Swaine Jack-pine Sawfly Research Articles

Kraft pulping of jack pine killed by the Swaine sawfly

Kraft pulping studies were done on jack pine (Pinusbanksiana Lamb.) defoliated by Swaine jack pine sawfly (Neodiprionswainei Midd.). Trees dead as long as 7 years, dead and living trees sprayed with Lindane insecticide, and dead trees wrapped in cotton to prevent secondary insect attacks were tested. There was a statistically significant decrease in unscreened pulp yield (adjusted to screened pulp permanganate No. 20) with length of time since death, e.g., 44.6% (1 year) to 43.4% (7 years); but sufficient variation exists between the trees in any category such that, from a practical viewpoint, all trees tested could be used for pulp manufacture. There were no apparent differences in pulp yield between treated and untreated trees dead for the same length of time. Pulp strength decreased approximately linearly with length of time since death. A decrease in the chip thickness range of −6 mm to +2 mm (total laboratory accepts) and an increase in the −2 mm (pan) thickness range with length of time since death were observed.

Increased Mortality of the Swaine Jack-pine Sawfly, and Foliar Nitrogen Concentrations After Urea Fertilization

Mortality of the Swaine jack-pine sawfly larvae (Neodiprionswainei Midd.) introduced as colonies on jack-pine (Pinusbanksiana Lamb.) foliage was measured in untreated and urea-treated plots of natural forest. Following applications of urea (400 kg N/ha) repeated in two successive years, natural mortality increased from 40 to 70% after 4 weeks, from 33 to 51% after 6 weeks, and from 18 to 36% after 4 weeks for larvae introduced as 1st instar, 2nd instar, and 3rd instar, respectively. This was accompanied by a marked reduction in foliage consumption as revealed by direct measurements or by the weight of frass collected. With 3rd-instar larvae sprayed with a suspension of the virus Borrelinavirusswainei (Smirnoff), viral infection developed much more rapidly in larvae placed on fertilized trees, mortality reaching 100%, double that measured on unfertilized trees. Single applications of urea at lower rates (100 and 200 kg N/ha) revealed a trend of increasing mortality for both unsprayed and virus-sprayed larvae with increasing urea application rate and increasing nitrogen concentration in the needles. Changes in the nitrogenous composition of needle tissue are considered an important factor in the increased larval mortality.

Coleopterous predators of the Swaine jack-pine sawfly, Neodiprion swainei Middleton (Hymenoptera: Diprionidae)

Thirty-four species of elaterids were collected in jack-pine stands. Eighty-six percent of the elaterid larvae (wireworms) collected from soil samples belonged to the genus Ctenicera which were effective predators of the Swaine jack-pine sawfly, Neodiprion swainei Middleton. The peak activity of wireworms occurred in late May and June which coincided with a high abundance of sound sawfly cocoons in the soil. Wireworms destroyed a constant proportion of cocoons with increasing cocoon densities indicating a density-independent response. Populations of wireworms also appeared independent of sawfly cocoon populations. It may be concluded that wireworms played only a minor role in the life system of N. swainei.Five of the 15 species of adult carabids, captured in jack-pine stands, were found to prey upon sawfly cocoons. These were Pterostichus punctatissimus Rand, P. adstrictus Esch., P. coracinus Newn., P. pensylvanicus Lec., and Sphaeroderus lecontei Dej. The peak activity of adult carabids coincided with peak abundance of sawfly cocoons in the soil. Adult carabids destroyed an increasing proportion of cocoons at higher cocoon densities indicating that they may be playing an important role in the life system of N. swainei.

Diapause in the Swaine jack-pine sawfly, Neodiprion swainel, as influenced by temperature and photoperiod

Larvae of Neodiprion swainei Midd. were reared to the adult stage under temperatures of 15, 22 and 30°C and photoperiods of ( L D ): 10 14 , 12 12 , 14 10 , 16 8 , 18 6 hr . Diapause was prevented when the larvae were subjected to a long photoperiod. The higher the temperature the greater the number of individuals not entering diapause at a long photoperiod. A varying percentage of individuals may enter a short diapause similar to a summer diapause. Some cocooned larvae may also stay in prolonged diapause for an undetermined period, regardless of temperature-photoperiod conditions.

A METHOD FOR DETECTING VIRAL INFECTION IN POPULATIONS OF NEODIPRION SWAINEI BY EXAMINATION OF PUPAE AND ADULTS

AbstractMicroscopic examinations revealed that free-floating hard black bodies in larvae, pupae and adults of the Swaine jack-pine sawfly, Neodiprion swainei Midd., often contained polyhedra. A simple and rapid method for detecting the presence of the virus infection before gross symptoms appear is described.

