Consumption of Foliage of Juvenile and Mature Red Oak Trees by Late Instar Gypsy Moth Larvae12

1978 ◽  
Vol 71 (3) ◽  
pp. 425-426 ◽  
Author(s):  
R. R. Braham ◽  
J. A. Witter
Keyword(s):  
Red Oak ◽  
Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1940-1946 ◽  
Author(s):  
Rachael A. Sitz ◽  
Vincent M. Aquino ◽  
Ned A. Tisserat ◽  
Whitney S. Cranshaw ◽  
Jane E. Stewart

The focus of investigation in this study was to consider the potential of arthropods in the dissemination of the bacterium involved in drippy blight disease, Lonsdalea quercina. Arthropod specimens were collected and tested for the presence of the bacterium with molecular markers. The bacterium L. quercina was confirmed on 12 different insect samples from three orders (Coleoptera, Hemiptera, and Hymenoptera) and eight families (Buprestidae, Coccinellidae, Dermestidae, Coreidae, Pentatomidae and/or Miridae, Apidae, Formicidae, and Vespidae). Approximately half of the insects found to carry the bacterium were in the order Hymenoptera. Estimates of the insects that are contaminated with the bacterium, and likely carry it between trees, is conservative because the documented insects represent only a subset of the insect orders that were observed feeding on the bacterium or present on diseased trees yet were not able to be tested. The insects contaminated with L. quercina exhibited diverse life histories, where some had a facultative relationship with the bacterium and others sought it out as a food source. These findings demonstrate that a diverse set of insects naturally occur on diseased trees and may disseminate L. quercina.


1981 ◽  
Vol 11 (3) ◽  
pp. 689-695 ◽  
Author(s):  
Craig G. Lorimer

Mortality and growth rates of trees in various crown classes and size classes were analyzed from 40-year permanent plot records of slope and ravine forest dominated by chestnut oak (Quercusprinus L.) and northern red oak (Quercusrubra L.). Average 5-year mortality rates for suppressed trees ≥2.5 cm dbh of chestnut oak and red oak in the slope forest were 26 and 45%, respectively. None of the suppressed red oaks survived the 40-year period, compared with 14% of the chestnut oaks and 33% of the red maples (Acerrubrum L.). Mortality of oak trees in the intermediate crown class was less than half that of suppressed trees, but still much higher than that of maples and birches on the tracts. Survival was reasonably high for oaks as long as the top of the crown was receiving direct sunlight, but the expected 40-year survival rate of red oaks in such a position is only 20%, with an average growth rate of 1.0 mm in diameter per year. Curves and equations expressing average mortality and growth rates at various levels of competition are presented for each species.


1997 ◽  
Vol 14 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Kevin W. Thorpe ◽  
Richard L. Ridgway ◽  
Ralph E. Webb

Abstract Aerial applications of Bacillus thuringiensis Berliner subsp. kurstaki (74.1 billion international units/ha per application; single and double applications), diflubenzuron [69 g (ai)/ha], and no treatment were evaluated. Treatment effects were estimated from frass collections, defoliation, counts of pupae under burlap, and egg-mass counts. Estimates of larval density in the canopy 20 days after treatment ranged from 318.3 to 55.5 larvae per m² in the control- and diflubenzuron-treated plots, respectively. Larval density was reduced in all treatments, and was lowest in the plots treated with diflubenzuron and two applications of B. thuringiensis. Population density rapidly declined in the control plots, and by June 20, when larvae were predominantly in the fifth and sixth instars, no significant differences in larval density were detected among the treatments. Significantly less defoliation occurred to oak trees in the treated plots, but no differences were detected among the spray treatments. Counts of pupae under burlap, postseason egg-mass counts, and percent reduction in egg-mass density did not differ significantly among treatments or versus controls. These results suggest that diflubenzuron and double B. thuringiensis treatments caused higher levels of larval mortality than occurred with a single B. thuringiensis application, but that with a naturally declining gypsy moth population the final levels of damage were the same under all treatments. North. J. Appl. 14(3):135-140.


1992 ◽  
Vol 9 (2) ◽  
pp. 47-51 ◽  
Author(s):  
Johann N. Bruhn ◽  
Robert L. Heyd

Abstract This paper explains the components of an integrated approach to oak wilt control which has strong potential for adaptation to red oak forests throughout the Lake States. Oak wilt epicenter containment involves (1) separating grafted root systems with a vibratory plow line or Vapam barrier, followed by (2) removal of all living red oaks inside the barrier, and sanitary treatment of wood capable of producing fungal mats. Use of a reference table developed for proper barrier location is described. Epicenters are established by insect vectors, often as a consequence of human activity. Establishment of epicenters can be prevented by: (1) sanitary treatment of diseased trees which may yet produce mats, (2) discouraging unsupervised movement of diseased wood, (3) minimizing the wounding of oaks during the spring and early summer, and (4) immediately painting all spring and summer wounds on oak trees with a tree wound dressing. Detection of new epicenters is important. Treatment of small epicenters minimizes site disturbance and the number of fungal mats produced, as well as the number of trees lost. Systematic aerial surveillance is useful for effective detection in large acre-ages of oak type. Prevention is the best control measure. Unfortunately, public relations are often inadequate. North. J. Appl. For. 9(2):47-51


2000 ◽  
Vol 24 (1) ◽  
pp. 6-10 ◽  
Author(s):  
Zical Xu ◽  
Theodor D. Leininger ◽  
James G. Williams ◽  
Frank H. Tainter

