Pristiphora Abietina Research Articles (Page 1)

Abstract Pristiphora abietina (Hym.: Tenthredinidae) and Thaumetopoea wilkinsoni (Lep.: Notodontidae) are among the most detrimental forest pests in Türkiye. In this study, a prototype oil-based formulation named Pa4-OD was developed to control both P. abietina and T. wilkinsoni . Under laboratory conditions, the mortality rates for P. abietina and T. wilkinsoni larvae were 95.5% and 98.6%, respectively, 14 days after treatment with a spore concentration of 1 × 10 8 spores/mL. The median lethal concentrations (LC 50 ) of Pa4-OD were determined to be 2.6 × 10 3 for P. abietina and 7.9 × 10 6 spores/mL for T. wilkinsoni . The formulation was applied against T. wilkinsoni in the field experiment, resulting in 89.9% mortality at 1 × 10 9 blastospores/mL after three weeks (p < 0.05). Furthermore, the mycoinsecticide exhibited minimal adverse effects on Calosoma sycophanta L. (a predator of T. wilkinsoni ), Rhizophagus grandis Gyllenhal (a predator of Dendroctonus micans Kugelann is one of the most important pests of spruce forestry) and Thanasimus formicarius L. (another predator for forestry pests). The mortality rate of Apis mellifera caucasica Pollmann adults resulted in 76.6%, with mycosis observed in only 21% of individuals after ten days of exposure to a spore concentration of 1 × 10 9 spores/mL. However, few side effects were observed at other doses (1 × 10 5 to 1 × 10 8 spores/mL). This study demonstrated that mycoinsecticide development from the local entomopathogenic fungus B. bassiana could potentially be utilized to control P. abietina and T. wilkinsoni in Türkiye. Pa4-OD provides effective pest control while minimizing harm to beneficial insects, reducing reliance on synthetic insecticides, and supporting environmentally sustainable forest management.

This datasheet on Pristiphora abietina covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Natural Enemies, Impacts, Prevention/Control, Further Information.

Abstract Outbreaks of lesser spruce sawfly, Pristiphora abietina (Christ) (Hymenoptera: Tenthredinidae), on conifers regularly occur in Turkey and other European countries. Chemical pesticides have been used to contain outbreaks, but those may damage the forest and disturb natural enemies. To minimize the use of chemical pesticides in the management of this forest pest, we identified the entomopathogenic fungi (EPF) that naturally occur on P. abietina and tested their efficacy against the pest under laboratory and semi‐field conditions. Using morphological and molecular techniques, 13 EPF isolates were obtained from the pest and identified as Beauveria bassiana (Bals.‐Criv.) Vuill., Beauveria pseudobassiana S.A. Rehner & Humber, and Lecanicillium muscarium (Petch.) Zare & W. Gams. A laboratory screening test at 106 conidia ml−1 showed that all isolates caused 59‐100% mortality after 14 days. Further experiments were performed with the three most effective isolates, all belonging to B. bassiana. For these isolates, an increase in conidia dose increased pest mortality. Also, the ability of horizontal transmission in the pest population was shown. All three isolates were effective in killing P. abietina on spruce under semi‐field conditions. These data will contribute to the development of an integrated pest management program for P. abietina based on microbial biological control.

This work has been done for the purpose of creating a complete struggle strategy against Pristiphora abietina (Christ), which is the cause of the spoil in Artvin Savsat spruce forests in the recent years and Pyrethrum and Bacillus thuringiensis biopesticides effects has been investigated and put into practice on the P. abietina . Under laboratory conditions, Pyrethrum (Spruzit Neu) and B. thuringiensis (Dipel DF) biopesticides were administered at different doses to the larvae of P. abietina and the results were evaluated according to the One Way Analysis of Variance and Duncan Test. The most effective applications for larval applications have been determined that Dipel 100 gr / 100 lt, Dipel 300 gr / 100 lt and Dipel 500 gr / 100 lt. The Pyrethrum (Spruzit Neu) efficiency ratio was determined 71.7% dose of 150 ml / 100 lt, 81% dose of 300 ml / 100 lt, 93.2% dose of 600 ml / 100 lt and Dipel DF was found to be 91.5% dose of 100 g / 100 lt, 93.6% dose of 300 gr / 100 lt and 98.8% dose of 500 gr / 100 lt, respectively. As a result, using of both biopesticides have been effective to against on larvae of P. abietina .

Pristiphora abietina Christ. is one of the most dangerous pests of coniferous forest stands, especially at those that are located outside their natural vegetation area. During four years this species was monitored in Lunca Bradului Forestry Department and it has been found that there is a trend of reduced infested areas and the degree of infestation. Infested area decreased from 2.85% (in 2010) to 0.39% (in 2013) of the total area of the Forestry Department. As a result of soil surveys it was found that larval hibernating density ranged from: 1.3 to 25.2 larvae / m² (in 2010, from 1.2 to 6.5 larvae / m² (in 2011) , between 1.1 to 2.9 larvae / m² (in 2012), and between 1.1 to 2.2 larvae / m² (2013). This trend is determined both by the action of chemical control of larvae and due to the contribution of useful entomofauna. In this infested stands, we proceeded to multiplying the ant mounds. Entomofauna of predatory Carabidae collected in Barber traps is represented by 36 species. The dominant species are: Carabus ulrichii Germar. and Harpalus distinguendus Duft.

