Editorial

6 pages, 684 KiB

Open AccessEditorial

Monitoring, Assessment and Management of Forest Insect Pests and Diseases

by Won Il Choi and Young-Seuk Park

Forests 2019, 10(10), 865; https://doi.org/10.3390/f10100865 - 03 Oct 2019

Cited by 12 | Viewed by 3478

Forest pests are one of the most important factors disturbing forest ecosystems, by impacting forestry economy, ecosystem services, biodiversity, and sustainable ecosystem management. Monitoring the occurrence of forest pests offers clues to understand their impacts on the forest ecosystem and develop a sustainable [...] Read more.

Forest pests are one of the most important factors disturbing forest ecosystems, by impacting forestry economy, ecosystem services, biodiversity, and sustainable ecosystem management. Monitoring the occurrence of forest pests offers clues to understand their impacts on the forest ecosystem and develop a sustainable ecosystem management strategy. This special issue is designed to create a better understanding of the changes and impacts of forest pests according to forest changes, caused by natural or anthropogenic causes. There are 13 papers published in this special issue, covering several issues concerning forest pests. Two of the papers reviewed the changes in forest pests in Korea or Poland. The remaining twelve papers covered issues concerning the monitoring, assessment, and management of forest pests. Through this special issue, we expect to contribute towards the improvement of our knowledge of the structures and processes in forest ecosystems relating to forest pests and fundamental information for the effective management of forest pests. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

Research

Jump to: Editorial, Review

11 pages, 2157 KiB

Open AccessArticle

Chemosensory Characteristics of Two Semanotus bifasciatus Populations

by Sufang Zhang, Sifan Shen, Shiyu Zhang, Hongbin Wang, Xiangbo Kong, Fu Liu and Zhen Zhang

Forests 2019, 10(8), 655; https://doi.org/10.3390/f10080655 - 02 Aug 2019

Cited by 4 | Viewed by 2382

Abstract

Semanotus bifasciatus (Motschulsky) (Cerambycidae: Coleoptera) is a major forest borer in China, and attractants provide a promising method for the control of this pest. Exploration of the chemosensory mechanisms of S. bifasciatus is important for the development of efficient attractants for this pest. [...] Read more.

Semanotus bifasciatus (Motschulsky) (Cerambycidae: Coleoptera) is a major forest borer in China, and attractants provide a promising method for the control of this pest. Exploration of the chemosensory mechanisms of S. bifasciatus is important for the development of efficient attractants for this pest. However, little information is available about the olfactory mechanisms of S. bifasciatus. Previous research has indicated that the trapping effects of the same attractant are different between Beijing and Shandong populations of S. bifasciatus. To explore the reasons for this, next-generation sequencing was performed to analyze the antennal transcriptome of both sexes of the two S. bifasciatus populations, and the olfactory-related genes were identified. Furthermore, the expression levels and single nucleotide polymorphisms (SNPs) of the olfactory-related genes between the two populations were compared. We found that the expression levels of odorant binding proteins (OBPs), odorant receptors (ORs), and sensory neuron membrane proteins (SNMPs) in male S. bifasciatus of the Beijing population were obviously lower than those in the Shandong population, and most of the conserved SNPs in OBPs and ORs of the two populations showed more diversity in the Beijing population. Our work provides a foundation for future research of the molecular olfactory mechanisms and pest management of S. bifasciatus, as well as other longhorn beetles. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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16 pages, 3451 KiB

Open AccessArticle

Simple Is Best: Pine Twigs Are Better Than Artificial Lures for Trapping of Pine Weevils in Pitfall Traps

by Michal Lalík, Jaroslav Holuša, Juraj Galko, Karolína Resnerová, Andrej Kunca, Christo Nikolov, Silvia Mudrončeková and Peter Surový

Forests 2019, 10(8), 642; https://doi.org/10.3390/f10080642 - 29 Jul 2019

Cited by 10 | Viewed by 3309

Abstract

The large pine weevil Hylobius abietis (Linnaeus 1758) is the main pest of coniferous seedlings in Europe and causes substantial damage in areas that have been clear-cut or otherwise disturbed. We compared the efficacy of different attractants for the capture of H. abietis [...] Read more.

