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Beekeeping and honey production have been of great historical, economic, and health interest in Lebanon. However, the Lebanese beekeeping sector is poorly documented, not to mention the challenging...

The effects of entomopathogenic nematodes EPN (Steinernematidae and Heterorhabditidae) and fungi EPF (Beauveria bassiana) strains were evaluated in laboratory assays against larvae of four xylophag...

Multi-drug resistance is posing major challenges in suppressing the population of pests. Many herbivores develop resistance, causing a prolonged survival after exposure to a previously effective pesticide. Consequently, resistant pests reduce the yield of agricultural production, causing significant economic losses and reducing food security. Therefore, overpowering resistance acquisition of crop pests is a must. The ATP binding cassette transporters (ABC transporters) are considered as the main participants to the pesticide efflux and their neutralization will greatly contribute to potentiate failed treatments. Real-Time PCR analysis of 19 ABC transporter genes belonging to the ABCB, ABCC, ABCG, and ABCH revealed that a broad range of efflux pumps is activated in response to the exposure to pesticides. In this study, we used beauvericin (BEA), a known ABC transporters modulator, to resensitize different strains of Tetranychus urticae after artificial selection for resistance to cyflumetofen, bifenazate, and abamectin. Our results showed that the combinatorial treatment of pesticide (manufacturer’s recommended doses) + BEA (sublethal doses: 0.15 mg/L) significantly suppressed the resistant populations of T. urticae when compared to single-drug treatments. Moreover, after selective pressure for 40 generations, the LC50 values were significantly reduced from 36.5, 44.7, and 94.5 (pesticide) to 8.3, 12.5, and 23.4 (pesticide + BEA) for cyflumetofen, bifenazate, and abamectin, respectively. While the downstream targets for BEA are still elusive, we demonstrated hereby that it synergizes with sub-lethal doses of different pesticides and increases their effect by inhibiting ABC transporters. This is the first report to document such combinatorial activity of BEA against higher invertebrates paving the way for its usage in treating refractory cases of resistance to pesticides. Moreover, we demonstrated, for the first time, using in silico techniques, the higher affinity of BEA to ABC transformers subfamilies when compared to xenobiotics; thus, elucidating the pathway of the mycotoxin.Other Information Published in: Scientific Reports License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1038/s41598-021-89622-5

The virulence of aerial conidia of the entomopathogenic fungi Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) has been documented on a very broad range of arthropods; however, the activity of blastospores against the two-spotted spider mite has been seldomly reported. Moreover, studies investigating the activity of blastospores under greenhouse conditions were not found in the literature. In this study, we tested the efficacy of blastospores and aerial conidia of two B. bassiana strains, against all life stages of Tetranychus urticae Koch (Acari: Tetranychidae). The concentration of 109 blastospores/ml of the Lebanese strain was the most efficient in laboratory experiments, and the recorded mortalities were 52, 67.9 and 95.3% in treated eggs, motile juveniles and adults, respectively. In greenhouse experiments, higher T. urticae mortalities were recorded among strawberry plants (Fragaria x ananassa) sprayed with blastospores of B. bassiana. Furthermore, the latter plants also recorded a higher yield (454.92 ± 5 g/plant) compared to infested control plants (144.42 ± 5 g/plant) during the growing season. In addition, this study also investigated for the first time the resistance development of T. urticae to different types of infective propagules of B. bassiana. Under selective pressure for 40 generations, the laboratory yielded aerial conidia (AC-TSM) and blastospores (BS-TSM) resistant strains of the mite recorded 28.8- and 8.4- fold change in LC50 values respectively when compared to the field strain; however, this resistance ratio was minimal when compared to those of chemical acaricides.

West Palearctic bumblebees are common wildflowers and crop pollinators that are well studied in their central and northern distribution ranges, but fewer information is available on their southern distribution areas. Lebanon falls on the southern limit of their distribution and no published information is available on the local bumblebees. Our study aims to produce a data baseline of the local bumblebee species. In order to do so we grouped available old records of bumblebees in Lebanon with recent author collections and produced preliminary distribution maps. We listed four species: Bombus terrestris, B. argillaceus, B. niveatus vorticosus and B. melanurus. Preliminary distribution shows that Bombus terrestris and B. argillaceus are widespread and have a large foraging range, whereas B. niveatus vorticosus and B. melanurus have a restricted distribution to altitudes above 1800 m with a smaller foraging range. The male cephalic labial gland secretions analysis of local Bombus terrestris specimens provides preliminary evidence that the local subspecies could be Bombus terrestris calabricus. Therefore, we highlight the importance of regulating foreign Bombus terrestris subspecies importation for agriculture purposes, as well as monitoring B. niveatus vorticosus and B. melanurus that are rendered vulnerable by their isolated populations.

The entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin is known to produce a broad range of secondary metabolites. Beauvericin, a cyclic hexadepsipeptide, is the best known mycotoxin produced by B. bassiana; however, reports discussing the insecticidal activity of beauvericin per se are limited. In this study, we assessed the lethal activity of beauvericin against Tetranychus urticae Koch (Acarina: Tetranychidae). In addition, screening for suitable application of the mycotoxin against T. urticae on greenhouse strawberries is discussed. Beauvericin was able to control successfully T. urticae where concentrations of 10, 100 and 1,000 µg/g recorded mortalities of 84%, 100% and 100%, respectively, against motile stages. Furthermore, beauvericin inhibited egg hatching up to 83.3%, 69.3% and 53.3%, respectively, using the same concentrations under laboratory conditions. Under greenhouse conditions, the efficacy recorded was 52.6%, 85.7%, 72.4% and 72.4% at 1, 3, 7 and 10 days post‐inoculation, respectively. Beauvericin was efficacious under greenhouse conditions since the application increased strawberry yields while showing no phytotoxicity and ecotoxicological risk. Resistance to beauvericin was not detected initially at the unselected strain of T. urticae. Yet, the laboratory selection of populations of T. urticae exposed to beauvericin resulted in relatively resistant T. urticae strain that displayed no cross‐resistance to cyflumetofen and bifenazate. The acaricidal activity of beauvericin documented in this study would increase the efficacy of integrated pest management strategies.

Drug discovery has been initially attributed to coincidence or trial and error where the traditional approach was complex, lengthy, and expensive. Conventional drug discovery methods require the costly random screening of synthesized compounds or natural products. Another downside for this approach is the wide dependency on the experimental use of animals for in vi-vo testing. Currently, in silico modeling has become a vital tool for drug discovery and repurposing, and molecular docking is being used to find the best matching between a ligand and a molecule. Practical application of in silico docking will predict the biomolecular interactions between the drug and the target host. Beauvericin (BEA) is an emerging mycotoxin produced by the entomopathogenic fungus Beauveria bassiana. Originally investigated for its pesticide capability, BEA is now considered as a molecule of interest for its potentially diverse biotechnological applications in the pharmacological industry and the field of medicine. In this manuscript, we will provide an overview of the repurposing of BEA into a potentially superior therapeutic molecule in a broad range of diseases. Furthermore, considerable attention has been given to the fundamental role of in silico techniques to i) further investigate the spectrum of this secondary metabolite and ii) elucidate the pathways of BEA for its promising therapeutic action

The study of wild bees has markedly increased in recent years due to their importance as pollinators of crops and wild plants, and this interest has been accentuated by increasing evidence of global declines in their abundance and species richness. Though best studied in Europe and North America, knowledge on the current state of wild bees is scarce in regions where they are particularly diversified, such as the Mediterranean basin. The eastern Mediterranean country of Lebanon, located at the heart of the Levant in a biodiversity hotspot, is particularly poorly studied. The aim of this paper is to produce a first annotated checklist of the wild bees of Lebanon from new and museum collections, literature records, and verified occurrences from online databases. The present list totals 573 species for Lebanon of which 289 are reported for the first time, but the estimated diversity is likely to be closer to 700. Preliminary information on local distributions and flower records are also presented. The local species assemblages indicate affinities with montane habitats of the Mediterranean and Anatolia and the semi-arid habitats of the Levant and north Africa. This study also encourages further research on local wild bee faunas and the use of this knowledge for conservation purposes.

The entomopathogenic fungus Beauveria bassiana has been successfully used for the control of phytopathogenic arthropods and there are a growing number of studies suggesting that this kind of fungus could also be used for the control of ectoparasites in mammals. This study evaluated for the first time the efficacy of different Beauveria strains against the eggs of Sarcoptes scabiei collected from experimentally infected pigs. Eggs were exposed to fungal conidia and monitored for hatching over 10 days. The strongest effect (28.75 % of hatching inhibition) was obtained with a commercial B. bassiana strain. Furthermore, the detection of fungal genomic within the surface-cleaned eggs demonstrated the ability of B. bassiana to penetrate and proliferate in the egg-shell of S. scabiei. This study provides the first evidence, using molecular techniques, that the development of mycoacaricides may be of interest for the control of S. scabiei infection.

