Scolytus Quadrispinosus Research Articles

Mortality patterns following a hickory decline event – Is density reduction key to maintaining bitternut hickory?

Bitternut hickory (Carya cordiformis (Wangenh.) K. Koch) is an important component of many hardwood forest systems in the northern hardwood forests of the Lake States. Extensive mortality of the species was observed in a long-term field experimental site in a second growth northern hardwood forest of Wisconsin between 2010 and 2016. We quantified and documented the characteristics of the mortality, investigated the relationship between bitternut hickory density and mortality patterns, and assessed the persistence of hickory regeneration. The presence of a pathogenic fungus (Ceratocystis smalleyi Johnson and Harrington) and hickory bark beetle (Scolytus quadrispinosus Say) were identified as the main cause of mortality in other instances of hickory decline during a similar time period in the Midwest and Northeast. We investigated the role of these agents through post hoc analysis. Tree surveys of mapped stems ≥10 cm dbh conducted periodically from 2005 to 2016 indicated mortality of hickory rose sharply to 35% year−1 from 2010 to 2016. This is a substantial increase in mortality relative to the dominant species at the site (Acer saccharum Marshall, Tilia americana L., and Fraxinus spp.) which was 1.11% year−1 in the same time period. Mortality rates were higher in larger stems (≥20 cm dbh) than smaller stems (10 < 20 cm dbh). Additional analyses evaluated whether mortality rates were affected by localized species composition, using the proportion of hickory stems among neighboring trees. Proportion of hickory stems, diameter, and crown class proved to be statistically important in predicting mortality in individual hickory stems. The density of hickory regeneration in the <30 cm tall height class decreased from 2010 to 2016. Overall the bitternut hickory population significantly declined, especially the larger sized trees, and this decline will have lasting consequences on the persistence of the species in the area. Potential management actions for mitigating impacts of such rapid hickory decline events, mainly selective thinning, are discussed. Methods for maintaining this co-occurring species is increasingly important as several other codominant species in northern hardwood forests are also decreasing.

Ceratocystis Canker of Bitternut Hickory Caused by Ceratocystis smalleyi in the North-Central and Northeastern United States.

Between 2006 and 2008, diffuse cankers without surrounding callus and callus-edged sunken cankers were observed on main stems of poletimber (13 to 28 cm in diameter at 1.4 m high) and sawtimber (>28 cm in diameter) bitternut hickory (Carya cordiformis) in Iowa, Indiana, Minnesota, New York, Ohio, and Wisconsin. Reddish, inner bark necrosis and reddish brown sapwood discoloration were associated with the cankers. Entry or exit holes of the hickory bark beetle (Scolytus quadrispinosus) were commonly associated with the cankers. Ceratocystis smalleyi was consistently isolated from the margins of cankers or discolored sapwood of assayed samples. When cultured on 2% malt yeast extract agar (MYEA), the isolates produced perithecia, ascospores, endoconidiophores, and conidia diagnostic of C. smalleyi (1). To confirm identification, the translation elongation factor (tef) 1-α gene and the internally transcribed spacer (ITS) regions were sequenced. DNA for both regions was extracted from mycelia growing on MYEA. The tef sequences (GenBank Accession Nos. GU201529-201539) and the ITS sequences (GenBank Accession Nos. GU190734-190745) were 98 to 100% similar to sequences of C. smalleyi isolates (GenBank Accession Nos. EF070408 and AY9907030-907032). Pathogenicity tests were conducted with local isolates (two per site) on healthy Carya cordiformis (13 to 28 cm in diameter) in forest stands in three states. In May 2007, one fungus-colonized MYEA disk or sterile MYEA agar was placed in one of two holes (0.6 cm in diameter) drilled to the cambium on stems of 10 trees in Allamakee County, IA. Sterile moist cotton and laboratory film held the disks in place. After 12 months, diffuse cankers were found for all but one fungus inoculation site; no cankers occurred with control inoculations. Reddish brown, inner bark necrosis (mean area 22.4 cm2) and sapwood discoloration (mean volume 38.1 cm3) were associated with the cankers. C. smalleyi was recovered from five of nine cankers, but not from the control wounds. In June 2008, 0.1 ml of spore suspension (1 × 104 ascospores/ml) of C. smalleyi or sterile dH20 was pipetted into four drilled holes (to the outer sapwood) of four trees in Chippewa County, WI. Holes were sealed with moist cotton and masking tape. Two months later, diffuse cankers with reddish inner bark (mean 49.7 cm2) surrounded 16 inoculation points; no cankers or inner bark necrosis was observed for the control points. In a similar trial, a spore suspension or sterile water was placed into four drilled holes covered with moist cotton and moldable putty on six trees in Olmstead County, MN. Fourteen months later, either diffuse or sunken cankers with reddish, inner bark necrosis (mean 22.3 cm2) were observed surrounding all inoculated points while all control points were callus closed. For the latter two trials, long, narrow discoloration (reddish brown) was found in the sapwood associated with each canker; no sapwood discoloration was observed for the control points. In addition, C. smalleyi was reisolated from all cankered stems in Wisconsin and from 21 of 24 cankers in Minnesota, but not from the controls. This report verifies the ability of C. smalleyi to cause a newly described canker disease on poletimber-sized hickories. We hypothesize that this disease is contributing to the death of hickory bark beetle-attacked Carya cordiformis in the eastern United States. Reference: (1) J. Johnson et al. Mycologia 97:1067, 2005.

