Seasonal occurrence of Grapholita dimorpha, new insect pest in apple orchards

KyungHee Choi,Dong-Hyuk Lee,Yugi Min 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.10

Major fruit moths in commercial apple orchards are known as Carposina sasakii and Grapholita molesta. In addition, recently G. molesta is dominant species compared with C. sasakii in apple orcahrds. In case of Japan, the fruit damage occurred a lot unexpectedly in apple orchards of the northern Nagano during the harvesting season in 2004. As the result of identifying after emerging the larvae collected from the damaged fruit, Grapholita dimorpha was found out. The morphology of Grapholita dimorpha are almost similar to that of Grapholita molesta, and the shape of the damaged fruits was too similar to distinguish them. We installed sex pheromone traps of Grapholita dimorpha in apple orchards to check if there were Grapholita dimorpha in Korean apple orchards and to survey seasonal occurrence. As a result of survey by installing sex pheromone traps of G. dimorpha at one apple orchard in Uiseong-Gun and Gunwi-Gun area respectively, we could find high population density of G. dimorpha in sex pheromone traps. The peak of the first generation of G. dimorpha was dated in early May. The first generation occurrence of G. molesta in sex pheromone traps was lower than that of Grapholita molesta. However, it had higher occurrence of sex pheromone traps than G. molesta since it increased after mid and late July. Also, as a result of identifying in G. molesta traps, there were 673 G. molesta and 8 G. dimorpha. As a result of survey of 1,102 G. dimorpha in its sex pheromone traps, there were 1,099 G. dimorphaand 3 G. molesta.

The Phenology and degree-day Model of Grapholita molesta (Tortricidae: Lepidoptera) in Apple Orchards

JeongJoon Ahn,Lalit Prasad Sah,Hyangmi Kim,Soonwon Lee,Chuleui Jung 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.04

The study was conducted to investigate the phenology of G. molesta adult, and to develop and validate the degree-day model of G. molesta in apple orchards. It was known that G. molesta is a multi-voltine insect depending on temperature and geographic location. G. molesta damage to many economically important fruit trees such as apple and pear. Data collection was carried out in five apple-growing location (Chungju, Bonghwa, Andong, Uiseong, and Geochang) and at least three commercial orchards of each location was selected for collecting data in 2011 and 2012. The commercial pheromone monitoring trap (GreenAgroTech) was used to investigate the flight phenology of G. molesta. The relationships between degree-day accumulated above the low temperature threshold and cumulative proportion of accumulated G. molesta caught per generation were used to predict the phenology of G. molesta. The phenology of G. molesta per generation was analyzed by Weibull 2-parameter function. The generation of G. molesta was depending on local environmental conditions, specially temperature. The first flight of G. molesta adult in Chungju was later than other places. The average number of G. molesta caught in Uiseong was significanlty decreased from 2011 to 2012. The occurrence of G. molesta adult was explained well by degree-day model using Weibull 2 parameter function. The developed model system could be applied to manage G. molesta population in apple orchards.

Spring emergence pattern and its forecasting of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) in stone fruit orchards

JeongJoon Ahn,Jiwon Kim,Soon Won Lee,Chuleui Jung 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

The study was conducted to investigate the spring emergence pattern of G. molesta and to forecast the emerging time of overwintering G. molesta on tree fruit orchards. G. molesta is one of major insect pests on fruit trees in Korea. The host range of G. molesta includes many economically important tree fruit plants such as apple, pear, peach and plum. The overwintering G. molesta emerge from late March as an adult lay eggs on the shoot of peach or fruits of apple, plum and peach. Therefore, it is important to understand the biofix and to forecast the emerging peak period of overwintering G. molesta for establishing the pest management strategy. The pheromone trap of G. molesta has been utilized to monitor the population density in apple orchard. The commercial stick trap (GreenAgroTech) and lure (Z8-12:AC, E8-12:Ac, Z8-12:OH, 95:5:1) was set to monitor the population density of G. molesta on each place (56 different fruit orchards). The record of temperature was received from meteorological center close to monitoring orchards. The parameters for forecasting the emerging time and peak period of overwintering G. molesta were calculated from the results of Yang et al (1997 and 2001). Although the estimated biofix of G. molesta was not fitted well, the peak period of overwintering G. molesta was explained by linear regression model. The spring emergence pattern of G. molesta was presented differently related to host plant and geographical location. The peak period of G. molesta at the same mornitoring county was presented differently according to host plant. The synchronization between host plant and G. molesta may be studied to figure out the spring emerging time of overwintering G. molesta.

Model of Grapholita molesta spring emergence in pear orchards based on statistical information criteria

Ahn, Jeong Joon,Yang, Chang Yeol,Jung, Chuleui 한국응용곤충학회 2012 Journal of Asia-Pacific Entomology Vol. No.

