• Title/Summary/Keyword: feeding preference

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Resistance of 'Tong-il' variety to the smaller brown planthopper, Laodelphax striatellus Fallen (애멸구에 대한 '통일' 벼의 저항성)

  • Choi S. Y.;Song Y. H.
    • Korean journal of applied entomology
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    • v.13 no.2 s.19
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    • pp.77-82
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    • 1974
  • The variety Tong-il from the IR667 lines have been reported as a variety resistant to the smaller brown planthopper, Laodelphax striatellus Fallen, in Korea. The resistance of Tong-il to the insect, however, have been mainly evaluated from a viewpoint of plant reaction of rice at the seedling stage. In this study, the nature of resistance of Tong-il to the insect was furthermore evaluated from the standpoints of feeding preference, antibiosis and plant tolerance in comparison with the resistant varieties Karsamba Red ASD-7 and Vellailangalayan. and the susceptible variety Jinheung which have been reported to the insect. The smaller brown planthopper much more prefered Tong-il for feeding than the resistant varieties ASD-7 and Vellailangalayan. The degree of antibiosis of Tong-il to the smaller brown planthopper was significantly lower than ASD-7 and Vellailangalayan. The results showed significantly lower nymphal mortality and higher adult emergence in Tong-il and Jinheung than other two resistant varieties. The degree o( tolerance of Tong-il to the insect was also lower than ASD-T and Vellailangalayan. Only. Tong-il seemed to be relatively more tolerable than Jinheung. The reason of showing resistant reaction of Tong-il in the mass screening test might be related with relatively lower feeding preference and more tolerance than Jinheung and other susceptible varieties.

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AN ECOLOGICAL STUDY OF TUNA LONG LINE CATCH DISTRIBUTION OBTAINED BY EXPERIMENTAL FISHING OPERATIONS (다랑어연승 실험조업의 조획물조성에 의한 어업생태학적연구)

  • PARK Sing Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.2 no.2
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    • pp.161-172
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    • 1969
  • Ten experimental tuna long line fishing operations were performed with the long lines A and B, in combination casting orders of BA and AB. The long line B differs from A in its additional main line length per basket and its greater depth of submersion (Table 1). The BA casting order results in an AB hauling order, so that the long line B is casted at an earlier time of a day and fishes for a longer period than A line (fig. 2). The number of fish caught was divided into subclasses in order to be subjected to $x^2-tests$ (Table 2). The first series of $x^2-tests$ were calculated using the hooking rates of two subclasses with other factors pooled (Table 3). The second series of $x^2-tests$ were calculated to obtain the interactions between two subclasses when other factors differed (Table 4). Attention was paid to the extremely small interactions as well as to the large interactions in order to find out whether a factor functions in the same way or in a contradictory way when the other factors involved differ. The test result is summarized in Table 5. The relationship between the hook casting time (relative to the sunrise time) and the hooking rates reveals the feeding behavior of particular species (fig. 3) A high hooking rate for yellowfin tuna shown in the period from one hour before sunrise to the moment of sunrise suggests that they feed actively in that period. Their poor hooking rate on earlier casted hooks suggests that they do not feed well under conditions of darkness and that they feed best while the hooks are sinking. Furthermore it is likely that yellowfin tuna maintain a shallow depth in the daytime, for the $x^2$ interaction between the line casting order BA and AB shows their persistant preferance of the long line A regardless of line casting order. Bigeye tuna show their feeding behavior under conditions of darkness, and show a preference for the sea's deeper layer. Alepisaurus borealis (Gill) show their feeding behavior under conditions of darkness more significantly than the bigeye tuna and their preferance for deep layers is also more significant. Marlins (mainly Makaria mazara) show a feeding behavior which is similar to the yellowfin tuna. The author emphasizes that certain variations of the hooking rates in relation to the line easting time were caused by an inadequate fishing depth as well as by the fish preference for a particular feeding time. When the part of the line casted in pre-dawn hours and hauled in the pre-sunset hours show a significantly lower hooking rate than other parts of the line, then it is concluded that tile hooks settled in a sea layer too deep for feeding.