Mediterranean stone pine nut is appreciated for its high economic and nutritional value. Starting in 2012, Pinus pinea nut production declined throughout the Mediterranean area. The dry cone syndrome associated with this decline and the introduction of Leptoglossus occidentalis occurred simultaneously. This study aims to evaluate potential reasons behind the decline in pine nut production in Lebanon, considering climatic factors and the invasion of L. occidentalis. Correlation analysis was used to examine a potential relationship between cone yield and the percentage of damaged seeds per cone. Climatic variables were also tested. Two time periods were considered for analysis: before and after 2012. Cone production and the percentage of damaged seeds were negatively correlated (r = −0.42). From 2012 to 2017, cone production declined by 50% and the percentage of damaged seeds increased on average from 3% in 2012 up to 60% in 2017. Correlations were detected between cone production and the temperature of the hottest three months of the year of harvesting, and between cone production and average temperatures during the year of cone initiation. A conjunction of factors that include L. occidentalis and climatic factors might have affected the pine nut production in Lebanon.

International audience; Pinus pinea is a species of great economic and ecological importance in Lebanon, but there is a lack of knowledge about the distribution of the pine forests, their vegetation dynamics and regeneration. Our study aims to produce the first classification of the pine stands according to their floristic composition and the abiotic factors of the Mount Lebanon region and to analyse natural pine recruitment. Floristic composition, environmental and soil factors as well as stand dendrometric characteristics and woody seedling regeneration were recorded on fifty plots distributed in the main stone pine stands of the study area. Using canonical correspondence and clustering analyses, we classified pine stands into five groups which were mainly influenced by physiographic factors (altitude, slope, temperature, rainfall), nature of the bedrock, and evidence of human interventions. Most stone pine stands in Mount Lebanon were dense (849 stems.ha−1), old (81 years) with a high basal area (49 m2.ha−1). Pine regeneration was particularly scant, and the understory was dominated by the oak species: Quercus calliprinos, mainly and Quercus infectoria, secondarily. Based on these results, we concluded that the presence of stone pine and its persistence are linked to human actions. In the absence of human intervention, the stone pine stands will progressively disappear and be replaced by oak formations. Thus, an urgent management plan is required to favour pine regeneration to allow for the renewal of the pine stands in the Mount-Lebanon region.

First records of 93 species of fungus weevils (Anthribidae), leaf rolling weevils (Attelabidae), seed weevils (Brentidae: Apioninae) and true weevils (Curculionidae) to the fauna of Lebanon are reported with the list of the 145 species of Curculionoidea collected by the Hungarian Natural History Museum and cooperating partners in Lebanon between 2015 and 2018. With 18 figures.

First records of four longhorn beetles to the fauna of Lebanon with list of the species collected by the members of the Hungarian Natural History Museum and cooperating partners in Lebanon between 2015 and 2018. With 42 figures.

BackgroundScabies is a frequent cutaneous infection caused by the mite Sarcoptes scabiei in a large number of mammals including humans. As the resistance of S. scabiei against several chemical acaricides has been previously documented, the establishment of alternative and effective control molecules is required.ObjectivesIn this study, the potential acaricidal activity of beauvericin was assessed against different life stages of S. scabiei var. suis and, in comparison with dimpylate and ivermectin, two commercially available molecules used for the treatment of S. scabiei infection in animals and/or humans.MethodsIn our in vitro model, developmental stages of S. scabiei have been placed in Petri dishes filled with Columbia agar supplemented with pig serum and different concentrations of the drugs. Moreover, the toxicity of beauvericin against cultured human fibroblast skin cells was evaluated using an MTT proliferation assayResultsBeauvericin showed higher activity against adults and eggs of S. scabiei when compared to dimpylate and ivermectin. In addition, cell sensitivity assays demonstrated low toxicity of beauvericin against primary human fibroblast skin cells.ConclusionThese results revealed that the use of beauvericin is promising and might be considered for the treatment of S. scabiei infection.

The analysis of forest structure is a useful tool to understand stand biodiversity characterizing forest ecosystems, and could help in suggesting appropriate management plans. Cedar forests in Lebanon are remnant patches that survived past human activities but are still threatened by other different anthropogenic and natural disturbances. Among these threats, the cedar web-spinning sawfly (Cephalcia tannourinensis) discovered in Tannourine Cedar Forest Nature Reserve in 1997, which is able to cause the death of trees. The aim of this study is to investigate the impact of this pest on the stand structure and regeneration of Cedrus libani in Tannourine Cedar Forest Nature Reserve located in North Lebanon. The dependence of stand structural attributes (diameter at breast height, total height and basal area) on the presence of infestation by the cedar web-spinning sawfly was identified using the Student’s t-test. The Ripley’s K(d) function was used to analyse the spatial pattern of cedar stands. In addition, the diameter, the vertical structure and the crown projection were characterized using the Weibull function and graphic representations. The results showed that stand structure and regeneration are significantly different between infested and non-infested stands. The cedar of Lebanon remains as the dominant species, with abundant young individuals and a good regeneration status (c = 1.0). The analysis of the spatial pattern showed a positive spatial relationship between mature Lebanese cedar trees as well as between mature and juvenile cedars, with a bigger aggregation in infested plots (6 to 10 meters) than in non-infested quadrates (2 to 7 meters), reflecting the impact of the cedar web-spinning sawfly on the stand structure and regeneration of Cedrus libani stands.

