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1.
Various immature stages of male and female California red scale,Aonidiella aurantii (Maskell) (Homoptera: Diaspididae), were treated with avermectin B1 (MK-936) at concentrations ranging from 10 to 100 ppm. Treatments at 10 ppm completely arrested crawler development and 20 and 100 ppm caused 100% mortality of 48-h and 7-day-old male and female 1st instar nymphs, respectively. The development of the 2nd instar was slightly affected by MK-936 at up to 40 ppm. Sublethal doses of the chemical applied to immature stages caused no dramatic reduction in the fecundity of the subsequent, mature females. MK-936 applied to male prepupal and pupal stages and mated females did not prevent male emergence, nor did it affect the ability of males to copulate and inseminate female scales, or the female fecundity. The development and adult emergence of treatedAphytis holoxanthus DeBach (Hymenoptera: Aphelinidae) larvae and pupae parasitizingChrysomphalus aonidum L. scales were not influenced by a 9 ppm MK-936 treatment; leaves sprayed with this concentration had residual toxicity onA. holoxanthus adults for only 24 h post-treatment. Feeding byChilocorus bipustulatus L. (Coleoptera: Coc-cinellidae) on 0.9 ppm MK-936-treated Florida red scales resulted in 100% mortality of 2nd instars and induced sterility in the females.  相似文献   

2.
Ethyl [2-(4-phenoxyphenoxy)ethyl] carbamate (RO 13-5223) at a dietary concentration of 100 mg kg-1 synergized the toxicity of thetrans- andcis-isomers of permethrin and cypermethrin in inhibiting the growth (measured as gain in larval weight) ofTribolium castaneum andMusca domestica vicina. With both species the synergism factor forcis-cypermethrin with 100 mg kg-1 synergist was 1.5- to twofold for RO 13-5223 and about fourfold for piperonyl butoxide. Synergism was more pronounced with first instar than with fourth instarT. castaneum larvae. Methoprene was not a pyrethroid synergist withT. castaneum larvae, so the synergistic effect of RO 13-5223 appears to depend on its structural features and not its insect-growth-regulator activity. Joint application of RO 13-5223 and pyrethroids resulted in a dual effect on bothT. castaneum andM. domestica: increased inhibition of larval growth due to pyrethroid synergism, and progeny suppression — expressed by larval and pupal mortality — due to RO 13-5223 juvenilizing activity.  相似文献   

3.
The prey consumption and preying ability ofCybocephalus micans Reittei,C. nigriceps nigriceps (J. Sahlberg), andC. binotatus Grouvelle, while fed on several armoured scales, were studied. Larvae and adults ofC. micans andC. n. nigriceps required small amounts of prey (developmental stages ofAonidiella aurantii [Maskell]) in order to complete their development, survive and reproduce. Adults were almost incapable of feeding on female diaspidid scales, and when supplied with females only, their survival was low and reproduction stopped. Adults of the imported speciesC. binotatus were able to feed and survive on females ofA. aurantii much better than was the local species. Under the same conditions of temperature and relative humidity, adult survival ofC. n. nigriceps under starvation was always longer than that ofC. micans  相似文献   

4.
F. Erler  I. Tunç 《Phytoparasitica》2001,29(4):299-305
Natural enemies associated with armoured scale insects were surveyed in Antalya province during the years 1992-1996. The surveys yielded 16 species of predators and 11 species of parasitoids associated with 11 species of scale insects. One predator species—Lestodiplosisaonidiellae Harris, one hyperparasite species—Ablerusperspeciosus Girault, and one parasitoid species—Coccophagoidesmoeris (Walker), are recorded for the first time in Turkey. Three coleopterans, namely,Chilocorus bipustulatus (Linnaeus),Cybocephalus fodori- minor Endrödy-Younga andRhyzobius lophanthae (Blaisdell), were found to be the most common predators and to be associated with the diverse species of diaspidids in Antalya and are known so also in other parts of Turkey. Among the parasitoids found,Aphytis chrysomphali (Mercet) andAphytis melinus DeBach are known to be relatively important onAonidiella aurantii (Maskell),Aphytis maculicornis (Masi) onParlatoria oleae (Colvée),Aphytis mytilaspidis (LeBaron) onLepidosaphes ulmi (Linnaeus), andEncarsia berlesei (Howard) onPseudaulacaspis pentagona (Targioni Tozzetti), in Antalya and/or other parts of Turkey.  相似文献   