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Feasibility in Differentiation of Resistance of Rice Varieties to Brown Planthopper (Nilaparvata lugens Stal) using Radisoisotope (P-32) Tracer-Technique (P-32를 이용한 벼멸구(Nilaparvata lugens Stal) 저항성 검정법에 관한 연구)

  • Chung K.H.;Kwon S.H.;Choi S.Y.
    • Korean journal of applied entomology
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    • v.20 no.4 s.49
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    • pp.207-211
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    • 1981
  • It has been documented that the resistance to planthoppers is attributed to the feeding preference of the insects. This might be related to difference in the amount of feeding plant sap between resistant and susceptible hosts. In this aspect, this study was conducted to verify it and to develop an effective screening method for resistance to planthoppers by tracer technique. An effective P-32 labelling of rice seedlings at $2\~3$ leaf stage was dipping the roots in concentration of $0.1{\mu}Ci/ml$ solution for 48 hours. Radioactivity was significantly higher in planthopers fed on susceptible variety for 48 hours as compared to those fed on resistant variety. Radioactivity of adults was higher than that of nymphs and also higher in female than male. The results were highly correlated to that indicated by the feeding preference of the insects and therefore, considered to be valid for a screening technique.

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Evaluation of Host Resistance of 18 Warm-Season and 20 Cool-Season Turfgrass Species and Cultivars to Spodoptera depravata(Butler) (잔디밤나방에 대한 난지형 잔디와 한지형 잔디의 내충성 평가)

  • 박봉주
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.4
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    • pp.74-81
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    • 2003
  • The need for insect and mite resistant turfgrass cultivars arose because of problems associated with pesticide use. Representative cultivars and genotypes of 18 warm-season turfgrass [Zoysia japonica Steud., Z. japonica${\times}$Z. metrella hybrids, Z. japonica${\times}$Z. tenuifotia hybrids, Z. matrella (L.) Merr., Cynodon dactylon (L.) Pers., C. dactylon${\times}$C. transvallensis hybrids, Paspalum notatum Flugge., P. vaginatum Swartz., Stenotaphrum secundatum (Walt.) Kuntze, Eremochloa ophiuroides (Munro.) and Buchloe dactyloides (Nutt.) Engelm.] and 20 cool-season turfgrasses [Poa pratensis L., Festuca arundinacea Schreb., F. rubra L., F. rubra var. commutata Gaud., F. ovina var. duriuscula L. Koch. Agrostis tenuis Sibth., A. palustris Huds., and Latium perenne L.] were evaluated for host resistance to feeding by the Spodoptera depravata (Butler) in the laboratory. Two experiments were set up in the laboratory using 8.5cm diameter${\times}$4.0cm deep plastic petri dishes as larvae feeding chambers. In experiment 1, one neonate larvae were place on the grass in each dish and the dishes were arranged with 5 replicates each within an environmental chamber maintained at $25^{\circ}C$ and 15h light: 9h dark Larval survival and larval weights at 7d and 14d, pupal weights, and days to pupation were compared among turfgrasses. In Experiment 2, 4cm sections of all grasses were oriented equidistant from each other in a pattern resembling the spokes of a wheel. Five one neonate larvae were introduced to the center of each dish. Dishes were immediately placed in an environmental chamber held at $25^{\circ}C$, 15h light: 9h dark Larvae were allowed to feed for 24h. Damage was rated from 0(no damage) to 9(completely consumed) were made for eachturfgrass. Resistance as antibiosis (high mortality, slowed growth, and least preference) was identified in Z. japonica${\times}$Z. tenuifolia hybirids ‘Emerald’, Z. japonica${\times}$Z. metrella hybirds ‘Miyako’ and Eremochloa ophiuroides (Munro.). Cool-season turfgrasses tested were susceptible to feeding by Spodoptera depravata (Butler).

