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1.
The essential oil of Artemisia annua L. was tested for its toxic repellent and development inhibitory activities against 2 economically important stored product insects: Tribolium castaneum (Herbst) and Callosobruchus maculatus (L.). Adult beetles of T. castaneum were repelled significantly by oil of A. annua at 1% concentration (vol:vol) and above in filter paper arena test. Dose-response relationship of A. annua oil revealed a significant negative correlation between larval survival; pupal survival and adult emergence of T. castaneum (i.e., increase in dose caused decrease in survival and adult emergence). Effective concentration (EC50) to reduce F1 progeny by 50% was calculated to be 2.6 and 4.1 microl/ml solvent against both the insect species, C. maculatus and T. castaneum, respectively. The relationship between bioactivity of oil from A. annua and responses of T. castaneum and C. maculatus is discussed. We found that oil from A. annua was largely responsible for both repellent (behavioral) and toxic (physiological) actions on 2 species of insect tested.  相似文献   

2.
Phyllocnistis citrella Stainton, the citrus-leafminer, is an important pest of citrus worldwide. Knowledge of natural parasitism levels is fundamental to the establishment of tactics of management and control of this species. This work aimed to evaluate the parasitism in two citrus orchards, one of 'Montenegrina' (Citrus deliciosa Ten.) and the other of 'Murcott' (C. sinensis (L.) Osbeck x C. reticulata Blanco), located in Montenegro, RS. In fortnightly samplings, from July/2001 to June/2003, all leaves containing P. citrella pupae from randomly selected plants were collected and maintained individually until emergence of the parasitoids or the citrus-leafminer. Parasitism was calculated considering the number of emerged parasitoids relative to the total number of emerged individuals. Correlation and linear regression tests were done to evaluate the relationship and the influence of biotic and abiotic factors upon the parasitism index. In both orchards the greatest parasitism percentage was registered on autumn in both years. The total percentage was 36.2% in 'Murcott' and 26.4% in 'Montenegrina' in the first year, and 30.2% and 37.6%, respectively, in the second year. In 'Murcott', this index did not differed between the years (chi2 = 2.06; df = 1; P > 0.05), in 'Montenegrina' the parasitism was significantly higher in the second year (chi2 = 7.36; df = 1; P < 0.05). The correlation and linear regression tests indicated a strong influence, in the parasitism index, of the host populational density registered in the previous 45 and 135 days.  相似文献   

3.
Seven species of Euryhaliotrematoides n. gen. and 1 species of Aliatrema n. gen. (Monogenoidea; Dactylogyridae) are described and reported from the gills of 15 species of butterfly fishes (Chaetodontidae) from the coral reefs of Moorea (French Polynesia), Wallis (Wallis and Futuna), Heron and Lizard (Australia), Palau (Micronesia), and New Caledonia: Aliatrema cribbi n. sp. from Chaetodon auriga, Chaetodon lunula, Chaetodon trifasciatus, Chaetodon ulietensis, Chaetodon vagabundus, Forcipiger flavisissimus, and Heniochus chrysostomus; Euryhaliotrematoides annulocirrus n. comb. from C. auriga, C. lunula, and C. vagabundus; Euryhaliotrematoides aspistis n. sp. from C. auriga, Chaetodon citrinellus, C. lunula, Chaetodon reticulatus, C. ulietensis, and C. vagabundus; Euryhaliotrematoides berenguelae n. sp. from C. citrinellus, Chaetodon ornatissimus, and F. flavisissimus; Euryhaliotrematoides grandis n. comb. from C. auriga, C. citrinellus, Chaetodon ephippium, Chaetodon kleinii, Chaetodon lineolatus, C. lunula, C. ornatissimus, C. trifasciatus, C. vagabundus, and H. chrysostomus; Euryhaliotrematoides microphallus n. comb. from C. auriga, C. citrinellus, C. ephippium, C. kleinii, C. lunula, C. ornatissimus, C. reticulatus, Chaetodon trifascialis, C. trifasciatus, C. vagabundus, F. flavisissimus, and H. chrysostomus; Euryhaliotrematoides pirulum n. sp. from C. auriga, C. citrinellus, C. lunula, C. trifasciatus, and C. vagabundus; and Euryhaliotrematoides triangulovagina n. comb. from C. auriga, C. citrinellus, C. kleinii, C. lunula, C. ornatissimus, C. vagabundus, F. flavisissimus, H. chrysostomus, and Hemitaurichthys polylepis. All reports of previously described species are new locality records. With exceptions of E. grandis and E. annulocirrus on C. auriga and C. lunula and E. triangulovagina and E. microphallus on C. auriga, all reports are new host records. Haliotrema hainanensis and H. affinis are considered junior subjective synonyms of E. triangulovagina and E. annulocirrus, respectively. Aliatrema n. gen. is characterized by marine dactylogyrids with tandem gonads (germarium pretesticular), haptoral hooks with upright acute thumbs, a coiled copulatory organ with counterclockwise rings and funnel-shaped base but lacking an accessory piece, and a dextral vaginal pore. Euryhaliotrematoides n. gen. is characterized by marine dactylogyrids having tandem gonads (germarium pretesticular), haptoral hooks with upright acute thumbs, a coiled copulatory organ with counterclockwise rings and funnel-shaped base, a vas deferens looping the left intestinal cecum, and a dextral vaginal pore.  相似文献   

