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1.
The susceptibility of the two single populations of root-knot nematodes invading tomato roots,Meloidogyne javanica andM. incognita acrita, in comparison with a mixed population of the two species was investigated to the granular nematicides, Nemacur and Temik. Root-gall indices ofM. incognita acrita were reduced more than ofM. javanica. In addition, root-gall indices of the mixed population and a single population,M. incognita acrita, were the same.  相似文献   

2.
Bracon instabilis Marshal is an ectoparasite attacking the larvae ofP. operculella in Egypt. According to available literatures, this is the first study onB. instabilis. The laboratory rearing of this parasite was undertaken on the third and fourth larval instars ofP. operculella and the method was mentioned in details. Certain aspects of the morphology of the immature and adult stages were given. The durations of the immature stages of the parasite were estimated at 15 and 25°C and 60±5% R.H. The total durations of the immature stages (from egg to adult) were 39.62 and 11.19 days at 15 and 25°C, respectively.  相似文献   

3.
Pot experiments were carried out to explore the role of macrochilid mites,Macrocheles muscaedomesticae (Scop.), and staphylinid beetles,Philonthus longicornis Steph. and collembola,Onychiurus sp. singly and in combination onTylenchulus semipenetrans (Cobb) on sour orange at 29±5°C 74±5% R. H. in green house. All tested soil mesofauna significantly reduced the population of the nematode. The highest predation rate was achieved by the predator mite,M. muscaedomesticae (Scop.) singly, followed by the combination of soil mite plus collembola. The numbers of soil mesofauna recovered from soil at the end of the experiment were significantly higher in treatments of nematode plus one of each of soil mesofauna than monoinoculation of each.  相似文献   

4.
Occurence ofAculops lycopersici and its predators as well as the biological aspects of this pest were studied. The mite was reared on excised leaves ofSolanum nigrum L. in the laboratory at 25±1 °C and R. H. 70%. Duration periods of immatures and longevity of the adult were determined.  相似文献   

5.
The adaptation of the primary internal parasitoid,Trichogramma evanescens (Westw.), as an egg parasitoid ofLobesia botrana (Den. & Schiff.) was the first report in Alexandria region, Egypt. The life-span of this parasitoid on eggs ofL. botrana andSitotroga cerealella Ol. was investigated. The duration from egg to adult, longevity of adult stage, sex-ratio and total life cycle each of the two hosts were recorded. The ovipositional periods of mated females ofT. evanescens on egg ofL. botrana at 27±2co and 75±2% R.H. were studied. Also, percentages of parasitism byT. evanescens ranged from 22%–64% on the eggs ofL. botrana. Therefore, this parasitoid was very efficient as a biocontrol agent against the most serious grape pestL. botrana in Egypt.  相似文献   

6.
Zusammenfassung Baumwolle, Weizen, Mais, Sojabohne, Zwiebel, Kichererbse und Sesam wurden hinsichtlich ihrer Anfälligkeit gegen die WurzelnematodenMeloidogyne javanica undM. incognita incrita untersucht. Sesam und Mais waren gegen beide Nematodenarten resistent. Baumwolle wurde vonM. javanica nicht befallen. Dagegen wurden Zwiebel und Sojabohne von diesem Nematoden stark geschädigt. Die statistische Analyse zeigte signifikante Befallsunterschiede zwischen den Wirtspflanzen undMeloidogyne-Arten.
Susceptibility of certain field crops to some Nematoda infection, Meloidogyne javanica (Treub) and M. incognita acrita (Kofoid & White) chitwood
Varietal susceptibility of certain field crops were tested. Sesame and maize were resistant toM. javanica andM. incognita acrita infection. Cotton was resistant toM. javanica only. Onion and soybean were highly infected withM. javanica in comparison with the other tested hosts. Soybean also was highly infected withM. incognita acrita. Wheat showed the presence of the lowest of nematode population of the two species on its roots. Severity of galls was paralleled to the mentioned nematode populations.Statistical analysis of the data indicates that there were significant differences between the tested hosts. Also, the interaction between nematode species and hosts was significant.