5.
The effectiveness of buprofezin (aqueous suspensions from 25% wettable powder) on cumulative nymph mortality and reproduction of two homopterous pests,Icerya purchasi Maskell (Margarodidae) andPlanococcus citri (Risso) (Pseudococcidae), was investigated under laboratory conditions. Buprofezin was very effective against crawlers of both species. Dipping in concentrations of 0.002%, 0.01% and 0.05% (a. i.) resulted in 91–99% nymph mortality ofP. citri, whereas 100% mortality was recorded whenI. purchasi was treated at 0.05% (a. i.); the 3rd-instar nymphs ofI. purchasi were less susceptible to the chemical. Death of the larval stages occurred mainly during the molting process to the 2nd-instar nymphs. At 0.05%, buprofezin sprayed on adults slightly reduced fecundity and decreased egg hatch to 31% forI. purchasi and, depending on the exposure period of the females, to 49-7% forP. citri. Buprofezin at 0.05% exhibited strong ovicidal activity onP. citri, resulting in inhibition of over 80% egg hatch.  相似文献   

6.
Margosine-0®, a commercial preparation of neem seed extract, was tested for its effects as a toxicant, growth inhibitor, or repellent against six species of cockroaches —Blatta orientalis L.,Blattella germanica (L.),Byrsotria fumigata Guérin-Méneville,Gromphadorhina portentosa (Schaum),Periplaneta americana (L.), andSupella longipalpa (F.) (Orthoptera: Blaberidae, Blattidae, and Blattel-lidae). Last-instar nymphs of these species fed Lab-Chow® pellets impregnated with neem extract at a rate of 0.5 ml/pellet showed increased mortality and retarded development. All lst-instar nymphs ofB, orientalis, B. germanica andS. longipalpa died after consuming treated Lab-Chow pellets. Topical application of 2 μl of Margosine-0 to the abdomens of last-instarB. orientalis nymphs, as well as injection of 0.5 μl, resulted in reduction of growth and increased mortality. Placing lst-instarB. orientalis nymphs on a surface treated with the neem extract had no notable effect. In a choice test,P. americana adults immediately preferred the pellets treated with 0.5 ml of neem extract, but pint cardboard cartons treated with 1.5 ml extract repelled them.  相似文献   

7.
The citrus thrips,Scirtothrips aurantii Faure (Thysanoptera: Thripidae), is a pest of mango in South Africa. The aim of the study was to monitor the different stages ofS. aurantii in mango orchards throughout the year. Populations ofS. aurantii were monitored using different methods,i.e., yellow sticky traps, dispersal/emergence traps, counts on fruit and in flowers. Eggs and emergence holes on the new leaves were recorded. The number of adults increased at the end of flowering (September) and remained at high levels until fruiting (November). Low numbers were present from May to August. Much higher population levels were present during 1995/96 than during the 1996/97 season. There was higher infestation present on the cultivar ‘Sensation’ than on ‘Zill’.S. aurantii was present on the fruit for only a short period (less than 10 weeks) during the season and the population was maintained on flush that was present throughout the year.  相似文献   

8.
Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) is an important solitary endoparasitoid of mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae). Studies on seasonal and biological interactions between host and parasitoid are important to optimize the mass production and field release of high-quality females. We investigated the influence of different crop seasons viz., pre-monsoon, monsoon and post-monsoon and host stages viz., three nymphal instars (1st, 2nd and 3rd) and adult stage of P. solenopsis on the development, longevity, fecundity and sex ratio of its parasitoid, A. arizonensis. A. arizonensis female parasitized all life stages of its host except the 1st instar nymphs. Only males emerged from parasitized 2nd instar nymphs, while the sex ratio in the later host instars was strongly female-biased. The adult host stage was most suitable for A. arizonensis in terms of shorter development time, while the 3rd instar nymphal stage was most suitable with respect to higher fecundity, proportion of adults emerged and more females in the progeny. Among different seasons, post-monsoon season (September–October) with temperature (25 to 29 °C) and relative humidity (68 to 73%) was most suitable for the overall fitness of the parasitoid. The findings of this study have implications in designing mass rearing of this parasitoid and devising an effective biological control strategy for P. solenopsis on cotton.  相似文献   