Phylogeny and taxonomy of the North American clade of the Ceratocystis fimbriata complex

Ceratocystis fimbriata is a widely distributed, plant pathogenic fungus that causes wilts and cankers on many woody hosts. Earlier phylogenetic analyses of DNA sequences revealed three geographic clades within the C. fimbriata complex that are centered respectively in North America, Latin America and Asia. This study looked for cryptic species within the North American clade. The internal transcribed spacer regions (ITS) of the rDNA were sequenced, and phylogenetic analysis indicated that most isolates from the North American clade group into four host-associated lineages, referred to as the aspen, hickory, oak and cherry lineages, which were isolated primarily from wounds or diseased trees of Populus, Carya, Quercus and Prunus, respectively. A single isolate collected from P. serotina in Wisconsin had a unique ITS sequence. Allozyme electromorphs also were highly polymorphic within the North American clade, and the inferred phylogenies from these data were congruent with the ITS-rDNA analyses. In pairing experiments isolates from the aspen, hickory, oak and cherry lineages were interfertile only with other isolates from their respective lineages. Inoculation experiments with isolates of the four host-associated groupings showed strong host specialization by isolates from the aspen and hickory lineages on Populus tremuloides and Carya illinoensis, respectively, but isolates from the oak and cherry lineages did not consistently reveal host specialization. Morphological features distinguish isolates in the North American clade from those of the Latin American clade (including C. fimbriata sensu stricto). Based on the phylogenetic evidence, interfertility, host specialization and morphology, the oak and cherry lineages are recognized as the earlier described C. variospora, the poplar lineage as C. populicola sp. nov., and the hickory lineage as C. caryae sp. nov. A new species associated with the bark beetle Scolytus quadrispinosus on Carya is closely related to C. caryae and is described as C. smalleyi.

Phylogeny and taxonomy of the North American clade of the Ceratocystis fimbriata complex

