Temperatures experienced during larval development can exert profound effects on life-history traits expressed later during the adult stage in insects. In this study, we explored how larval rearing temperature (18, 23, and 28℃) would affect adult lifespan and reproductive performance in Drosophila melanogaster Meigen (Diptera: Drosophilidae). Larval developmental period was shortened with increasing rearing temperature. Larvae reared at colder temperatures reached the adult stage at a larger size than those reared at higher temperatures, thus conforming to the temperature-size rule. More importantly, we found strong evidence for significant effects of larval rearing temperature on both adult lifespan and early-life egg production rate. Lifespan increased progressively as the larval rearing temperature decreased from 28 to 18℃. In contrast, egg production rate was lower for flies raised at 18℃ compared to those at 23 and 28℃. These results highlight the importance of thermal environments experienced during the development in shaping life-history plasticity in insects.

Drosophila melanogaster is mainly found in fermented and rotten fruits and is tolerant to chemicals emitted during the fermentation process. Its distinctive habitat suggests an evolutionary adaptation to environmental chemicals. In order to understand the physiological adaptation of D. melanogaster to the chemicals, we treated LC20 concentration of three chemicals (acetic acid, ethanol and 2-phenylethanol) and differential expression of the female whole body transcripts were compared with control fly (no chemical treatment). Compared to control fly, 94, 137 and 59 genes were up-regulated, while 85, 184 and 166 genes were down-regulated in acetic acid, 2-phenylethanol and ethanol treated flies, respectively. According to the KEGG enrichment analysis, genes categorized in metabolic pathway, Toll/IMD signaling pathway, lysosome and autophagy were ranked in the top groups of most changed gene sets after three chemical treatment. In addition, we selected 7 genes showing different expression levels in transcriptome analysis, and investigated their expression changes in the flies exposed to various concentration of three chemicals using quantitative PCR.

Spotted wing drosophila, Drosophila suzukii, causes damage on several fruits include strawberry in Korea. D. suzukii lays egg inside fruit surface, and this behavior makes D. suzukii hard to detect, so many countries designated D. suzukii as a quarantine pest. Recently, Australian government demand methyl bromide fumigation on Korean export strawberry to prevent D. suzukii invasion. In this study, we tested methyl bromide to control D. suzukii, and also tested separate and concurrent treatments of methyl bromide to evaluate phytotoxicity on strawberry. When 40 g/m3 of methyl bromide was treated for 3 hours, all stages of D. suzukii were completely controlled. When treated separate and concurrent with cold temperature treatments of methyl bromide, there’s no specific phytotoxicity on strawberry. This result indicates that separate and concurrent treatments of methyl bromide do not cause phytotoxic effect on strawberry and methyl bromide is effective to control D. suzukii.

The Ryanodine Receptor in wild type Drosophila melanogaster has an amino acid substitution which is known to cause Chlorantraniliprole resistance in Pluteall xylostella. Even though we have reported that two Chlorantraniliprole resistant Drosophila strains have elevated total esterase activities, our report does not fully explain the significantly increased resistant ratios in two Chlorantraniliprole resistant Drosophila strains. Thus, we further analyzed alteration of reactive oxygen species and mitochondria activities in two Chlorantraniliprole resistant Drosophila strains. Our result suggested that Chlorantraniliprole resistance development in Drosophila requires alteration of various signal transduction pathways.

