The small brown planthopper, Laodelphax striatellus, and the white backed planthopper, Sogatella furcifera, are important agricultural pests. L. striatellus could overwinter in Korean peninsula as nymph stage but S. furcifera could not. We investigated the survivorship and fecundity of two species for comparing population growth. The longevity and fecundity of two species were investigated at temperatures of 12.5, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5, and 35.0℃. Adult longevity and fecundity of two species were significantly influenced by temperature. Longevities of L. striatellus were longer than those of S. furcifera at different temperatures. Specially, oviposition period of L. striatellus was twice as long as that of S. furcifera. Total fecundity per female of L. striatellus were also more than those of S. furcifera. The oviposition model of each species was consisted of three components - age specific survival rate, age specific oviposition rate and total fecundity per female. The relationship between adult developmental rate and temperatures was described by exponential function. The age specific survival rate and the age specific cumulative oviposition rate were explained by two parameter inversed-Weibull function and Weibull function. Temperature dependent fecundity was estimated using three parameter Gaussian function. Daily egg production of two species in relation to adult age and temperature was estimated.

본 연구는 우리나라의 대표적인 노지작물인 고추에서 이상고온에 따른 생육 및 생리장해 등 피해정도를 파악하기 위해 수행되었다. 아울러 고온피해를 최소화하기 위한 화학적 대응 기술을 확립하기 위해 빈나리(diniconazole)를 사용하여 그 효과를 검정하고자 하였다. 고추의 신장생장은 생육적온인 25℃보다 온도가 높아질수록 향상되었으나 경직경은 낮았으며, 특히, 30℃에서 재배한 고추 식물체는 연약한 생장을 보였다. 반면 뿌리생육은 생육온도에 따라 큰 차이는 없었다. 고추의 생육적온인 25℃보다 고온에서 재배하면 엽수는 증가하였고, 엽면적도 높았다. 또한 생체중 및 건물중도 높았다. 반면 수확량은 생육적온인 25℃에 비해 고온인 30℃에서는 생산량이 17% 감소하였다. 고추의 생육온도에 따라 낙화율에 차이가 있었으며, 생육적온인 25℃에서는 낙화율이 28.0%였으나, 27.5℃에서는 33.5%, 30℃에서는 52.3%로 온도가 높아질수록 낙화율이 높았다. 칼슘 결핍증은 고추의 생육적온에서는 나타나지 않았으나 온도가 높아질수록 경미하게 증가하는 경향이었다. 반면 역병발병율은 생육온도에 따른 차이는 없었다. 30℃의 이상고온은 낙화율이 문제되었으나, 빈나리를 처리하면 낙화율이 감소하여 10 mg/L처리에서는 대조구에 비해 수량이 10% 향상되었다.

본 연구는 노지채소 작물인 고추를 대상으로 이상 고온조건을 인위적으로 부여하여 화분발아력을 검정 하며, 이상 고온에서의 화분발아력을 향상시킬 수 있는 방법을 강구하기 위해 수행되었다. 고추에서 화 분 발아에 최적온도는 25℃였고, 27.5℃와 30℃에서는 화분발아율이 낮았다. 화분발아에 적합한 sucrose 농도는 10~15%였고, 30% 이상의 농도에서는 화분 발아율이 감소하였다. 화분발아 배지의 적정 pH 5.5 ~6.5였고 이들 조건에서 화분발아율이 높았고, 화분관 신장도 좋았다. 화분 채취시간에 따른 화 분 발아율은 채취 시간에 따라 차이가 있었다. 전반적으로 오전 10시에 채취한 화분에서 발아율이 가장 높았고, 반면 오후에 채취한 화분일수록 화분활력이 저하되었다. 화분발아 배지에 아미노산인 asparagine과 glutamine를 첨가하면 고온에서 화분발아율이 향상되었다. 또한 폴리아민류인 putrescine 과 spermine도 화분 발아율을 향상시켰다. 전반적으로 고온에서 고추 화분발아성을 증진시킬 수 있는 첨가물질 및 처리농도는 supermine 1 mM 처리였고, 대조구에 비해 화분발아율이 15.0% 향상되었다.

