Research Highlights
The first ever detailed images of the fungus carrying structure of the southern pine beetle
Kier Klepzig, kklepzig@fs.fed.us
In this cooperative research between Dr. Kier Klepzig and researchers at Mississippi State University (led by Dr. Cetin Yuceer), scientists were able to utilize advanced microscopy to examine in detail the structure (mycangium) used by the southern pine beetle to transport the fungi it uses to help kill trees (and consumes for food). This gives researchers new insight into the interactions between bark beetles and their associated fungi. This type of basic information can be used to devise new control strategies, identify new antibiotics and is applicable to other bark beetle systems. The research occurred at SRS-4552 in Pineville, LA and at Mississippi State University. The results were published in Acta Zoologica, a peer reviewed journal. The researchers had to painstakingly dissect small structures from very small beetles and use scanning electron microscopy to examine these mycangia. The results were made possible through a cooperative agreement awarded by the SRS to Mississippi State.
Trap lure for pine longhorn beetles in southeastern USA
Daniel R. Miller, dmiller03@fs.fed.us
Exotic invasive species pose significant threats to economies and healthy forests throughout the world. In particular, longhorn beetles (Cerambycidae) have arisen as a major threat both from losses from direct attacks by beetles and by pathogens vectored by such species. The sawyer beetles (Monochamus spp) carry the pinewood nematode which causes pine wilt disease, a major factor limiting wood shipments from the United States to Europe. We developed a trap lure for the southern pine sawyer, Monochamus titillator, and several species of associated longhorn beetles in the southeast. Field studies were conducted in stands of loblolly, slash and longleaf in Louisiana, Georgia, Florida and Virginia in 2006-2007. We exploited the responses of longhorn beetles to volatiles produced by stressed pine trees as well as their responses to the pheromones produced by associated species of bark beetles. Our lure blend of ethanol, α-pinene, ipsenol and ipsdienol can be easily incorporated into national programs (CAPS and EDRR) as well as in programs overseas. Traps baited with our new quaternary blend could be important in future certification programs for exported wood products. Many of the same compounds are used by other species in North America as well as Europe and Asian.
Impact of imidacloprid for control of hemlock woolly adelgid on nearby aquatic macroinvertebrate assemblages
James Hanula, jhanula@fs.fed.us
Imidacloprid is a systemic insecticide is used to control hemlock woolly adelgid (Adelges tsugae Annand) which is killing hemlock trees throughout the eastern U.S. The objective of this study was to determine if soil injection with imidacloprid for hemlock woolly adelgid control near streams adversely impacts aquatic invertebrates. Eastern hemlocks (Tsuga canadensis) in the watersheds surrounding 4 streams (60 trees were treated per watershed) in the southern Appalachian region of GA and NC were treated with imidacloprid. Our results indicate that soil injections of imidacloprid can safely be used in the southern Appalachian area to control hemlock woolly adelgid, although caution should be used when applying these results to other areas with different soil types (e.g. low organic matter content) that may not bind imidacloprid as tightly.
Effects of Fertilizer and Low Rates of Imidacloprid on Adelges tsugae (Hemiptera: Adelgidae)
James Hanula, jhanula@fs.fed.us
Maintaining healthy hemlock trees (Tsuga canadensis), with moderate infestations of hemlock woolly adelgid (Adelges tsugae) populations should favor retention and population growth of adelgid predators like Laricobius nigrinus Fender (Derodontidae) and Sasajiscymnus tsugae (Sasaji & McClure) (Coccinellidae). Eastern hemlock trees were treated with 0, 10 or 25% of the recommended rate of imidacloprid (Merit 75WP) insecticide and were either fertilized or not. The goal was to use low rates of insecticide to suppress adelgid populations without eliminating them and use fertilizer to increase the number of eggs they lay which the predators eat. After two years, more ovisacs and eggs were found on trees receiving 10% imidacloprid than 25%. Adelgids on fertilized trees produced more eggs, which was positively correlated with total foliar N. Trees treated with low rates of imidacloprid were healthier than untreated trees, but only trees treated with the 10% dosage had sufficient adelgids to sustain adelgid predators over extended periods of time which would allow the predators to increase in number and spread to infested hemlocks in the adjoining forest.
