Toxicity of naturally occurring Bio-fly and chitosan compounds to control the Mediterranean fruit fly <i>Ceratitis capitata</i> (Wiedemann)

<div><p>The efficacy of five compounds of a biopolymer chitosan and Bio-fly (<i>Beauveria bassiana</i> fungus) as biopesticide was evaluated on <i>Ceratitis capitata</i> under laboratory conditions. The inhibitory effects on acetylcholinesterase (AChE) and adenosinetriphosphatase (ATPase) as biochemical indicators were also determined <i>in vivo</i>. The results indicated that <i>B. bassiana</i> based Bio-fly exhibited significant toxicity against <i>C. capitata</i> (LC₅₀ = 3008 and 3126 mg/L after 48 h in females and males, respectively) followed by the derivatives of chitosan, <i>N-</i>(4-propylbenzyl)chitosan and <i>N-</i>(2-nitrobenzyl)chitosan. Bio-fly displayed remarkable inhibition of AChE activity (IC₅₀ = 2220 mg/L) while <i>N-</i>(<i>2-</i>chloro,<i>6-</i>flourobenzyl)chitosan, <i>N-</i>(<i>4</i>-propylbenzyl)chitosan and <i>N-</i>(3,4-methylenedioxybenzyl) chitosan had no significant difference in inhibitory action. In adult males, <i>N-</i>(<i>2-</i>nitrobenzyl)chitosan exhibited the highest inhibitory action (IC₅₀ = 6569 mg/L). In addition, the toxic effects of the tested compounds on the activity of ATPase indicated that highly significant inhibition was found with <i>N-</i>(4-propylbenzyl)chitosan with an IC₅₀ of 8194 and 8035 mg/L, in females and males, respectively.</p></div

Dimethoate residues in Pakistan and mitigation strategies through microbial degradation: a review

Organophosphate pesticides (OPs) are used extensively for crop protection worldwide due to their high water solubility and relatively low persistence in the environment compared to other pesticides, such as organochlorines. Dimethoate is a broad-spectrum insecticide that belongs to the thio-organophosphate group of OPs. It is applied to cash crops, animal farms, and houses. It has been used in Pakistan since the 1960s, either alone or in a mixture with other OPs or pyrethroids. However, the uncontrolled use of this pesticide has resulted in residual accumulation in water, soil, and tissues of plants via the food chain, causing toxic effects. This review article has compiled and analyzed data reported in the literature between 1998 and 2021 regarding dimethoate residues and their microbial bioremediation. Different microorganisms such as bacteria, fungi, and algae have shown potential for bioremediation. However, an extensive role of bacteria has been observed compared to other microorganisms. Twenty bacterial, three fungal, and one algal genus with potential for the remediation of dimethoate have been assessed. Active bacterial biodegraders belong to four classes (i) alpha-proteobacteria, (ii) gamma-proteobacteria, (iii) beta-proteobacteria, and (iv) actinobacteria and flavobacteria. Microorganisms, especially bacterial species, are a sustainable technology for dimethoate bioremediation from environmental samples. Yet, new microbial species or consortia should be explored