The sweetpotato/cotton whitefly, Bemisia tabaci(Gennadius) is a major pest of several crops worldwide. In addition to the direct damage induced, it has the ability to transmit some of the most dangerous plant viruses rendering it a very critical pest.The development of whitefly resistance to several groups of pesticides forced farmers and researchers to adopt integrated pest management strategies and to look for alternative control measures. Studies using molecular markersshowed the coexistence in Lebanon oftwo species, the “Middle East-Asia Minor 1 species” also known as biotype B and the “Mediterranean species”also known as biotype Q. In greenhouse trials, the Beauveriapseudobassianaisolated in Lebanon wasfound to be quite efficient for themanagement ofB. tabaci. Sprays containing spore suspensions of 107spores/mL caused around75% mortality of the early growth stages: egg, crawler,second and third instar larvae. The addition of a surfactant such as corn oil improved the mortality level thatreached 98% in the egg /crawler stage and 84% in the second and third instar larvae at a spore concentration as low as 105conidia/mL. In view of the promising results, further medium size trials under commercial greenhouse conditions are planned.

New data and new catalogue of the Coleoptera Cerambycidae of Lebanon (Coleoptera, Cerambycoidea). Faunistical prospectings and bibliographical researches gives several interesting or new information justifying a new list of Cerambycidae species from Lebanon. Our work rises to 125 the number of species known from this country ; Mesoprionus lefevrei, Arhopalus ferus, Trichoferus fasciculatus, Stenopterus flavicornis, Callimus (Procallimus) egrerius, Deilus rugosicollis, Echinocerus floralis, Agapanthia (Epoptes) pustulifera, Agapanthia (Smaragdula) lais, Mallosia (Eumallosia) imperatrix, Phytoecia (Helladia) armeniaca, P. (H.) ferrugata, P. (H.) pretiosa, P. (Phytoecia) pubescens and Pteromallosia albolineata are new records for Lebanon. Numerous taxonomical and nomenclatural modifications are given according the most recent synthetic work., Des prospections faunistiques et des recherches documentaires ont permis de recueillir un nombre intéressant d’informations nouvelles qui justifient la présentation d’une nouvelle liste d’espèces de Cerambycidae du Liban. Notre travail porte le nombre d’espèces connues de ce pays à 125, parmi lesquelles Mesoprionus lefevrei, Arhopalus ferus, Trichoferus fasciculatus, Stenopterus flavicornis, Callimus (Procallimus) egrerius, Deilus rugosicollis, Echinocerus floralis, Agapanthia (Epoptes) pustulifera, Agapanthia (Smaragdula) lais, Mallosia (Eumallosia) imperatrix, Phytoecia (Helladia) armeniaca, P. (H.) ferrugata, P. (H.) pretiosa, P. (Phytoecia) pubescens et Pteromallosia albolineata sont nouvellement citées du Liban. De nombreuses modifications taxonomiques et nomenclaturales sont effectuées en référence au travail de synthèse le plus récent., Cocquempot Christian, Nemer Nabil, Brustel Hervé, Tanios Challitah. Nouvelles données et nouveau catalogue des Coléoptères Cerambycidae du Liban (Coleoptera, Cerambycoidea). In: Bulletin de la Société entomologique de France, volume 121 (1),2016. pp. 91-104.

International audience; Tannourine cedars forest, dominated by cedars (Cedrus libani, Richard), suffers from native sawfly attacks, Cephalcia tannourinensis (Chevin). The current study assesses the presence of entomopathogenic nematodes (EPNs) endemic to the forest for their potential use as biocontrol agents in an integrated pest management to control C. tannourinensis. A survey was conducted using Galleria mellonella baits in fifteen selected sites taking into consideration the cedars' different habitats. One EPN species, Steinernema feltiae, as determined by morphometric and molecular analyses, was found in one site in the forest and was tested under laboratory conditions against C. tannourinensis prepupae, causing a mortality of 64% at 250 Infective Juveniles (IJs)/prepupa. In light of previous studies, Heterorhabditis bacteriophora (commercial strain) was accordingly considered for the controlled in situ experiments where the pathogenicity of this EPN was evaluated on C. tannourinensis. A concentration of 625,000 IJs/m(2) of H. bacteriophora caused a mortality rate of 85% on C. tannourinensis following inundative treatments conducted in jars buried in the forest's soil. While EPN succeeded to emerge from G. mellonella cadavers under the same conditions, no EPN emerged out of C. tannourinensis despite the high mortality percentage; also, opportunistic nematodes emerged unexpectedly out of C. tannourinensis cadavers.