과일 초파리(Drosophila melanogaster)는 실온 조건에서 한 주기가 12일 전후로, 세대가 짧고 번식력이 높아 일상생활 에서 다양한 피해를 주고 있다. 초파리 방제를 위해 살충제제 형태도 개발되어 있으나 주로 주방이나 음식물 근처에 발생하므로 약제 활용보다 살충 성분을 포함하지 않은 트랩 제품을 사용하는 것이 현 소비 트렌드에 적합한 것으로 보인다. 소비량이 높은 실온 과일 중, 바나나의 초파리 유인도를 확인하고 실질적으로 초파리 트랩 제품의 효능을 검정하기 위해 특정 공간 내(1.5x1.5x1.5 m)에서 초파리 유인도를 확인하였다. 국내 및 해외에 유통 중인 초파리 트랩 제품은 단독 평가 시 바나나 반 송이를 기준으로 과일과 동등한 유인 효과를 나타냈다. 그러나 과일과 함께 평가를 진행하는 경우, 과일에 유도된 초파리에 비하여 제품이 초파리를 유인하는 효과는 현저히 낮은 것으로 확인되었다. 본 결과를 바탕으로, 향후 초파리 트랩 제품 개발 시 실생활에 대한 환경을 상정하여 시험법을 개발할 필요가 있다.

Spotted wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is an important quarantine insect pest on blueberry and strawberry exportation in Korea. Due to IPPC recommendations of replacement of methyl bromide (MB) and recent critical issue about its chronic inhalation toxicity to fumigator and related workers along with post-fumigation, alternatives to MB is urgently required. Thus, we evaluated efficacies of ethyl formate (EF) to SWD eggs using two different bioassay methods; using eggs oviposited on artificial diet and on blueberries naturally infested with SWD adults. In results, there was no differences between two bioassay methods in terms of LCT99 value of EF.

Drosophila suzukii Matsumura (Diptera: Drosophilidae) is known as a pest that has a wide host range. This study was carried out to investigate the occurrence of D. suzukii by trapping D. suzukii in Korean strawberry greenhouse and its surrounding woodland from November, 2017 to April, 2019. As a result of trap monitoring, the greatest capture was recorded in fall and secondary peak was confirmed in summer in a lower capture. It was confirmed that there was a statistically significant difference between the occurrence among inside and outside of the greenhouse and the woodland. The strawberry greenhouse cultivation area of Korea is mainly located in the plain region, whereas most of the other host plants for D. suzukii are usually grown at the ridge of the mountain or hillside. Therefore, if considering the living environment of host plant, monitoring result that showed more capture in woodland than strawberry greenhouse would be explained.

MicroRNAs (miRNAs) are a group of small non-coding RNAs consisting of 18~24 nucleotides in length. Each miRNA is expected to bind a few hundreds of putative target mRNAs, thus inhibiting their translation into protein products mostly by degradation of targets. With its biogenesis extensively deciphered, miRNAs have been implicated in a variety of biological processes, including early development and cellular metabolism. In addition, dysregulation of miRNAs and subsequent alterations in the expression of its target molecules are thought to be linked to the pathophysiology of multiple human illnesses, including cancer. To establish the miRNA-target relationships important for developing a specific disease, it is critical to validate the putative targets of each miRNA suggested by computational methods in vivo. In this review, we will first discuss oncogenic and tumor-suppressive roles of miRNAs in human cancer and introduce computational methods to predict putative targets of miRNAs. Then, the value of Drosophila melanogaster as an alternative model system will be further discussed in studying human cancer and in validating the miRNA-target relationships in vivo. Finally, we will present a possibility of applying the mammals-to-Drosophila-to-mammals approach to study the roles of miRNAs and their targets in the pathophysiology of oral cancer, an intractable type of cancer with poor prognosis and survival rate.

The fruit fly, Drosophila melanogaster, is a good model organism in various areas of biological science. Since D. melanogaster has been thought to be adapted to the chemical stress environment caused by the overripen, decay and fermented fruits, identification of the genes involved in chemical tolerance and investigation of their expression patterns are essential for better understanding of the physiological evolution in D. melanogaster. For investigation of the gene expression level, quantitative real-time PCR (qRT-PCR) can be applied to quantify gene expression level and selection of reliable reference gene(s) for normalization is an accurate step. In the present study, therefore, we validated the expression stabilities of ten candidate reference genes using three softwares (geNorm, NormFinder and BestKeeper) in D. melanogaster exposed to different concentrations of acetic acid, ethanol and 2-phenylethanol. Although three programs resulted in slightly different gene stability ranks, but overall tbp encoding TATA box binding protein was most stable gene in acetic acid and ethanol exposed fly, while nd encoding NADH dehydrogenase was the most suitable reference gene in the case of 2-phenylethanol treatment. In the comparison of three chemical treatment condition, nd was also suggested to be most optimal reference gene. In addition, optimal number of reference gene for accurate normalization was calculated by geNorm pairwise analysis, and selection of multiple reference genes was suggested to be better for target gene normalization method than use of a single reference gene.

