and progeny production inhibitors and consequently are suitable for the control of pests in stored commodities.