The large pine weevil Hylobius abietis (Linnaeus 1758) is the main pest of coniferous seedlings in Europe and causes substantial damage in areas that have been clear-cut or otherwise disturbed. We compared the efficacy of different attractants for the capture of H. abietis adults in white pitfall traps. The field experiment was performed from mid-April to the end of August 2018 at six plots in Central Europe located in spruce stands that had been clear-cut. At each plot, we compared five attractants: one pine twig with ethanol, Hylodor, alpha-pinene + ethanol, turpentine oil and ethanol (separated), and turpentine oil + ethanol (not separated). Traps without attractant served as a control. Six traps for each attractant or control were distributed at each plot. Of the total number of H. abietis adults trapped, 43.3%, 20.5%, 17.9%, 9.8%, 8.5% and 0.5% were captured in traps with pine twigs with ethanol, alpha-pinene, Hylodor, turpentine, oil + ethanol (separated), turpentine oil + ethanol (combined), and no attractant, respectively. The bottom of each trap contained propylene glycol to kill and preserve beetles. The small number of beetles captured in the control traps confirms that the propylene glycol:water mixture did not influence the trapping of H. abietis. The use of pitfall traps with a suitable attractant (especially pine twigs and ethanol) should be useful for monitoring of H. abietis, because it is simple and cost-effective. The use of such pitfall traps to control H. abietis by mass trapping would require 50 to 100 traps per ha. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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14 pages, 6471 KiB

Open AccessArticle

Review of Japanese Pine Bast Scale, Matsucoccus matsumurae (Kuwana) (Coccomorpha: Matsucoccidae), Occurring on Japanese Black Pine (Pinus thunbergii Parl.) and Japanese Red Pine (P. densiflora Siebold & Zucc.) from Korea

by Jinyeong Choi, Deokjea Cha, Dong-Soo Kim and Seunghwan Lee

Forests 2019, 10(8), 639; https://doi.org/10.3390/f10080639 - 29 Jul 2019

Cited by 4 | Viewed by 6560

Abstract

Matsucoccus matsumurae (Kuwana, 1905), commonly known as Japanese pine bast scale, is a destructive pest on pine trees in North America, East Asia, and Northern Europe. The spread of damage to black pine trees, Pinus thunbergii Parl., due to M. matsumurae has been [...] Read more.

Matsucoccus matsumurae (Kuwana, 1905), commonly known as Japanese pine bast scale, is a destructive pest on pine trees in North America, East Asia, and Northern Europe. The spread of damage to black pine trees, Pinus thunbergii Parl., due to M. matsumurae has been reported throughout Southern and some Eastern and Western coastal regions in Korea, under the name M. thunbergianae, which was described by Miller and Park (1987). Recently, M. thunbergianae was synonymized with M. matsumurae by Booth and Gullan (2006), based on molecular sequences and morphological data. However, M. thunbergianae is still considered a valid species in Korea. Since supporting data for the synonyms are unavailable in any DNA database (e.g., GenBank and BOLD), we performed morphological and molecular comparisons to review the results of Booth and Gullan (2006) using samples of M. matsumurae collected from Japan and topotype materials of M. thunbergianae from Korea. Our study supports the opinion of Booth and Gullan (2006), as the morphological features of the adult female and male of M. thunbergianae are identical to those of M. matsumurae, and DNA sequences (18S and 28S) of M. thunbergianae show identical or very low genetic distances with those of M. matsumurae. Additionally, regional sampling of Korea produced the first documented occurrence of M. matsumurae in Jeju. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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12 pages, 3804 KiB

Open AccessArticle

Occurrence Prediction of the Citrus Flatid Planthopper (Metcalfa pruinosa (Say, 1830)) in South Korea Using a Random Forest Model

by Dae-Seong Lee, Yang-Seop Bae, Bong-Kyu Byun, Seunghwan Lee, Jong Kyun Park and Young-Seuk Park

Forests 2019, 10(7), 583; https://doi.org/10.3390/f10070583 - 12 Jul 2019

Cited by 22 | Viewed by 4093

Abstract

Invasive species cause a severe impact on existing ecosystems. The citrus flatid planthopper (CFP; Metcalfa pruinosa (Say, 1830)) is an invasive species in many countries. Predicting potential occurrence areas of the species related to environmental conditions is important for effective forest ecosystem management. [...] Read more.

