Chemical composition and biological activities of Salvia officinalis essential oil from Tunisia

The aim of this study is to evaluate the chemical composition, antioxidant, antimicrobial, insecticidal and allelopa- thic activities of Tunisia Salvia officinalis essential oil (SoEO). The SoEO was characterized by the presence of 49 components with camphor (25.14 %), α-thujone (18.83 %), 1,8-cineole (14.14 %), viridiflorol (7.98 %), β-thu- jone (4.46 %) and β-caryophyllene (3.30 %) as the major components, determined by gas chromatography-mass spectrometry. The level of antioxidant activity, determined by complementary tests, namely 2,2-diphenyl-1-pic- rylhydrazyl radical-scavenging (IC50= 6.7 mg/mL), linoleic acid peroxidation (IC50= 9.6 mg/mL) and ferric reduc- ing assays (IC50= 28.4 mg/mL), was relatively moderate. The SoEO was also screened for its antimicrobial activity. Good to moderate inhibitions were recorded for most of tested microorganisms. It also exhibited important insec- ticidal activity against Spodoptera littoralis larvae and Tribolium castaneum adults with LC50 values of 55.99 and 97.43 µl/L air, respectively. The effect of the SoEO on seeds germination and growth showed different activities against radical and hypocotyl elongation of the tested species. These results suggest the potential use of the SoEO as natural antimicrobial preservative in cosmetic, pharmaceutical industry and in pest management

The State of the Art of the Tunisian Apidae Fauna (Hymenoptera: Anthophila)

Based on a review of the available literature, the state of the art and a checklist of the fauna of the Apidae family of Tunisia is presented. The first list of the species of the family is given. 184 species and subspecies belonging to 19 genera, 12 tribes and three subfamilies were listed. Distribution of recorded taxa from Tunisia and from the world is provided. Apinae is the subfamily with the highest species richness with 89 species. Nomada has the highest number of species represented by 62 taxa. The Tunisian East center is the least species-diversified regions with only 16 species and subspecies reported so far. Five species are endemic to Tunisian fauna. Eight Nomada and one Anthophora species were collected from Tunisia, but their identity should be re-confirmed. The presence of Thyreomelecta sibirica (Radoszkowski, 1893) in Tunisia is doubtful and a re-examination and confirmation are needed

Repellency and insecticidal activities of Thapsia garganica crude extract against some important pests

Repellency and insecticidal activities of Thapsia garganica leaf methanolic extract were investigated against Tribolium castaneum, Myzus persicae, Phthorimaea operculella, and Spodoptera littoralis. Repellency and toxic activities (by ingestion and topical application) were evaluated on T. castaneum nymphs and adults. Topical application treatment caused total larval growth inhibition at 10%, until mortality after 7 days. The highest mortality was recorded with 94% at the same concentration. Methanolic extracts incorporation into T. castaneum larvae artificial diet at 10% caused 100% mortality after 3 days. The extract at 1% cause high repellent effect on T. castaneum after 60 min of exposure, while M. persicae was less sensitive. P. operculella female’s showed sensitivity by a repellent effect at oviposition. Egg’s number laid on treated tubers at 1% and 2% decreased significantly to 32% and 72%, respectively. In addition, methanolic extracts had a preventive effect on P. operculella larval penetration. In fact, the number of larvae was reduced by 30.46% and 76.12% in the treated tubers at 1% and 2%, respectively. For S. littoralis, a low antifeeding effect was recorded. However, the relative growth rate (RGR), conversion of ingested and digested food to biomass, were decreased. The approximate digestibility increased. Moreover, a delay in larval development was observed. This study suggests that the leaf extract of T. garganica could be applied as bio-insecticide

The Tunisian Artemisia Essential Oil for Reducing Contamination of Stored Cereals by Tribolium castaneum

