Henryana Yoshimoto, 1983 is a rare genus in Tetrastichinae, Eulophidae with only one species known from USA and Brazil. A species of the genus is newly recognized in South Korea. The genus has peculiar characters for a tetrastichine species. The genus can be easily distinguished from other genera by following characters: head with postgenal sulcus and with strongly swollen gena; vertex extending much higher that dorsal margin of eye; submarginal vein with usually 3 short dorsal setae that are in distinct contrast to the very long setae on marginal vein; entire body extremely elongated. Images and description of diagnostic characters are given in the present study.
It was first recorded that Elasmus japonicus Ashmead had occurred from three Polistes nests in Busan city, Wanju-gun, and Pyeongchang-gun of South Korea. The 2 females and 14 males were collected from the nest of Polistes rothneyi koreanus in Busan city (N35°17′57.71″ E129°06′33.24″), 12 females and 2 males from P. djakonovi in Wanju-gun (N35°47′35.05″ E127°15′30.48″), 18 females and 3 males from P. snelleni in Pyeongchang-gun (N37°39′7.84″ E128°35′15.81″). P. rothneyi koreanus and P. djakonovi were first recorded as new hosts.
To date, two Elasmus species, E. nephantidis and E. viridiceps, have been reported from South Korea. In this study, we provide diagnosis, description, and photos of female and photos of male of E. japonicus.
A new species of Closterocerus (Hymenoptera: Eulophidae: Entedoninae) is described from South Korea. The species is reported for the first time as an egg parasitoid of Pachynematus itoi Okutani (Hymenoptera: Tenthredinidae), of which recent sudden outbreak caused severe damage in larch forests. In total 61 species in Chalcidoidea are recorded as primary parasitoids of various tenthredinid sawflies in the Palaearctic area. However, no chalcidoid parasitoids have previously been recorded from P. itoi. The genus Closterocerus is cosmopolitan in distribution, and with an extremely wide host range from Symphyta, leaf-mining and gall-inducing insects to scale insects and plant lice. In Korea, one species of Closterocerus, three Chrysonotomyia, two Desmatocharis, one Neochrysocharis and one Teleopterus were known; most of them, except Chrysonotomyia sudoensis Paik, now are placed under Closterocerus. The new species is compared with 13 other species of Closterocerus that are known from the Far East.
Occurrence of Liriomyza trifolii and its biological control efficacy using Neochrysocharis formosa were evaluated in two eggplant cropping systems of spring and autumn cultivation. L. trifolii adults began to be attracted on a yellow sticky traps from late April and they increased from early June. A high density of L. trifolii adults was maintained from middle June to middle July. The releases of two N. formosa per plant with 3 times as weekly intervals from May 25, 2004 for spring culture resulted control effect of 90.1% in parasitism to L. trifolii in late July. The releases of two N. formosa per plant with 4 times as weekly intervals from Auguest 31, 2004 for autumn culture resulted control effect of 81.3% in population of L. trifolii with 64.4-69.9% in parasitism.
Biological control of Liriomyza trifolii (Burgess) using Diglyphus isaea (Walker) has been evaluated in tomato greenhouse, for three seasonal culture types: spring type (March-July), summer type (June-October) and autumn type (July-December). For spring type, totally 5.8 individuals/㎡ of D. isaea has been released at six times from late April, when the density of L. trifolii was about 1.0 individuals/plant. Corrected mortality of Liriomyza trifolii caused by parasitoids was 97.6% at early July, and the proportion of D. isaea was 88.9% of all parasitoids collected in the greenhouse. In the case of summer type, totally 1.8 individuals/㎡ of D. isaea has been released at five times from early July, when the density of L. trifolii was about 0.4 individuals/plant. Corrected mortality of L. trifolii caused by parasitoids was 84.4% during the whole season, but the proportion of D. isaea was very low (only 13.8%). Immigrating parasitoids such as Chrysocharis penthus were synchronized to control the leafminer in the greenhouse. For autumn type, totally 2.7 individuals/㎡ of D. isaea has been released at four times from mid September, when the density of L. trifolii was about 0.7 individuals/plant. Corrected mortality of L. trifolii caused by parasitoids was 85.7% at mid December, and the proportion of the D. isaea was 83.4%.
Experiments have been performed to investigate biological characteristics of Diglyphus isaea (Walker), an ectoparasite of Liriomyza trifolii (Burgess). At 25℃, development time of D. isaea was estimated as 1.3 days for eggs, 4.5 days for larvae and 6.3 days for pupae. Adult longevity was 25.1 days, and a female adult could lay 305.3 eggs throughout its lifetime. Number of L. trifolii parasitized or killed by the wasp was 962.2 individuals/adult. Most of all parasitized or killed larvae were identified as third instar. With 20% honeyed water as food source, half of the adults could survive 180 days at 5℃, 150 days at 10℃, and 90 days at 15℃. After storing at 10℃ with absolute honey for 30 days, 70 days and 140 days, a female adult in room temperature laid eggs 190.8 individuals, 104.0 individuals and 89.4 individuals, respectively.
아메리카잎굴파리의 내부기생봉인 Neochrysocharis formosa의 산란과 기주체액섭취 선호성을 조사하였다. N. formosa는 기주유충의 몸 뒤쪽에 대부분 산란하였다. 온도 조건에 따른 일산란수와 일기주체액섭취수를 조사한 결과 온도가 높을수록 증가하는 경향이었으며 15, 20, 25, 3에서의 산란수와 체액섭취수의 비율은 각각 0.5, 0.9, 1.0, 1.0이었다. 항온조건하에서 N. formosa의 총산란수와 기주체액섭취수는 각각 176개 188.7개이었으며 산란수와 기주체액섭취수 비율은 0.9이었고 암컷 수명은 11.8일이었다. 산란과 기주체액섭취는 주로 아메리카잎굴파리 3령유층을 선호하였다.
토마토에서 Hemiptarsenus zilahisebessi에 의한 아메리카잎굴파리의 밀도억제 효과를 실내와 온실에서 확인하였다. 토마토에서 외부기생봉류에 의한 아메리카잎굴파리의 기생율은 26~45%이었으며 이 중 H. zilahisebessi의 비율은 47~75%이었다 암컷 성충의 기주체액섭취율이 기주 1령유충과 3령유충에서 각각 40.4%와 37.9%이었으나 1령과 3령유충을 동시에 접종할 때 1령보다는 3령유충을 주로 체액섭취하였다 사육실에서 H. zilahisebessi 암컷과 기주 3령유충을 1 : 10, 1 : 20, 1 : 30으로 접종시 기주 시망율은 각각 93.1%, 92.1%, 89.8% 이었다. 토마토 포장에서 주당 암컷 3마리, 5마리를 접종한 결과 접종 4주째에 80%정도의 기생율을 나타냈으며 시간이 경과됨에 따라 아메리카잎굴파리의 유충밀도도 감소되는 경향을 보였다. 피해엽률 또한 접종 4주후부터 무접종구에 비하여 낮아지는 경향을 보였다. 그러나 접종밀도에 따른 기생을, 기주 유충 생충율 및 피해엽률의 차이는 없었다.