4.
Abstract.  Variation between strains of Callosobruchus maculatus in several life-history traits is well known. Differences in functional anatomy of egg pores and larval respiration rates have also been reported in strains from Brazil and Yemen. The response of five strains of C. maculatus to seeds of two host species, cowpea ( Vigna unguiculata ) and mung bean ( Vigna radiata ), was measured along with the larval respiration rates of the same strains on both hosts. There was significant variability of response to the two hosts. Strains with higher larval respiration rate (µL O2/insect/day) showed higher seed consumption, which significantly affected adult emergence per seed on both hosts. This finding provides support for the hypothesis that differential feeding rate is an important mechanistic component of the larval competition outcome observed in strains of C. maculatus .  相似文献   

5.
[目的]褐带蚜小蜂Aphelinus maculatus是2016年的中国新纪录种,是桃蚜Myzus persicae的重要寄生蜂之一.为科学评估褐带蚜小蜂对桃蚜的控制作用,研究了褐带蚜小蜂产卵器刺入对寄主桃蚜存活、生长发育和繁殖力的影响.[方法]培养皿中用油菜叶单头饲养、每天记录被褐带蚜小蜂产卵器刺入1次的桃蚜存活数...  相似文献   

6.
The effectiveness of pulverised plant materials; Tithonium diversifolia, Afromomum melegueta, Nicotiana tabacum, Monodora myristica and Piper guineense as ovicidal, larvicidal and adult deterents of fish beetle (Dermestes maculatus) in smoked catfish (Clarias gariepinus) during storage were evaluated. Leaves of T. diversifolia, N. tabacum and seeds of A. melegueta, M. myristica and P. guineese were dried and pulverised into powder. Adults and larvae of third generation (F3) of D. maculatus were introduced into Kilner jars containing disinfested fish samples. Pulverised plant materials were applied to the surface of the fish samples at 10% (w/w) and monitored for 40 days, while egg hatchability of the insects was monitored for seven days. The result showed that all the plant materials had varying degree of insecticidal activities. Pulverised powder of P. guineense and A. melegueta were the most effective and significantly (P < 0.05) inhibited egg hatchability and adult emergence of D. maculatus in smoked catfish. N. tabacum gave the lowest insecticidal effect on adults, larvae and eggs of D. maculatus. However, the larvae of D. maculatus were not significantly (P > 0.05) affected by the plant materials. The percentage weight loss in fish treated with P. guineense and A. melegueta were minimal compared with the untreated fish sample. The result of this study showed that pulverised plant materials obtained from P. guineense and A. melegueta could be used to deter egg hatchability and adult emergence of D. maculatus in smoked catfish during storage. This could also reduce percentage losses due to insect infestation on smoked fish during storage.  相似文献   

