• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.649-655
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• 1993

A series of experiments on the effects of ${\gamma}-irradiation$ was performed to reveal the pathogenicity of ${\gamma}-irradiated$ oocysts of E tenella from Cobalt-60 and its progeny. The SPF chickens were inoculated with differnt doses of radiation and inoculum. The level of 100 Gy ${\gamma}-irradiation$ from $^{60}Co$ and the level of inoculum with $1{\times}10^4$ oocysts were recognized more pathogenic than those of the other groups by comparison of body weight gains, blood in feces and lesion scores. The signs of blood in feces, lesion score and the number of excreted oocysts in the feces were revealed as the lowest in the group of the ${\gamma}-irradiated$ oocysts, the average in the group of the 1st and the 3rd progeny, and the highest in the group of non-irradiated oocysts of E $tenell\grave{a}$. The body weight gain of the group immunized with ${\gamma}-irradiated$ oocysts of E tenella was higher than those of the non-irradiated, the 1st and 3rd progeny groups. The body weight gain of the groups immunized with the 1st and the 3rd progeny of E tenella were higher than that of the non-irradiated group. The feed conversion ration of the group immunized with ${\gamma}-irradiated$ oocysts of E tenella was lower than those of the non-irradiated, the 1st and the 3rd progeny groups. The feed conversion ratios of the group immunized with the 1st and 3rd progeny of ${\gamma}-irradiated$ oocysts were lower than that of the group infected with non-irradiated E tenella. The anticoccidial index(ACI 190.6) in the chickens immunized with the ${\gamma}-irradiated$ oocysts of E tenella and those(ACI 142.8 and 107.4) of the 1st and the 3rd progeny groups were higher than that (ACT 87.4) of the group infected with non-irradiated E tenella. It was thought that the pathogenicity of ${\gamma}-irradiated$ E tenella would be recovered according to increase the number of generation passaged in chicken.

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.657-664
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• 1993

To reveal the immunogenicity of ${\gamma}-irradiated$ E tenella and its progeny, a series of experiments on the effects of Cobalt-to ${\gamma}-irradiation$ was performed. The SPF chickens inoculated with diffenrt doses of inoculum were challenged with $1{\times}10^5$ oocysts of virulent E tenella. The levels of 100 Gy ${\gamma}-irradiation$ from $^{60}Co$ and of inoculum with $1{\times}10^4$ oocysts were recognized as proper as immunogen by comparison of survival rates, body weight gains, blood in feces and lesion scores in the chickens. In these trials of challenge with virulent E tenella after inoculation with $1{\times}10^4$ oocysts of the ${\gamma}-irradiated$ E tenella and its progeny, the survival rates of the chickens challenged with the virulent E tenella after immunization with the 1st and the 3rd progeny groups of ${\gamma}-irradiated$ E tenella oocysts were higher(l00%) than that(87.0%) of the challenged control group. The signs of blood in feces and the lesion scores were seen markedly lower with the ourput of the smaller number of oocysts, i.e. OPG 103,900 and 25,800 in the groups of the 1st and the 3rd progeny, respectively, than those(OPG 1,658,900) of the challenged control group. The body weight gains of the 1st and the 3rd progeny groups, the 1st week and the 2nd week after challenge, were higher (2.6g and 155.4g, 11.6g and 168.9g respectively) than those(-85.8g and 63.6g, respectively) of the challenged control group, and the feed conversion ratios(FCR 3.28 and 2.96) of the 1st and the 3rd progeny groups were lower than that(FCR 5.60) of the groups challenged control group. The anticoccidial indices(70.5 and 93.9) of the groups challenged with the virulent oocysts of E tenella after immunization with the 1st and the 3rd progeny of the ${\gamma}-irradiated$ E tenella were significantly higher than that (ACI -81.9) of the challenged control group. It was thought that the immunogenicity of ${\gamma}-irradiated$ E tenella would be increase according to increase the number of generation passaged in chicken. That might be because of increasing the pathogenicity of ${\gamma}-irradiated$ E tenella according to increase the number of generation passaged in chicken.

• Animal cells and systems
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• v.3 no.4
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• pp.369-374
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• 1999

The life history and development of Tetrastichus sp. parasitizing fallwebworm pupa in Korea were studied. The mean lifetime fecundity was 94.7 with a maximum of 125, and the portion of female progeny averaged 90.3%. A male and a female lived for an average of 19.8${\pm}$4.5 and 21.7${\pm}$4.2 days, respectively. The duration of development for each stage was as follows: egg, 2 d; the 1st instar larva, 2${\pm}$1 d; the 2nd instar larva, 2${\pm}$1 d: the 3rd instar larva, 3${\pm}$1 d; the 4th instar larva, 6${\pm}$2 d; and pupa, 8${\pm}$2 d. Total developmental duration from hatching of the larva to adult emergence required 21.1${\pm}$3.7 d, and females took 1-2 days more than males in the incubator (28$^{\circ}C$, 70% RH, and 16:8 LD).

