The pine processionary moth (
Thaumetopoea pityocampa
) was reported for the first time in North Bul-garia in 2022. Winter nests of the pest were observed in a number of pine plantations in more than ...10 sites of four Forest State Enterprises (Troyan, Sevlievo, Gabrovo, Plachkovtsi). The penetration of the pest into the new localities is due to a long-distance dispersion by vehicles. In January 2023, the nests in new localities contained fifth-instar larvae of
T. pityocampa
. Only about 3% of them were empty as larvae had descended in the soil for pupation. Based on the high population density and presence of old nests in some localities, it was assumed that the pest penetrated into Northern Bulgaria most likely 3-4 years ago.
Control biològic de la papallona de la processionària del pi Thaumetopoea pityocampa (Denis i Schiffermuller, 1775) mitjançant diversos extractes vegetals La finalitat del present estudi és oferir ...alternatives amb bioinsecticides elaborats a partir de productes naturals per combatre la papallona de la processionària, Thaumetopoea pityocampa (T. pityocampa), considerada una plaga defoliadora a causa dels danys que produeix en la silvicultura. Aquest insecte ocasiona així mateix problemes de salut en boscos o zones forestals obertes al públic. Amb aquest objectiu hem avaluat la toxicitat de sis extractes procedents de dues plantes: Taxus baccata i Populus nigra, recollits en diferents zones de Blida, contra larves en estadi 1 de T. pityocampa. Els assajos biològics han demostrat una reducció significativament diferent d’aquests insectes amb cadascun dels sis extractes. Els valors LD50 (dosi letal) es van calcular aplicant l’anàlisi probit amb la taula de Finney. Els valors LD50 van ser baixos en el cas de dos extractes: el metanol de pollancre (Populus Methanol) i el cloroform-metanol de pollancre (Populus Methanol Chloroform), amb 1,4 mg/ml i 3,3 mg/ml, respectivament. En canvi, les dosis LD50 de la resta d’extractes van ser relativament elevades. En conclusió, els insecticides biològics metanol de pollancre (PMP) i cloroform-metanol de pollancre (PMC) van resultar més eficaços i, per tant, es podrien integrar en el control biològic de T. pityocampa juntament amb parasitoides d’ous.
Akanthomyces spp. species are known for their capacity to biocontrol of certain insects and plant pathogens; however, their ability to biocontrol the pine processionary (Thaumetopoea pityocampa) and ...certain phytopathogenic fungi belonging to the genera Fusarium and Curvularia have not been studied before. In this study, a strain from Akanthomyces muscarius was isolated from wheat grains and then identified by morphological and molecular tests. The strain was further studied for its capacity to control Thaumetopoea pityocampa larvae through dose-mortality tests, and its ability to control some phytopathogenic fungi strains of the genera Fusarium and Curvularia was studied through direct confrontation tests. Dose-mortality tests at three concentrations of Akanthomyces muscarius against the first instar larvae revealed a mortality of 92.15% after 11 days for the concentration of 2.3 × 106conidia.ml−1, with a median lethal concentration of 7.6 x103 conidia.ml1. Our isolate also showed antifungal activity against these phytopathogenic fungi with inhibition rates ranging from 39.61% to 52.94%. Akanthomyces muscarius proved to be a promising biocontrol agent for plant pests and diseases.
The region of Gyumyurdzhinski Snezhnik in the Eastern Rhodopes is the closest in Bulgaria to the Aegean Sea. However, the climate is characterized by specific parameters that are determined by its ...relief. It is poorly protected from the invasion of cold air masses from the north. From the south, the Gyumyurdzhinski Snezhnik hill restrains the Mediterranean influence. The orography of the area favors the retention of cold air masses and a further drop in temperatures. The experimental material for the study includes 5 generations of
Thaumetopoea pityocampa
(2016, 2017, 2018, 2019, and 2022), collected in 31 locations of four State Forestry Enterprises: Kirkovo, Ardino, Momchilgrad, and Zlatograd. The sample for analysis included 693 egg batches with 148420 eggs in them. Seven primary egg parasitoids were established in this region:
Ooencyrtus pityocampae, Baryscapus servadeii, Pediobius bruchicida, Anastatus bifasciatus, Eupelmus vesicularis, E. vladimiri, Trichogramma
sp. and one hyperparasitoid (
B. transversalis
). Dominant parasitoids were
B. servadeii
and
O. pityocampae
, and
E. vladimiri
and
P. bruchicida
- occasional parasitoids. The hyperparasitoid B. transversalis participated in the complex with a relatively low share. The survival of the egg parasitoids in the laboratory conditions, in which the samples were kept, was low. The total mortality of the parasitoids in larval and adult stages was 47.8%. After collecting the samples, in laboratory conditions, a total of 442 individuals of the hyperparasitoid
B. transversalis
emerged, of which 56.3% were females and 43.7% were males. The average number of pine processionary moth eggs in a batch was 214.2. 70.8% of all the eggs in the samples hatched successfully. The egg parasitoids are a very serious natural factor, regulating the density of the pine processionary moth, but their impact varied from 2.1% to 30.3%. The natural characteristics of the area, the air temperature during the stages of eggs and young larvae, are favorable for the development of the pine processionary moth. Unhatched larvae without the influence of entomophages were 7.2%.