Effect of trap type, trap position, time of year, and beetle density on captures of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)
James Hanula, jhanula@fs.fed.us
The exotic redbay ambrosia beetle (Xyleborus glabratus) and the fungus (Raffaellea lauricola) it carries, are responsible for killing large numbers of redbay (Persea borbonia) trees throughout South Carolina, Georgia and Florida. Effective traps and lures are needed to monitor spread of the beetle and for early detection at ports of entry, so we conducted a series of experiments to find the best trap design, color, lure, and trap position for detection of X. glabratus. Manuka oil proved to be the most effective lure tested, particularly when considering cost and availability. Funnel traps caught twice as many beetles as cross-vane traps and 3 times as many as sticky traps. When comparing height, traps 1.5 m above the ground captured 85% of the beetles collected but a few were caught at each height up to 15 m. Catching beetles at low densities is important to port of entry monitoring programs where early detection of infestations is essential. Our trials show that multiple funnel traps near ground level baited with a single manuka oil lure were effective for capturing X. glabratus, even when no infested trees were visible in the area.
Removing an exotic shrub from riparian forests increases butterfly abundance and diversity
James Hanula, jhanula@fs.fed.us
Invasive plants are one of the greatest threats to endangered insect species and a major threat to butterflies in eastern North America. We investigated the effects of the invasive shrub Chinese privet (Ligustrum sinense) and two methods of removing it from riparian forests on butterfly communities and compared them to untreated, heavily invaded control plots and to “desired future condition” forests that never had extensive privet cover. Privet mulching resulted in nearly twice as many butterflies as privet felling and both treatments had more butterflies two years after privet removal than untreated control plots. Butterfly communities on control plots differed from those on the two treatments and the desired future condition forests. A number of forest characteristics were evaluated but only herbaceous plant cover (excluding privet) was positively correlated with butterfly abundance and diversity. Removing Chinese privet from riparian forests in the southeastern United States greatly improved forest habitats for butterflies.
Emerald ash borer biological control
Michael Ulyshen, mulyshen@fs.fed.us
The emerald ash borer, a buprestid beetle native to Asia, is one of the most ecologically and economically significant invasive forest pests in North America. As a postdoctoral research associate at Michigan State University, Michael Ulyshen collaborated with Dr. Leah Bauer (North Central Research Station, Lansing MI) and Dr. Jian Duan (ARS, Newark DE) to carry out a series of experiments addressing the biology of three parasitic wasp species (Oobius agrili, Tetrastichus planipennisi and Spathius agrili) introduced from China and their potential to control this damaging pest. Significant findings/accomplishments include 1) the development of a simple yet highly reliable and productive rearing method for T. planipennisi; 2) that S. agrili has the potential to outcompete T. planipennisi for host resources, suggesting the two species should be released separately in time or space; 3) fourth instar emerald ash borer larvae are best for rearing T. planipennisi whereas second instars produce too few wasp progeny to benefit rearing efforts and 4) the design and use of field-cages for assessing the climatic suitability of release sites for S. agrili and T. planipennisi.
Improved collection techniques for the recently introduced kudzu bug (Megacopta cribraria)
Large numbers of the exotic bug Megacopta cribraria were first collected in northeast Georgia beginning in October 2009. The insect’s native range is Asia and the Indian Subcontinent where it is known to predominantly feed on legumes (Fabaceae) such as kudzu and soybean. Predicting potential economic and ecological damage by M. cribraria outside its natural range is difficult. However, one important first step is to establish baseline information on population numbers and seasonal activity, as well as potential trapping techniques that allow for rapid field assessment of these parameters. The effect of trap color on collection performance has been studied extensively for many groups however no information exists for M. cribraria. We set out to determine if colored traps could be deployed for monitoring adults of the kudzu bug. We established four rows of five different colored cross-vane traps (white, yellow, purple, red, and black) and operated them continuously from May-July. We collected a total of 4,057 adults and found that both white and yellow traps captured significantly more kudzu bugs than the other colors. Even further, white traps were twice as effective as the yellow traps catching 53% of the bugs for the entire study. This study provides researchers and land managers an effective tool for early detection and monitoring relative abundance of this new pest species.