Ceratocystis fimbriata is a widely distributed, plant pathogenic fungus that causes wilts and cankers on many woody hosts. Earlier phylogenetic analyses of DNA sequences revealed three geographic clades within the C. fimbriata complex that are centered respectively in North America, Latin America and Asia. This study looked for cryptic species within the North American clade. The internal transcribed spacer regions (ITS) of the rDNA were sequenced, and phylogenetic analysis indicated that most isolates from the North American clade group into four host-associated lineages, referred to as the aspen, hickory, oak and cherry lineages, which were isolated primarily from wounds or diseased trees of Populus, Carya, Quercus and Prunus, respectively. A single isolate collected from P. serotina in Wisconsin had a unique ITS sequence. Allozyme electromorphs also were highly polymorphic within the North American clade, and the inferred phylogenies from these data were congruent with the ITS-rDNA analyses. In pairing experiments isolates from the aspen, hickory, oak and cherry lineages were interfertile only with other isolates from their respective lineages. Inoculation experiments with isolates of the four host-associated groupings showed strong host specialization by isolates from the aspen and hickory lineages on Populus tremuloides and Carya illinoensis, respectively, but isolates from the oak and cherry lineages did not consistently reveal host specialization. Morphological features distinguish isolates in the North American clade from those of the Latin American clade (including C. fimbriata sensu stricto). Based on the phylogenetic evidence, interfertility, host specialization and morphology, the oak and cherry lineages are recognized as the earlier described C. variospora, the poplar lineage as C. populicola sp. nov., and the hickory lineage as C. caryae sp. nov. A new species associated with the bark beetle Scolytus quadrispinosus on Carya is closely related to C. caryae and is described as C. smalleyi.

Evidence of Prehistoric Corn (Zea mays) and Hickory (Carya spp.) Planting in New York City: Vegetation History of Hunter Island, Bronx County, New York

LOEB, R. E. (Natural Sciences and Mathematics, Milwaukee Area Technical College, Milwaukee, WI 532331443). Evidence of prehistoric corn (Zea mays) and hickory (Carya spp.) planting in New York City: Vegetation history of Hunter Island, New York. J. Torrey. Bot. Soc. 125:74-86. 1998.-The fossil pollen record of Mishow Marsh, Hunter Island, Bronx County, New York City provides evidence of corn (Zea mays) planting between 1075 and 1285 A. D. Arboreal pollen changes, about the time of corn planting cessation, indicate Siwanoy native Americans planted the field with hickory (Carya spp.). Dutch and English colonial settlers protected forests in the locale to maintain a source of wood and for feeding livestock, however, the Island's forest was cut for the British Navy during the American Revolution. Soon after 1812, John Hunter created a gentleman's farm on the Island including forested tracts along the shores and on field edges. Following the purchase of Hunter Island in 1888, the New York City Parks Department supported social agencies clearing trees in field edges to build campgrounds as well as along the south shore to form a beach. In 1908, the chestnut blight eliminated American chestnut (Castanea dentata) from the forest and soon afterward, a hickory bark beetle infestation decimated the hickory population. An arboreal survey in 1934 showed that the Mishow Marsh watershed contained a field and a forest dominated by oak (Quercus spp.) and yellow poplar (Liriodendron Tulipifera). The Island was converted to a day use picnic area in 1943, which removed all the woody plants with stems less than ten centimeters in diameter. Reduced funding after 1964 led to picnic facilities removal which increased forest redevelopment on the Island. A resurvey of the Mishow Marsh watershed in 1988 revealed oak and yellow poplar remained dominant in the old forest and a hickory and sassafras (Sassafras albidum) stand grew in the field.

Urban ecosystem management and change during the past millennium: a case study from New York City

Changes in a deciduous forest and salt marsh ecosystem, Hunter Island, New York City, are related to management over the past millennium. Sequential methods, fossil pollen analysis, map and aerial photography series, and vegetation resampling were performed to supplement the historical and archaeological records. The enhanced ecosystem management history provides an expanded context to examine management planning alternatives. Siwanoy native Americans utilized Hunter Island to provide fuel, land for corn planting, and living space through cutting forests in at least the northeast portion of the island. The fossil pollen record indicates that about the time of site abandonment, the Siwanoy planted the forest opening with hickory. Dutch colonial settlers protected forest in the area, but later the island's forest was cut for the British Navy during the American Revolution. John Hunter created a gentleman's farm on the island beginning in 1812. The New York City Parks Department purchased Hunter Island in 1888 and permitted social agencies to clear trees for recreation during the next 46 years. The chestnut blight eliminated American chestnut from the forest in 1908, and at the same time a hickory bark beetle infestation decimated the hickory population. A survey in 1934 showed that the northeast portion of the Island contained a forest, dominated by oak and yellow poplar, and a field. The island became a day-use picnic site in 1943, and for this purpose all the woody plants with stems less than 10 cm in diameter were removed. Aerial photography demonstrated a trend of forest replacing field over the past century. A resurvey of the northeast section of the island in 1988 revealed that oak and yellow popular remained dominant in the old forest, and the field became a hickory and sassafras stand. The hickory dominance, which is typical of Hunter Island, is unusual for New York City forests and could be related to native American plantings over 700 years ago. The management plan for Hunter Island is focused on preservation of the field and forest legacy of the recent recreation period. Instead of preserving an environmental patchwork common in New York City parks, an alternative management focus could enhance the hickory forest component to represent the former native American cultural setting.

