Three isolates of the entomopathogen Beauveria bassiana along with one strain of Metarhizium anisopliae were cultured on seven media with different ca

Essential oils (EOs) are some of the outstanding compounds found in Thymus that can exert antifungal, phytotoxic, and insecticidal activities, which encourage their exploration and potential use for agricultural and food purposes. The essential oils (EO) obtained from Thymus kotschyanus collected in the East Azerbaijan Province (Iran) were characterized using a gas chromatography-mass spectrometry (GC-MS) analysis. Thymol was the most important compound (60.48%), although 35 other active compounds were identified in the EO. Significant amounts of carvacrol (3.08%), p-cymene (5.56%), and γ-terpinene (6.67%) were found in the EO. The T. kotschyanus EO was tested against important phytopathogenic fungi (Botrytis cinerea, Aspergillus niger, and Penicillium expansum). The antifungal assay showed that the use of ≥500 ppm of EO resulted in a fungicidal effect against all funguses tested. In a similar way, the use of ≥500 ppm of EO inhibited the germination of all crop weed seeds (Amaranthus retroflexus L. and Panicum miliaceum L.) and their subsequent growth, which demonstrated its herbicidal effect. Finally, the insecticidal capacity of T. kotschyanus EO was also observed against selected insects (Oryzaephilus surinamensis and Sitophilus oryzae). O. surinamensis was more susceptible to the effect of EO (LC₅₀ = 4.78 µL/L air) than S. oryzae (LC₅₀ = 13.20 µL/L air). The obtained results of the present study can provide new safe resources to the development of new products for the food, agriculture, and pharmaceutical industries.

Plant secondary metabolites play an important role in plant-insect interactions and therefore such compounds may have insecticidal or biological activity against insects. Fumigant toxicity of essential oils of leaves and fruits from oriental arborvitae (Platycladus orientalis (L.) Franco) (Cupressaceae) was investigated against adults of cowpea weevil (Callosobruchus maculatus Fab.), rice weevil (Sitophilus oryzae L.), and red flour beetle (Tribolium castaneum Herbst). Fresh leaves and fruits were subjected to hydrodistillation using a Clevenger-type apparatus and the chemical composition of the volatile oils was studied by gas chromatography-mass spectrometry (GC-MS). Twenty-six compounds (92.9%) and 23 constituents (97.8%) were identified in the leaf and the fruit oils, respectively. The major components of both leaves and fruits oils were α-pinene (35.2%, 50.7%), α-cedrol (14.6%, 6.9%) and Δ-3-carene (6.3%, 13.8%), respectively. Both oils in the same concentration were tested for their fumigant toxicity on each species. Results showed that leaf oils were more toxic than fruit oils against three species of insects. Callosobruchus maculatus was more susceptible than S. oryzae and T. castaneum. LC510 values of the leaf and the fruit oils at 24 h were estimated 6.06 and 9.24 μL L¹ air for C. maculatus, 18.22 and 21.56 μL L-1 air for S. oryzae, and 32.07 and 36.58 μL L4 air for T. castaneum, respectively. These results suggested that P. orientalis oils may have potential as a control agent against C. maculatus, S. oryzae, and T. castaneum.

Astigmatid mites have potential as supplementary prey items to support generalist predator populations in crops. However, applying living prey mites has some disadvantages; if not predated they have the potential to cause crop damage and allergies. In this study, we evaluated various diets based on the astigmatid mite Tyrophagous putrescentiae (Schrank) as a supplemental food source for the predatory mite Amblyseius swirskii Ahias-Henriot. Eggs and larvae of T. putrescentiae were reared on a diet of dog food (rich in proteins and fat) or bran (rich in carbohydrate); they were offered either frozen or alive, and either with or without cattail pollen (Typha angustifolia L.). Oviposition rate of A. swirskii fed with frozen mite larvae reared on dog food was similar to the rate observed when they were fed with cattail pollen or living prey mites, but developmental time of A. swirskii was longer on this frozen diet than on a diet of living prey mites or pollen. Both living and frozen prey mites were, in contrast with cattail pollen, not suitable for oviposition by western flower thrips, Frankliniella occidentalis Pergande. In a greenhouse study, the use of frozen prey mite stages as supplemental food on chrysanthemum plants allowed populations of A. swirskii to establish, but not increase; in contrast, provision of living prey mites and pollen increased A. swirskii populations on plants. Hence, our study shows that living prey mites, but not frozen prey mites, had the greatest potential as a supplemental food source for A. swirskii.