A bee-vectoring method has been recently developed against greenhouse insect pests. In this study, we conducted experiments to determine if bumble bees, bombus terrestris L. could vector Bacillus thuringiensis subsp. aizawai from hives equipped with a pathogen dispenser to leaf and flower of sweet pepper. First, in laboratory, insecticidal activity of B. t. subsp. aizawai NT0423 WP (Tobagi, Dongbu Hitek Co.) against 2nd instar larva of Spodoptera litura Fabricius was evaluated to determine if the amount of B. thuringiensis deposited on the leaf and flower would be sufficient to control the tobacco cutworm. The B. t concentration of the product in this experiment was estimated as 2.8-3.1 x 109 CFU/ml. The B. t. concentration on the body of bumble bees that was captured as they exited hives with filled pathogen dispensers was 4.6 x 109 cfu/ml. At the laboratory bioassay, the mortality of tobacco cutworm was serially measured depending on the pathogen concentrations. At the cage trials, the B. t. delivered by bumble bees was detected in bees, flowers and leaves. Through the several trials, the control effect on the tobacco cutworm has been investigating. The side effect on bumble bee from the first trial was not found in this experiment.

The repellency to female Stomoxys calcitrans (L.) of 21 essential oils alone or in combination with Calophyllum inophyllum nut oil (tamanu oil) was examined using a skin bioassay. Results were compared with those following treatment with the commonly used repellent DEET (N,N-diethyl-3-methylbenzamide). As judged by the protection time (PT) to first bite at 0.5 mg cm-2, patchouli (3.67 h) was the most effective essential oil, followed by clove bud, lovage root, clove leaf and thyme white essential oils (3.50-2.12 h). Thyme red, oregano and geranium essential oils exhibited moderate protection time (PT, 1.24-1.11 h). At 0.25 mg cm-2, effective protection time of clove bud, clove leaf and lovage root essential oils was about 1 h. The protection times of DEET were 4.47 and 2.17h at 0.5 and 0.25 mg cm-2 respectively. The remarkable increase in the protection time were produced by binary mixtures of five essential oils (clove bud, clove leaf, thyme white, patchouli and savory) and tamanu oil (0.25:2.0 mg cm-2) compared with those of either the constituted essential oil, tamanu oil or DEET alone, indicating the involvement in synergy. These essential oils, tamanu oil and binary mixtures did not cause any adverse effects on the human volunteers at 0.5 mg cm-2 except savory oil. Thus binary mixtures of essential oils and tamanu oil described merit further study as potential insect repellents for protection from humans and domestic animals from biting and nuisance caused by S. calcitrans.

Growth and physiological disorders caused by abnormally low temperatures were evaluated in pepper, an important field crop in Korea. In addition, the effects of chemical treatment using glutamine was verified on minimizing the damages by low temperature. The growth of pepper plants in stem length and diameter was suppressed as the temperature decreased from 25℃, and the suppression level was the highest for plants grown for 90 days at 20℃. However, root growth was not affected by the different temperatures. The number of leaf and leaf area decreased at the temperatures below 25C, an optimum temperature for growth. Fresh weight and dry weight decreased for plants grown at 20℃. Pepper fruit yield also decreased by 11% at 20℃ in comparison to 25℃. Falling blossom rate was different depending on the growth temperature, and the rate was 27.2% at 25℃, 35.2% at 22.5℃, and 41.0% at 20℃, indicating that falling blossom rate increased as temperature decreased. Different growth temperatures did not affected on the level of symptom of calcium deficiency and Phytopathora blight. Falling blossom was severe at abnormally low temperature of 20℃, but the treatment of glutamine reduced falling blossom rate and increased the yield by 7.0% as compared to control. The optimum concentration of glutamine treatment was 10 mg/L for yields.