Studies on Culex pipiens Mosquitoes in Korea 1. Feeding and Resting Behavior of Culex pipiens pallens Coquillett (韓國産 Culex pipiens에 관한 硏究: 1. Culex pipiens pallens Coquillett 의 吸血 및 休息習性 調査)

  • 李漢一
    • The Korean Journal of Zoology
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    • v.13 no.2
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    • pp.51-56
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    • 1970
  • Studies on the feeding and resting behavior of Culex pipiens pallens, a possible vector of Japanese encephalitis in Korea, was carried out at Kobu-Ri, Kobu-Myon, Chongup Kun. Cholla Pukdo in 1967. 1. Indoor and outdoor human biting collections showed that 47.3 per cent Culex pipiens pallens were collected indoors and 52.7 per cent outdoors. 2.Feeding occurred throughout the night from dusk to dawn, with the peak period from 23:00-24:00 hours outside the house and from 24:00-01:00 hours inside. 3. Culex pipiens pallens females preferred man for their blood feeding to domestic animals. The results of human and cow biting collections showed that the feeding ratio between man and cow was 2.1 to 1. As to the feeding preference to the domestic animals, the ratio among cow, pig and horse was 7.3 to 5.1 to 5.4 4. Daytime resting collections showed that large numbers of Culex pipiens pallens females rest inside the house, especially in the bed room and the chicken pen. As temperatures increased, fewer mosquitoes resting indoors and more mosquitoes rest ing outdoors were caught. By means of sweep-net collections at outdoors resting places, a small number of Culex pipiens pallens mosquitoes were caught in such places as grass fields, vegetable fields, barley fields, bean fields, culverts, bomb shelters, and so on. A comparison between number of mosquitoes collected resting during the day in bedrooms and verandahs with resting collections in the same places at night showed that more mosquitoes were present at night. It was observed that the majority of the unfed females rested before feeding at night.

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A Comparative Study on the Perception of the Impediment Factors between Mothers and Nurses in Nursery (모유수유 저해요인에 대한 산모와 신생아실 간호사간의 인식정도 비교 연구)

  • Lee, Mi-Ja
    • Women's Health Nursing
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    • v.1 no.1
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    • pp.138-152
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    • 1995
  • The condition of nutrition during infancy will greatly affect infants' physical, emotional growth, especially breast feeding is important in their growth and development, and emotional stability, too. Despite such advantages of breast-feeding, its rate has continued to fall year after year in Korea : the 95% rate in 1960's has fallen to 25.4% in 1990. It is known that such a downfall of breast-feeding rate is associated with various factors. The purpose of the study is to examine mother's and nurses' in nursery perception of the impediment factors of breast-feeding : to compare those between of breast-feeding : to compare those between two groups : to provide fundamental data for developing strategies for increasing breast-feeding. The subjects were 45 new mothers from one hospital and the same number of nurses sampled from 3 university hospitals, in Seoul. The data were collected for 11 days from April 12 to April 23, 1994 and a questionnaire was developed based on the interview with 14 nurses and 10 mothers and the literature reviews. Liker's Five-Point Scale was used as measurement. The Data were analyzed using SPSS / PC and descriptive statistics, t-test, ANOVA. The results of study are as follows : 1) Most new mothers get the information about breast-feeding from their mothers, books or newspaper, and relatives in rank than professionals(nurses or doctors). 2) The impediment factors the breast-feeding are categorized as mothers, hospital system, medical personnels and social factors. The most frequently mentioned impediment factors from mothers are 'Difficulty by operational wounds'(3.13), 'Lack of will for breast-feeding'(3.47), 'Insufficient rest and sleep'(3.52) and 'Opposition from husband or his family members'(4.77)in rank. On the other hand those factors from nurses are 'Inadequate nipple condition'(2.37), 'Decreasing milk secretion given medicine after operation'(2.63), 'Mothers knowledge deficit by poorly prepared education'(2.79) and 'Mothers abhorance of breast-feeing'(3.87) in rank. 3) As for the hospital system, the highly perceived impediment factors by mothers are 'Seperation of baby from mother after birth'(2.78), 'Lack of space for breast-feeding in the hospital'(2.93), 'Lack of facility for informing the time for breast-feeding'(3.18) and 'Because of babys' preference artificial nipple by being accustomed to it in hospital(3.97), in rank. Meanwhile, those from nurses are "Seperation of baby from mother after birth",(1.92), "Inconsistency between hospital's nursing time and mother's breast secretion time" scretion time(2.97), "Lack of space for breast-feeding in the hospital"(3.39), and "Lack of facility for informing the time for breast-feeding"(3.74) 4) As for the medical personnels, the highestly perceived Impediment factor from mothers in "Lack of professional nurses for breast-feeding"(2.96), and the lowestly perceived one is "Doctors' reluctance"(4.75). Nurses perceived same as mothers, too. 5) As for the social factors, the highestly perceived impediment factor by mothers and nurses is "Inconvience of social activities"(2.83) and the lowestly ones are "The sense of self-sacrifice"(4.22) by mothers, and "The sense of old fashioned"(4.13) by nurses. 6) The difference of the perception of impediment factors between mothers and nurses is statistically significant only in mother factor.