Cedars of Lebanon Cedrus libani have been attacked since 1990s by a hymenopteran sawfly, Cephalcia tannourinensis (Chevin), causing considerable damage to the foliar buds. A biological control programme using entomopathogenic nematodes (EPNs) was conducted in vitro against C. tannourinensis prenymphs. Two EPNs strains belonging to the same species Heterorhabditis bacteriophora were used; one indigenous to the country (LIB04) and the other a commercial strain (HbCom). Four EPNs concentration rates (40, 100, 250, 480 infective juveniles) were tested against C. tannourinensis prenymphs. Higher mortality was noted for the indigenous strain, LIB04, independently from all concentrations (100%). Emergence of EPNs was observed following 12–17 days from the first contact between EPNs and C. tannourinensis prenymphs. This parameter indicated that EPNs succeeded to complete all their reproductive cycle inside the C. tannourinensis cadavers before emerging. Bioassays were realised in jars containing soil extracted fr...

International audience; Pinus pinea is an important species for ecological and economic reasons in the Mediterranean area and especially in Lebanon. However, conditions of its natural regeneration have received little attention. Our study aimed to test the influence of soil disturbances, predation and autotoxicity on pine regeneration. A seed sowing field experiment was conducted in a mature stand in which two types of soil disturbances were tested (soil scarification and litter burning) in presence or absence of predation. In addition, a laboratory experiment evaluating the influence of litter (present, absent or burned) and green needle leachates (i.e. in order to mimic potential autotoxicity) on seed germination and seedling growth was conducted. Results showed a strong effect of soil disturbance, in particular soil scarification which promoted seedling emergence and early survival, whereas the role of predation was low. Forty to sixty days after seed installation, seedling density peaked at 14.9 ± 0.4 seedling.m in the scarification treatment, 13.1 ± 0.4 in the burning treatment and 8.4 ± 0.4 in the control treatment. However, an unexpected high mortality rate was recorded at the end of the field experiment in all treatments, as after seven months seedling density dropped to 0.2 ± 0.02. In the laboratory experiment, we emphasized an autotoxic effect of green needle aqueous extract on seed germination and seedling growth in the presence of litter. This allelopathic effect could be potentially linked to the presence of quinic acid which was measured as the major metabolite detected in needle aqueous extracts. In conclusion, we recommend soil preparation treatments to favour seedling emergence in combination with thinning to achieve seedling development on the long term.

The cedar web-spinning sawfly, Cephalcia tannourinensis (Hymenoptera: Pamphiliidae) is considered a major defoliator of the cedar forests in Lebanon. In the early 1990’s, a severe damage of the Tannourine Hadath El-Jebbeh cedar forest was caused by the sudden outbreak of this insect. The insect has a complex life cycle with two types of diapause: annual diapause and multiple years diapause. The present study aimed at studying soil characteristics and their influence on the survival and diapausing cycles of C. tannourinensis prepupae. Different soil samples collected from three different cedars forests in Lebanon were incubated with prepupae of C. tannourinensis under laboratory conditions. The effect of soil origins and properties on prepupal mortality, annual diapause and multiple years diapause cycles were analyzed. The influence of soil moisture and soil temperature on prepupal development was studied separately through two constant temperatures and three constant soil moisture levels. Prepupal mortality was found to be highly correlated with soil properties and types. Prepupae survived well in soil coming from Tannourine and Bcharry followed by Chouf. However mortality was almost 100% in the two reference soils sand and peat. Diapause cycle was strongly correlated with temperature while the effect of moisture was mainly on the prepupal survival. Keywords: Cephalcia tannourinensis, soil moisture, soil temperature, annual diapause, multiple years diapauses.African Journal of Biotechnology, Vol 13(47) 4369-4381

The entomopathogenic fungus Beauveria bassiana is used as a natural pest killer in many agricultural systems due to its power of overcoming the host immune system. This is partially due to its genome content that expresses key proteins involved in its virulence. In this study, we used Real-Time PCR technique to analyze the relative expression at 48 and 72 h post inoculation of the Hyd1, Hyd2, Bbchit1, Cdep1, Bbbeas, Bbbsls and Vlp4 genes implicated in the pathogenesis process of an indigenous strain (LTB) and a commercial strain (IND) of B. bassiana. This analysis revealed a higher induction of Bbbeas, Bbbsls and Vlp4 genes by the LTB strain when comparing to the IND strain and the calibrator. Furthermore, a more rapid repression of Hyd1 and Hyd2 gene was notable by LTB strain. No significant difference was recorded by the expression of the Cdep1 gene between the test samples and the control. Finally, a significant difference was recorded with the expression of Bbchit1 gene by the IND strain 72 h post-inoculation. In conclusion, these results suggest that B. bassiana strains have differential expression of virulence genes that could reflect adaptation to their geographical environment and could help classifying their entomopathogenic efficacy accordingly.

