by Dr. Molly Darr | Jun 7, 2022 | 2011-2020 Publications
Abstract
The southern pine bark beetle guild (SPBG) is arguably the most destructive group of forest insects in the southeastern USA. This guild contains five species of bark beetles (Coleoptera: Curculionidae: Scolytinae): Dendroctonus frontalis, Dendroctonus terebrans, Ips avulsus, Ips calligraphus, and Ips grandicollis. A diverse community of illicit receivers is attracted to pheromones emitted by the
SPBG, including the woodborers Monochamus carolinensis and Monochamus titillator (Coleoptera: Cerambycidae). These woodborers have been traditionally classified as resource competitors; however, laboratory assays suggest that larval M. carolinensis may be facultative intraguild predators of SPBG larvae. This study used polymerase chain reaction (PCR)-based molecular gut content analyses to characterize subcortical interactions between M. titillator and members of the SPBG. The half-lives of SPBG DNA were estimated in the laboratory prior to examining these interactions in the field. A total of 271 field-collected M.
titillator larvae were analyzed and 26 (9.6 %) tested positive for DNA of members of the SPBG. Of these larvae, 25 (96.2 %) tested positive for I. grandicollis and one (3.8 %) for I. calligraphus. Failure to detect D. terebrans and D. frontalis was likely due to their absence in the field. I. avulsus was present, but primers developed using adult tissues failed to amplify larval tissue. Results from this study support the hypothesis that larval Monochamus spp. are facultative intraguild predators of bark beetle larvae. Additionally,
this study demonstrates the capabilities of PCR in elucidating the interactions of cryptic forest insects and provides a tool to better understand mechanisms driving southern pine beetle guild population fluctuations.
To read the full article please visit the link below:
Schoeller, Erich N., Claudia Husseneder, and Jeremy D. Allison. 2012. “Molecular Evidence of Facultative Intraguild Predation by Monochamus Titillator Larvae (Coleoptera: Cerambycidae) on Members of the Southern Pine Beetle Guild.” Naturwissenschaften 99 (11): 913–24. https://doi.org/10.1007/s00114-012-0973-6.
by Dr. Molly Darr | Jun 7, 2022 | 2011-2020 Publications
Abstract
A field study was conducted to evaluate the response of Dendroctonus frontalis and Dendroctonus mexicanus to two commercially available semiochemical lures (1) frontalin + α-pinene, (2) frontalin + blend of α-pinene and β-pinene + endobrevicomin, and to know the relative abundance of both species in an altitudinal gradient. The study was carried out on pine-oak forests within the Sierra Gorda Biosphere Reserve, in the state of Queretaro, Mexico. Study sites were on an altitude gradient of 1,672 to 2,530 m asl. Semiochemicals were attached to 12-unit Lindgren funnel traps hung from non-host trees, and bark beetles were collected biweekly
during 1 year. The identification of the species was based on external characters as well as on the form of genitalia. The response to the treatments was determined through an analysis of variance at a 0.05 level of significance, followed by a Tukey- Kramer mean comparison test. The abundance of D. frontalis and D. mexicanus was different in response to the two semiochemical lures. Frontalin + blend of α-pinene and β-pineno + endo-brevicomin attracted 30 times more bark beetles than frontalin + α-pinene. On the other hand, both species were found coexisting at all five elevation points; however, D. frontalis was more abundant from 1,672 to 2,040 m asl, while D. mexicanus was more abundant from 2,291 to 2,530 m asl. These results have implications for monitoring and mass trapping these two pine bark beetle species since for each 100 specimens captured in traps baited with frontalin + α-pinene, 3,000 would be captured if frontalin + blend of α-pinene and β-pineno + endobrevicomin is used. That means 30 times more time and effort for insect identification and counting. Therefore, if the objective of a trapping system is to detect the presence of D. frontalis and D. mexicanus, or to determine the flight periodicity of these species in an area of interest, it is sufficient to use frontalin + α-pinene. On the other hand, if we aim to complement sanitation cutting to help control small infestations, or to avoid bark beetle dispersion from infested logs in log collection centers, it is more appropriate to use frontalin + endo-brevicomin + blend of monoterpenes, with the necessary measures to avoid spill over the attacks.