Science Delivery Highlight
Establishment of a Cogongrass Task Force
James H. Miller, jmiller01@fs.fed.us
Dr. Jim Miller worked with Alabama’s State Forester and Assistant State Forester and other agency staff to form the multi-agency Alabama Cogongrass Task Force by contributing to the formulation of the MOU. The Task Force was organized around principles that Miller had formulated and presented at numerous conference and workshops. Dr. Miller’s lead role in the development of a Memorandum of Understanding and Strategic Plan was used by the Alabama Forestry Commission to obtain a $6.281 million grant through the American Reinvestment and Recovery Act (ARRA) to 1) create jobs and 2) control, mitigate, and eradicate cogongrass—a federally listed noxious weed—in Alabama in 2009. These activities led to the formation of the Alabama Cogongrass Control Center and developed a State-wide organization, strategies, tactics, and provided the latest research findings for eradication and restoration of infested lands. http://www.forestry.state.al.us/Cogongrass_control_program.aspx?bv=3&s=2. Recognizing the lack of coordination among the 8 States with cogongrass infestations (AL, GA, MS, SC, TN, TX, LA and FL), Miller formed and chairs a multi-state effort that promotes communications among States agencies through conference calls, sharing of the latest information by postings on www.cogongrass.org, and Miller with States and the Center for Invasive Science and Ecosystem Health at the University of Georgia created a regional map of cogongrass severity and presents a unified strategy of action to coordinate individual State action (posted on www.cogongrass.org).
Partnership Highlights
International Relationship with The Forest Agriculture and Biotechnology Institute (FABI) at the University of Pretoria in South Africa
Kier Klepzig, kklepzig@fs.fed.us
Dr. Kier Klepzig has fostered and built a relationship with a key international partner. The Forest Agriculture and Biotechnology Institute (FABI) at the University of Pretoria in South Africa is the premier forest pathology program in the world. Dr. Klepzig has continued research on the Sirex woodwasp (an invasive, pine killing insect new to the United States and well established in South Africa). He has also worked with FABY on developing graduate student candidates from the US to study abroad at FABI. He recruited a new MS student for Forest Pathology program at FABI, and a potential technician/ PhD student in the Forest Entomology program.
Forest Service Termiticide Testing Program: Working to Bring New and Effective Termite Control Products to the American Public
Terry Wagner, twagner01@fs.fed.us .
The U.S. Forest Service has been the primary provider of efficacy data for federal and state registrations and has tested every termiticide registered in the United States. In 2011, the Forest Service has managed and administered >20 collection agreements with industry cooperators. Products typically undergo 24 months of laboratory screening and five years of field testing at sites in Arizona, Florida, Mississippi, and South Carolina. Through a Memorandum of Understanding with the U.S. Environmental Protection Agency, and in partnership with state regulators as a member of the Termiticide Label Review Committee of the Association of Structural Pest Control Regulatory Officials, we provided comment to product manufacturers and EPA on several new and amended termiticides under registration review. We also hosted the Association of Structural Pest Control Regulatory Officials’ sponsored training for the Registration Branches of EPA at the Harrison Experimental Forest Termiticide Test Site, during which we gave a presentation and tour of site.
Key Partners: Federal and state regulators and their associations (EPA, Florida Bureau of Pesticides, Louisiana Structural Pest Control Division, Mississippi Bureau of Plant Industry, North Carolina Structural Pest Control Division, South Carolina Department of Pesticide Regulation, Association of Structural Pest Control Regulatory Officials, etc), product manufacturers and their associations (BASF, Bayer, Dow, DuPont, FMC, Sumitomo, Syngenta, and Responsible Industry for a Sound Environment, etc.), the pest control industry and their association (Orkin, Terminix, National Pest Management Association, etc.), University of Arizona, the U.S. military, American homeowner.