해충의 예찰 없이 작물 정식 초기에 천적을 먼저 적용할 수 있는 천적-서식처 혼합적용(Natural Enemy in First; NEF)기법의 방제효과를 확인하였다. 시설 딸기에서 조사 12주차에 NEF처리구와 천적 단독 처리구에서 친환경자재 처리구 대비 각 83%, 70%의 점박이응애 밀도 억제효과를 확인할 수 있었다. 또한 예찰 없이 작물 정식 초기에 NEF를 적용한 처리구에서 천적 단독 처리구보다 3배 이상의 높은 천적 밀도를 확인하였다.

본 연구는 감귤의 해충인 귤굴나방(Phyllocnistis citrella Stainton) 의 포식 기생자 천적의 종류와 기생률을 조사하기 위하여 수행하였다. 2013～2014 제주 감귤원에서 발견된 귤굴나방 포식 기생자 천적은 좀벌상과에 속한 총 7종을 발견되었다. 그 중 좀벌과에 속한 Sympiesis striatipes가 73%, Quadrastichus sp.가 22%로 우점하였다. 나머지 종은 Neochrysocharis sp., Ageniaspis sp., Pnigalio sp., Holcopelte sp., Trichomalopsis sp. (Pteromalidae) 등이었다. 천적의 평균 기생률은 관행방제 과원에서 10.7%, 무농약 과원에서는 32.2% 이었다.

Biological control is becoming an increasingly important part of integrated pest management programs in Korea. For this reason, effective and sustainable insect pest management is a priority for many growers. And the success of biological control depends upon the use of the economical methods such as a combination of proper natural enemies and plants (banker, habitat, trap, companion, etc.). For the last nine years, we have developed simple and reliable new habitat plants system with natural enemies, and named it『Natural Enemy in First Method』that we are introducing here. Our goal was to better understand the potential for effective use of beneficial insects and their habitat plants for the management of thrips, spider mites, and aphids in greenhouses. This approach is being developed to improve biological control in various crops in Korea.

Minute pirate bug, Orius minutus (L.), is a native predator of many small insects such as aphid, scale, thrips, and mites in Korea. Seven chemical pesticides with lower ecotoxicity being used to control those pests were evaluated for acute toxicity against adult female O. minutus in glass scintillation vial assay. In the 1st batch experiment with three pesticides, flonicamid and buprofezin were least toxic whereas in the 2nd batch experiment with four pesticides spirotetramat and spiromesifen showed least toxicity. The corrected mortality of buprofezin and flonicamid became 100% on 55 and 47 h of exposure in 1st batch and that of spirotetramat and spiromesifen became 100% on 75 and 71 h of exposure in 2nd batch, respectively. In conclusion, flonicamid, buprofezin, spirotetramat, and spiromesifen was least toxic among the seven pesticides tested against adult female of O. minutus.

Trialeurodes vaporariorum is an important greenhouse pest worldwide. We compared the efficacy of a new strain of Beauveria bassiana (ARP14) with a commercialized one (GHA) against 2nd instar and 4th instar of T. vaporarioum. Those nymphs were exposed to the fungus in a concentration of 1×108 conidia/mL by leaf dipping method. There was no difference in mycosis rates at any observation time between the two strains in both 2nd (100.0%) and 4th instar (100.0%). Lethal median time (LT50) wasn't different between the two strains in both 2nd and 4th instar. In conclusion, the new B. bassiana strain (ARP14) would be a good candidate of mycoinsecticide for whitefly management.

본 연구는 지속가능한 유기농업의 실천을 위하여 국내 작부체계와 농업환경에 적합한 한국형 현장적용 기법을 구축하고자 수행하였다. 본 연구의 기본 개념은‘Natural Enemy in First (NE가 먼저)’로 해충 발생시기의 예찰 없이 주 작물을 정식함과 동시에 천적과 선발한 보조식물을 혼합 적용해서 해충발생 이전에 천적을 포장에 먼저 정착시키는 생물적 방제기법이다. 미끌애꽃노린재 서식처로 Portulaca sp.를, 콜레마니진디벌 서식처로 옥수수를 선발하여 시설 토마토에서 방제효과를 확인하였다. 미끌애꽃노린재 단독처리와 천적 서식처(Portulaca sp.) 혼합처리구에서 관행방제 처리구(약제처리)대비, 각각 82%, 73%의 총채벌레 밀도 억제 효과를 확인할 수 있었다. 진딧물의 경우, 모든 처리구에서 3줄기 당 평균 0.5마리 이하의 낮은 밀도를 유지하였다.