The effect of climate change on forests varies with the geographical zone and climatic conditions of countries and regions. While climatic records for the Western Mediterranean show slight trends towards warmer and drier conditions over the last century, parts of the Eastern Mediterranean have experienced cooler and wetter conditions. Mediterranean forests are likely to be impacted by these changes, which could reduce their mitigation potential. If climate change occurs faster than new ecosystem structure and function can be developed, then the historical relationships between animal, plant and climatic conditions may not be reestablished and biological diversity will be reduced. During the last three decades, an expansion of the geographic range of major forest insect pests, caused by increased winter temperatures, have been observed worldwide. In Lebanon, changes in climatic conditions are linked with an altitudinal shift in bioclimatic zones. Cedar forest reserves, typical of the Montane-Medit...

A Lebanese isolate of a Beauveria species originally isolated from a hymenopterous insect pest was found to be very effective against the pine processionary moth Thaumetopoea wilkinsoni. In laboratory bioassays, high mortality rates of the five larval stages were attained with spore concentrations of about 5000–50,000 spores/larva. The efficacy of kill on the first three larval stages was similar to the growth regulator diflubenzuron, but it was significantly higher on the fourth and fifth larval stages. Sequences of the DNA lyase gene and the EF-1α gene were used for molecular characterisation of this Beauveria isolate. The DNA lyase gene showed more polymorphism than the previously reported ITS region and EF-1α gene. This constitutes the first report on the possibility of using the DNA lyase gene as a molecular tool in fungal taxonomy.

Prangos species have been commonly used in traditional medicine in East Mediterranean and Middle Eastern countries. The hydrodistilled essential oils by HDC from different fresh aerial parts (stems and leaves, flowers and fruits) of Prangos asperula Boiss., growing wild in Lebanon were analyzed by gas chromatography-mass spectrometry. Forty two, 46 and 4 compounds representing 75.5%, 86.9% and 99.8% of the total fresh stems and leaves, flowers and fruits oils were, respectively, identified. The main compounds characterizing these oils were nerolidol (15.2%), p-menth-3-ene (13.3%), β-myrcene (9.2%) in stem and leaves; p-menth-3-ene (14.9%), nerolidol (14.7%), β-phellandrene (7.9%) in flowers; sabinene (43.5%), β-phellandrene (36.1%), α-phellandrene (11.9%) and α-terpinene (8.3%) in fruits. The antimicrobial activity of the total essential oil evaluated by growth inhibition and MIC values revealed variable levels of susceptibility in the tested bacteria and fungi. S. aureus displayed highest sensitivity (15.06 mm, MIC 5.0 μl), followed by E. coli (11.80 mm, MIC 10.0 μl), A. fumigatus (9.16 mm, MIC 10.0 μl), T. mentagrophytes (7.3 mm, MIC 25 μl), S. enteritidis (3.8 mm, MIC 25 μl) and C. albicans (1.96 mm, MIC 50 μl). The oil displayed a remarkable activity against both S. aureus being more effective than the antibiotic Norfloxacine (10 μg) and T. mentagrophytes which was completely resistant to the antifungal Nystatine (100 μg). The findings confirm the traditional use and promising potential of the antibacterial properties of this plant oil. This opens the possibility for further research on other biocidal activities and investigations of individual antimicrobial and antifungal component.

Larvae of the cedar web-spinning sawfly, Cephalcia tannourinensis Chevin (Hymenoptera: Pamphiliidae), infected with a white fungus were collected from the Tannourine-Hadath El-Jebbeh cedar forest. Macro- and micro-morphological data based on the examination of colonies, conidiophores, and conidial shape of the fungus suggested a Beauveria species. Sequence analysis of the internal transcribed spacer regions of the isolated fungus showed that it is most closely related to isolates of B. bassiana Clade C. The present study showed that the isolated B. bassiana is a naturally occurring entomopathogenic fungus parasitizing the larvae of C. tannourinensis in Lebanon. Laboratory bioassays showed that B. bassiana caused high mortality of eggs and larvae. The infected eggs turned brownish in color, while larvae of the first instar ceased feeding and showed immobility and rigidity within 5 days and before sporulating conidial mat appeared on their cuticle. Second and third larval instars took longer time to show fungal sporulation: mortalities ranged between 85 and 100% within 7 days when treated with different conidial concentrations. The efficacy of control of C. tannourinensis using B. bassiana was higher or equal to the reference insect growth regulator, diflubenzuron, suggesting the possibility of its success as a biological control agent.