Different laboratory strains of Drosophila melanogaster are reported to differ considerably in their physiology, behavior, and life-histories, due to their adaptations to different laboratory conditions. Recent advances in insect aging research have highlighted the importance of protein:carbohydrate (P:C) balance as a key dietary determinant of lifespan and other components of fitness, but it remains unexplored whether P:C balance affects the fitness-related traits of D. melanogaster in a strain-specific manner. The purpose of this study was to compare the life-history consequences of six different laboratory strains of D. melanogaster (three Canton-S substrains, w1118, yw, and Oregon-R) allocated to four synthetic diets differing in P:C ratio (1:16, 1:4, 1:1, or 4:1). Five components of fitness (lifespan, fecundity, larval viability, development time, and body mass) were recorded from flies maintained at 25oC under L:D 12:12 photoperiod. All strains exhibited qualitatively similar responses to dietary P:C balance, with the increase in P:C ratio being associated with shortened lifespan and improved egg production. In all strains, fly larvae confined to P:C 1:16 suffered high mortality, retarded growth, and reduced body size. As indicated by significant diet×strain interactions for all measured fitness components, the magnitude of such diet effect varied among different laboratory strains in D. melanogaster. Possible explanations for such strain differences are discussed.

Diet and temperature are the two most critical environmental factors affecting life-history traits in insects, but the combined effects of these factors have been rarely investigated. In this study, various life-history traits were recorded from adult and larval Drosophila melanogaster fed on one of eight synthetic diets differing in protein:carbohydrate ratio (P:C=1:16, 1:8, 1:4, 1:2, 1:1, 2:1, 4:1, or 8:1) under one of six ambient temperatures (13, 18, 23, 28, 31, or 33oC). The patterns of adult and larval life-history traits expressed across 48 diet-by-temperature combinations were visualized using thin-plate spline technique and the presence of any significant linear, quadratic, and correlational effects of diet and temperature on trait expressions was analyzed using a second-order polynomial multiple regression. Life-history traits exhibited qualitatively different responses to variations in both diet and temperature, with the maximal expression of each trait being achieved at a completely divergent region of the diet-temperature fitness landscape. In adult females, for example, lifespan was maximized at P:C 1:16 under 13oC, but fecundity was maximized at P:C 4:1 under 28oC. These results provide empirical support for the emerging notion that environmental factors, such as diet and temperature, can mediate life-history trade-offs in insects.

Spotted wing drosophila, Drosophila suzukii, is an important pest of grape and strawberry because it lays egg inside fruit by damaging fruit surface. Recently, D. suzukii has been widely spreaded and causes several problems, so many countries include Australia designated D. suzukii as an important quarantine pest. Because of this, Korean farmers have trouble to export strawberry. In this study, we tested ethyl formate and phosphine to control D. suzukii, and also tested concurrent treatment of ethyl formate and phosphine to reduce phytotoxicity and enhance efficacy. When treated 35g/m3 of ethyl formate for 4 hours, mortality of egg, larvae, pupae and adult stages of D. suzukii was 22.2%, 21.1%, 19.2% and 28.3%, respectively. When treated 1g/m3 of phosphine for 24 hours, all stages of D. suzukii was completely controlled, but caused phytotoxic effect on strawberry. When treated with 35g/m3 of ethyl formate and 1g/m3 of phosphine concurrently for 4 hours, efficacy has been increased with less phytotoxicity than separate treatment. This result indicates that concurrent treatment enhanced efficacy with less phytotoxicity.

