by Dr. Molly Darr | Jun 15, 2022 | 1970 and Earlier Publications
Abstract
During the fall of 1938 a study was begun of the southern pine beetle in Gloucester County, Virginia. Examinations of the infested pine bark disclosed many dead larvae, and specimens were sent to Dr. J. G. Harrar, Plant Pathologist, Virginia Polytechnic Institute. Dr.
Harrar reported that the larvae were infested with nematodes and later added highest among larvae, being 51.3 percent for the overwintering brood and 35.1 percent for the first brood.
To read the full article please visit the link below:
Hetrick, I. A. 1940. “Some Factors in Natural Control of the Southern Pine Beetle, Dendroctonus Frontalis Zimm.” Journal of Economic Entomology33: 554–56. https://www.cabdirect.org/cabdirect/abstract/19406625307
by Dr. Molly Darr | Jun 15, 2022 | 1970 and Earlier Publications
Abstract
The blue-staining fungus Ceratocystis minor (Hedge.) Hunt is a frequent associate of the southern pine beetle, Dendroctonus frontalis Zimmerman (Dixon and Osgood 1961, Francke-Grosmann 1967). The beetles introduce the fungus into tree phloem, and from there it spreads into the xylem (Bramble and Hoist 1940, Hedgcock 1906, Nelson 1934, Nelson and Beal 1929) where it causes rapid wilting of the tree. Although it has been observed that miscellaneously stained phloem is unfavorable to bark beetle development (Franklin 1970), there is little information available on the role of this fungus in the complex microhabitat of the insect in the host phloem. Most C. minor isolations have not been made from phloem when beetles were present, but from and about older frass-filled galleries or from xylem (Rumbold 1929, 1931). Research reported here indicates that C. minor acting alone is detrimental to D. frontalis development, but that its growth and perithecia production are inhibited in the phloem when it is present with the beetle and other associated microorganisms.
To read the full article please visit the link below:
BARRAS, SJ. 1970. “ANTAGONISM BETWEEN DENDROCTONUS-FRONTALIS COLEOPTERA-SCOLYTIDAE AND FUNGUS CERATOCYSTIS-MINOR.” Annals of the Entomological Society of America63 (4): 1187-. https://doi.org/10.1093/aesa/63.4.1187.
by Dr. Molly Darr | Jun 15, 2022 | 1970 and Earlier Publications
Abstract
Hopkins (1909) reported that female southern pine beetles possess a transverse ridge or callus across the anterior area of the pronotum, while males have no such structure. He attached no further significance to the morphological feature. The characteristic was subsequently mentioned by Lyon (1958) and Wood (1963), among others. Dissection of 100 insects by Osgood and Clark (1963) revealed that the ridge was 100% accurate for sexing the species. It is the purpose here to show that the ridge represents the external evidence of a mycangium reported by Francke-Grosmann (1965).
To read the full article please visit the link below:
BARRAS, SJ. 1967. “THORACIC MYCANGIUM OF DENDROCTONUS FRONTALIS (COLEOPTERA -SCOLYTIDAE) IS SYNONYMOUS WITH A SECONDARY FEMALE CHARACTER.” Annals of the Entomological Society of America60 (2): 486-. https://doi.org/10.1093/aesa/60.2.486.
by Dr. Molly Darr | Jun 15, 2022 | 2011-2020 Publications
Abstract
The southern pine beetle (SPB) (Dendroctonus frontalis Zimmermann) is the most economically important pest of southern pine forests. Beetles carry fungal cells within specialised cuticular structures, called mycangia. Little is known about the mycangia ultrastructure or function. We used cryo-fracturing and scanning electron microscopy to examine the ultrastructural features of SPB mycangia and surrounding tissues. Mycangia, one on each side of anterior portion of the prothorax, are terminated on the dorsal side at a ‘mycangial bridge’. This sclerotised mycangial bridge does not appear to provide a passage between the two mycangia, suggesting that each mycangium functions independently. Mycangia are surrounded by abundant tracheoles connecting the structures to the outside via openings within the prothorax. Previously unknown pits overlying the mycangial gland cells were also observed in both the inner wall and anterior fold of prothorax. We hypothesise that these openings and pits may play roles in determining which fungi enter, and grow within, the mycangium.
Keywords
pine, bark beetle, southern pine beetle, mycangia, gland cells, symbiosis
To read the full article please visit the link below:
Yuceer, Cetin, Chuan-Yu Hsu, Nadir Erbilgin, and Kier D. Klepzig. 2011. “Ultrastructure of the Mycangium of the Southern Pine Beetle, Dendroctonus Frontalis (Coleoptera: Curculionidae, Scolytinae): Complex Morphology for Complex Interactions.” Acta Zoologica92 (3): 216–24. https://doi.org/10.1111/j.1463-6395.2011.00500.x.
by Dr. Molly Darr | Jun 15, 2022 | 2011-2020 Publications
Abstract
Southern pine beetle (SPB) (Dendroctonus frontalis Zimm) outbreaks and wildfire occurrence in recent decades has triggered growing concerns regarding their possible interactions. However, few studies have quantified the fuel characteristics of SPB-killed stands, especially the dynamics of the resulting fuel complex. More importantly,
how changes in the fuel complex will affect fire behavior remains unclear. Using field measurements in combination with fire modeling systems, we studied fuel dynamics and its implication to potential fire behaviors by sampling non-outbreak, early post-outbreak (2–3 years), and late post-outbreak (7–8 years) loblolly pine dominated stands in Georgia and South Carolina, USA. We found that the loadings of 1-hr, 10-hr, 100-hr, 1000- hr fuels, and litter depth were significantly greater in post-outbreak stands than in non-outbreak stands. Stand structure was altered in post-outbreak stands, which contained fewer live pines and more hardwoods. We used the Fuel Characteristic Classification System (FCCS) combined with actual data to construct representative fuel beds from the field data. These customized fuel beds were then used to model surface fire behavior that could be altered by the changes in fuel loading and stand structure resulting from SPB outbreaks. Both FCCS and BehavePlus fire modeling systems predicted a faster rate of spread and longer flame lengths in post-outbreak stands than in non-outbreak stands. Late post-outbreak stands under extremely dry conditions were predicted to have the most extreme fire behavior. Our results fill a critical knowledge gap, which will help forest managers make informed decisions on the management of loblolly pine-dominated stands after the southern pine beetle outbreak.
Keywords
Fuel dynamics, Fire behavior, Loblolly-dominated forests, Southern pine beetle outbreaks, Piedmont
To read the full article please visit the link below:
Xie, Hongtao, Jennifer E. Fawcett, and G. Geoff Wang. 2020. “Fuel Dynamics and Its Implication to Fire Behavior in LoblollyPine-Dominated Stands after Southern Pine Beetle Outbreak.” Forest Ecology and Management466 (June): 118130. https://doi.org/10.1016/j.foreco.2020.118130.
