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1.
The incubation period ofM. incognita acrita eggs took 24–72 hours till the appearance of the second larval stage hatching from eggs in the laboratory at 25±5°C and at 60±5 R. H. The second larval stage, was observed in cotton roots 48 hours after the addition of it to soil beside cotton seedlings. The 3rd and 4th larval stage and adult female were observed in cotton roots 7, 11, and 24 days, respectively, after the addition of second larval stage to soil beside cotton seedlings. The total life cycle ofM. incognita acrita on cotton, (Gossypium barbadense) lasted for 33–38 days, at 25±5°C and at 60±5 R. H.  相似文献   

2.
The eggs ofArgas reflexus were splashed with the LiCl and Na2Cr2O7 saturated solutions on the 2nd day after laying and were kept at 25° C and 30% RH.Both examined chemical compounds caused great disturbances in embryogenesis ofArgas reflexus. Under influence of Na2Cr2O7 24.8% eggs died. The LiCl solution appeared to be more harmful on larvae development. 21.8% dead eggs, 11.6% dead embryos, and 8.9% larvae hatched abnormally were observed in these experiments
Zusammenfassung Hemmende Faktoren bei der Embryonalentwicklung vonArgas (Argas) reflexus (Fab.) (Acari, Argasidae)Die Eier vonArgas reflexus wurden am 2. Tag der Embryonalentwicklung bei 25° C und 30% r. L. der. Wirkung gesättigter Lösungen von LiCl und Na2Cr2O7 unterzogen.Beide chemischen Verbindungen verursachten große Störungen der Embryogenesis vonArgas reflexus. Unter dem Einfluß von Na2Cr2O7 starben 24.8% der Eier ab. LiCl erwies sich als schädlicher für die Embryonalentwicklung dieser Zeckenart als Na2Cr2O7.Bei den Experimenten mit LiCl wurden 21.8% Eier, 11.6% Embryos und 8.9% (abnormal geschlüpfte) Larven getötet.

With one table  相似文献   

3.
The development, longevity, fecundity and sex ratio of the predatory miteAmblyseius longispinosus (Evans) were studied at different constant and alternating temperatures withTetranychus cinnabarinus as prey. Alternating temperatures had no significant effect on the developmental times, in comparison with optimal constant temperature. At the alternating temperature of 33/23°C the mean duration of the life cycle from egg to adult was obvious longer with 5.0 and 4.4 days forA. longispinosus females and males than at alternating temperature of 30/20°C with 4.2 and 4.1 days for females and males. At 25°C constantly the egg stage was the longest during development and required a mean of 2.2 days.A. longispinosus females and males remained in larval stage for 0.5 and 0.6 days. The protonymphal and deutonymphal stage lasted for 0.7 and 1.1 for females and for 0.7 days for males, respectively. At all temperatures the development of females required significantly longer than of males. Longevity ofA. longispinosus adults was variable to tested temperatures: At 25°C females lived for 33.1 days, at 30/20°C for 30.6 days and at 33/23°C for 29.9 days. At 25°CA. longispinosus females produced a mean total progeny of 48.8 eggs and the mean duration of oviposition period was 21 days; at 30/20°C and at 33/23°C a mean number of 49.1 and 48.2 eggs was laid during an oviposition period of 20 days. Temperature had no effect on the sex ratio of predatory mites, about 70% of mites became females at all temperatures.  相似文献   

4.
Effect of temperature and relative humidity on embryonic development and egg hatch ofHyalomma marginatum Koch (Acari, Ixodidae) Effect of different temperatures (25, 30, 35, 40°C) and relative humidity (RH) levels (50, 75, 90%) on embryonic development and hatching ofHyalomma marginatum was investigated. The percentage of dead eggs and embryos, percentage of morphologically normal larvae, percentage of abnormally hatched larvae and percentage of larvae with morphological malformations were determined for each condition. Embryonic development and egg hatch proceeded at 25–35°C in all relative humidity levels tested. However 50% RH was unfavourable for these processes. The optimal conditions for larval development were found to be: temperature of 25–30°C and relative humidity of 75%. Under these conditions 72.7–87.8% of examined egg hatched into normal larvae.  相似文献   