The oriental fruit moth, Grapholita molesta, is becoming a large threat to Korean pear production. Timely management of the egg and early larval stages from the spring emergence is critical to reduce the G. molesta population during the pear growing season. A model was developed to precisely predict the spring occurrence of G. molesta adults as a function of accumulated degree-days. The model was validated with male moth caught in sex pheromone-baited traps placed in pear orchards at two major pear production regions (Icheon and Naju) of Korea in 2010. We applied nine distribution models to describe the cumulative proportions of G. molesta males caught relative to accumulated degree-days. The observed phenology of the G. molesta spring population was well described by the nine models. The predicted dates for the cumulative 50% male moth catches were within a 5 day period. Based on statistical information criteria (Akaike's and Bayes-Schwartz information criteria), we recommend the sigmoid function referred by Brown and Mayer, because of its ease of use and meaningfulness; the parameter "b" denotes the degree-day accumulation at 50% moth emergence. The G. molesta spring emergence model could be applied to determine optimal chemical treatment timing for controlling G. molesta in fruit tree orchards and further help to develop a full-cycle phenology model of G. molesta.

Development of The Seasonal Phenology Model of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) in Pear Orchards and Application to Other Fruit Orchards

Jeong Joon Ahn,Lalit Prasad Sah,Chuleui Jung 한국응용곤충학회 2012 한국응용곤충학회 학술대회논문집 Vol.2012 No.05

The study was conducted to develop the full seasonal phenology model of G. molesta in pear orchard. G. molesta is a multi-voltine insect with four to five generations per year depending on temperature, food resources and geographic location. For precise model construction, information on temperature-dependent development and the distribution of developmental completion of overwinteirng and summer G. molesta population was used. The performance of model was based on single cohort population of G. molesta. The validation of model system was performed with the male moth catches in sex pheromone-baited traps of pear orchards in four pear production regions (Anseong, Icheon, Naju and Ulju), three apple production regions (Andong, Chungju and Geochang), and four plum orchards (Uiseong) of Korea in 2010 and 2011, respectively. The observed phenology of seasonal population of G. molesta was explained by our model system. The predicted dates for the cumulative 50% male moth catches per each generation were within seven days variation per each generation. The precise predictive model of G. molesta adult occurrence could help decision making and enhancing control efficacy.

Simultaneous mating disruption of two <i>Grapholita</i> species in apple orchards

Kim, Kyusoon,Park, Changgyu,Kim, Yonggyun 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.2 No.1

<P><B>Abstract</B></P> <P>Two <I>Grapholita</I> species (<I>G. molesta</I> and <I>G. dimorpha</I>) cause serious losses in apple production by means of direct fruit damage and destruction. These two congeners occurred at similar seasons in the same orchards. Furthermore, the two species occurred in similar population sizes in apple orchards, though <I>G. molesta</I> occurred much more in total occurrence density than did <I>G. dimorpha</I> in a pear orchard. The two species share two major sex pheromone components, (<I>Z</I>)-8-dodecenyl acetate (<I>Z</I>8-12:Ac) and (<I>E</I>)-8-dodecenyl acetate (<I>E</I>8-12:Ac), but differ with regard to the relative mixture ratio necessary to create conditions of maximal attraction. To develop a simultaneous mating disruption (SMD), a mass ratio of 95:5 of <I>Z</I>8-12:Ac and <I>E</I>8-12:Ac was selected due to its high cross-calling activity and subsequent high mating disruption against both species. When the mixture was applied to orchards, it resulted in significant mating disruption against both species. However, mating disruption efficacy was slightly higher in <I>G. dimorpha</I> than in <I>G. molesta</I>. Application dose and dispenser type affected efficacy duration of SMD. In addition, the high density occurrence of <I>G. molesta</I> significantly reduced the SMD efficacy. Using a wax-type of dispenser, an application of SMD in 100 g per hectare dispersed in early spring recorded >90% mating disruption efficacy through the entire growing season against both <I>Grapholita</I> species.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two <I>Grapholita</I> species share major sex pheromone components. </LI> <LI> Simultaneous mating disruption (SMD) has been devised using cross-attracting sex pheromone composition. </LI> <LI> SMD application resulted in >90% mating disruption against both species. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Simultaneous mating disruption of two Grapholita species in apple orchards

김규순,박창규,김용균 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.4

Two Grapholita species (G. molesta and G. dimorpha) cause serious losses in apple production by means of direct fruit damage and destruction. These two congeners occurred at similar seasons in the same orchards. Furthermore, the two species occurred in similar population sizes in apple orchards, though G. molesta occurred much more in total occurrence density than did G. dimorpha in a pear orchard. The two species share two major sex pheromone components, (Z)-8-dodecenyl acetate (Z8-12:Ac) and (E)-8-dodecenyl acetate (E8-12:Ac), but differ with regard to the relative mixture ratio necessary to create conditions of maximal attraction. To develop a simultaneous mating disruption (SMD), a mass ratio of 95:5 of Z8-12:Ac and E8-12:Ac was selected due to its high cross-calling activity and subsequent high mating disruption against both species. When the mixture was applied to orchards, it resulted in significant mating disruption against both species. However, mating disruption efficacy was slightly higher in G. dimorpha than in G. molesta. Application dose and dispenser type affected efficacy duration of SMD. In addition, the high density occurrence of G. molesta significantly reduced the SMD efficacy. Using a wax-type of dispenser, an application of SMD in 100 g per hectare dispersed in early spring recorded > 90% mating disruption efficacy through the entire growing season against both Grapholita species.

