| 1. |
- Lyytikäinen-Saarenmaa, P, et al.
(författare)
-
Monitoring the European pine sawfly with pheromone traps in maturing Scots pine stands
- 2006
-
Ingår i: Agricultural and Forest Entomology. - : Wiley. - 1461-9555 .- 1461-9563. ; 8:1, s. 7-15
-
Tidskriftsartikel (refereegranskat)abstract
- 1. During 1989-93, field studies were conducted in Finland to develop a method based on pheromone traps to monitor and forecast population levels of the European pine sawfly (Neodiprion sertifer Geoffr.) and tree defoliation. 2. Three traps per site were baited with 100 μg of the N. sertifer sex pheromone, the acetate ester of (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol), in maturing pine stands in southern and central Finland. In addition, three different dosages (1, 10 and 100 μg) of the pheromone were tested in 1991-92. 3. The highest number of males was observed in traps baited with the highest dose. On average, there was a 10-fold increase in trap catch between lure doses. 4. Density of overwintering eggs was used to evaluate the effectiveness of pheromone traps in predicting sawfly populations. The proportion of healthy overwintering eggs was determined each year. A model based on the number of current shoots on sample trees, diameter at breast height and tree height was formulated to estimate eggs per hectare. 5. Linear regression analysis produced high coefficients of determination between number of males in traps and density of total eggs in the subsequent generation, when populations were at peak densities. The relationships were not significant for low population densities. The results indicate a risk of moderate defoliation when the seasonal trap catch is 800-1000 males per trap or higher.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Lyytikäinen-Saarenmaa, Päivi, et al.
(författare)
-
Predicting pine sawfly population densities and subsequent defoliation with pheromone traps
- 2001
-
Ingår i: INTEGRATED MANAGEMENT AND DYNAMICS OF FOREST DEFOILIATING INSECTS, PROCEEDINGS. ; 277, s. 108-116
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Field in Finland to develop a monitoring and prediction trials were conducted from 1989 to 1993 method using pheromone traps for European pine sawfly (Neadiprion sertifer Geoffr.) population densities and needle defoliation. Three traps per site were baited with 100 mug of(2S,3S,7S) - 3,7 - dimethyl - 2 - pentadecyl acetate (diprionyl) at sites representing advanced pine stands. The number of overwintering eggs per sample branch was used to evaluate the effectiveness of using pheromone traps to estimate sawfly populations. The relationships between the number of males in traps, the number of eggs per branch in the subsequent generation, and the number of needle-year classes after the subsequent growing season were highly correlated. The risk threshold for moderate to heavy defoliation was around 1,000 males/trap. Our results suggest that after some minor improvements, a pheromone-based monitoring system for the European pine sawfly would provide an effective tool for integrated pest management programs and successful forest management in coniferous pine-dominated forests.
|
|
| 6. |
- Anderbrant, O., et al.
(författare)
-
Electrophysiological and morphological characteristics of pheromone receptors in male pine sawflies, Diprion pini (Hymenoptera : Diprionidae), and behavioural response to some compounds
- 1995
-
Ingår i: Journal of Insect Physiology. - : Elsevier BV. - 0022-1910. ; 41:5, s. 395-401
-
Tidskriftsartikel (refereegranskat)abstract
- The morphology and physiology of pheromone receptors on the antennae of male pine sawflies, Diprion pini L., were investigated. Using scanning electron microscopy, five sensillar types were recognized. The type shown to be pheromone sensitive has a long (50-70 μm) cuticular hair, is single-walled, and is innervated by 8 or 9 sensory cells as revealed by transmission electron microscopy. Electroantennography (EAG) showed similar activity of the acetate and propionate of (2S,3R,7R)-3,7-dimethyl-2-tridecanol, precursor of the main constituent of the female-produced sex pheromone. No other isomer induced any significant response. Single-sensillum recordings confirmed the results of the EAG, and also showed that several neurons were excited by the active compound. EAG recordings and combined gas chromatographic-electroantennographic detection indicated that esters of three 3,7-dimethyl-2-pentadecanol (diprionol) isomers were active, but field tests could not demonstrate any behavioural effect. Diprionol esters are used as sex pheromones by all other pine sawflies investigated so far, and D. pini is thus the first diprionid species shown to use a different sex pheromone.
|
|
| 7. |
|
|