Grapholita molesta (Busck) is a major pest of stone fruits. Immature fruits of apricot and plum are well known food source during early summer for G. molesta, but those immature fruits have rarely been evaluated. Thus, we assessed biological and behavioral attributes of G. molesta when provided with immature fruits of apricot and plum in laboratory. The initial response rate (when larva reached to the center from release point in Y-tube olfactometer) of first instar was not different between apricot (70.0%) and plum (60.0%) of which sugar content was more on plum (5.92 brix in apricot and 7.30 brix in plum). However, pupal weight was less in apricot (7.5 mg) than in plum (11.4 mg), and this might be affected by difference in hardness of the fruits (17.2 N on apricot and 13.3 N on plum). The preoviposition period was also longer in apricot (6.3 d) than plum (3.6 d), and fecundity was lower on apricot (64.5) than on plum (135.0). Therefore immature plum fruit would be better food source for G. molesta than apricot during early summer.

Orius minutus (L.) (Hemiptera: Anthocotidae) is a native predator of mites, thrips, and aphids whereas Orius laevigatus (Fieber) is a commercialized predator were assessed against O. metasequiae in laboratory and field. Adult females of both predator predated equally O. metasequiae adult after 3 hours of exposure in the laboratory on no choice assay. Orius minutus and O. laevigatus released with Portulaca oleracea plant in Metasequouia glyptostroboides tree reduced O. metasequiae population equally by 48.3% and 42.7% on first week after exposure. But O. laevigatus released without P. oleracea plant reduced 52.4% on the first week whereas O. minutus reduced only 6.2% of O. metasequiae population. We found only 3 O. minutus eggs on M. glyptostroboides leaves where 22 O. laevigatus eggs were found when treated without P. oleracea plant. Orius laevigatus laid 160.0 eggs on P. oleracea plant where as O. minutus laid only 25.7 eggs per plant. These result demonstrate that O. laevigatus can be applied for conservation biological control to suppress O. metasequiae population.

본 연구는 지속가능한 유기농업의 실천을 위하여 국내 작부체계와 농업환경에 적합한 한국형 현장적용 기법을 구축하고자 수행하였다. 본 연구의 기본 개념은 ‘Natural Enemy in First (NE가 먼저)’로 해충발생시기의 예찰 없이 주 작물을 정식함과 동시에 천적과 보조식물을 혼합 적용해서 해충발생 이전에 천적을 포장에 먼저 정착시키는 생물적 방제기법이다. 시설재배 딸기에서 칠레이리응애, 사막이리응애, 콜레마니진디벌과 천적의 서식처 3종을 주 작물의 정식과 동시에 적용한 결과, 관행방제구에 비해 80%이상의 해충 밀도억제효과를, 천적 단독처리구에 비해 3배 이상의 높은 천적의 밀도를 확인할 수 있었다. 또한 포장 환경과 천적의 방사방법에 구애받지 않고 천적의 해충 방제효과를 극대화시킬 수 있는 라인을 적용한 결과, 약제와 천적 혼합처리구에서 라인을 적용하지 않은 처리구에 비해 해충의 밀도가 급격히 감소하고, 천적의 밀도는 2배 이상 높게 유지되는 것을 확인할 수 있었다.

Bemisia tabaci (Gennadius) is an important polyphagous pest and transmits plant pathogenic virus to numerous agriculture crops. We compared the efficacy of Beauveria bassiana ARP14 strain with commercialized GHA strain against 2nd instar and 4th instar of B. tabaci. The nymphs were exposed in 1×108 conidia/mL by dipping method. There was no difference in mycosis rate between the two strains in both 2nd and 4th instar. After 72 h, mycosis rate of 2nd instar was 100.0% in B. bassiana ARP14 strain followed by 97.4% in B. bassiana GHA strain. In 4th instar, B. bassiana ARP14 strain caused 100.0% while B. bassiana GHA strain caused 93.3%.