7.
To control coconut leaf beetle, Brontispa longissima (Gestro), the pupal parasitoid Tetrastichus brontispae Ferrière was imported from Taiwan and its biology was studied in quarantine in Hainan, China. The parasitoid development includes an egg, three larval instars and three pupal stages. Its developmental time from egg to adult was 19.5±0.5 days under conditions of 24±2°C and 75±5% relative humidity (RH). Temperature had no effect on the sex ratio of offspring, but significantly affected the parasitism rate and reproduction. The parasitism rates were 98.07, 97.97 and 95.03% at 28, 24 and 20°C, respectively, whereas the parasitism rate was 52.18% at 18°C and 69.48% at 30°C, respectively. Furthermore, the parasitoids reared at 18 and 30°C produced fewer offspring than those at 20, 24 and 28°C, respectively. With the increase in temperature, developmental time decreased linearly from 46.19 days at 18°C to 17.10 days at 28°C. RH significantly influenced development, parasitism rate and the reproduction of T. brontispa. With the decrease of RH, developmental time increased from 22.94 days at 20% RH to 18.84 days at 95% RH. In contrast, parasitism rate and the number of offspring per female increased with the increase of RH. Though emergence rates between 50 and 95% RH were much higher than those between 20 and 35% RH, the sex ratios between 20 and 95% RH were not different. Photoperiod had no effect on parasitism, the number of offspring per female, emergence and the sex ratio of T. brontispae, but developmental time was significantly different for different photoperiods. Sucrose, honey and glucose significantly enhanced adult longevity, parasitism and the number of offspring per female of T. brontispae, but had no effect on the sex ratio and survival. Females of T. brontispae only parasitized fourth to fifth larval instars and 1–5-day-old pupae, but there was a significant difference in the number of offspring per female, development time, emergence and the sex ratio of offspring in different instars. These results showed that 1-day-old pupae, a temperature of 24–28°C and 65–95% RH were optimal for T. brontispae. These findings should be helpful in developing a production system to rear and release T. brontispae in large enough quantities to effectively control coconut leaf beetle.  相似文献   

8.
甘蓝型油菜与蔊菜的原生质体融合与植株再生   总被引:1,自引:0,他引:1  
以甘蓝型油菜下胚轴和蔊菜叶片为外植体提取原生质体, 采用PEG-高pH、高Ca2+附加DMSO的原生质体融合方法, 用液体浅层静置培养融合体, 获得了10株融合杂种, 观察了杂种形态学和细胞学。结果表明:1%纤维素酶+0.2%离析酶+3 mmol/L MES 酶解14 h 可获得较高产率的油菜原生质体, 0.25% 纤维素酶+0.5%离析酶+5 mmol/L MES酶解12 h可获得较高产率的蔊菜原生质体; 30% PEG + 0.3 mol/L葡萄糖+50 mmol/L CaCl2&#8226;2H2O +15%DMSO的融合条件下, 获得了10.4%的融合率; 实验所获的原生质体融合材料可作为新种质。  相似文献   

9.
在28℃下,以小菜蛾3龄幼虫作寄主,研究了菜蛾绒茧蜂与菜蛾啮小蜂间的相互关系.当寄主供2种蜂同时产卵寄生时,与只供1种蜂时相比。绒茧蜂的寄生率无显著变化,而啮小蜂的寄生率则显著下降;2种蜂的合计寄生率与任一种蜂单独存在时相比无显著差异.当寄主先供绒茧蜂寄生,再供啮小蜂寄生时,绒茧蜂的成功寄生率不受影响,而啮小蜂的寄生率仅为8%~13%;啮小蜂能寄生在寄主体内的绒茧蜂高龄幼虫.绒茧蜂能寄生已被啮小蜂寄生的寄主幼虫,其子代部分个体能正常发育至成虫羽化.当已被绒茧蜂寄生和未被寄生的寄主同时存在时,啮小蜂主要寄生未被寄生的寄主.表明绒茧蜂具有竞争优势。但这种优势可因啮小蜂的寄生而被削弱.  相似文献   

