The two-spotted spider mite Tetranychus urticae is a worldwide crop pest with a high insecticide resistance and an extensive host range. The aim of the present study was to evaluate the effect of PaeciPora®, which was formulated from the aerial conidia of an entomopathogenic fungus Paecilomyces lilacinus strain HY-4, to control T. urticae in cucumber field. In the field study, conidia of P. lilacinus HY-4 and a chemical acaricide azocyclotin were investigated for their control of the adult females of T. urticae. The strain produced a mortality of 56.0% on day 3 and 63.6% on day 7 post-treatment respectively at 1×107 conidia/mL, and no evidence of a mortality benefit was seen in the control group. Additionally, in the pesticide injury test, no agrochemical damage was found in hot pepper, watermelon, Chinese cabbage, oriental melon or strawberry by spraying PaeciPora® on them. The results indicated the possibility of the use of P. lilacinus HY-4 as a microbiological control agent against T. urticae in the Integrated Pest Management program.

An entomopathogenic filamentous fungus, Paecilomyces lilacinus strain HY-4, has a great potential as a promising bio-pesticide due to its superior pathogenicity against Adoretus tenuimaculatus and Tetranychus urticae. When the fungal strain infects host cuticle, it secrets a combination of hydrolytic enzymes including chitinase to solubilize the cuticle. Thus, we investigated effects of different carbon and nitrogen sources on the production of a chitinase from P. lilacinus strain HY-4. The organism produced an extracellular chitinase at a relatively high level (45.4 mU/ml) when cultivated for 5 days on a medium supplemented with insect pupa (0.5%) and colloidal chitin (1%), which was prepared by treating chitin from crab shells (Sigma-Aldrich Co. Ltd.) with 12 N HCl solution. However, extracellular secretion of chitinase by strain HY-4 was found to be significantly repressed in the presence of glucose (1%).

Paecilomyces lilacinus HY-4 is an entomopathogenic filamentous fungus that has exhibited insecticidal activity against Adoretus tenuimaculatus and Tetranychus urticae. Strain HY-4 has attracted a great deal of industrial concerns because this organism can be applicable as a potent bio-pesticide. In this study, we developed an optimal diphasic fermentation technique for HY-4 conidial production. The substrate prescription which was made up of hulls or brans was obtained by screening of agricultural products, and the conidial production could reach a minimum of 2.5×1010 conidia/g after solid fermentation for 12 days in a given condition. It was interesting to note that strain HY-4 was propitious to sporulate more efficiently and productively in liquid fermentation process in the presence of insect pupa. For the industrial application of the HY-4 spores, their pH and thermal stabilities were evaluated on SDA agar plate as well. Additionally, the germination rate of HY-4 spores was still above 90% even when they were stored for 5 months at ambient temperature.

선충기생(線蟲寄生)곰팡이(Paecilomyces lilacinus)를 이용(利用)한 당근뿌리혹선충(線蟲)(Meloidogyne hapla)의 생물학적방제(生物學的防除) 가능성(可能性)을 규명(糾明)하기 위(爲)하여 Telone II, Telone C-17, Dowfume MC-II 등(等) 3종(種)의 토양훈증제(土壤燻蒸劑)와 함께 밀양(密陽)의 시설원예포장(施設園藝圃場)에 처리(處理)하여 상치와 고추를 전후작실험(前後作實驗)한 결과(結果), 뿌리혹선충(線蟲) 밀도(密度)는 처리후(處理後) 25일(日)에 P.lilacinus 처리구(處理區)는 22마리, Telone II, Telone C-17, Dowfume MC-II구(區)는 각각(各各) 2, 24, 0마리로 무처리구(無處理區)의 685마리에 비(比)해 현저(顯著)히 낮았으며 처리후(處理後) 350일(日)에는 P. lilacinus, Telone II, Telone C-17, Dowfume MC-II구(區) 각각(各各) 2,917, 173, 180, 361마리로 무처리구(無處理區) 8,635마리에 비(比)해 각각(各各) 66%, 98%, 98%, 96%의 방제효과가 있었다. 전작물(前作物)인 상치는 P.lilacinus, Telone II, TeloneC-17, Dowfume MC-II구(區)에서 각각(各各) 49, 43, 31, 109% 증수(增穗)되었다. 고추의 생체중(生體重)과 초장(草長)은 훈증제(燻蒸劑) 처리구(處理區)에서는 모두 높게 나타났으나 P. liacinus처리구(處理區)는 무처리구(無處理區)에 비(比)하여 차이(差異)가 없었다.