To read the full article please visit the link below:
Sanchez-Martinez, Guillermo, and Jose Francisco Resendiz-Martinez. 2020. “Response of Dendroctonus Frontalis Zimmerman and Dendroctonus Mexicanus Hopkins(1) to Two Semiochemical Lures in the Sierra Gorda of Queretaro, Mexico.” Southwestern Entomologist 45 (2): 511–20. https://doi.org/10.3958/059.045.0219.
by Dr. Molly Darr | Jun 7, 2022 | 2011-2020 Publications
Abstract
Southern pine beetle (SPB) prevention cost-share programs provide a financial incentive to private forest landowners in exchange for undertaking forest management practices that improve stand health. Healthy pine trees in low density stands offer the best defense against the SPB, helping to ensure that timber resources and other benefits of forests are protected against infestations. This study evaluates the preferences of forestland owners for selected forest management treatment practices (e.g., thinning) offered under this program. An attribute-based choice experiment approach was used to achieve the task. Results indicate that replanting is the option most favored by forestland owners, while prescribed burning is observed to produce disutility. Thinning was statistically insignificant, as were spatial interaction terms and a variable representing the relative rate of landowner participation in the choice scenario.
Keywords
Choice experiment, Forest management, Financial incentive, Southern pine beetle, Cost-share program, Landowner survey
To read the full article please visit the link below:
Rossi, Frederick J., Douglas R. Carter, Janaki R. R. Alavalapati, and John T. Nowak. 2011. “Assessing Landowner Preferences for Forest Management Practices to Prevent the Southern Pine Beetle: An Attribute-Based Choice Experiment Approach.” Forest Policy and Economics 13 (4): 234–41. https://doi.org/10.1016/j.forpol.2011.01.001..
by Dr. Molly Darr | Jun 7, 2022 | 2011-2020 Publications
Abstract
Myotis septentrionalis (Northern Long-eared Bat) is a federally threatened insectivorous bat facing devastating population declines due to white-nose syndrome (WNS). Our study provides pre-WNS (2009) capture rates and roosting-behavior data for Northern
Long-eared Bats in the southern Appalachians. We conducted mist-net surveys at 37 sites and radio-tracked female Northern Long-eared Bats to their day roosts in eastern Tennessee and western North Carolina. We compared tree and plot characteristics for roosts and corresponding random trees using Wilcoxon rank-sum tests. Our 43 survey nights yielded 302 bats of 11 species; Northern Long-eared Bats were the most commonly captured species (n = 97). We located 14 unique roosts for 7 radio-tracked bats; Pinus strobus (White Pine) snags (n = 8) were the most common roost sites. We observed a colony of 72 bats using a White Pine snag as a maternity roost. Roost trees were significantly larger in diameter and had more solar exposure above the roost and within the plot than random trees. Our data show the high abundance of Northern Long-eared Bats pre-WNS, highlight the use of White Pine roosts in an area impacted by a Dendroctonus frontalis (Southern Pine Beetle) outbreak, and support previous determinations of roost-selection flexibility by Northern Long-eared Bats across their range..
To read the full article please visit the link below:
Rojas, Vanessa G., Joy M. O’Keefe, and Susan C. Loeb. 2017. “Baseline Capture Rates and Roosting Habits of Myotis Septentrionalis (Northern Long-Eared Bat) Prior to White-Nose Syndrome Detection in the Southern Appalachians.” Southeastern Naturalist 16 (2): 140–48.
by Dr. Molly Darr | Jun 7, 2022 | 2011-2020 Publications
Abstract
Spatial synchrony and cycles are common features of forest insect pests, but are often studied as separate phenomenon. Using time series of timber damage caused by Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae) (southern pine beetle) in 10 states within the southern United States, this study examines synchrony in D. frontalis abundance, the synchronizing effects of temperature extremes, and the evidence for shared cycles among state populations. Cross-correlation and cluster analyses are used to quantify synchrony across a range of geographic distances and to identify groups of states with synchronous dynamics. Similar techniques are used to quantify spatial synchrony in temperature extremes and to examine their relationship to D. frontalis fluctuations. Cross-wavelet analysis is then used to examine pairs of time series for shared cycles. These analyses suggest there
is substantial synchrony among states in D. frontalis fluctuations, and there are regional groups of states with similar dynamics. Synchrony in D. frontalis fluctuations also appears related to spatial synchrony in summer and winter temperature extremes. The cross-wavelet results suggest that D. frontalis dynamics may differ among regions and are not stationary. Significant oscillations were present in some states over certain time intervals, suggesting an endogenous feedback mechanism. Management of D. frontalis outbreaks could potentially benefit from a multistate regional approach because populations are synchronous on this level. Extreme summer temperatures are likely to become the most important synchronizing agent due to climate change.
Keywords
Dendroctonus frontalis, southern pine beetle, synchrony, weather, cycle
To read the full article please visit the link below:
Reeve, John D. 2018. “Synchrony, Weather, and Cycles in Southern Pine Beetle (Coleoptera: Curculionidae).” Environmental Entomology 47 (1): 19–25. https://doi.org/10.1093/ee/nvx159.