5.
The development of the red palm weevil, Rhynchophorus ferrugineus (Olivier) was investigated on a newly developed semiartificial diet as compared with two natural diets namely sugarcane stem and banana fruit. The weevil was successfully maintained on these diets and duration of the life cycle for males and females, respectively were 164.97 and 194.61 days on the semiartificial diet, 192.5 and 186.5 days on banana, and 172.00 and 170.00 days on sugarcane. The average egg production per female was shown to be significantly higher on the semiartificial diet, being 184.00?±?18.68 eggs compared with an average of 125.00?±?11.97 and 133.00?±?15.21 eggs on banana and sugarcane, respectively. The fertility ranged between 94?–?100?% in those eggs deposited by females previously reared on the tested diets. The developed semiartificial diet was shown to be suitable for maintaining laboratory colonies of the red palm weevil, and it can substitute natural diets.  相似文献   

6.
Studies on the biology of the predaceous mite Cunaxa capreolus Berl. (Acari, Prostigmata, Cunaxidae) During life cycleCunaxa capreolus Berlese passes through egg, larva, three nymphal stages and adult. Each moving stage is proceeded by a quiescent one. Biological process such as hatching, moulting and mating were investigated. Female usually deposites its eggs singly in protected places. Number of deposited eggs per female, when fed on book lice (Psocoptera), was positively correlated with temperature. It averaged 24.6, 30.7, 40.7, and 43.5 eggs at 15°, 20°, 25° and 30 °C. Incubation period as well as duration of immature stages and adult longevity were negatively effected with temperature. The generation period (from egg to egg) ranged from 24.8 to 64.2 days when temperature changed from 30° to 15 °C. Within these limits of temperature, the simple regression indicated that an increase of 1 °C decreased the generation period for about 2.6 days.  相似文献   

7.
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 (rm) became greater with rising temperatures from 0.123 at 20?°C to 0.180 at 30?°C. The net reproduction rate (Ro) was highest at 25?°C (25.0 females/female) and lowest at 20?°C (18.8 females/female), while To decreased with increasing temperatures, from 23.8 days at 20?°C to 17.5 days at 30?°C.  相似文献   

8.
The rose-grain aphid,Metopolophium dirhodum (Wlk.), is a species living onRosa spp. as winter hosts and Gramineae as summer hosts. Thus, the planting of roses along roadsides and highways may be of importance in connection with the migration of the aphids to cereals. In March 1982 the nymphs hatched from eggs, which were laid in autumn on long shoots. One or two days after hatching they fed on buds in batches up to 15 individuals. Somewhat later they dispersed on the hostplants. The nymphal mortality of the first generation was high, namely about 79%. For further population development the number of fundatrices was less important due to their high reproduction capacity. Nymphs and adults of the first generation often changed their feeding site on the shoots. The specimens of the 2nd and 3rd generation were more stationary and formed dense colonies. The population density drastically increased during the 3rd generation. The development of the aphid populations on the primary host took place during 2–3 generations and lasted until the beginning of June, when the winged forms left the hosplant. In the second generation, i. e. at the beginning of May, the first emigrantes appeared and the size of the aphid colonies increased up to 115 individuals. Most colonies consisted of less than 11 aphids namely 30.9%. Natural enemies were present in large numbers during the end of May when the populations of aphids decreased due to emigration. They did not influence the density of aphid colonies, except the predacious larvae of hover-flies. Trophobiosis between ants and rose-grain aphids was not observed on the primary hostplant.  相似文献   

