scholarly journals Experimental evidence for associational resistance against the European pine sawfly in mixed tree stands

Silva Fennica ◽  
2007 ◽  
Vol 41 (2) ◽  
Author(s):  
Pekka Kaitaniemi ◽  
Janne Riihimäki ◽  
Julia Koricheva ◽  
Harri Vehviläinen
1999 ◽  
Vol 124 (2-3) ◽  
pp. 113-121 ◽  
Author(s):  
Päivi Lyytikäinen-Saarenmaa ◽  
Olle Anderbrant ◽  
Jan Löfqvist ◽  
Erik Hedenström ◽  
Hans-Erik Högberg

1968 ◽  
Vol 46 (5) ◽  
pp. 724-725 ◽  
Author(s):  
Bart A. Thielges

Modified polyphenol metabolism in Pinus sylvestris was correlated with European pine sawfly attack. The unknown compound was not restricted to damaged tissue, indicating a more general response to injury.


1967 ◽  
Vol 99 (6) ◽  
pp. 670-672 ◽  
Author(s):  
Ronald W. Kobylnyk

Laser treatment of larval and pupal stages within cocoons of Neodiprion sertifer (Geoff.) requires an accurate assessment of viability and the antero-posterior alignment of the cocoon content. The use of the candling technique to assess qualitative features of avian eggs depends on the translucency of the egg shell and the differences in light transmission by other elements within it (Romanoff and Romanoff 1949). Transmitted-light methods have been employed for insects within cocoons by Cushman (1913) and Hanna (1935). A type of candling technique different from previous methods and which was developed in the Zoology Department, University of Guelph, enables N. sertifer cocoon content to be ascertained and is herein described.


1976 ◽  
Vol 108 (11) ◽  
pp. 1137-1144 ◽  
Author(s):  
J. N. All ◽  
D. M. Benjamin

AbstractAntifeedants for controlling larval feeding of several Neodiprion sawflies were evaluated in laboratory and field studies. Nine commercially available insect antifeedants and a hexane extract of the juvenile foliage of jack pine, Pinus banksiana Lambert, were tested on larvae of six species. In laboratory bioassays larvae exhibited varying sensitivity to antifeedants; generally species with monophagous or restricted oligophagous feeding habits were most sensitive. In the laboratory the Swaine jack pine sawfly, Neodiprion swainei Middleton, had severely restricted feeding, development, survival, and fecundity. Triphenyltin hydroxide was toxic to N. swainei and to European pine sawfly, N. sertifer (Geoffroy). In field tests certain antifeedants disrupted N. swainei feeding and development. The colonial behavior of larvae often was disrupted and solitary larvae fell from trees or wandered on twigs. Colony disruption by most antifeedants was temporary and many larvae resumed feeding.


1961 ◽  
Vol 93 (9) ◽  
pp. 799-801 ◽  
Author(s):  
Thelma Finlayson

Aptesis basizona (Grav.), a parasite of pine sawflies in Europe, was propagated at Belleville, Ont. (Green, 1938) for release against the European spruce sawfly, Diprion hercyniae (Htg.), the European pine sawfly, Neodiprion sertifer (Geoff.) and other Diprionidae. Development of the insects in the laboratory was allowed to continue until feeding was completed and cocoons were spun, and was then retarded by placing the insects in cold storage pending shipment to release areas. Frequently stock for propagation was incubated after a period of cold storage, and occasionally the schedule was interrupted by decreases in the reproductive capacity of the adults. It seemed that there was some relationship between the fertility of the adults and the temperatures at which the immature stages were held, both while feeding and after they had reached the fully-fed stage. Experiments were initiated to investigate this hypothesis.


1959 ◽  
Vol 37 (3) ◽  
pp. 267-281 ◽  
Author(s):  
A. W. Ghent

Many Neodiprion sawflies lay their eggs in a row in small pockets cut into the edges of the mature needles of various pines. These rows of eggs are remarkable for the regularity of the spacing between successive egg pockets. The regularity of egg spacing by N. sertifer is shown to arise from a stereotyped pattern of leg movements during the shift between the sites of successive egg pockets. Spacing is effected by two sets of leg movements, in each of which the three pairs of legs move forward in order from back to front. While the effective forward movement of all legs is the same, the total forward movement of the metathoracic legs is greater than that of the other legs by an amount equal to the length of an egg pocket. The metathoracic legs retrace their steps by this length as the initial incision for each new egg pocket is cut, evidently providing the force by which this incision is made. The grip-points of the legs are on the needle edge opposite to that receiving eggs, so that the wider the needle, the greater the proportion of leg length required to reach across it, and the smaller the proportion of leg movement reflected in the spacing between eggs. In this way egg spacing varies inversely with needle width. Observations on copulation, antennal movement, and related oviposition behavior are included.


2019 ◽  
Vol 61 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Valentyna Meshkova ◽  
Serhii Nazarenko ◽  
Maryna Kolienkina

Abstract Pine sawflies (Hymenoptera, Symphyta, Diprionidae) are the most spread foliage browsing insects of pine forests in Europe, especially monovoltinous European pine sawfly Neodiprion sertifer (Geoffroy, 1785) and common pine sawfly Diprion pini (Linnaeus, 1758), which develops in one or two generations per year depending on weather. The outbreaks of both pine sawflies are the most frequent and intensive in the Steppe zone of Ukraine, especially in the Low Dnieper region, where pine forest (Pinus sylvestris Linnaeus and Pinus pallasiana D. Don) was planted on moving sands in the sixties of the 20th century. This research is aimed at the evaluation of the parameters for D. pini outbreak dynamics in the Low Dnieper region. Outbreak severity, specific foci area and mean score of stand threat by D. pini were evaluated from the regional statistical reports. In the regional scale for 1979–2017, notable outbreaks of D. pini were registered in 1982, 1993, 2002, 2006 and 2017. An interval between maximums was from 4 to 11 years, in average 9 years. The growth of foci area in 1979–1998 as compared to 1999–2017 as well as correlation between pine stand area and annual area of this pest’s foci in different forests was not statistically significant. Graphical analysis of dynamics of D. pini focal area for 2010–2017 was done based on individual threat levels. Our study confirms the fact of three outbreaks for this period in three forest and hunting enterprises (FHE), two outbreaks in one FHE and one outbreak in one FHE. An interval between the outbreaks makes three or six years. The causes of such shortening of interval are discussed.


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