Olive tree is considered one of the most important cultivated crops in Lebanon. The cultivated area is mainly concentrated in the north and south Lebanon. Among the obstacles affecting olive cultivation is the olive fruit fly infestation which negatively alters the quality of olive oil. Olive fruit fly (Bactrocera oleae) is mainly controlled by chemical means. At the present time, no biological program against this pest is considered in Lebanon. The aim of this study is to investigate the status of olive fruit fly parasites in Lebanon. The study was conducted for one year in 28 orchards located in five regions of olive production. Fruit samples were collected weekly from June to October. A total of 23096 fruits was collected from all orchards. Eight parasites were detected. Eupelmus urozonous and Opius concolor were the most abundant parasites in most orchards, the others were restricted to specific locations. The only exception was observed at Abdeh site where most of the parasites were isolated. Parasitism rates ranged from 2.4 to 42.1 % and the average rate of all locations was 13.3%. The low parasitism rate recorded in this study is insufficient to control olive fruit fly. Introduction and rearing of natural enemies along with other management tactics may enhance the control of olive fruit fly infestation

It is difficult to find a genus of Lepidoptera showing the high variability of life history traits observed in Thaumetopoea. There are typical summer feeding close to winter feeding species, and in one special case a recent switch has been detected even within one species, the pine processionary moth, indicating that the natural history traits are constantly evolving at a fast rate. There are species adapted to cold conditions of high mountains and high latitude close to truly Mediterranean and sub-desert region species. All species have gregarious behaviour as larva and are protected against vertebrate predators by urticating setae.

Summary Host preference bioassays for adults of the sweetpotato whitefly were performed with leaves of the chinaberry tree Melia azedarach L., tomato, cucumber and bean. Fruit and leaf extracts of the chinaberry tree were tested against adults of the sweetpotato whitefly. Fruit extracts were tested against eggs, first and second instar nymphs, and pupae of the insect. Treatments included aqueous, methanol, and acetone fruit extracts of 200 mg ml−1 and serial dilutions of 20.0 and 2.00 mg ml−1, ether extract, the botanical insecticides Azatin® and Margosan® -O and the control, water or water with Triton®. Mortality data was collected at 6, 7, and 8 days after treatment of the eggs, nymphs and pupae, respectively. Results of the host preference bioassays indicated a significantly lower number of live insects on leaves of the chinaberry tree vs leaves of bean, cucumber, and tomato after 24 h. This indicates that M. azedarach is not a good host for the sweetpotato whitefly. Adults of the insect were significantly more repelled from tomato plants treated with the undiluted extracts when compared to the control after 72 h. There were significant differences in percent mortality of nymphal instars when exposed to the undiluted extracts compared to other extracts and the control. However, there was no significant effect of the fruit extracts on the egg and pupa instars. Thus M. azedarach extracts were found to be repellent to the whitefly adults, while the fruit extracts have shown a significant detrimental effect against early nymphal instars. In general, the methanol extracts were more active against B. tabaci than extracts with other solvents.

Aqueous extracts of fruits and leaves of the Chinaberry tree, Melia azedarach L. were tested for their efficacy versus other biotic and synthetic insecticides against the pea leafminer, Liriomyza huidobrensis (Blanchard). The study included field experiments on naturally infested swiss chard, Beta vulgaris var. Cicla L., and greenhouse experiments on artificially infested cucumber, Cucumis sativus L. that were conducted in 1995–96. The other treatments included azadirachtin (0·25%), ultrafine mineral oil, abamectin, cyromazine, imidacloprid, pyrazophos and control. Results of field experiments indicated that Melia fruit extract and the other insecticides significantly lowered the number of larvae per swiss chard plant as compared to the control, at 5 days sampling after second spray or 15 days after first spray, when two consecutive sprays were performed. However, at 10 days after second spray, the fruit extract did not differ significantly from the control, but it was comparable in its effect to the insecticides, except abamectin and cyromazine. In greenhouse experiments, the pea leafminer larvae were found at higher densities on cucumber leaves located at the lower plant part (10–60 cm) compared to other leaf positions. The Melia fruit extract and the other pesticides significantly decreased the number of live larvae per cucumber leaf compared to the control, 10 days after each spray. The fruit extract, abamectin, cyromazine, imidacloprid and pyrazophos lowered the leafminer population significantly compared to the control, throughout the period of the experiments. However, the fruit extract was significantly less effective than these insecticides at the final count, 20 days after second spray. Abamectin and cyromazine consistently showed a significant decrease in number of larvae, in both field and greenhouse experiments. At certain periods of the experiments, Melia extracts were comparable in their efficacy to the tested commercial biorational and synthetic pesticides. Thus, they have a good potential to be used in the management of the pea leafminer. This is the first report for use of M. azedarach against L. huidobrensis.