Global warming is predicted to cause distributional changes in organisms whose geographic ranges are controlled by temperature. We report a recent latitudinal and altitudinal expansion of the pine ...processionary moth, Thaumetopoea pityocampa, whose larvae build silk nests and feed on pine foliage in the winter. In north-central France (Paris Basin), its range boundary has shifted by 87 km northwards between 1972 and 2004; in northern Italy (Alps), an altitudinal shift of 110-230 m upwards occurred between 1975 and 2004. By experimentally linking winter temperature, feeding activity, and survival of T. pityocampa larvae, we attribute the expansions to increased winter survival due to a warming trend over the past three decades. In the laboratory we determined the minimum nest and night air temperatures required for larval feeding and developed a mechanistic model based on these temperature thresholds. We tested the model in a translocation experiment that employed natural temperature gradients as spatial analogues for global warming. In all transects we transferred colonies of T. pityocampa larvae to sites within zones of historical distribution, recent distribution, and outside the present range. We monitored air and nest temperature, incoming solar radiation, larval phenology, feeding activity, and survival. Early-season temperature effects on phenology were evident, with delayed development of colonies in the more extreme (colder) sites. In the coldest months, our model was consistent with the observed patterns of feeding activity: Feeding was progressively reduced with increasing latitude or elevation, as predicted by the lower number of hours when the feeding threshold was reached, which negatively affected final survival. Insolation raised nest temperature and increased feeding activity on the south but not the north aspect. Prolonged temperature drops below the feeding thresholds occurred at all sites, leading to starvation and partial mortality. Nonetheless, even the most extreme sites still allowed some feeding and, consequently, up to 20% colony survival and successful pupation. Given that the present distribution of the oligophagous T. pityocampa is not constrained by the disribution of its actual or potential hosts, and that warmer winters will cause the number of hours of feeding to increase and the probability of the lower lethal temperature to decrease, we expect the trend of improved survival in previously prohibitive environments to continue, causing further latitudinal and altitudinal expansion. This work highlights the need to develop temperature-based predictive models for future range shifts of winter-limited species, with potential applications in management.
Investigations on the egg parasitoid complex of the pine processionary moth (PPM), Thaumetopoea pityocampa, were performed in 2020-2022 in seven sites located in NW Italy to determine the parasitoid ...species composition, seasonal emergence, parasitoid species incidence, and parasitism rate. Furthermore, we examined whether the egg batches parameters and the parasitism rate were influenced by altitude and summer temperatures. A sample of 832 egg batches was collected, each batch consisting on average of 206 ± 5.73 eggs. In total, 35,881 egg parasitoids emerged, mainly represented by four primary species, namely Ooencyrtus pityocampae, Baryscapus servadeii, Anastatus bifasciatus and Trichogramma sp.. Parasitism ranged from 4.27% to 24.41% and the most representative species were O. pityocampae (68.38%) in 2020-2021, and Trichogramma sp. (56.50%) in 2021-2022. The altitude of the sites (808-1303 m a.s.l.) had a negative correlation with all the investigated egg batches parameters (e.g. batch length), and with the parasitism rate by A. bifasciatus and B. servadeii, while a positive correlation was found only for O. pityocampae. The number of days with temperatures above 30°C was positively correlated with parasitism rate for A. bifasciatus and O. pityocampae, and negatively for Trichogramma sp., while no correlation was found with B. servadeii. Since the performance and distribution of the natural enemies is highly dependent on climatic conditions, the regulating effect of parasitoids, reducing PPM population needs to be further investigated, to compare the complex of natural enemies across a wider geographic and climatic range.
The current study aims at investigating the spatial distribution of pine processionary moth (PPM) in parts of Al-Jabal Al-Akhdar region in Libya (in Shahat area). Two Pinus halepensis stands in the ...area (in Al-Mansurra and the ancient city of Cyrene) were chosen for field data collection. Growth parameters for pine trees including; tree height, crown height, diameter at breast height, stand density level, location within the stand, health condition, in addition to the observed number of PPM nests per tree were recorded. Pearson correlation coefficient analysis and variance analysis were applied to assess the relationship between obtained variables, and evaluate growth conditions for both stands. Results revealed relatively better growth conditions at Al-Mansurra site compared to Cyrene site. Moreover, PPM nests occurrence was positively correlated with trees growing isolated or on the stand edge (r = 0.54, P value <.001), and negatively correlated with tree height (r = - 0.4, P value <.001) emphasizing more dispersal rate among young pine trees. Crown height, dbh, and tree’s health condition showed no significant effect on PPM spread in the area. In-depth investigations of the population dynamics of PPM are highly recommended to provide insights into their spatial distribution in the region.
The purpose of the present work is to study the temperature effect on the flight initiation of the Thaumetopoea pityocampa. Our results show that the flight initiation of males is at relatively lower ...temperatures than females. Also, the average temperature for the flight initiation of the summer form is lower than for the winter one. This indicates a better adaptability of the summer form to lower ambient temperatures which should favour its spread in habitats located at a higher altitude in the country.
Pine processionary caterpillar nests are made from raw silk. Fibroin protein is the main component of silk which, in the case of pine processionary caterpillar, has some unusual properties such as a ...higher resistance to chemical hydrolysis. Isolation of microorganisms naturally present in silk nests led to identification of
and
strains that in a defined minimal medium were able to carry out extensive silk biodegradation. A LasB elastase-like protein from
was shown to be involved in silk biodegradation. A recombinant form of this protein expressed in
and purified by affinity chromatography was able to efficiently degrade silk in an in vitro assay. However, silk biodegradation by
strain was mediated by a SubC subtilisin-like protease. Homologous expression of a subtilisin Carlsberg encoding gene (
C) allowed faster degradation compared to the biodegradation kinetics of a wildtype
strain. This work led to the identification of new enzymes involved in biodegradation of silk materials, a finding which could lead to possible applications for controlling this pest and perhaps have importance from sanitary and biotechnological points of view.
PDF