Long-term human disturbance of an urban park forest, New York City

Development of an urban park forest, the Turtle Pond Watershed, Alley Park, Queens, New York, was analyzed from historical, vegetation, and pollen records. After 1800, the forest began to develop as a hickory ( Carya spp. Nutt.) dominated stand following release of the land from agricultural use. Pollen and sediment analysis of a section from the bog in Turtle Pond showed that before 1900, residential development introduced pine ( Pinus spp. L.) to the area, reduced the hickory population, and caused the Pond to change from bog to fen conditions. From 1908 to 1912, the hickory bark beetle reduced hickory and chestnut blight killed off American chestnut ( Castanea dentata (Marsh.) Borkh.). Although the area containing the Watershed forest was incorporated into Alley Park in 1927, private structures were not removed until 1937. Forest canopy inventory data from 1936 showed canopy gaps left open by the losses of American chestnut and hickory trees permitted flowering dogwood ( Cornus florida L.) to become the forest dominant. Comparison of the 1936 data with an inventory of the forested Watershed in 1987 indicated the flowering dogwood was decimated in the intervening years and the open growing space was occupied by maple ( Acer spp. L.), birch ( Betula spp. L.), American beech ( Fagus grandifolia Ehrh.), sweet gum ( Liquidambar styraciflua L.), black gum ( Nyssa sylvatica Marsh.), black cherry ( Prunus serotina Ehrh.), and oak ( Quercus spp. L.). The pollen record indicates that stresses of recreational use and abuse in the Watershed forest since 1973 have negatively affected reproduction in maple, birch, and sweet gum. The history of human disturbance provides information to guide recreation of past forest types and to increase diversity through the selection of hardy species to plant.

Secondary Sex Characters of Scolytus laricis1

A rapid, accurate method of sexing bark beetles is valuable in various studies, especially those involving live, unharmed beetles. Blackman (1934) reported several secondary sex characters for the genus Scolytus Geoffroy. These and other sex differences were tested and reported for the Douglas-fir engraver, S. Unispinosus LeConte, by Atkins and McMullen (1957) and for the hickory bark beetle S. quadrispinosus Say, by Goeden and Norris (1964). We observed and tested several secondary sex characters during biological studies of S. laricis Blackman, which infests pole-size western larch, Larix occidentalis Nuttall, in Oregon, Washington, Idaho, Montana, and British Columbia. In this article, the more prominent of these characters are illustrated and their relative accuracy and usefulness as sex indicators are reported.

A chemical basis for bark beetle ( Scolytus) distinction between host and non-host trees

The bark beetle, Scolytus quadrispinosus, tolerated 5-hydroxy-1,4-nappthoquinone from a host tree, Carya ovata, that was a deterrent to feeding by Scolytus multistriatus. S. multistriatus fed as extensively on the benzene extract of C. ovata twig bark when 5-hydroxy-1,4-naphthoquinone was removed as it did on the benzene extract of its host, Ulmus americana. S. multistriatus feeding on the benzene extract of U. americana also was deterred by the addition of an extract of Quercus alba twig bark. These findings indicate that deterrency by chemicals in the bark of non-host trees is an important basis for bark beetle distinction between non-host and host tissues.