9.
More than 200 shipments of beneficial insects for the biological control of soft scale insects, armoured scale insects, whitefly, aphids, mealybugs and the Mediterranean fruit fly, were imported to Israel during 1976-1987 by the quarantine facility of the Israel Cohen Institute for Biological Control. Laboratory culture was initiated with 89 species of primary parasites and predators; 60 species were successfully cultured. Of these, 56 species were released in the field and 29 were recovered; six are established and have effected successful biological control ofSaissetia oleae (Olivier) andDialeurodes citri (Ashmead).  相似文献   

10.
白蜡绵粉蚧Phenacoccus fraxinus Tang是白蜡Fraxinus chinensis Roxb.的一种重要害虫。为筛选出高效防治白蜡绵粉蚧的药剂,本试验采用浸渍法测定了5种药剂对不同龄期白蜡绵粉蚧的毒力。测试的5种药剂对白蜡绵粉蚧1龄若虫致死中浓度为18.48~24.52 mg/L,均表现较高的毒力。对2龄若虫和成虫的致死中浓度分别为18.48~76.25 mg/L和44.00~79.53 mg/L,毒力稍低于1龄若虫。但5种药剂对白蜡绵粉蚧3龄若虫的毒力明显低于其他龄期,除20%丁硫克百威乳油毒力较高(42.00 mg/L)外,其余4种药剂的致死中浓度为97.73~132.24 mg/L。因此,5种药剂对白蜡绵粉蚧1、2龄若虫和成虫毒力较强且稳定,均可作为防治白蜡绵粉蚧低龄若虫和成虫的优良药剂,但3龄若虫最好选用毒力较高的20%丁硫克百威乳油进行防治。  相似文献   

11.
Four juvenile hormone analogs (JHAs), fenoxycarb. Pro-drone, R-20458 and dofenapyn, and three benzoylphenyl urea molt-inhibiting compounds (MICs), teflubenzuron, triflumuron and hexaflumuron, were evaluated in the laboratory at two concentrations (5 and 50 ppm) as to their effect on the Florida wax scale,Ceroplastes floridensis Comstock. In general, when the first nymphal stages were treated, the number of adults on treated guava plants at the end of the first generation was clearly reduced in comparison with that observed on untreated plants. The JHAs fenoxycarb and R-20458 arrested the development of the insect and no adults emerged at the end of the first generation. With 50 ppm of the JHA Pro-drone only 5.2% of the nymphs developed and transformed into adults. Triflumuron was superior to the other insect MICs in hampering development, as was dofenapyn. The adults emerging at the end of the first generation were used as parental scales for the next generation. Delayed adverse effects were observed on female fecundity and egg hatchability. There was a significant difference between the egg numbers laid by the females in the treatments and the control, and also between the different IGRs. No eggs hatched with dofenapyn and egg hatchability was 46% for teflubenzuronvs 88% for the control. Furthermore, in contradistinction to the control, insects on treated plants deposited only small amounts of wax in an irregular formation.  相似文献   

12.
During 1972–1976 four species of African encyrtid wasps were introduced into Israel and released against the Mediterranean black scale,Saissetia oleae (Olivier), in citrus and olive groves.Metaphycus helvolus (Compere) andM. aff. stanleyi Compere were recovered in small numbers.M. bartletti Annecke and Mynhardt andM. lounsburyi (Howard), which were found in large numbers on citrus during the release season, seem to be promising for the biological control of the black scale.  相似文献   