Mit 2 Tabellen  相似文献   

7.
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   

8.
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   

9.
The present paper deals with developmental duration, emergence, longevity and fecundity ofAleurotuberculatus takabashi David & Subramaniam at different temperatures and humidity levels. The developmental time from egg to adult was 81.8, 56.9, 39.6, 29.9, 20.6 days at 15±1, 20±1, 25±1, 30±1, 35±1°C under constant relative humidity (RH) of 70±5%, respectively. At 25±1°C, the total developmental time was slightly affected by humidity, ranging from 46.4 days at 40±5% RH to 39.2 days at 90±5% RH. The developmental threshold and the thermal constant for the stage from egg to adult were 10.1°C and 542.8 day-degrees. It was estimated that the whitefly has about 10 generations a year in Fuzhou region in southeastern China. Lowest mortality rates of 12.4% for the egg, 6.8% for the nymph and 3.1% for the puparium were obtained at 15±1°C, while they were highest with 92.1% for the egg, 48.2% for the nymph and 36.3% for the puparium at 35±1°C. The mortality rates were slightly affected by humidity, ranging from 17.6% at 40±5% RH to 27.9% at 90±5% RH for the egg, 11.2% at 40±5% RH to 19.6% at 90±5% RH for the nymph, and 6.4% at 40±5% RH to 11.6% at 90±5% RH for the puparium. The emergence rate of adults decreased as temperature increased, ranging from 89.1% at 15±1°C to 21.5% at 35±1°C, so did the longevity of adults, ranging from 9.6 days at 15±1°C to 2.9 days at 35±1°C. The number of eggs per female was significantly affected by temperature (P.01), valuing 29.4 eggs per female at 15±1°C, 36.7 at 20±1°C, 52.4 at 25±1°C, 42.9 at 30±1°C, and 6.1 at 35±1°C. The optimal temperature for reproduction was about 25°C.  相似文献   

10.
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   

11.
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   

12.
The Relative Growth Rate of the larvac ofA. rosae at a temperature of 20°C amounts to 0.45–0.63 (RGR of Myzus persicae=0.17–0.39) corresponding to a doubling of the body weight within 1.1 to 1.5 days. The daily intake of plant material reached twice the amount of the respective initial body weight. The diapause ofA. rosae is induced by the photoperiod; temperature seems to be of minor importance. The onset of pigment evasion from the larval eye signalizes the termination of diapause. Diapause ended earlier at temperatures of 5°C and 12°C than at 20°C but even at the latter temperature diapausing individuals eventually yielded adults.  相似文献   

13.
The effect of space on the multiplication of the reniform nematode,Rotylenchulus reniformis on cowpea was determined under green house conditions. Both plant growth as estimated by root and shoot weights as well as its lengths and multiplication of the reniform nematode were greatly affected by the amount of space (soil). The population ofR. reniformis increased with an increase in the amount of space (soil) around seedling; highest being observed at 1,250 g of soil. The growth pattern of cowpea was attaining highest growth in 1,000 g of soil. Population ofR. reniformis increased with an increase in soil up to 1,250 g with 5 seedlings. The growth of cowpea was highest in 500 g of soil with 2 seedlings.  相似文献   

14.
The effect of various host plants; chickpea (varieties Arman, Hashem, Azad and Binivich), bean varieties (Phaseolus vulgaris L.), common bean (Khomein), white kidney bean (Dehghan), red kidney bean (Goli), cowpea (variety Mashhad) and tomato (variety Meshkin) on the life table parameters of the cotton bollworm, Helicoverpa armigera (Hübner) were evaluated under laboratory conditions (25 ± 1 °C, 65 ± 5 % RH and a 16:8 h light:dark photoperiod). Records for larval period, pupal period, and development time of H. armigera were longest on tomato (24.9, 15.1, and 45.4 days, respectively) and shortest on chickpea Arman (17.5, 9.1, and 31.7 days, respectively). Among various host plants fecundity (total number of eggs laid per female) was highest (2,665 eggs) on chickpea Arman and the lowest (700 eggs) on tomato. The net reproductive rate (R 0) was significantly affected by various host plants being highest on chickpea Arman (1,422) and lowest on tomato (111.3 females/female/generation). The highest and lowest intrinsic rates of natural increase (r m) were observed on chickpea Arman (0.244 day?1) and tomato (0.123 day?1) varieties, respectively. Cluster analysis of the life table parameters of H. armigera on various host plants indicated that tomato, in comparison to other plants was an unsuitable host to H. armigera.  相似文献   

15.
The eggs ofArgas (Argas) reflexus (Fab.) were exposed to 0.05% colchicine on 9th, 15th or 23rd–25th days of embryonic development at 25°C and 30% RH. The eggs on the 15th and 23rd–25th days of development were the most sensitive to colchicine. In these experiments 6.9% and 9.4% embryos died, respectively. The largest number of disturbances of egg hatch (11.5%) were observed after exposure of the eggs to colchicine on 23rd–25th days of embryogenesis.  相似文献   