Effects of different sex pheromone compositions and host plants on the mating behavior of two Grapholita species

정충렬,정진교,김용균 한국응용곤충학회 2013 Journal of Asia-Pacific Entomology Vol.16 No.4

The two congener species Grapholita molesta and Grapholita dimorpha share two major sex pheromone components:cis-8-dodecenyl acetate (Z8-12Ac) and trans-8-dodecenyl acetate (E8-12Ac). In fact, commercial sex pheromone lures composed of only these two major components attract the males of both species. In this study, we aimed to determine the reproductive isolation components of these two species by analyzing the effects of the minor sex pheromone components and host plants. First, different ratios of the two major sex pheromone components were greatly favored by either male species. Sex pheromone gland extracts of G. dimorpha contained a lesser proportion of Z8-12Ac than that of G. molesta. In the three (apple, pear, and peach) orchards investigated in this study, a larger number of G. molesta males were attracted to the 95:5 pheromone mixture (Z8-12Ac and E8-12Ac, respectively), while a larger number of G. dimorpha maleswere attracted to the 85:15 mixture. Second,therewas a significant variation inmale attractions in different host plants. G. molesta malesweremore attracted to the sex pheromone lure in the apple orchards than that in the pear and peach orchards. In contrast, G. dimorpha males were more attracted to the lures in the pear and peach orchards than that in the apple orchard. Third, the minor sex pheromone components were important for reproductive isolation. Among the four minor components tested, addition of (Z)-8-dodecenol (Z8-12OH) to the major sex pheromone components significantly suppressed male attraction in G. dimorpha and slightly elevatedmale attraction in G. molesta. The discriminating effect of Z8-12OH was further validated using male electroantennogram analysis. These results suggest that reproductive isolation between two congeners can be achieved by variations in the minor sex pheromone components and in the host plants, as well as by changes in the ratio of the two major components.

Impact of temperature change on the spring emergence of Grapholita molesta (Busck) (Lepidoptera: Tortricidae)

Jeong Joon Ahn,Kyoung San Choi,Sang Wook Kho 한국응용곤충학회 2016 한국응용곤충학회 학술대회논문집 Vol.2016 No.10

The spring emergence of individual insect would be influenced by surface temperature during winter season. The oriental fruit moth, Grapholita molesta, overwinter as a full-grown larva within spherical and compactly woven cocoons in the clefts of tree bark. It consume new shoots early and fruits later in the growing season. To estimate the spring emergence of G. molesta, we used the lower developmental threshold (8.14°C) and thermal constant (279.3) for overwintering G. molesta. The climate data were obtained from the web site of the Korea Meterological Administration(KMA) from 1975 to 2015 at 61 locations, respectively. The spring emergence of G. molesta was changed depending on ambient temperature of each year.

Evolution of two Grapholita sibling species in orchards

Chung Ryul Jung,Yonggyun Kim 한국응용곤충학회 2012 한국응용곤충학회 학술대회논문집 Vol.2012 No.10

The oriental fruit moth (Grapholita molesta) and the plum fruit moth (G. dimorpha) are internal feeders of stone and pome fruits and highly similar in morphological characters and feeding behaviors. These two species share their two main sex pheromone components, Z8-dodecenyl acetate(Z8-12Ac) and E8-dodecenyl acetate(E8-12Ac) although pheromone compositions are different. But, two males of these species were cross-attracted to G. molesta and G. dimorpha pheromone trap, respectively. Their host plants are also very similar in Rosaceae including apples, plums, paches, etc. These sympatric and similar pheromone ratios and biological characters suggest their recent speciation divergence. To determine genetic origin of this speciation, were analysed transcriptomes associated in sex pheromone biosynthesis in these sibling species. Total RNAs were collected from pheromone glands and read by a short read deep sequencing technology using an lllumina HiSeq2000. Almost 3-4 Gb reads were de novo assembled and resulted in 76,361 contigs of G. dimorpha and 104,463 contigs of G. molesta. More than 70% of these contigs were annotated and classified by a typical GO analysis. Transcriptomes related with sex pheromone biosynthesis were selected and grouped into fatty acid synthase, fatty acid oxidation, desaturase, reductase, and isomerase. These analyses identified sex pheromone biosynthesis machineries, which showed significant differential expressions between two sibling species. Field monitoring assays indicated the minor components (Z8-12OH) resulted from fatty acid reductase were crucial in isolating two sibling species.