ABSTRACT
Chitosan was extracted from the oriental hornet, Vespa orientalis [L.], Vespinae, Order; Hymenoptera, as a new source of insect chitosan, using chemical methods. We assessed the physical properties of the wasp's chitosan using different approaches including: preliminary color-change identification, Fourier Transform Infrared spectroscopy [FTIR], X-ray diffraction and Nuclear Magnetic Resonance spectroscopy [1H-NMR]. The results showed that it gave a
higher purity, solubility and Degree of Deacetylation [DD] compared to crustacean chitosan. Also, it is soluble in a very low concentration of acetic acid from 0.25% to 0.5% while that of Crustacea was soluble in more than 1% acetic acid, so the oriental hornet could be a novel alternative source of higher pure and more soluble chitosan
ABSTRACT
The mosquitocidal plant extracts of the myrrh Commiphora molmol; namely, oil and oleoresin demonstrated larvicidal activity against Culex pipiens larvae. Oleoresin induced a significant higher toxic action than oil. Solvent did not perform any toxic activity. The impact of both oleoresin and oil extracts on the protein profile of the treated larvae was evaluated in order to explain their mode of action. Electrophoretic analysis of total proteins, lipoproteins and glycoproteins revealed an inhibitory action of the used plant extracts on the protein contents. Larvicidal activity of the oleoresin and oil was related to the loss of certain enzymes inhibited by these extracts which affected the metabolic processes
Subject(s)
Insecta , Plant Oils/pharmacology , Larva , Plant Extracts , Mosquito Control , Resins, Synthetic/pharmacologyABSTRACT
The efficiency of Bacillus thuringiensis [Bt] as a microbial housefly control agent was evaluated in one of the natural maggot breeding medium; namely, poultry feces. Two commercial formulations [a wettable powder and a liquid concentrate] were assayed against Musca domestica sorbens in synthetic fly breeding media and in chicken feces. The latter favored maggot breeding when compared with the synthetic one. Both formulations resulted in a significant reduction in maggot numbers, pupal development and adult emergence. The concentration significantly affected the adult emergence. The liquid concentrate induced higher larvicidal activity than dry powder formulation. Contaminated feces produced from orally fed chickens were significantly toxic to the breeding maggots reaching maximum larvicidal activity till the 4th day post-feeding feces and continued in less activity till the 6th day