Invasive species cause a severe impact on existing ecosystems. The citrus flatid planthopper (CFP; Metcalfa pruinosa (Say, 1830)) is an invasive species in many countries. Predicting potential occurrence areas of the species related to environmental conditions is important for effective forest ecosystem management. In this study, we evaluated the occurrence patterns of the CFP and predicted its potential occurrence areas in South Korea using a random forest model for a hazard rating of forests considering meteorological and landscape variables. We obtained the occurrence data of the CFP in South Korea from literature and government documents and extracted seven environmental variables (altitude, slope, distance to road (geographical), annual mean temperature, minimum temperature in January, maximum temperature in July, and annual precipitation (meteorological)) and the proportion of land cover types across seven categories (urban, agriculture, forest, grassland, wetland, barren, and water) at each occurrence site from digital maps using a Geographic Information System. The CFP occurrence areas were mostly located at low altitudes, near roads and urbanized areas. Our prediction model also supported these results. The CFP has a high potential to be distributed over the whole of South Korea, excluding high mountainous areas. Finally, factors related to human activities, such as roads and urbanization, strongly influence the occurrence and dispersal of the CFP. Therefore, we propose that these factors should be considered carefully in monitoring and surveillance programs for the CFP and other invasive species. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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14 pages, 3239 KiB

Open AccessArticle

Current and Future Distribution of Ricania shantungensis (Hemiptera: Ricaniidae) in Korea: Application of Spatial Analysis to Select Relevant Environmental Variables for MaxEnt and CLIMEX Modeling

by Sunghoon Baek, Min-Jung Kim and Joon-Ho Lee

Forests 2019, 10(6), 490; https://doi.org/10.3390/f10060490 - 07 Jun 2019

Cited by 14 | Viewed by 4191

Abstract

Since the first report on its occurrence in 2010, Ricania shantungensis Chou & Lu in Korea has quickly spread. This pest population in agricultural areas has increased by over 100% each year and has caused serious economic damage in the last few years. [...] Read more.

Since the first report on its occurrence in 2010, Ricania shantungensis Chou & Lu in Korea has quickly spread. This pest population in agricultural areas has increased by over 100% each year and has caused serious economic damage in the last few years. This study was conducted to predict the potential habitat and the current and future distribution of R. shantungensis in Korea using CLIMEX and the Maximum Entropy Model (MaxEnt), and to suggest a new parameter selection method for both modeling programs. Weights of variables used in CLIMEX and those used in MaxEnt were determined using spatial association indices of spatial analysis by distance indices (SADIE). Weather data of Zhejiang province in China and those of all Korean territories were compared with Climate Matching in CLIMEX. MaxEnt was applied and evaluated with 295 data points on the presence and absence of R. shantungensis and eight environmental variables that were preselected by spatial and correlation tests. In MaxEnt, maximum temperature of the warmest month, annual mean temperature, mean temperature of the coldest month, and precipitation of the driest month were determined to be the most important variables affecting the distribution of R. shantungensis in Korea. The results of this study indicated that R. shantungensis had a higher probability of occurrence in western areas than in eastern areas of Korea, and showed great potential to spread eastward. These results are expected to be helpful for managing R. shantungensis in Korea and selecting relevant environmental variables for species distribution modeling. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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16 pages, 2097 KiB

Open AccessArticle

Mite Communities (Acari, Mesostigmata) in the Initially Decomposed ‘Litter Islands’ of 11 Tree Species in Scots Pine (Pinus sylvestris L.) Forest

by Jacek Kamczyc, Marcin K. Dyderski, Paweł Horodecki and Andrzej M. Jagodziński

Forests 2019, 10(5), 403; https://doi.org/10.3390/f10050403 - 09 May 2019

Cited by 15 | Viewed by 3182

Abstract

Replacement of native deciduous forests by coniferous stands was a common result of former European afforestation policies and paradigms of forest management and led to considerable ecological consequences. Therefore, the most popular management strategy nowadays in multi-functional forestry is the re-establishment of mixed [...] Read more.