Liriomyza huidobrensis, the pea leafminer, is a recently identified pest on vegetables in Lebanon. The objectives of this study were to survey the leafminer infestation, to study its dispersion and its development on cucumber, swisschard and bean. In general, the infestation level was found to be higher in the middle coastal sites than in the other sites during the period of the study 1994–95. In the former sites, the pest was found to thrive on swisschard in October and November, in presence of cucumber under greenhouses, while it was encountered in significantly higher numbers on cucumber during the spring season, in absence of swisschard. Pairwise comparisons of Taylor's and Iwao's regression slope for L. huidobrensis larval mines indicated a contagious dispersion on leaves of cucumber and bean, while the pattern was random to slightly aggregated on swisschard. There was a significantly higher number of larval mines on the lower plant stratum compared to the middle and upper strata of cucumber through the cropping season. There was a significant difference in the overall development duration (19·6–22·3 days) of the insect among the three hosts. The larval development duration was significantly shorter on bean compared to swisschard and cucumber consecutively. However, there was no significant difference in egg or pupa duration among the three hosts. Results of this study provide bases for appropriate management of the pest, taking into consideration its infestation level, spatial pattern, and development duration on the mentioned hosts.

International audience; The cedar shoot moth, Dichelia cedricola Diakonoff, is considered as an important defoliator of the Lebanese cedars, Cedrus libani in Lebanon and Turkey. A recent outbreak revealed the need for a new tool to monitor the population within an integrated forest health management approach. To achieve this objective, a sex pheromone was identified by using solid phase microextraction (SPME) of calling female head space and female gland extracts, analyzed by gas chromatography/mass spectrometry. The biological activity of the identified components was assessed by field trapping in the Lebanese cedar forests. (Z)-11-tetradecenyl acetate and (Z)-11-tetradecen-1-ol were identified as the sex pheromone components of D. cedricola. The field studies showed that (Z)-11-tetradecenyl acetate and (Z)-11-tetradecen-1-ol (65:35) is an efficient formulation. The chemical composition is discussed in the view of biosystematics within Archipini tribe. These findings will contribute to the implementation of an integrated management program using the pheromone of D. cedricola and the assessment of the pest presence or absence in the cedar forest ecosystems of the Mediterranean regions.

The pine processionary moth, Thaumetopoea wilkinsoni, is the most damaging pest of pine trees in Lebanon and other countries of the Mediterranean region. It spreads in Lebanon on Pinus halepensis, P. brutia and P. canariensis. The study assesses the importance of egg parasitoids of the pine processionery moth. The egg masses collected from two locations of different altitudes were placed in the environmental chamber at a constant temperature of 22 ± 2.5°C. Emergence of the parasitoids was recorded daily in the laboratory and the peak of emergence was determined for each parasitoid species. The most widely spread species in Lebanon were identified as Baryscapus servadeii and Ooencyrtus pityocampa. A significant correlation was determined between length of the egg mass and the number of eggs/egg mass for a given row number. The impact of egg parasitoids varied from 10-16%. The followup on parasitoid emergence showed different peak emergences for the two major egg parasitoids, O. pityocampae and B. servadeii and explained the coincidence between egg deposition by T. wilkinsoni and emergence of the adult parasitoids.

The cedar web-spinning sawfly, Cephalcia tannourinensis Chevin (Hymenoptera: Pamphiliidae), is a pest that has been causing serious damage to cedar (Cedrus libani) forests in Lebanon since 1990. The existence of a sex pheromone was shown in field experiments in a cedar forest in Lebanon and in laboratory tests in olfactometers with and without airflow. More males were caught in traps baited either with virgin females or with a hexane extract of the whole female body than in traps baited either with males alone or with mixed males and females. Male and female C. tannourinensis were active during the day. Mating and pheromone production were observed to occur during midday hours (1000–1400) in the field and under laboratory conditions. Olfactometer tests with extracts prepared from different body parts of the female indicated that the pheromone is produced in the abdominal region, and tests with different dilutions of female extract showed that the male response is dose-dependent.