Some Biological and Ecological Aspects of Ovipositional Attack in Carya spp. by Scolytus quadrispinosus (Coleoptera: Scolytidae)1

The habits of the hickory bark beetle, Scolytus quadrispinosus Say, during gallery construction, mating, and oviposition are described in detail. The host affinities of this beetle to Carya spp. are interpreted in light of these behaviorisms and the result s of field and laboratory experimentation. The host-selection mechanisms of S. quadrispinosus during ovipositional attack involve an initial response to volatile degradation products of abnormal tree physiology (primary attractant) reinforced by an attractant associated with ovipositing females (secondary attractant).

The Behavior of Scolytus quadrispinosus (Coleoptera: Scolytidae) During the Dispersal Flight as Related to Its Host Specificities1

Newly emerged Scolytus quadrispinosus Say were collected by tanglefoot-coated barriers during flight to crowns of paired, healthy host and nonhost trees ( Carya ovata (Mill.) K. Koch and Quercus alba L., respectively). As weekly collections were comparable in both tree species, the dispersal flight apparently was random with respect to both tree species, This phenomenon indicated that the host specificities of S. quadrispinosus for maturation feeding were not governed by attractants peculiar to healthy, host tissues.

Attraction of Scolytus quadrispinosus (Coleoptera: Scolytidae) to Carya spp. for Oviposition1

The flight patterns of hickory bark beetles, Scolytus quadrispinosus Say, attracted to girdled Carya cordiformis (Wangenh.) K. Koch were sampled by a barrier technique. Initial beetle response was directed and chemotactic. Log sections per se proved attractive to beetles, but data demonstrated a secondary beetle attractant associated with the presence of beetles in host material.

Insecticides on Shade Trees and Ornamentals

A series of tests were conducted to determine tolerance of various trees and shrubs to dormant oil sprays. At Stamford, Connecticut, the sugar maple, black walnut, butternut and beech were found to be very susceptible to oil injury, and certain conifers, particularly the spruces, were apt to be injured where excessive amounts were used. The other trees and shrubs sprayed with various oils at dormant strength were not injured by the application. Dormant oil 1-16 was very effective in killing the overwintering young of the tulip tree scale, Toumeyella liriodendri. The white pine bark aphid, Adelges pinicorticis, was very satisfactorily controlled with a dormant oil at 1–25. 1–50 and 1–50 to which was added nicotine sulfate (40%) 1–800. Tests of several commercial sprays applied to spruce branches and the latter then immediately covered with paraffin bags resulted in no appreciable injury, indicating that high humidity was probably not an important factor in causing injury. A lead oleate, coated arsenate of lead applied to twigs upon which feeding hickory bark beetles, Scolytus quadrispinosus were confined resulted in appreciably more killing than in the case of others sprayed with ordinary arsenate of lead. A spray of 2% summer oil plus nicotine sulfate 1–800 and a commercial vegetable oil, soap, nicotine sulfate mixture diluted 1–10 gave practically 100% kill of young juniper scale, Diaspis carueli, in midsummer. A very satisfactory control, 95–100%, was secured in the case of a number of insects by spraying with the vegetable oil, soap, nicotine spray.

Observations on Shade Tree Insects

There has been widespread insect injury to shade trees the past season in the northeastern United States. Three introduced pests—the elm leaf beetle, (Galerucella xanthomelaena), the Japanese beetle (Popillia japonica) and the Europead willow leaf beetle (Plagiodera versicolora)—have defoliated an estimated one ann three quarter million trees. The larch case bearer (Coleophora laricella), seriously injured a quarter of a million larches growing as ornamentals; while the native fall webworm (Hyphantria textor) and the bagworm (Thyridopteryx ephemeraeformis) have seriously damaged an estimated quarter of a million trees each. In addition, the native walnut caterpillar (Datana integerrima) has been very injurious. The total seriously affected is estimated at two and a half million trees, many being well grown, handsome additions to lawns, streets or parkways. Not a few are highly prized for sentimental reasons. These trees may easily be worth an average of $100 each, the total value therefore being $250,000,000. Repeated annual defoliations mean serious lowering of vitality, and if continued for several years a condition obtaining in many sections, the beauty and utility of the trees are destroyed. The probabilities indicate more sweeping damage in 1932. Sickly, dying trees may be a liability rather than an asset. The time is approaching and has come in certain localities, when it will be necessary to provide systematic protection for shade trees, if we would avoid extensive and irreparable losses. The weakening of trees by several abnormally dry seasons and the general loss of foliage described above has produced ideal conditions for serious damage by borers, especially the hickory bark beetle (Scolytus quadrispinosus), the two-lined chestnut borer (Agrilus bilineatus) and the bronze birch borer (Agritus anxius). This has already commenced and more severe damage may be expected in the next season or two. It is by all means advisable to make comprehensive plans for spraying in areas where these various insects were numerous last year. This alone is not sufficient, since the weakened trees need feeding. Otherwise they may succumb to attack by various borers.

