Alternative fumigants to methyl bromide for the control of pest infestation in grain and dry food products

The primary aim of the current study is to evaluate the potential use of the known isothyiocyanates (ITC) as compared to a new ITC isolated from Eruca sativa (salad rocket) as fumigants for the control of stored products insects. The biological activity of methyl iodide (CH3I), carbon disulphide (CS2), benzaldehyde (C7H60) and essential oils were also evaluated. The toxicity of the various fumigants was assessed against adults and larvae of a number of major stored-product insects. ITCs are potential candidates because only very low concentrations are needed for the control of stored-product insects. It should be mentioned that Eruca sativa is used worldwide as a food supplement. Methyl thio-butyl ITC the main bioactive component in this plant has high toxicity against insects, but lower mammalian toxicity as compared to other active ITCs. Comparative studies with CH3I, CS2 and C7H60 showed that the first was the mot active compound against stored-product insects followed by the second and the third. CH3I was found less sorptive and to be less penetrative in wheat than CS2. The activity of some essential oils was also evaluated. In this context, we should keep in mind that a general consensus is very difficult to achieve in order to introduce broadspectrum fumigants like methyl bromide or phosphine. Because of this, alternative fumigants could be developed against particular species of insects or to be used for specific food product commodity. Keywords: Fumigants; Isothiocyanates; Methyl iodide; Carbon disulfide; Benzaldehyde

Artemisia spp. essential oils against the disease-carrying blowfly Calliphora vomitoria

Background: Synanthropic flies play a considerable role in the transmission of pathogenic and non-pathogenic microorganisms. In this work, the essential oil (EO) of two aromatic plants, Artemisia annua and A. dracunculus, were evaluated for their abilities to control the blowfly Calliphora vomitoria. A. annua and A. dracunculus EOs were extracted, analysed and tested in laboratory bioassays. Besides, the physiology of EOs toxicity and the EOs antibacterial and antifungal properties were evaluated. Results: Both Artemisia EOs were able to deter C. vomitoria oviposition on fresh beef meat. At 0.05 μL cm-2 A. dracunculus EO completely inhibited C. vomitoria oviposition. Toxicity tests, by contact, showed LD50 of 0.49 and 0.79 μL EO per fly for A. dracunculus and A. annua, respectively. By fumigation, LC50 values were 49.54 and 88.09 μL L-1 air for A. dracunculus and A. annua, respectively. EOs AChE inhibition in C. vomitoria (IC50 = 202.6 and 472.4 mg L-1, respectively for A. dracunculus and A. annua) indicated that insect neural sites are targeted by the EOs toxicity. Finally, the antibacterial and antifungal activities of the two Artemisia EOs may assist in the reduction of transmission of microbial infections/contaminations. Conclusions: Results suggest that Artemisia EOs could be of use in the control of C. vomitoria, a common vector of pathogenic microorganisms and agent of human and animal cutaneous myiasis. The prevention of pathogenic and parasitic infections is a priority for human and animal health. The Artemisia EOs could represent an eco-friendly, low-cost alternative to synthetic repellents and insecticides to fight synanthropic disease-carrying blowflies