10.
In West Africa, Uscana lariophaga (Hymenoptera: Trichogrammatidae) parasitizes the eggs of Callosobruchus maculatus (Coleoptera: Bruchidae), an important pest of stored cowpea. The impact of the egg parasitoid on pest populations was evaluated in clay pots used in traditional storage in Niger. At the beginning of the storage period cowpeas were infested with different densities of larval instars and adults of C. maculatus and inoculated with one density of U. lariophaga. The higher the initial densities of C. maculatus, the better the egg parasitoid was able to establish itself and to control the population of C. maculatus, limiting the damage to cowpea. After three months of storage, the egg parasitoid significantly reduced the number of C. maculatus adults by 68 at the lowest and 86 percent at the highest initial density of the beetle; the percentage of damaged beans was reduced by 13 and 19% respectively.  相似文献   

11.
The mermithid,Hexamermis albicans (Siebold) was recovered from larvae ofLymantria (Porthetria) dispar (L.) collected from various localities in Burgenland, Austria in 1974 and 1975 and from Würzburg, Germany, in 1974. It was recovered also fromStilpnotia salicis (L.) in Austria in 1974. The mermithid was recovered from all field collected larval instars. The majority of the nematodes emerged fromL. dispar larvae collected as second and third larval instars although some nematodes were recorded from larvae collected as first instar larvae still on the egg mass. Peak emergence occurred in the laboratory during the period June 11–17 of both years, but emergence continued at a much lesser degree through the end of larval development. The nematode was found in both high and low host density populations. In 3 localities studied both years, there was a general increase in the percentage parasitism the second year. However, except for one locality in Austria in 1975 where individual samples produced up to 11% parasitism, the overall parasitism increased from 0.4% in 1974 to only 2.5% in 1975.  相似文献   

12.
Bruchid beetle larvae cause major losses in grain legume crops throughout the world. Some bruchid species, such as the cowpea weevil (Callosobruchus maculatus) and the Mexican bean weevil (Zabrotes subfasciatus), are pests that damage stored seeds. The Mediterranean flour moth (Anagasta kuehniella) is of major economic importance as a flour and grain feeder; it is often a severe pest in flour mills. Plant lectins have been implicated as antibiosis factors against insects. Bauhinia monandra leaf lectin (BmoLL) was tested for anti-insect activity against C. maculatus, Z. subfasciatus and A. kuehniella larvae. BmoLL produced ca. 50% mortality to Z. subfaciatus and C. maculatus when incorporated into an artificial diet at a level of 0.5% and 0.3% (w/w), respectively. BmoLL up to 1% did not significantly decrease the survival of A. kuehniella larvae, but produced a decrease of 40% in weight. Affinity chromatography showed that BmoLL bound to midgut proteins of the insect C. maculatus. 33 kDa subunit BmoLL was not digested by midgut preparations of these bruchids. BmoLL-fed C. maculatus larvae increased the digestion of potato starch by 25% compared with the control. The transformation of the genes coding for this lectin could be useful in the development of insect resistance in important agricultural crops.  相似文献   

13.
The parasitism efficiency of the Braconidae wasp, Diachasmimorpha longicaudata (Ashmead), was checked on four guava cultivars (Paluma, Sassaoca, Pedro Sato and Kumagai) infested with larvae of medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Five blocks of eight fruits, each with two fruits of each cultivar, were put inside C. capitata adult cages, during 2h for oviposition, and a week later, when the larvae inside guavas were developed, the fruits were exposed to parasitoids for 24h. The mean fruit weight, larvae mortality, number of pupae, percentage of medfly and parasitoid emergence were evaluated. There was not statistical difference among cultivars to weight, larvae mortality, number of pupae e emergence of medfly. The percentage of parasitism was higher in Pedro Sato cultivar (19.8%) compared with Kumagai cultivar (2.9%), but it was statistically similar to the other cultivars.  相似文献   