The Spatial Distribution of Cocoons of Neodiprion swainei Middleton in a Jack Pine Stand: I. A Cartographic Analysis of Cocoon Distribution, With Special Reference to Predation by Small Mammals

AbstractInsight into the source of aggregation in the spatial distribution of cocoons of the Swaine jack-pine sawfly, Neodiprion swainei Middleton was gained by the use of special techniques enabling the sampling of units of forest floor in contiguous 2 × 2-inch square samples, as well as by randomized one-square-foot samples taken over a larger area. It was concluded that cocoon distribution is initially random but marked aggregation results from the subsequent transportation of cocoons into feeding stations by predacious small mammals, mostly of the genus Sorex. The feeding stations tended to be distributed near decaying stems and stumps on the forest floor, a factor which augmented the extent of aggregation. Of cocoons not preyed upon by small mammals, slightly higher counts were recorded directly under crown canopies as opposed to open areas, at a tree density of approximately 920 per acre.

Notes on Insect Parasites and Predators of the Swaine Jack-Pine Sawfly in Wisconsin

The Swaine jack-pine sawfly, Neodiprion swaine Middleton, has been reported in outbreak frequently in Canada, but only once in the Lake States. Reasons for this apparent natural control were sought in a survey of biotic enemies of the sawfly in central and southern Wisconsin. Parasites were reared from eggs, cocoons from feeding-instar collections, cocoons field recovered, cocoons from sleeve cages, and cocoons purposely exposed in cages at ground level. Parasites and predators collected are listed, and general comments on their relative importance lire included.

Biology of the Swaine Jack-Pine Sawfly in Wisconsin

AbstractThe Swaine jack-pine sawfly, Neodiprion swainei Midd., is a serious defoliator of jack pine in Canada, and has been reported widely in the Lake States. The largest populations in Wisconsin were on plantations and windbreaks. It is host specific and feeds primarily on old foliage. Damage to new foliage is sporadic, usually being heaviest late in the season. When forced to feed on red, eastern white, or Scotch pines the sawfly develops abnormally. It is not a serious threat to these species. In southern Wisconsin, adults emerge during June; eggs are present from mid-June to mid- July; larvae feed during July and August; heaviest feeding damage occurs in late July and early August; late larval populations feed throughout September. Fecundity was 116 ± 17 eggs. Eggs are placed in new needles, and "paired eggs" are characteristic. The distribution pattern of eggs within a single cluster is characterized for long and for short shoots of new growth. Female larvae require five or six feeding instars, males five. Phenological observations are correlated with sawfly development.

THE SUPPRESSION OF GROWTH RINGS IN JACK PINE IN RELATION TO DEFOLIATION BY THE SWAINE JACK-PINE SAWFLY

An investigation of the radial growth of jack pine (Pinus banksiana Lamb.) defoliated by the Swaine jack-pine sawfly (Neodiprion swainei Midd.) disclosed that growth rings were discontinuous and missing in cross-sectional disks from severely damaged trees. In young and open-grown trees with dead tops, the incidence of such deficiencies in radial growth was especially high in disks from upper regions of the stems, in the vicinity of the dead tops; radial growth was suspended for 1 year and subsequently resumed in disks from the lower regions of some stems. Cambial inactivity was more generalized in trees from an old and dense stand and it was detected in disks representing major portions of some of the stems sampled; the death of some trees followed 2 to 6 years of cambial inactivity in disks cut at various heights along their entire stems. Growth deficiencies in the young stand were clearly effects of severe sawfly defoliation. Data from the old, dense stand indicated that sawfly defoliation had perhaps merely hastened the gradual deterioration of the stand in which intertree competition was intense.

SOME EFFECTS OF ARTIFICIAL DEFOLIATION ON THE GROWTH OF JACK PINE (PINUS BANKSIANA LAMB.)

Young jack pine (Pinus banksiana Lamb.) were defoliated manually to measure the effects of defoliation on growth of this species, and to determine the relative efficiency of foliage of different ages with respect to growth. The removal of 2-year-old or 3-year-old foliage had no appreciable effect on tree growth, but their joint removal reduced height growth. Height growth was also reduced by the removal of 1-year-old foliage. Current foliage was found essential for the maintenance of normal height, diameter, and shoot growth; in addition, its removal induced high bud mortality, the production of profuse adventitious growth, and a reduction in the rate of shoot elongation. Trees deprived of all but current foliage showed marked reductions in height, diameter, and shoot growth. Complete defoliation resulted in tree death shortly thereafter. Growth reductions resulting from some of the treatments approximated that following defoliation by the Swaine jack-pine sawfly (Neodiprion swainei Midd.). Also, the present results are compared with those obtained by several other workers in this field.

Swaine Jack-Pine Sawfly in Wisconsin

Journal Article Swaine Jack-Pine Sawfly in Wisconsin Get access Daniel M. Benjamin, Daniel M. Benjamin Search for other works by this author on: Oxford Academic PubMed Google Scholar Norbert B. Underwood Norbert B. Underwood Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 46, Issue 4, 1 August 1953, Page 703, https://doi.org/10.1093/jee/46.4.703 Published: 01 August 1953