9.
Methanolic extract ofMelia azedarach fruits enriched by washing with petrolether and ethyl acetate was used for laboratory treatments of two lepidopteran pests in Egypt. The experiments were carried out with concentrations of 10, 15, 25, 50, 100 and 1000 ppm in a diet and compared with control insects. In both insects food consumption, weight gain and conversion of ingested food (ECI) in body matter decreased with increasing extract amounts. The conversion of digested food (ECD) was lowered gradually by using higher concentrations ofMelia extract. Some antifeedant activity was observed in larvae ofS. littoralis andA. ipsilon. The percentage of mortality increased with application of higher concentrations ofMelia extract in both species. Starting from 3rd larval instar the larvae of both species reduced significantly their weight until pupation in 25 ppm and higher extract concentrations, while the larval period was prolonged. The pupal weight was significantly reduced at 15, 25 and 50 ppm. At higher concentrations the larvae failed to pupate. Duration of pupal period was affected only inA. ipsilon. All reproduction parameters, as period of oviposition, fecundity, fertility and longevity of males and females were affected using emerged adults from treated larvae with concentrations of 10, 15 and 25 ppmMelia extract. InS. littoralis no adult emerged from pupae originated from larvae treated with 50 ppm and higher amounts and no larva hatched from eggs laid by adults treated with 25 ppmMelia concentration as larvae. In both species the oviposition period was shortened at 15 and 25 ppm extract, the fecundity and fertility were drastically reduced, and the longevity of males and females was reduced. Cross sections of the midgut showed that the epithelial cells are destroyed in both pests. This can be one of the reasons for the observed effects.  相似文献   

10.
Investigations with freshly laid, one and two days old eggs ofPlodia interpunctella were carried out at +8°C in a cooled warehouse and at +12°C in the laboratory. The development of eggs and larvae at rel. humidities of 50 and 70% after different days of cold influence was determined. After 11 days at +8°C or 15 days at +12°C no further development was observed.  相似文献   

11.
Laboratory experiments were undertaken to study the interrelationships which may be detected when rearing the ectoparasitoid,Bracon brevicornis onSesamia cretica larvae after being injected with the bacterial pathogen,Serratia marcescens at five constant temperatures. Many effects detrimental to the parasitoid were found through rearing onSerratia-infected larvae ofSesamia e.g. decreased the deposited eggs especially at 35°C; reduced the formed cocoons and produced adults at all temperatures (15–35°C); and prolonged developmental, repriod especially at 20 or 25°C. Number of infected host larvae which allowed complete successful development for the parasitoid was significantly decreased especially at the extremes of temperatures.  相似文献   

12.
研究测定了松褐天牛肿腿蜂对松褐天牛1～3龄幼虫的控制作用,采用林间和室内罩网相结合的方法研究了2组松褐天牛肿腿蜂对松褐天牛幼虫的寄生情况.结果显示:在室内试验条件下,松褐天牛肿腿蜂产卵之前的刺蛰、补充营养取食能直接造成松褐天牛1～3龄幼虫死亡,对1、2及3龄幼虫的平均致死率分别为95.66％、85.91％、57.88％,并可产卵寄生2、3龄幼虫;林间释放2组松褐天牛肿腿蜂后,在刺蛰和补充营养取食后能有效寄生寄主的肿腿蜂雌蜂数量比例变化较大,有效肿腿蜂率最高为14.9％,最低为2.3％.松褐天牛肿腿蜂寄生行为不受寄主聚集程度的影响,但刚羽化出茧肿腿蜂雌蜂的寄生效率比经饲喂后的雌蜂高近5倍.从肿腿蜂单一个体来看,每头雌蜂补充营养取食和产卵寄生致死的松褐天牛幼虫数为2.1～7.7头.松褐天牛肿腿蜂雌蜂的补充营养习性及刺蛰、取食致死寄主行为在防治中有很重要的作用,表明该种肿腿蜂是防治松褐天牛的重要天敌,在生物防治松褐天牛幼龄幼虫上具有良好的应用前景.  相似文献   

13.
环斑猛猎蝽生物学特性的研究*   总被引：4，自引：0，他引：4       下载免费PDF全文
据北京室内饲养观察，环斑猛猎蝽一年发生一代，以４龄若虫越冬。卵期９．９±１．１ｄ。若虫共５龄，历期３１５．０±４．９ｄ。成虫羽化后７－２５ｄ交配，交配后２２－２３ｄ开始产卵。描述了各虫态形态特征。记述了生物学特性。试验表明该虫是杨扇舟蛾、黄刺蛾、杨叶蜂、舞毒蛾、油松毛虫、黄褐天幕毛虫、刺槐蚜等多种林木害虫的捕食性天敌。  相似文献   