14.
A range of crops have been transformed with delta-endotoxin genes from Bacillus thuringiensis (Bt) to produce transgenic plants with high levels of resistance to lepidopteran pests. Parasitoids are important natural enemies of lepidopteran larvae and the effects of Bt plants on these non-target insects have to be investigated to avoid unnecessary disruption of biological control. This study investigated the effects of Cry1Ac-expressing transgenic oilseed rape (Brassica napus) on the solitary braconid endoparasitoid Cotesia plutellae in small-scale laboratory experiments. C. plutellae is an important natural enemy of the diamondback moth (Plutella xylostella), the most important pest of brassica crops world-wide. Bt oilseed rape caused 100% mortality of a Bt-susceptible P. xylostella strain but no mortality of the Bt-resistant P. xylostella strain NO-QA. C. plutellae eggs laid in Bt-susceptible hosts feeding on Bt leaves hatched but premature host mortality did not allow C. plutellae larvae to complete their development. In contrast, C. plutellae developed to maturity in Bt-resistant hosts fed on Bt oilseed rape leaves and there was no effect of Bt plants on percentage parasitism, time to emergence from hosts, time to adult emergence and percentage adult emergence from cocoons. Weights of female progeny after development in Bt-resistant hosts did not differ between plant types but male progeny was significantly heavier on wildtype plants in one of two experiments. The proportion of female progeny was significantly higher on Bt plants in the first experiment with Bt-resistant hosts but this effect was not observed again when the experiment was repeated.  相似文献   

15.
Aspects of the abundance, reproduction, and feeding habits of Dormitalor maculatus, Eleotris pisonis , and Guavina guavina were assessed in the shallow waters of the Mundaú/Manguaba estuarine system, north-east Brazil. Dormitator maculatus , the most abundant species, was caught in salinities ranging from 0·1 to 20·3 ppt and temperatures from 25·0 to 36·0° C. Eleotris pisonis , the second most abundant species, occurred in salinities from 0·1 to 18·2 ppt and temperatures from 25·0 to 33·0° C. Guavina guavina was rare at the stations sampled. Peak gonadal development was found during the winter (wet season) in D. maculatus and E. pisonis , and probably may occur during this season in G. guavina . Size-at-maturity was 51 and 46 mm T.L. for males and females of D. maculatus , respectively, and 57 and 43 mm T.L. for males and females of E. pisonis , respectively. Dormitator maculatus was omnivorous, and ingested primarily macrophytes, followed by sediment, and unidentified eggs; E. pisonis and G. guavina were predaceous, with the former preying mainly upon the gastropod Neritina virginea , and the latter mainly upon the crab Goniopsis cruentata. Dormitator maculatus and E. pisonis appear to coexist because of differences between the two in microhabitat and food utilization. The two more similar species, E. pisonis and G. guavina appear to coexist due to differences in spatial distribution.  相似文献   

16.
We studied the parasitoid complex of Bactrocera oleae Rossi (Diptera: Tephritidae) in order to analyse the parasitism response to landscape structure at different spatial extents. Olive fruits were sampled and incubated in the laboratory for insect emergence, thus allowing the calculation of parasitoid emergence rates. A landscape analysis was performed in five concentric buffers, ranging from 0.5 to 2 km diameter around the sampling points. Woodland was chosen as focal class. The percentage of landscape and the splitting index, a measure of fragmentation, were used to quantify landscape composition and configuration, respectively. Significant effects of landscape on parasitism rates were detected. In particular, the percent parasitoid emergence was negatively affected by the splitting index of woodland at a spatial extent ranging from 1 to 2 km. These findings suggest that landscape characteristics are likely to affect parasitoids in well-structured agroecosystems as well. In particular, connectivity at a large scale may favour B. oleae parasitoids more than the abundance of woodland. Potential implications for conservation biological control are discussed.  相似文献   