Replacement of native deciduous forests by coniferous stands was a common result of former European afforestation policies and paradigms of forest management and led to considerable ecological consequences. Therefore, the most popular management strategy nowadays in multi-functional forestry is the re-establishment of mixed or broadleaved forests with native species on suitable habitats. However, our knowledge about the effects of tree species introduced into coniferous monocultures on soil mesofauna communities is scarce. We investigated abundance, species richness and diversity of Mesostigmata mite communities in decomposed litter of seven broadleaved (Acer platanoides L., A. pseudoplatanus L., Carpinus betulus L., Fagus sylvatica L., Tilia cordata Mill., Quercus robur L., Q. rubra L.) and four coniferous (Abies alba Mill., Larix decidua Mill., Picea abies [L.] Karst., Pinus sylvestris L.) species. We collected 297 litterbags after 6, 12 and 18 months of exposition in Scots pine (Pinus sylvestris) monocultures in Siemianice Experimental Forest (SW Poland). Generally, species richness and diversity in litter samples were much lower than in the soil mite pool. The highest abundance was found in P. sylvestris and A. alba litter, while the lowest was found in A. platanoides. The most abundant families were Zerconidae, Parasitidae, Veigaiidae, and Trachytidae. Our study revealed that neither species richness nor diversity were affected, but that mite abundance was affected, by the tree species (litter quality). The mite communities were similarly comprised in both high- and low-quality litter and mite abundance decreased during the decomposition process in nutrient-poor Scots pine forests. Moreover, few mite species benefited from the decomposed litter. Additionally, a litter of various tree species was inhabited mainly by eu- and hemiedaphic mite species. Mite assemblages in A. alba, P. sylvestris, and Q. robur litter had higher abundances. Exposition time seems to be an important driver in shaping the mite community during the early stages of litter decomposition. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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11 pages, 1747 KiB

Open AccessArticle

The Spring Assessing Method of the Threat of Melolontha spp. grubs for Scots Pine Plantations

by Hanna Szmidla, Monika Małecka, Miłosz Tkaczyk, Grzegorz Tarwacki and Zbigniew Sierota

Forests 2019, 10(5), 399; https://doi.org/10.3390/f10050399 - 09 May 2019

Cited by 3 | Viewed by 2674

Abstract

Root-feeding Melolonthinae larvae are a forest pest species in Europe that can exert serious damage. In Poland, they are classified as the most dangerous pest on land dedicated to afforestation and the most serious threat to natural regeneration in the stands. This study [...] Read more.

Root-feeding Melolonthinae larvae are a forest pest species in Europe that can exert serious damage. In Poland, they are classified as the most dangerous pest on land dedicated to afforestation and the most serious threat to natural regeneration in the stands. This study was performed in three forest districts in east Poland (Lubartów, Marcule, and Wyszków forest districts) in mixed conifer forests, where the presence of Melolontha spp. grubs was evaluated in autumn and spring of 2012 to 2017, respectively. In spring 2012, 2014, and 2016, consecutively ‘small sawdust pits’ in rows between seedlings were prepared, and in adjacent inter-rows similar control pits without sawdust were marked. In spring and autumn of the following year, sawdust and soil from both types of pits were sieved and Melolonthinae larvae were counted and compared. More grubs were found in sawdust pits in spring than in autumn. In Marcule Forest District (FD) (2014), more grubs were found in inter-rows than in rows with seedlings, when compared to grubs detected using the traditional method of “autumn large pits assessment”, recommended by Polish forest rules. The Melolonthinae population size and location of grubs were related to the weather conditions in the evaluated periods, as well. We conclude that to properly assess the cockchafer threat, it is necessary to perform spring assessment and to search in inter-rows. This could be recommended for decisions on control. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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14 pages, 2314 KiB

Open AccessArticle

Initial Location Preference Together with Aggregation Pheromones Regulate the Attack Pattern of Tomicus brevipilosus (Coleoptera: Curculionidae) on Pinus kesiya

by Fu Liu, Chengxu Wu, Sufang Zhang, Xiangbo Kong, Zhen Zhang and Pingyan Wang

Forests 2019, 10(2), 156; https://doi.org/10.3390/f10020156 - 12 Feb 2019

Cited by 6 | Viewed by 2435

Abstract

Research Highlights: We found that the initial attack location together with the aggregation pheromones played an important role in mediating the aggressive behavior of T. brevipilosus on P. kesiya. Background and Objectives: T. brevipilosus was identified as an aggressive species, which possesses [...] Read more.