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Survey on utilization of Pan-fried food items at institiutional foodservice establishments in Pusan (부산시내 단체급식소에서 전유류의 이용실태조사)

  • Kim, Kyung-Ja;Cha, Eun-Jeung
    • Korean journal of food and cookery science
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    • v.10 no.4
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    • pp.309-314
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    • 1994
  • This study was conducted to survey on utilisation of pan-fried food items questioning by dietitians from 40 foodservice establishments in Pusan. The results of this study are summarized as folIows. 1. Feeding numbers among the type of the foodservice centers were varied widley from 90-3200 and the number of foodservice personnels were insufficient when comparing with the feeding numbers. Also, it was shown that most of surveyed institutions managed by conventional foodservice system 2. 52.5% of requirements answered that they served pan-fried food items three times a month, and they were inconvenient food items because of their complecated cooking method(100%). But the preference of that was high(57.5%) 3. Equipped rate was very poor and proper equipments were not provided to prepare pan-fried foods effectively.

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Studies on the Varietal Resistance of Rice to the Smaller Brown Planthopper, Laodelphax striatellus Fallen(IV) (애멸구에 대한 벼의 품종저항성에 관한 연구(VI))

  • Choi S. Y.;Song Y. H.;Park J. S.;Choi K. Y.
    • Korean journal of applied entomology
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    • v.13 no.1 s.18
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    • pp.11-16
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    • 1974
  • Experiment was conducted to select the rice varieties and lines resistant to the smaller brown planthopper, Laodelphax striatellus Fallen, and study the cause of varietal resistance to the insect. The nature of varietal resistance was evaluated from the viewpoints of feeding and ovipositional preferences and antibiosis. Among the IRRI sources the varieties H 105, Muthumanikam, Vellailangalayan, Karsamba Red ASD-7. Manavari Co 22, Mudgo, PTB-18, IR 8 and IR 20 were selected as resistant sources. Among the domestic sources. only Suweon 213-1, Suweon 214 and Suweon 215 originated from the IR667 lines were resistant, and other leading varieties ail susceptible. The cause of resistance of rice to the insect seemed to be highly related with the non-feeding preference, not non-ovipositional preference. Nymphal mortality and rate of adult emergence were significantly different from the resistant and susceptible varieties. The rate of adult emergence was significantly lower in the resistant than In the susceptible varieties. The primary cause of lower adult emergence seemed to be due to the fact that the infects were suffered higher nymphal mortality in the resistant than in the susceptible varieties.

