Octanoic acid kills Lucilia sericata (Diptera: Calliphoridae) by affecting two major defence systems: cuticular free fatty acids and immunocompetent cells
Agata Kaczmarek , Anna Katarzyna Wrońska , Mieczysława Irena Boguś
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引用次数: 0
Abstract
This work examines the insecticidal activity of octanoic acid (C8:0), a short-chain fatty acid detected in entomopathogenic fungus – Conidiobolus coronatus medium, against Lucilia sericata larvae and adults. The LD50 value was calculated as 3.04±0.26 µg/mg (3040 mg/kg) of insect body mass, which places the compound in category 5 of acute toxicity (slightly hazardous). The presented research also describes its probable mechanism, with a particular focus on changes in two main insect defense mechanisms: (1) the composition of the cuticle (GC–MS analysis) and (2) immunocompetent cells (microscopic analysis of cultured hemocytes). More precisely, octanoic acid application resulted in changes in cuticular free fatty acid (FFA) profiles in both adults and larvae; generally, treatment increased short-chain FFAs, and a decrease of middle- and long-chain FFAs. Both in vivo and in vitro applications of octanoic acid resulted in vacuolisation, disintegration, and destruction of nets formed by plasmatocytes. As the compound has also previously been found to be toxic against Galleria mellonella, it appears to have lethal potential against insects in both the Orders Diptera and Lepidoptera, indicating it may have strong entomopathogenic potential. It is worth noting that octanoic acid is approved as a food additive with well-documented insecticidal activity, and hence may be a valuable component in the design of new insecticides that are safe for both humans and the environment.
期刊介绍:
The Journal of Invertebrate Pathology presents original research articles and notes on the induction and pathogenesis of diseases of invertebrates, including the suppression of diseases in beneficial species, and the use of diseases in controlling undesirable species. In addition, the journal publishes the results of physiological, morphological, genetic, immunological and ecological studies as related to the etiologic agents of diseases of invertebrates.
The Journal of Invertebrate Pathology is the adopted journal of the Society for Invertebrate Pathology, and is available to SIP members at a special reduced price.