Research Highlights: We found that the initial attack location together with the aggregation pheromones played an important role in mediating the aggressive behavior of T. brevipilosus on P. kesiya. Background and Objectives: T. brevipilosus was identified as an aggressive species, which possesses the ability to kill live, healthy P. kesiya. In this scenario, we study the top-down attack pattern of T. brevipilosus on P. kesiya during the entirety of the reproductive period. Materials and Methods: We investigated the phenology of trunk attack on P. kesiya over a period of three years in Pu’er City, China. The hindguts extracts of the females and males T. brevipilosus were analyzed by coupled gas chromatography-mass spectrometry (GC-MS). The candidate aggregation pheromone compounds of T. brevipilosus were determined through electrophysiology experiments (electroantennographic detection, EAD and electroantennography, EAG), laboratory olfactometer bioassays, and field trapping. Results: we found that the pioneer beetles preferentially infested the crown of P. kesiya at the early stage of attack following spring flight with the later arriving beetles selectively attacking the lower area of the trunk to avoid intraspecific competition and better utilize limited resources, which exhibits a top-down attack pattern. During gallery initiation, the beetles release aggregation pheromones to attract conspecifics to conduct a mass attack. The chemical analyses indicated that the hindgut extracts of gallery-initiating beetles contained a larger amount of myrtenol, cis-verbenol, trans-verbenol, and verbenone. Myrtenol and trans-verbenol were identified as candidate aggregation pheromone compounds. In addition, a blend of these two components with S-(−)-α-pinene and S-(−)-β-pinene attracted more T. brevipilosus individuals in a field bioassay. Conclusions: We concluded that the preference for the initial attack location together with the aggregation pheromones played an important role in mediating the top-down attack pattern of T. brevipilosus on P. kesiya. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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14 pages, 3960 KiB

Open AccessArticle

Calcium and Potassium Imbalance Favours Leaf Blight and Defoliation Caused by Calonectria pteridis in Eucalyptus Plants

by Thaissa P. F. Soares, Edson A. Pozza, Adélia A. A. Pozza, Reginaldo Gonçalves Mafia and Maria A. Ferreira

Forests 2018, 9(12), 782; https://doi.org/10.3390/f9120782 - 18 Dec 2018

Cited by 9 | Viewed by 3891

Abstract

The supply of nutrients in balanced proportions leads to greater crop yields and represents an alternative practice for the management of plant diseases. Accordingly, we investigated the effect of the doses of and the nutritional balance between calcium (Ca) and potassium (K) on [...] Read more.

The supply of nutrients in balanced proportions leads to greater crop yields and represents an alternative practice for the management of plant diseases. Accordingly, we investigated the effect of the doses of and the nutritional balance between calcium (Ca) and potassium (K) on the severity of leaf spot and defoliation caused by the fungus Calonectria pteridis. Moreover, the effect of the treatments on the growth of interspecific hybrid eucalyptus clone seedlings (Eucalyptus grandis Hill ex Maiden × E. urophylla S.T. Blake), which are highly susceptible to the disease, was evaluated. The 25 treatments comprised combinations of one of five doses of Ca (1.2, 3.0, 6.0, 9.0 and 12.0 mmol L⁻¹) with one of five doses of K (0.8, 2.0, 4.0, 8.0 and 12.0 mmol L⁻¹) and five replicates of each treatment were included in the study. The supply of high concentrations of K favoured C. pteridis infection and resulted in high disease severity, although defoliation was not observed. However, the supply of both nutrients in excess (12.0 mmol L⁻¹ Ca × 9.0 mmol L⁻¹ K) resulted in a higher disease severity and an increased defoliation percentage (82 and 64%, respectively). Defoliation not associated with Calonectria leaf blight disease was observed with the imbalanced treatments, that is, the treatments combining a low concentration of one nutrient and an excess concentration of the other nutrient. The supply of K at a level near the standard dose (6 mmol L⁻¹) and of Ca at a dose above 4 mmol L⁻¹ (standard dose) ensured high mean values for the morphological variables root and shoot biomass, plant height and chlorophyll a and b contents. These treatments also resulted in low disease severity and defoliation percentages, indicating that a balanced supply of Ca and K ensures reductions in disease severity and defoliation and contributes to higher growth. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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14 pages, 1050 KiB