17.
We evaluated the effects of constant low-temperature storage on Diaeretiella rapae (McIntosh) (Braconidae, Aphidiinae). Diaeretiella rapae mummies were stored at 5?±?1°C for 0–36 days. The percentage of D. rapae emergence varied (100-83%) after 0–32 days of storage. After 32 days, emergence reduced to 55%. According to our Probit analysis, 50% mortality (LT50) of the population of D. rapae was reached after 40 days of storage at 5°C. Storage for up to 32 days did not negatively affect emergence and survival. Cold exposure of D. rapae for 36 days did not influence morphological malformations, sex ratio, and emergence of the F1 generation. After 4–36 days of storage, D. rapae showed a gradual decrease in emergence, longevity, reproductive capacity, and F1 sex ratio. Diaeretiella rapae can be stored for up to 24 days at 5°C, at which time the percentage of parasitism and the F1 sex ratio remain above 38% and at 0.50, respectively.  相似文献   

18.
ABSTRACT

This study evaluated the potential of two aphelinid parasitoids, Encarsia sophia (Girault & Dodd) and Eretmocerus hayati (Zolnerowich & Rose) to control the sweetpotato whitefly Bemisia tabaci, (Gennadius) using a banker plant system over two consecutive years. The parasitism rates of both parasitoids on a tomato (Solanum lycopersicum L.) crop were determined using melon, Cucumis melo L. (Cucurbitaceae) and castor bean, Ricinus communis L. (Euphorbiaceae), as banker plants, respectively. The emergence rates of Er. hayati and En. sophia parasitoids from parasitised whiteflies on both banker plants exceeded 90% and 85%, respectively, which is 17–20 percentage points higher than that on the pupal card under field cage conditions. Parasitism (%) on banker plants was significantly higher for both parasitoids in the third week after release as compared to adult releases in the first year, reaching 15.2?±?1.3 and 24.0?±?1.4% for En. sophia and Er. hayati, respectively. However, no significant difference in parasitism (%) was observed between banker plant and pupal card release treatments in the second year. The combined release of the two parasitoids during the second year clearly showed a continuous increase in parasitism, which was higher than parasitism in the single parasitoid-release treatments by the 4th week after release. Whitefly populations were significantly lower in all parasitoid-release treatments than in the no-release control by 4–6 weeks into the study period in the second year, while no other significant differences were observed between treatments in either year. This study found that both banker plants efficiently supported populations of both parasitoids and improved their emergence compared to the pupal card.  相似文献   

19.
The parasitism rates by Trichogramma cacoeciae Marchal (Hymenoptera, Trichogrammatidae) using Ephestia kuehniella Zell. (Lepidoptera, Pyralidae) eggs held at 0, 4 and 8°C and for up to 31 days was measured. Parasitism was lowest on eggs held at 8°C and highest on eggs held at 0°C. The highest parasitism, 97.8%, was measured for parasitoids attacking eggs held for 3 days and stored at 0°C. Parasitism of eggs stored at all three temperatures decreased with increasing duration of storage. The number of T. cacoeciae successfully developing and emerging as adults after storage in E. kuehniella eggs held at 0, 4 and 8°C was measured. Parasitoid emergence was >83% from E. kuehniella eggs stored at 8°C for 3 weeks. Storage at 0°C caused a significant decline in parasitoid emergence after 2 weeks (P<0.05). Storage at 0°C for more than 4 weeks reduced fecundity by 50%. T. cacoeciae parasitized the highest number of E. kuehniella eggs 1 day after adult emergence. The oviposition period lasted 6–7 days, although the parasitoids lived up to 13–14 days. Impact of storage time and temperature on parasitism rates by T. cacoeciae stored while in E. kuehniella eggs was measured. As storage time and temperature increased, subsequent parasitism rates of resulting adult T. cacoeciae decreased. Eggs of E. kuehniella can be stored at 0°C for up to 31 days. Trichogramma cacoeciae developing in eggs of E. kuehniella can be stored at 4°C for up to 5 weeks prior to release.  相似文献   

20.
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