14.
Zusammenfassung Die Weibchen vonT. angustum legen ihre Eier bei Temperaturen zwischen 15° und 35° C ab. Die hö chste durchschnittliche Eizahl (52 Eier/Weibchen) wurde bei 25°C/20% rel. Feuchte erreicht. Ein Teil der abgelegten Eier ist nicht entwicklungsfähig. Ihr Prozentsatz ist von der Temperatur während der Eiablage abhängig.Die Eientwicklung war zwischen 17,5° und 30° C und bei Feuchten von 5 bis rd. 100% möglich. Bei 15° C konnte die Eientwicklung nur bei Feuchten zwischen 5 und 20%, bei 32,5°C bei Feuchten von 5 bis 80% erfolgreich abgeschlossen werden. In den Randzonen des Entwicklungsbereiches kam es zu Schlupfstörungen.Die Zucht der Larven bis zum adulten Tier gelang auf verschiedenen wichtigen Vorratsgütern. Als besonders geeignet erwiesen sich Getreide und Getreideprodukte, Nüsse und pflanzliche Rückstände der Ö lgewinnung. Doch auch tierische Produkte, z. B. Trockenfleisch, waren als Nahrung geeignet. Wolltextilien wurden im Zwangsfraßversuch etwas angefressen, ohne daß sichtbare Schadstellen entstanden. Die angesetzten Larven verhungerten. Die Entwicklungszeit vom Ei bis zum adulten Tier dauerte auf geeignetem Futter bei 20° C etwa 17–21 Wochen, bei 25° C etwa 9–15 Wochen. Bei unserem Klima ist unter Lagerbedingungen im allgemeinen nur mit einer Generation im Jahr zu rechnen.T. angustum kann an Vorräten schädlich werden, dürfte jedoch bei uns kaum größere Bedeutung erlangen.
Summary The females ofT. angustum lay their eggs at temperatures between 15 and 35° C. The maximum average number of eggs (52 eggs per female) was observed at 20° C and 20% R. H. A percentage of eggs — depending on the temperature during the egg-laying period — did not develop.Eggs were found to develop between 17,5°C and 30° C, and 5% R. H. to about 100% R. H. At 15° C a relative humidity between 5 and 20% and at 32,5° C from 5 to 80% was required for full development. In marginal zones of the developing area hatching was disturbed.Breeding of larvae up to adults was carried out successfully on a number of important stored products. Cereals, nuts, and oil-cakes proved to be particularly favourable; also animal products, e.g. dried meat, are suitable foodstuffs. Woolen fabrics were gnawed only, and no visible damage occurred; larvae fed on such materials only died of starvation.On suitable foodstuffs the development from egg up to adult at 25° C took 9 to 15 weeks, at 20° C from 17 to 21 weeks approximately. Therefore, under the climatic conditions of this country no more than one generation per annum may be expected. T. angustum may cause damage to stored products; in this country, however, it will hardly attain major importance.
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15.
InA. barkeri a relation was found between the duration of copulation and the resulting egg production. After 15 min of copulation no eggs were produced but after respectively 30, 60, 120, 180 min an increasing number of eggs were deposited. A male showed a high reproductive ability for more than 16 days and was able to mate more than once in excess of females, with maximum of six times. The effect of single and multiple mating on longevity, fecundity and sex ratio of the predacious miteAmblyseius barkeri (Hughes) was studied. Fecundity of females mated more than once was twice as females mated only once.  相似文献   

16.
During the last 12 years Arborvitae Leaf Miner (Argyresthia thuiella) was imported from North America to Western- and Central-Europe (1971 the Netherlands, 1975 Federal Republic Germany and 1976 Austria) onThuja occidentalis L. (Cupressacea). In Lower Austria and Vienna there is a tendency rapid to the east, through the dominate westerly winds. Fligh-time took 27 days, moth-slip was 5–10 h in the morning; maximum about 5–6 h. Index of sexus was displated in favour of the males (51.7–66.7%). The moths fed with water-honey showed a longaevitas of 1–15 days maximum about 4 days, and fed with pure water of 8 days. Attack-degree (variational limit) amounted to 2.6–24.5%. The parasitism-role (Necremnus sp., Eulophidae) was between 1.2% and 15.7%. In the laboratory chemical-therapeutics in spray form were without effect. Author's opinion is that this eminent exotic injurious insect must already be calculated as a part of the European fauna.  相似文献   