Open AccessArticle

The Use of qPCR Reveals a High Frequency of Phytophthora quercina in Two Spanish Holm Oak Areas

by Beatriz Mora-Sala, Mónica Berbegal and Paloma Abad-Campos

Forests 2018, 9(11), 697; https://doi.org/10.3390/f9110697 - 10 Nov 2018

Cited by 16 | Viewed by 3292

Abstract

The struggling Spanish holm oak woodland situation associated with Phytophthora root rot has been studied for a long time. Phytophthora cinnamomi is considered the main, but not the only species responsible for the decline scenario. This study verifies the presence and/or detection of [...] Read more.

The struggling Spanish holm oak woodland situation associated with Phytophthora root rot has been studied for a long time. Phytophthora cinnamomi is considered the main, but not the only species responsible for the decline scenario. This study verifies the presence and/or detection of Phytophthora species in two holm oak areas of Spain (southwestern “dehesas” and northeastern woodland) using different isolation and detection approaches. Direct isolation and baiting methods in declining and non-declining holm oak trees revealed Phytophthora cambivora, Phytophthora cinnamomi, Phytophthora gonapodyides, Phytophthora megasperma, and Phytophthora pseudocryptogea in the dehesas, while in the northeastern woodland, no Phytophthora spp. were recovered. Statistical analyses indicated that there was not a significant relationship between the Phytophthora spp. isolation frequency and the disease expression of the holm oak stands in the dehesas. Phytophthora quercina and P. cinnamomi TaqMan real-time PCR probes showed that both P. cinnamomi and P. quercina are involved in the holm oak decline in Spain, but P. quercina was detected in a higher frequency than P. cinnamomi in both studied areas. Thus, this study demonstrates that molecular approaches complement direct isolation techniques in natural and seminatural ecosystem surveys to determine the presence and distribution of Phytophthora spp. This is the first report of P. pseudocryptogea in Europe and its role in the holm oak decline should be further studied. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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9 pages, 1499 KiB

Open AccessArticle

Comparing Methods for Monitoring Establishment of the Emerald Ash Borer (Agrilus planipennis, Coleoptera: Buprestidae) Egg Parasitoid Oobius agrili (Hymenoptera: Encyrtidae) in Maryland, USA

by David E. Jennings, Jian J. Duan and Paula M. Shrewsbury

Forests 2018, 9(10), 659; https://doi.org/10.3390/f9100659 - 22 Oct 2018

Cited by 13 | Viewed by 4064

Abstract

The emerald ash borer, Agrilus planipennis Fairmaire (EAB), is an invasive beetle that has caused widespread mortality of ash trees in North America. To date, four parasitoids have been introduced in North America for EAB biological control, including the egg parasitoid Oobius agrili [...] Read more.

The emerald ash borer, Agrilus planipennis Fairmaire (EAB), is an invasive beetle that has caused widespread mortality of ash trees in North America. To date, four parasitoids have been introduced in North America for EAB biological control, including the egg parasitoid Oobius agrili Zhang & Huang (Hymenoptera: Encyrtidae). Monitoring EAB egg parasitism is challenging because female beetles oviposit in bark crevices and EAB eggs and O. agrili are small (<1 mm in diameter). Consequently, multiple methods have been developed to recover this parasitoid. Here we compared two methods, visual surveys and bark sifting, used to monitor establishment of O. agrili in Maryland, USA. From 2009 to 2015, a total of 56,176 O. agrili were released at 32 sites across the state. In 2016, we surveyed nine of the study sites for O. agrili establishment using both methods. We compared the amount of time spent searching for eggs separately in each method, and also analyzed the effects of years-post release, total number of parasitoids released, and median month of release, on percent parasitism of EAB eggs, and the percentage of trees per site with parasitized EAB eggs. We found that visually surveying ash trees for EAB eggs was more efficient than bark sifting; the percent parasitism observed using the two methods was similar, but visually surveying trees was more time-efficient. Both methods indicate that O. agrili can successfully establish populations in Maryland, and June may be the best month to release O. agrili in the state. Future research should investigate EAB phenology in the state to help optimize parasitoid release strategies. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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Review