Hymenopteran specificity of Bacillus thuringiensis strain PS86Q3

The flight activity of spruce tenthredinids were studied using Malaise traps and yellow sticky boards in young spruce forests in the Nízký Jeseník Hills during years 2005 and 2006. In most cases, studied species (<I>Pristiphora abietina, Pristiphora saxesenii, Pristiphora gerula, Pristiphora leucopodia</I>) showed a statistically significant correlation between numbers of specimens caught at two- or three-day periods and numbers of budded spruces in both years.

Several methods of Pristiphora abietina adults catching were compared (Malaise trap, white and yellow sticky boards, sweeping). The yellow sticky boards are handy in the field, and under the high population density appear to be a reliable method of detecting sawfly populations: 1. There was a statistically significant coincidence between the samples of Malaise traps and yellow sticky boards. 2. There was a highly significant linear correlation between the number of caught adults on five sticky boards and the degree of defoliation in seven localities. 3. We did not observe any statistically significant differences between the samples on yellow sticky boards taken in different intervals. To estimate the abundance of adults, it is sufficient to install yellow sticky boards before swarming and check them after the swarming. 4. No statistically significant differences were found between the catch means per board in line with different number of boards, it means with different distance, in both male and females.

The population dynamics of Pristiphora abietina, an important pest in Norway spruce in central Europe, is significantly influenced by factors causing nymph mortality during the cocoon stage. In contrast to other findings reported in the literature, pathogenic fungi of the genera Beauveria, Paecilomyces and Metarhizium were found to be important natural enemies. Their epizootics occur soon after cocoon formation by the larvae in the ground litter, i.e. in June/July, and progress only slightly in autumn and winter. ‘Obscure’ mortality, which is ascribed mainly to abiotic factors, is observed more in winter. Field and laboratory experiments as well as histological analyses suggest that the fungal disease in nymphs is due to spore contamination occurring before cocoon formation, and that penetration of fungi from outside through the intact cocoon wall appears very unlikely. Thus, the infection rate of cocoons depends on the spore density in the ground litter of spruce stands during the cocoon spinning period of May/June. Perspectives for biocontrol arising from these findings are discussed.

Various species of Carabidae inhabiting spruce stands damaged by Pristiphora abietina (Christ 1791) show significant ecological peculiarities related to their predational meaning. Field studies on the mortality of cocoons of P abietina due to predators show their importance as antagonists. The most important species of ground beetles, antagonistic to P abietina and found in the investigated stands, were ascertained by feeding experiments. Altitude, exposition, age of stands, and vegetation of the sites support or affect the abundance of distinct species of Carabidae, and therefore influence their diversity. Though monocultures of spruce with little ground vegetation impede an optimal diversity of Carabidae, there is no difference of cocoon mortality due to predators between stands with sparse and those with more dense ground vegetation. On impoverished stands, the higher population densities of some of the essential antagonistic species of Carabidae probably compensate the more equally distributed frequencies and the greater diversity of Carabidac on sites with more ground vegetation. Therefore, low diversity of ground beetles does not seem to influence the duration of mass outbreaks of P abietina.

Abstract: Studies on ecophysiological aspects of the hibernation of the Spruce Sawfly, Pristiphora abietina Christ. (Hym., Tenthredinida). Pristiphora abietina survives the winter as a nymph in a cocoon resting in the upper layer of soil litter. In order to understand the causes of doubtful nymph mortality, the cold resistance and some features related to it were tested by experiments. During the period from July to March, the nymphs exhibit poor supercooling abilities, in the range from −3.6 to −7.7°C. The mean supercooling points show seasonal changes, with the lowest temperatures in November/December. The nymphs usually survived freezing at temperatures a few degrees beyond the supercooling point in dry and wet environments. Thus, Pristiphora abietina nymphs appear to be tolerant to freezing, as well as to inoculative freezing. Because the cocoon is permeable to water it does not protect the nymphs from superficial wetting. The cocoons represent an efficient shelter against transpiration, but even naked nymphs lose water very slowly in dry air. Therefore, a negative correlation between sensitivity to desiccation and tolerance to inoculative freezing is presumed. Physiological and ecological aspects of this feature are discussed within the context of hibernation.

Monitoring populations of defoliating sawflies in forests of Southwest Germany

The direct and indirect damaging effect of fertilizers, in forest perts. Insects depend on the physiological conditions of the plants on which they feed. Heat and dryness increases the content of sugar, aproximatly up to 50%, and other untrients in the plants during rainy seasons the proportion of sugar decrease. The osmotic valuation can be used as indicator of the physiological conditions of the plants. The high concentration of sugar stimulates the development of the insects. But they also thrives on plants with high turger. For example young larvae crowth only on newly burst open most turgescent needles and leaves. This will be demonstrated by the larvae ofLiparis monacha L.,Limantria dispar L., Pristiphora abietina Christ. and two Dreyfusia on the young needles of the silvec fir. Radio-active fertilizers enter the plants and insect feeding. Phosphorus (P 34) is mainly found in the intesties Calcium (Ca 45) is much more deposited in the Vasa Malpighi. Wie have the idea that the fertilizing may over-feed this organs. Our experiences demonstrates that the physiological conditions of the plants in spring and summer has upon the insects no decisive effect. The direct damaging effect of the fertilizers on the larvae is more violent. The absorbed fertilizers dangerously disturb the metabolism of the insects.

Some Observations on the Mortality of Pristiphora abietina (Christ) and Other Spruce Nematini during the Oviposition Period, and on the Effect of Temperature on Flight Intensity