17.
Results of laboratory experiments revealed that the total development period (egg to adult emergence) of the common green lacewing Chrysoperla carnea lasted for 19.15, 19.35, 19.95, 20.15, 20.60 and 22.50 days when the larvae were fed with Bemisia tabaci, eggs of Corcyra cephalonica, Heliothis armigera, Aphis gossypii, Amrasca biguttula and neonates of Heliothis armigera respectively. Larval development was rapid on eggs of C. cephalonica (8.20 days) and prolonged on neonates of H. armigera (11.10 days). Pupal development period was quicker on B. tabaci and A. biguttula (7.40 days) and prolonged on neonates of H. armigera (8.40 days).During development each larva of C. carnea consumed an average of 732.35 eggs of C. cephalonica, 662.53 eggs of H. armigera, 419,18 A. gossypii, 409.55 neonates of H. armigera 329.70 pupae of B. tabaci and 288.45 nymphs of A. biguttula. In all the cases, the third instar larvae consumed the major portion of the total number consumed (60–80%). The most suitable preys, resulting in rapid development, for C. carnea were pupae of B. tabaci and eggs of C. cephalonica.With 2 tables  相似文献   

18.
Under laboratory conditions, when reared onPhorodon humuli aphid,Adalia bipunctata deposited 1011 ova and mean longevity of males and females was 55–73 days respectively. When reared onAphis fabae orA. fabae + Aphis craccivora diet, females ofA. pipunctata deposited 41–63 ova, and mean longevity of males and females was 20–32 days respectively. Larvae reared onP. humuli completed development in average 8.9 days, and mortality was 16.7%. Larvae reared onA. fabae, orA. fabae + A. craccivora aphids, completed development in 14–15 days, and mortality was 83–90%. It is concluded thatP. humuli aphid is an essential food forA. bipunctata, whereasA. fabae andA. craccivora aphids, are unsuitable foods.  相似文献   

19.
The predacious miteAgistemus exsertus Gonzalez was reared in the laboratory on the eriophyid miteAculops lycopersici (Massee) for studying the development, fecundity and predation efficiency. At 30°C and R.H. 75% the duration of the predator egg incubation, immature stages, life cycle, oviposition and longevity of the adult female was 0.92, 2.10, 3.02, 4.89 and 7.20 days respectively in average. The consumption by one adult female ofA. exsertus per day on the different stages of the eriophyid miteA. lycopersici was 60.3 eggs and 45.3 immature and mature stages.  相似文献   

20.
This study was carried out to determine the development, survival and reproduction responses of Adalia fasciatopunctata revelierei (Mulsant) (Coleoptera: Coccinellidae) feeding on Hyalopterus pruni (Geoffroy) (Homoptera: Aphididae), using 20, 40, 80, 160 and 250 prey densities. All experiments were conducted at 25±1°C, 60±5% relative humidity, 16:8 light:dark under laboratory conditions. The average daily prey consumption of A. fasciatopunctata revelierei immatures and adults increased with increasing prey densities. Predation was not different for the larval stages at 80, 160 and 250 prey densities. The longevities of adult females were 35.67, 35.33, 49.00, 58.33 and 57.16 days when 20, 40, 80, 160 and 250 H. pruni were provided, respectively. The mean daily and total fecundity of A. fasciatopunctata revelierei increased with increasing prey densities. Females of A. fasciatopunctata revelierei feeding on H. pruni laid 89 eggs at 20 prey density and 301.67 eggs at 160 prey density. The search rate of females was higher than that of all larval instars; and the search rate of the fourth-instar larvae was higher than that of younger instars. Handling time decreased with development from larval stages to adult.  相似文献   

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