Drosophila suzukii (Matsumura) is one of the most destructive pest of thin-skinned fruits such as blueberry, strawberry, raspberry, and cherry. We tested effect of fruit damage on the infestation of D. suzukii by using partially peeled blueberry fruits in assays of behavioral choice and development. In choice test, D. suzukii preferred partially peeled blueberry fruit than normal. But in development test, we did not found difference in adult emergence rate between normal and partially peeled blueberry fruit.

We evaluated three previously known repellents of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), i.e., carvacrol, cis-jasmone, and methyl jasmonate for the attraction of commercialized predators, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae), and native predator, O. minutus (L.), in Y-tube olfactometer. Higher proportion of O. laevigatus (mated unfed adult females) moved to the arm of methyl jasmonate or cis-jasmone than the arm of clean air. However, O. minutus did not show any significant preference to the chemicals tested. These results suggest that, among the tested chemicals, methyl jasmonate or cis-jasmone would be a good attractant for O. laevigatus.

To find best humidity condition for the use of Beauveria ARP14 against Grapholita molesta (Busck), first instar of G. molesta was treated with three conidial concentrations (1×107, 1×108, and 1×109 conidia/ml) in three different relative humidities (RH; 55, 75, and 95%). Mortality varied depending on concentration and humidity. Mortality in 95% RH was 1.5 and 2.7 times higher than 75 and 52% humidity at 1×109 conidia/ml and 16 hours after the exposure. However, the mycosis rates after 14 days were all not different among the treatments. In conclusion B. bassiana ARP14 could be most effective when applied higher at RH condition.

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is an important pest of horticultural and agricultural crops worldwide. The repeated use of chemical insecticides resulted in the development of insecticide resistance. We evaluated response of F. occidentalis to three synthetic herbivore-induced plant volatiles (HIPVs), methyl salicylate, methyl anthranilate, and nonanal known as attractants of thrips’ natural enemy, in Y-tube olfactometer. Mated fed adult females of F. occidentalis showed lowest response rate to methyl salicylate than methyl anthranilate, and nonanal. These results show that methyl salicylate may act as repellent to F. occidentalis, and can be used as a component of push-pull strategies for the management of F. occidentalis.

Riptortus pedestris (F.) (Hemiptera: Alydidae) is one of major pests of fruit trees and cause economic injury by piercing and sucking fruits. Although growers usually depend on synthetic insecticides to control this pest, demand for using environment-friendly insecticide is increasing. As, in our previous studies, extracts of Nicotiana tabacum L. and Allium sativum L. was effective against Grapholita molesta (Busck), we evaluated them also on the different life stages (< 24 h) of R. pedestris at 2 mg/ml in laboratory by glass scintillation vial assay. The toxicity of N. tabacum, A. sativum, and their mixture to second instar nymph was not different compared to methanol control. But, N. tabacum was more toxic to fourth instar nymph with LT50 of 59.0 h. In adult stage, the toxicity of both N. tabacum and A. sativum was higher compared to the mixture and methanol control. Thus, N. tabacum could be potential botanical insecticide against R. pedestris.

A native minute pirate bug, Orius minutus (L.), is a generalist predator of small insect pests such as thrips, mites, scale, etc. By comparing with Tetranychus urticae Koch in choice test, we evaluated the prey preference by counting number of prey killed for 4 hours on Amphitetranychus vienensis (Zacher), Frankliniella intonsa (Trybom), Stephanitis pyrioides Scott, and Eriococcus sp. nymph. Among them F. intonsa was the only one killed more than T. urticae by O. minutus. In no choice test, mean number of prey killed was highest in F. intonsa (7.2) followed by T. urticae (3.0), A. vienensis (2.4), Eriococcus sp. (2.0), and S. pyrioides (0.0) for 4 hours. This experiment shows that O. minutus could be a good predator for F. intonsa and T. urticae.