13.
The present study was carried out in southern Greece during 1993-1995 on sour orange trees infested with the diaspididParlatoria pergandii Comstock. The activity of the natural enemies of the scale, the composition of their population during the year as well as their relation with hymenopterous parasitoids of coccinellids, were studied.P. pergandii was parasitized by a hymenopterous endoparasite of the genusEncarsia and the extent of parasitization ranged between 5.2% and 14.1%. The observed predators were the coccinelidsChilocoms bipustulatus Linnaeus andRhyzobius lophanthae Blaisdell and the nitidulidCybocephalus fodori Endrödy-Younga. The predominant predator wasR. lophanthae (84.3% of the larvae and 73.3% of the adults), which was active throughout the whole year in all of its developmental stages. Second most abundant was the predatorC. bipustulatus (15.7% of the larvae and 20% of the adults) and third the predator C.fodori (6.7% of the adults). Larvae ofC. bipustulatus were observed to be parasitized by the hymenopterous parasitoidsHomalotylus flaminius Dalman (Encyrtidae) andTetrastichus coccinellae Kurdjumov (Eulophidae). The parasitization percentage increased gradually from 4% in mid June to 94% around the end of September. Laboratory tests confirmed that the above mentioned parasitoids cannot infest larvae or nymphs ofR. lophanthae.  相似文献   

14.
A newly discovered bacterial species, Pseudomonas floridensis, has emerged as a pathogen of tomato in Florida. This study compares the virulence and other attributes of P. floridensis to Pseudomonas syringae pv. tomato, which causes bacterial speck disease of tomato. Pseudomonas floridensis reached lower population levels in leaves of tomato as compared to the P. syringae pv. tomato strains DC3000 and NYT1. Analysis of the genome sequence of the P. floridensis type strain GEV388 revealed that it has just nine type III effectors including AvrPtoBGEV388, which is 66% identical to AvrPtoB in DC3000. Five of these effectors have been previously reported to be members of a ‘minimal effector repertoire’ required for full DC3000 virulence on Nicotiana benthamiana; however, GEV388 grew poorly on leaves of this plant species compared to the DC3000 minimal effector strain. The tomato Pto gene recognizes AvrPtoB in race 0 P. syringae pv. tomato strains, thereby conferring resistance to bacterial speck disease. Pto was also found to confer resistance to P. floridensis, indicating this gene will be useful in the protection of tomato against this newly emerged pathogen.  相似文献   

15.
Susceptibility to the insectBactrocera oleae and the fungiSpilocaea oleagina andSphaeropsis dalmatica was investigated in four olive cultivars, two for table fruit production (Kalamon and Chondrolia Chalkidikis) and two for oil production (Lianolia and Koroneiki). Cv. Chondrolia Chalkidikis was the most susceptible to all three pathogens, followed by cv. Kalamon. Soil plowing and the organic fertilizer Bio-Trust® (10-3-6+8% MgCO3+10% CaCO8) increased the susceptibility of all four tested olive cultivars to the insect and the two fungi. Correlations were found between the attacks byB. oleae and infections byS. oleagina andS. dalmatica on the four olive cultivars.  相似文献   

16.
A botanical natural product,AkseBio2, was evaluated under laboratory conditions for its oviposition deterrent, ovicidal and larvicidal (nymphicidal) effects against the pear psyllaCacopsylla pyri (L.) (Hemiptera: Psyllidae). The product exhibited a strong oviposition deterrent effect for winterform and summerform females and caused a reduction in the total number of eggs laid in both choice and no-choice assays. Significant mortalities in freshly laid eggs (0–48 h) and various nymphal stages of the pest were recorded in toxicity assays. At a concentration of 0.1% (formulation), the highest biological activity of the product was recorded against the young (1st and 2nd) nymphal stages (up to 87.4% mortality) in comparison with the other biological stages of the pest. It was less active against the older (3rd-5th) nymphs, causing 62.1% mortality at the same concentration. In assays with non-target organisms, a significant negative effect was not observed. There were no significant changes on treated plants up to 7 days after treatment in any trial, nor was there any phytotoxicity on plant tissue as a result ofAkseBio2 treatments. The results suggest that the product can be used in psylla control instead of synthetic insecticides and may serve as an integrated pest management (IPM) component in pear orchards. http://www.phytoparasitica.org posting July 14, 2004.  相似文献   