In order to accumulate the ecological information of Drosophila suzukii for export negotiations of domestic strawberry, we weekly monitored occurrence of D. suzukii at three strawberry fields located in Gok-seong, Dam-yang and Hwa-sun using the best combination of trap and attractant from November 2017 to May 2018, the period of strawberry production. Monitoring was carried out at three sites (a hill located 150 meter distant to greenhouse, outside greenhouse and inside greenhouse) in Gok-seong. Drosophil suzukii was trapped at three short periods from November to the beginning of December, from the end of December to the beginning of January, and from April in a hill. At outside greenhouse, D. suzukii was trapped at two short periods from November to the early December and the beginning of May. In inside greenhouse, it occurred once after May 24th. Gok-seong data can be summarized as more occurrence for longer period as the distance to greenhouse increases. Dam-yang occurred once in a short period inside greenhouse and hill, respectively on May. In case of Hwa-sun, D. suzukii did not trapped in whole trapping sites during trapping period, except for the surrounding grape and peach cultivation areas at the end of November. Summarized, no occurrence periods are from November 20th, 2017 to May 14th, 2018 inside greenhouse; from December 11th, 2017 to May 3rd, 2018 outside greenhouse; and from January 8th, 2018 to April 12th, 2018 on a hill. In connection with strawberry culture, the D. suzukii tends to occur at the beginning and the end of the strawberry production period. We expect this result can serve as a helpful data for export negotiation for quarantine.

This study was carried out to confirm the parasitic and developmental features of A. japonica and D. suzkii was used as a parasitic natural enemy. A. japonica attacked the D. suzukii larvae and the emergence of adults were observed from D. suzukii pupae. Black spots were observed in parasitized D. suzukii larvae. Mortality of parasitized larvae, rate of parasitic and developmental feature were investigated according to developmental stages of host, D. suzukii. Mortality and rate of parasitic of D. suzukii larvae were the highest when second instar larvae were attacked. Developmental period of parasitized D. suzukii larvae showed differences to developmental stages, but there was no significant difference in developmental stage of pupal period.

The spotted wing drosophila(Drosophila suzukii)is one of the serious fruit pest that has a wide range of fruit crops like blueberries, cherries and grapes. It came up the larvae cause dagmage by feeding on the pulp inside fruits and berries and spotted wing drosophila also has a adversely affect export to Austrailia and New zealand as a quarantine pest. This study conduct to survey occurrence of drosophila spp. from 2016 to 2018 on harvest period of grapevine in vinyard of Okcheon ,Yeongdong and fruit packing place for export to New zealand and USA. Vinegar and wine mixture was used to attract fruits flies. We also investigated to what color is the best stimulus to catch a vinegar flies. Our result shows that significant differences were observed in total flies trapped in red and black colors. This study will contribute to future research for monitoring and control drosophilid flies.

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.

Spotted wing drosophila (SWD), Drosophila suzukii, is a serious pest of berry fruits and grapes in East-Asia and USA. SWD female oviposits eggs into the skin of ripening fruits, and the larvae dig a burrow inside the fruits. Secondary infestation by other insects and pathogens to the oviposition spots cause substantial economic damages worldwide. SWD has recently been spreading to Europe and USA, and it is becoming a global threat in terms of biosecurity. A quite useful paper has been published in Journal of Chemical Ecology in the most recent issue (Vol. 44, #10) which is titled ‘Advances in the chemical ecology of the spotted wing drosophila (Drosophila suzukii) and its applications’ written by Cloona et al. This article introduces chemical constituents from many odor sources such as fermentation, yeast, fruit, and leaf sources, and commercial lures and traps developed using these compounds. Authors said that the current food-based lures and trap technologies are not expected to be specific to SWD and thus capture large numbers of non-target drosophilids. Attractive and aversive compounds are being evaluated for monitoring, mass trapping, and for the development of attract-and-kill and push-pull techniques to manage SWD populations. (Supported by PJ011756022018, RDA)