Abstract The Arborsonic Decay Detector (ADD; Fujikura Europe Limited, Wiltshire, England) was used to measure the time it took an ultrasound wave to cross 280 diameters in red oak trees with varying degrees of bacterial wetwood or heartwood decay. Linear regressions derived from the ADD readings of trees in Mississippi and South Carolina with wetwood and heartwood decay yielded significantly different lines for some combinations and locations. The results of this study suggest that the ADD cannot yet be used to detect wetwood in oak trees with enough certainty to be of practical use to a forester or land manager. However, regression lines describing ADD readings of trees with wetwood at both study sites were located between those of healthy trees and decayed trees suggesting some, albeit limited, ability to differentiate wetwood trees. The use of ultrasound to detect bacterial wetwood in red oaks may be improved by designing a system that allows measurement of signal amplitude and evaluation of waveform patterns. The ability to successfully detect trees with heartwood decay was better, especially for trees with advanced decay. South. J. Appl. For. 24(1):6-10.


1969 ◽  
Vol 47 (12) ◽  
pp. 1965-1971 ◽  
Author(s):  
John C. Zasada ◽  
Robert Zahner

Earlywood formation was observed in 60-year-old forest-grown red oak trees in southern Michigan. Extreme care in removing samples from the cambial region of the main stem at 1.4 m and 18 m, and from small branches at about 24 m, permitted the following conclusions. First vessel elements were initiated in the second or third xylem derivative radially removed from the previous year's latewood, possibly in overwintering derivatives, simultaneously throughout the bole and branches of the tree, some 2 weeks before bud enlargement. Vessel elements enlarged first in the tangential dimension (to about 200 μ.) within a few days after initiation of differentiation. Enlargement in the radial direction required up to 2 weeks to grow 300 μ, occurring as the entire xylem mother cell zone was displaced outward by cambial growth to either side—tangentially—of the vessel element. The duration of earlywood formation was about 10 weeks, while the duration of shoot elongation was less than 2 weeks. First earlywood vessels were fully mature about 5 weeks after initiation, coinciding with the unfolding of first leaves. All foliage was mature several weeks before complete maturation of later formed earlywood vessels. Detailed stem analysis and bark peeling studies revealed that stem sections clear of branching contained few lateral junctions between axial vessels. There were many such junctions where twigs joined larger limbs and where limbs joined the main stem; all such junctions were between adjacent vessels from the same limb.


Plant Disease ◽  
2008 ◽  
Vol 92 (2) ◽  
pp. 270-275 ◽  
Author(s):  
Maya Hayslett ◽  
Jennifer Juzwik ◽  
Bruce Moltzan

Beetles in the family Nitidulidae can transmit the oak wilt fungus, Ceratocystis fagacearum, to fresh wounds on healthy oak trees, leading to infection and disease development. Historically, nitidulid beetles have not been considered important vectors of the pathogen in Missouri. Studies were conducted in the spring of 2005 and 2006 to determine frequencies of nitidulid beetle species contaminated with C. fagacearum visiting fresh wounds on red oak trees in central Missouri. Colopterus truncatus, C. niger, and C. semitectus were the most abundant species collected from fresh wounds and the only species found to be contaminated with Ceratocystis fagacearum. Of 230 beetles assayed for C. fagacearum, 23 yielded the fungus. Contamination frequencies were higher for beetles collected in April than May; no beetles collected in June were contaminated. We hypothesize that Colopterus truncatus, C. niger, and C. semitectus are principal nitidulid beetle vector species in Missouri during spring. The risk for pathogen transmission by these beetles appears to be greatest in April and least in June.


1983 ◽  
Vol 61 (12) ◽  
pp. 2984-2995 ◽  
Author(s):  
Jane M. Bowles ◽  
Marc-André Lachance

Yeasts associated with exudates of 16 red oak trees (Quercus rubra) were sampled repeatedly over a 2-year period. The 210 yeasts isolated were assigned to 28 species whose frequencies were characteristic of each habitat. Significant variation among the habitats was detected in the species diversity, composition, nutritional breadth, and physiological specificity of their yeasts. Some exudates were recognized as "typical" sap fluxes by their physical characteristics and their similar yeast florae. Others differed to various degrees in their yeast species composition, or in the physiological structure of their yeast communities. Among the factors linked to the observed variation were features of the adjacent vegetation, colonization by ants, or growth in open parts of the study area.


1967 ◽  
Vol 99 (11) ◽  
pp. 1145-1149 ◽  
Author(s):  
David E. Leonard

AbstractAfter feeding, gypsy moth larvae construct a silk mat (resting mat) on which they remain. Prior to molting, this mat is reinforced, or a new, dense mat is constructed (molting mat). Late in the last larval instar, a sparse cocoon is constructed. When larvae are starved, a shift in behavior is noted, with increased locomotion, irritability, and the trailing of a strand of silk as larvae wander. First-instar larvae, quiescent and anchored on resting mats, are not readily induced to spin down on silk threads; hence are not readily dispersed by wind. Hungry first-instar larvae, more apt to be spinning down, are presumed to be more readily dispersed by wind. Larvae which undergo an additional instar have a longer prefeeding phase and might be more readily dispersed than "normal' larvae. The effects of hunger may also cause the shift in diel periodicity of mid- and late-instar larvae, resulting in some dispersal of these larvae away from areas where food will be depleted.


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