17.
A common mycoparasite,Verticillium biguttatum, was found to kill sclerotia ofRhizoctonia solani placed on an inert material (perlite) as well as in soil at 15°C and 20°C, but not at 10°C. Compared with the effectivity ofV. biguttatum, that ofGliocladium roseum, Gliocladium nigrovirens, Hormiactis fimicola andTrichoderma hamatum on sclerotia was only low. In laboratory experiments, treatment of sclerotia-bearing seed potatoes withV. biguttatum reduced disease symptoms in the first stage of growth of the potato plant.V. biguttatum was found to occur on the subterranean part of the potato plant. On untreated plants the surface of the sprouts was colonised byV. biguttatum originating from the soil, presumably partly in response to the presence ofR. solani mycelium. In a preliminary field experiment,Verticillium treatment did not reduce symptoms on the stem. However, there was a marked reduction in sclerotium formation on the newly formed potato tubers. This offers perspectives for a commercial use ofV. biguttatum in the control ofR. solani.  相似文献   

18.
为明确梨木虱在不同品种梨树上的发生规律,于2015-2016年对天津市混栽梨园中3个品种梨树上中国梨喀木虱Cacopsylla chinensis的周年发生情况进行调查。结果表明,中国梨喀木虱冬型成虫在早酥梨树上的出现日期为2月底,在黄冠和晚秋黄梨树上的出现日期为3月上旬至中旬。3月中下旬始见第1代卵,4月上旬达高峰期,4月下旬孵化为若虫并达到高峰期,4月底至5月初始见第1代夏型成虫,5月上旬至下旬达高峰期;5月下旬第2代若虫孵化,6月初达高峰期,中旬成虫羽化,下旬成虫达高峰期;6月底至7月初第3代若虫陆续出现,7月上旬至下旬达高峰期,下旬成虫羽化;8月上旬第4代若虫出现,中下旬达高峰期;9月中旬第5代若虫出现,月底达高峰期。早酥梨树上中国梨喀木虱发生高峰期的数量显著高于黄冠和晚秋黄梨树上的数量,晚秋黄梨树上1、2代的发生量显著高于黄冠梨树上的发生量。  相似文献   

19.
Seven aphid species were screened with twelve entomopathogenic fungi for the selection of the most effective fungus. Beauveria bassiana CKB-048 caused the highest mortalities for all aphid species tested in their nymphal stage. The cowpea aphid (Aphis craccivora Koch) was chosen for further studies in its adult stage using B. bassiana CKB-048 as a biocontrol agent, and carbosulfan was used for a comparison in greenhouse testing. The mode of action of the fungal killing was studied by scanning electron microscopy. The endophytic colonization of the cowpea plant by B. bassiana CKB-048 was studied and confirmed using both stereo microscopy and transmission electron microscopy. The chitinase enzyme activity of cowpea plants after they were sprayed with the fungus or carbosulfan was found to fluctuate throughout five days. The lethal concentrations of B. bassiana CKB-048 suspensions that killed 50 % (LC50) of A. craccivora was 6.69 × 107 conidia/ml for the nymphs and 8.25 × 107 conidia/ml for the adults. The time for lethality (LT50) with a concentration of 2 × 108 conidia/ml was 3.25 days for nymphs and 4 days for adults.  相似文献   

20.
The Phenology and natural enemies of the scale insect Kermes echinatus Balachowsky (Hemiptera: Kermesidae), which infests the holly oak Quercus ilex (Fagaceae), were studied between November 2015 and November 2017, in southern Greece (Kalamata, Peloponnese). Kermes echinatus is a univoltine, oviparous and biparental species. It overwinters as 1st instar nymphs, settling on the branches of the trees. The second instar nymphs appear by the middle of April, followed by 3rd instar nymphs until the end of May. The male larvae and pupae were recorded from the end of April to the end of May. Mature females, pre-ovipositing and ovipositing adults, were recorded during May and June. The newly hatched crawlers appeared by the end of June, which remained at this stage, settled on branches during the rest of summer and winter periods till next April. The parasitoid species Metaphycus gennaroi Guerrieri & Noyes and the hyperparasite Cheiloneurus claviger Thomson (Hymenoptera: Encyrtidae) were recorded on the colonies of the scale. The parasitism level of the scale reached to 21%. The predator Chilocorus bipustulatus L. (Coleoptera: Coccinellidae) was also recorded on the colonies of the scale.  相似文献   

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