Developing Resistance or Tolerance to Insect Attack

There are many peculiarities in relation to insect attacks which have not been explained. Some are undoubtedly physiological, others may have a distinct relation to the vigor or condition of the plant, as in the case of the Hessian fly, Phytophaga destructor Say, the lace bugs of rhododendrons and azaleas, Stephanitis rhododendri Horv. and Stephanitis pyrioides Scott, respectively. Injury is also somewhat proportionate to the size and vigor of the host, as evidenced by European corn borer, Pyrausta nubilalis Hubn., infestations. Extended injuries by the elm leaf beetle, Galerucella xanthomelaena Schrank, are dependent in considerable measure upon favorable climatic conditions, these latter undoubtedly resulting in a less vigorous growth. A peculiar and unexplained physiologic-al reaction by gipsy moth larvae, Porthetria dispar Linn., is also mentioned. Evidence available indicates that a number of the cambium borers, namely the bronze birch borer, Agrilus anxius Gory, the two-lined chestnut borer, Agrilus bilineatus Web., the hickory bark beetle, Scolytus quadrispinosus Say, and the cedar bark beetle, Phloeosinus dentatus Say. successfully invade trees with a lowered vitality and that in the case of the first named, it is possible to stimulate growth by feeding and aid trees to actually destroy the borers. It is suggested that a uniform and satisfactory supply of moisture throughout the season and feeding to promote a vigorous growth may be valuable preventive measures in the case of certain insects at least.

Weather, a Factor in Outbreaks of the Hickory Bark Beetle

The contents of this paper indicates that weather has a marked effect on barkbeetle outbreaks. A hickory barkbeetle, Eccoptogaster quadrispinosus , outbreak occurred during the drought period of 1925 in North Carolina. The marked deficiency in precipitation weakened hickory trees by checking growth and rendered them attractive to beetle attacks, favoring brood development. An excess of precipitation during periods of beetle flight resulted in a partial mortality of the adults, thereby considerably reducing the number attacking and also rendered trees unfavorable for brood development.

The Effect of Deficiency and Excess in Rainfall upon the Hickory Bark Beetle

An epidemic of the Hickory Bark-Beetle started in Syracuse in 1912 and has extended to the present time, with a decided checking in 1915. This was preceded by semi-drought conditions over a period of several years before the epidemic started. While the trees were undoubtedly affected, as is shown by a study of the rings of growth, the indirect effect through the lessening of the vitality of the trees is not sufficient to account for all the phenomena. The greatest effect was the more direct one upon the insects themselves, as the deficiency came during the summer months. A deficiency at this time is beneficial to both adults and larvae, and an excess, as in 1915, acts as a distinct check. When the adults are active, continued rain kills many while feeding and establishing their burrows and also checks egg-laying. Excess rainfall, humidity and cloudiness kills the larvae because it produces an excess of water in the plant tissues and this is set free into the larval mines. Deficiency in rainfall has a beneficial effect upon both adults and larvae. This may be put to practical use. It is known that there has been a deficiency in rainfall extending over several years, an intelligent lookout can be made for the first signs of undue increase of dangerous forms and these can be controlled before they reach epidemic proportions.