Esencijalna ulja triju vrsta roda Artemisia (A. absinthium L., A. campestris L. i A. herba-alba (Asso)) ispitana su spregnutom tehnikom plinske kromatografije i masene spektrometrije (GC-MS), te je utvrđen njihov mogući insekticidni i repelentni učinak na skladišnog štetnika žitarica Tribolium castaneum (Herbst). Provedeni su in vitro pokusi ispitivanja fumigacijskog i repelentnog učinka. Kemijska karakterizacija esencijalnih ulja pokazala je da u pelinovom ulju prevladavaju biciklični monoterpeni. Ulje pravog pelina (A. absinthium) sadržavalo je najviše bicikličnih monoterpena, bicikloheptana, naftalena i cikloalkena, a ono vrste A. campestris najviše seskviterpena i acikličnih monoterpena. Bijeli pelin (A. herba-alba) imao je najviše p-mentan tipa monoterpena, tetrahidropirana, kumena, tetrahidrofurana, ketona, benzenoidnih spojeva i monocikličnih monoterpena. Ispitivanje fumigacijskog učinka pokazalo je da su tri zasebno primijenjena ulja prouzročila veliki mortalitet štetnika. Najmanju srednju smrtnu dozu (LC50=142,8 μL/L) imalo je ulje bijelog pelina. Ulje vrste A. absinthium imalo je jači i brži repelentni učinak od ostalih vrsta. Mješavina esencijalnih ulja triju vrsta pelina imala je antagonistički učinak u svim ispitanim kombinacijama. Ovaj rad naglašava važnost moguće primjene esencijalnih ulja pelina, naročito vrsta A. herba-alba (bijelog pelina) i A. absinthium, na suzbijanje štetnika na uskladištenim proizvodima.Essential oils of three species of Artemisia genus (A. absinthium L., A. campestris L. and A. herba-alba (Asso)) were analyzed by gas chromatography–mass spectrometry (GC-MS) and their potential insecticidal and repellent activities against the stored grain insect Tribolium castaneum (Herbst) was investigated. Fumigant and repellent activity bioassays were investigated in vitro. Chemical characterisation of essential oils showed that the bicyclic monoterpenes were predominant in all Artemisia essential oils, A. absinthium essential oil having the highest content of bicyclic monoterpenes, bicycloheptanes, naphthalenes and cycloalkenes. A. campestris had the highest content of sesquiterpenoids and acyclic monoterpenoids. A. herba-alba was characterised by the highest amounts of menthane monoterpenoids, oxanes, cumenes, oxolanes, ketones, benzenoids and monocyclic monoterpenes. Fumigant bioassay demonstrated that the three types of oil applied separately caused significant insect mortality. The lowest median lethal dose, LC50=142.8 μL/L, was observed with A. herba-alba. In repellency test, essential oil of A. absinthium was more potent with more rapid action than all other species. The mixture of Artemisia sp. essential oils showed an antagonistic effect in all the tested combinations. This study highlighted an important potential of Artemisia sp. especially A. herba-alba and A. absinthium in the control of the pests of stored products

Evaluation of a Bacillus thuringiensis isolate-based formulation against the pod borer, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

AbstractThe present study focuses on the evaluation of the potential of a Tunisian Bacillus thuringiensis (Bt) isolate named Hr1, isolated from dead and diseased pod borer, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) larvae under laboratory and field semi-controlled conditions. The bacterial strain Hr1 showed an insecticidal activity against the pest’s neonates in comparison to the spinosad-based insecticide (Tracer 240 SC®) during bioassays under laboratory conditions. A carboxymethyl cellulose-talc (CMC-talc)-based formulation of the Bt isolate was prepared to evaluate the potential of the bacterium on tomato plants infested with H. armigera under semi-controlled field conditions with and without rain simulation. The results showed the efficacy of the formulation than the spinosad-based insecticide and the treatment with unformulated bacterium. The results also showed the persistence of Bt isolate activity even after rain-wash than the treatment with unformulated bacterium.</jats:p