Jump to: Editorial, Research

15 pages, 1421 KiB

Open AccessReview

Changes in Major Insect Pests of Pine Forests in Korea Over the Last 50 Years

by Won Il Choi, Youngwoo Nam, Cha Young Lee, Byoung Ki Choi, Yu Jin Shin, Jong-Hwan Lim, Sang-Hyun Koh and Young-Seuk Park

Forests 2019, 10(8), 692; https://doi.org/10.3390/f10080692 - 15 Aug 2019

Cited by 22 | Viewed by 8731

Abstract

Understanding the occurrence patterns of forest pests is fundamental for effective forest management from both economic and ecological perspectives. Here, we review the history of the occurrence patterns and causes of outbreaks and declines of pests in Korean pine forests over the last [...] Read more.

Understanding the occurrence patterns of forest pests is fundamental for effective forest management from both economic and ecological perspectives. Here, we review the history of the occurrence patterns and causes of outbreaks and declines of pests in Korean pine forests over the last 50 years. During this period, the major pests of pine forests in Korea have shifted from pine caterpillar (Dendrolimus spectabilis Butler) to the pine needle gall midge (PNGM, Thecodiplosis japonensis (Uchida and Inouye)) and finally to pine wilt disease (PWD) caused by the pine wood nematode (Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle). Outbreaks of pine caterpillar, a native species in Korea, have been recorded as far back as 900 years, and it was the most relevant forest pest in Korea until the 1970s. The decline of its importance has been attributed to reforestation and higher levels of subsequent natural enemy activity. The PNGM is an invasive species, first discovered in Korea in 1929, that became widely distributed by 1992 and the major forest pest in the 1980s and 1990s. A suite of parasitic wasps attacking the PNGM contributed at least partially to the decline of PNGM densities. Following the decline of the PNGM, damage from PWD has increased since 2003. These shifts in major forest pests might be related to changes in forest composition and interactions among forest pests. Therefore, a new management strategy for controlling forest pests is required to mitigate the decline of pine forests in Korea. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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17 pages, 2532 KiB

Open AccessReview

Abiotic and Biotic Disturbances Affecting Forest Health in Poland over the Past 30 Years: Impacts of Climate and Forest Management

by Zbigniew Sierota, Wojciech Grodzki and Andrzej Szczepkowski

Forests 2019, 10(1), 75; https://doi.org/10.3390/f10010075 - 21 Jan 2019

Cited by 50 | Viewed by 9810

Abstract

The current nature of forest management in Poland reflects its history and more than 100 years of economic activity affecting forests since independence in 1918. Before that time, different forest management models were used, related to the nature of the Prussian economy in [...] Read more.

The current nature of forest management in Poland reflects its history and more than 100 years of economic activity affecting forests since independence in 1918. Before that time, different forest management models were used, related to the nature of the Prussian economy in the north of the country, the Russian economy in the central-eastern part, and the Austrian economy in south-eastern Poland. The consequence of these management models, as well as the differing climate zones in which they were used, resulted in varied forest health. Since the end of World War II, forest coverage within Poland‘s new borders has increased from 20.8% to currently 29.6%, mainly as a result of afforestation of wastelands and former agricultural lands. This paper describes changes in the health of forests and their biological diversity in Poland in the context of weather extremes, species composition, forest management, the forest industry, and damage from insects and pathogenic fungi over the last 30 years. Full article

(This article belongs to the Special Issue Impacts, Monitoring and Management of Forest Pests and Diseases)

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