• Korean journal of applied entomology
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• v.12 no.1
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• pp.1-21
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• 1973

Some experiments were conducted to investigate the effects of the chemosterilant, hempa, on the biology of the rice weevil, Sitophilus oryzae L., and the transmission of the lethal factors in the progeny. One to three days old adult males were fed on the wheat grains treated with concentrations of 0.0625, 0.125, 0.25, and $0.5\%$ of hempa water solution. The effects of the treatment on the mortality, longevity, and the performance of oviposition were examined for the Pl generation, and the hatchability and mortality in the postembryonic development were also tested in the $F_1,\;F_2,\;BC_1,\;F_3,\;and\;BC_2$ generations to analyze the inheritance of the lethal factors. The results obtained were summarized as follows. (1) The average longevity of the treated males were ranged from 26.6 to 30.4 days, and indicated no statistical differences. (2) The mortality of the treated males were ranged between $3.3\%\;and\;13.3\%$ and showed no statistical significance. (3) The overall mean number of eggs laid by a female mated to a treated male with concentrations of 0.0625, 0.125, 0.26 and $0.5\%$ were 3.78, 4.05, 3.75 and 3.61 for the respective treatments, and they were not differ significantly from those of control which were 3.60 per female per 3 day period. The unmated female laid 1.91 in the same period, and significantly differ from those in other experimental groups. (4) The overall mean hatchability of the eggs laid by the females mated with males that had been treated with various concentrations of hempa were 86.82, 64.77, 53.47, 40.33 and $24.78\%$ for the respective concentrations of 0, 0.0625, 0.125, 0.25 and $0.5\%$. The hatchability decreased with the increasing concentrations. (5) The minimum hatchabilities were obtained from the eggs laid in the period of 10-12 days after treatment, then the hatchability increased showing some recovery. The recovery seemed to be very much delayed for the males which had been treated with the greater concentrations. Such a difference in hatchability might be related with the sensitivity of the developmental stages of the sperms, and broader spectrum in the stages and severer effects seemed to be associated with the increased concentrations. (6) The overall mean of larval mortality in the $F_l$ generation were 6.55, 17.89, 27.40, 35.42 and $52.17\%$ for the respective concentrations of 0,0.0625, 0.125,0.25 and $0.5\%$. And there was a tendency to increase in the mortality with the increase of concentrations. (7) The correlation coefficients between per cent sterile eggs and larval mortality for the experimental plots of 0.125, 0.25 and $0.5\%$ treatments showed r=+0.83 and +0.85, respectively, and it seemed to be close correlation between the lethal effects on the embryonic and post-embryonic developments. (8) Since the $SC_{50}$ of the sterile eggs was $0.133\%$ and $SC_{50}$ of the larval mortality was $0.565\%$, it was considered that tile lethal factors expressed more in the egg stages than the larval stages. (9) The ratio of female to male in the $F_l$ adults showed 100 : 125, 100 : 108 and 100 : 124 for the plots of 0.125, 0.25 and $0.5\%$ treatments, respectively. And it n·as considered that the sex ratio distortions might occur with the higher concentrations. (10) When the F, males originated 1.on the eggs had been laid by p, in the period of 16-18 days after treatment, were crossed to normal females $(BC_1)$ and made sib matings $(F_2)$, the per cent sterile eggs of the $BC_1$ generation were 13.88 and $33.04\%$ , and were 31.01 and $38.73\%$ for the $F_2$generation with the plots of 0.0625 and $0.125\%$ treatment, respectively. And these seemed to be a results of the $F_1$ individuals are carrying some chromosomal aberrations (11) The larval mortality was the highest in the $F_2$ plot and followed the female backcross plot, and the least in the male backcrosses. (12) The proportions of 1st and 2nd instar larvae among the larval development at tile 17th day after oviposition were 10.98, 27.26, 32.98 and $15.73\%$ in the normal female $\times$ normal male, $F_1$ female$\times$normal male, normal $female \;\times F_1$ male and $female \;\times F_1$ male plots, respectively. It was considered that the larval development might be delayed by the treatment in the 2nd generation. (13) Per cent larval mortality and sterile eggs were greater in the $F_2$ sib mating plots $(F_3)$ than both of $F_2$ backcrosses. Therefore, it seemed that some of the recessive lethal mutations might affect in the further generations. (14) The sterility, induced by the treatment of chemosterilant, hempa, was considered as the result of the dominant lethal mutations due to chromosomal aberrations such as translocation and/or deletion. The effects of these lethal factors seemed to be inherited tip to 3rd generation after treatment.