16.
Investigations conducted in the laboratory for comparing the efficacy of phosphine with that of mixtures of the gas plus carbon dioxide against diapause larvae ofTrogoderma granarium showed that addition of varying concentrations of CO2 (20, 50, 75 and 100%) to fixed PH3-concentrations had a negative influence on phosphine efficacy against diapause larvae of Khapra Beetle at 30°C for short exposure periods of 18 and 24 hours. On the other hand, it was found that for longer exposure periods of 48 and 72 hours, the addition of CO2 to phosphine induced significantly higher larval mortality than that by PH3 alone, whereby an additive effect was proved for mixtures contained PH3+75% and 100% CO2. The addition of 20% and 50% CO2 to PH3 at 20°C did not show any increase in larval mortalities of the mixtures for exposure periods between 24–96 hours. The larval mortalities obtained for an atmosphere contained 20 and 50% CO2 alone at 20 and 30°C was (0–6%) and (10–40%), respectively, after 10 days exposure period.  相似文献   

17.
The entomophagous Serangium parcesetosum Sicard (Col., Coccinellidae) is an effective predator of some whitefly species. However, information on the influence of the preys host plant species on its biological and ecological characteristics is still lacking in the literature. Therefore, the current study focuses on the possible influence of three greenhouse and two field host plant species of Bemisia tabaci (Genn.) (Hom., Aleyrodidae) on the number of eggs laid by S. parcesetosum. In addition, because of the economic importance and widespread planting of cucumber in greenhouses and cotton in the field, these plants were selected for further investigation into the development, mortality, longevity and reproduction of S. parcesetosum at a high temperature in the laboratory. Results showed that S. parcesetosum was able to lay eggs on all five host plant species of B. tabaci, whether greenhouse or field plants. However, among the three greenhouse plant species studied, S. parcesetosum females laid the highest number of eggs on cucumber followed by tomato and then sweet pepper. Of the two field plant species, significantly higher numbers of eggs were laid on tobacco than on cotton. S. parcesetosum could develop either on cucumber or on cotton as preferable host plant species for B. tabaci. There were significant differences in mean developmental duration of larval instars of the same sex between both host plant species; the duration was significantly shorter on cucumber than on cotton. There were no significant differences for mean total developmental duration from egg to adult emergence between both host plant species within the same sex; females showed a mean of 15.9 days and males of 15.1 days on cucumber, while on cotton the means were 17.2 days for females and 16.2 days for males. Total mortality percentage of S. parcesetosum during development from egg to adult stage was lower on cucumber than on cotton, 20.6 and 23.8%, respectively. Longevity of S. parcesetosum varied according to host plant species and sex with a mean of 63.4 days for females and 50.3 days for males on cucumber, and 92.4 days for females and 52.5 days for males on cotton. On cucumber, mean period of oviposition of S. parcesetosum was significantly longer than on cotton. Mean total fecundity was significantly higher on cucumber than on cotton, with means of 97.7 and 31.0 eggs/female, respectively.  相似文献   

18.
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   

19.
By breeding grape moth,Lobesia botrana Den. et Schiff., in laboratory conditions the effect of constant temperatures on the growth and reproduction of the pest was investigated. On the basis of collected data the sum of effective temperatures for every stage of growth as well as the threshold temperature for the growth were calculated. For the embryonic development the temperatures are 74,0°C±2,3°C and 8,8°C; for the larval development in males 384,6°C±30,1°C and 7,3°C, in females 362,3°C±20,9°C and 9,4°C; for the chrysalis stage in males 162,1°C±23,5°C and 7,1°C, in females 151,5°C±24,0°C and 9,1°C. The sums of effective temperatures of the particular growth stages were completed by their quantil values (Q30, Q50, Q75, Q95). The threshold temperature for the life of moths was set up as 11,0°C in males and 12,8°C in females. The reproduction activity in the majority of females begins at temperatures above 15°C. The effect of the temperature on the actual fertility has proved to be significant. The optimal temperatures for the oviposition are within the range of 20,0°C–27,0°C. The relation between the actual fertility and temperature is at these temperatures determined by the regression line equation Y=?5,75·X+293. Temperatures below or above the limits of this interval are less favourable for the oviposition because they lead to a decreasing of actual fertility. The limit temperature (15°C) of reproduction activity in the majority of females is considered to be the lowest extreme temperature for the oviposition.  相似文献   

20.
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   

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