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Habitat Characteristics and Feeding Ecology of the Korean Endemic Species, Iksookimia pacifica (Pisces: Cobitidae) in the Bukcheon (stream), Korea (한국고유종 북방종개 Iksookimia pacifica (Pisces: Cobitidae)의 서식지 특성 및 섭식생태)

  • Ko, Myeong-Hun
    • Korean Journal of Ichthyology
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    • v.27 no.4
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    • pp.275-283
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    • 2015
  • Habitat characteristics and feeding ecology of Iksookimia pacifica were investigated in this study to provide baseline data for its ecological characteristics in Bukcheon (stream), Goseong-gun, Gangwon-do, Korea. The main inhabit of I. pacifica was found to be sand bottoms of Bb or Bc river type with slow water flow. Based on studies of their habitat preferences according to age, their preference for sand bed was the same. However, their preference for depth and velocity was different. When their age was increased, their depth preference was also increased ($24.9{\pm}17.61cm$ for 0+ year, $69.6{\pm}30.32cm$ for 1+ year, $82.4{\pm}33.30cm$ for 2+ years, and $90.0{\pm}31.55cm$ for $3+{\leq}$ years). The water velocity was found to be 3.8 ~ 4.0 cm/sec for ages between 0+ and 1+ and 6.0 ~ 7.3 cm/sec for ages between 2+ and $3+{\leq}$. They were active on sand from March to November. They would hibernate in sand during the winter season. During the day from 12 pm to 24 am, they were highly active with high food consumption. Their main food sources analyzed with index of relative importance (IRI) include Chironomidae (76.7%), Simuliidae (10.3%), Rotatoria (7.3%), and Arcellidae (2.2%). Their juveniles (total length 20~40 mm) would feed on small-sized preys such as Rotatoria, Copepoda, and Arcellidae. Older I. pacifica would feed on big-sized preys such as Chironomidae and Simuliidae.

Effects of Outdoor Housing of Piglets on Behavior, Stress Reaction and Meat Characteristics

  • Yonezawa, Tomohiro;Takahashi, Asahi;Imai, Satomi;Okitsu, Aya;Komiyama, Sonomi;Irimajiri, Mami;Matsuura, Akihiro;Yamazaki, Atusi;Hodate, Koich
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.6
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    • pp.886-894
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    • 2012
  • Well-designed housing systems are important from the viewpoint of animal welfare and improvement of meat production. In this study, we investigated the effects of outdoor housing of pigs on their behavior, cortisol levels, and meat characteristics. Two groups that were born and raised in a spacious outdoor pen ($4{\times}10$ m for every two sows) or a minimum-sized standard pen in a piggery ($1.9{\times}2.2$ m for every sow) were studied. When their behaviors at the age of 2 to 3 wk were observed, the number of rooting episodes tended to be larger (p = 0.0509) and the total time of rooting tended to be longer (p = 0.0640) in the outdoor-housed piglets although the difference was not significant. Basal salivary cortisol levels of the outdoor piglets at the age of 4 wk were significantly lower than those of the indoor piglets ($5.0{\pm}0.59$ ng/ml vs. $11.6{\pm}0.91$ ng/ml, 30 min after treatment), although their plasma cortisol levels were similar ($53.3{\pm}3.54$ ng/ml vs. $59.9{\pm}4.84$ ng/ml, 30 min after treatment). When the ears were pierced at weaning, plasma and salivary cortisol levels were increased in both groups, even at 15 min after piercing. However, the increase in the outdoor-housed group was significantly less than that in the indoor-housed group. Throughout their lives, body weight and daily gain of the pigs were not significantly different between the two groups. In a meat taste preference test taken by 20 panelists, saltiness, flavor, and color of the outdoor-housed pork were found to be more acceptable. Moreover, when an electronic taste-sensing device was utilized, the C00 and CPA-C00 outputs ($3.78{\pm}0.07$ and $-0.20{\pm}0.023$), which correspond to compounds of bitterness and smells, respectively, were significantly lower in the outdoor-housed pork ($5.03{\pm}0.16$ and $-0.13{\pm}0.009$). Our results demonstrate that the outdoor housing system for piglets induces natural behaviors such as rooting and suppresses the strongest stress reaction of piglets, which could be important for animal welfare. Moreover, the outdoor housing system might change muscle characteristics and improve pork bitterness, flavor, and color. These changes may be preferred by consumers, increasing the sale of these meats.