Insecticidal properties of Solanum nigrum and Armoracia rusticana extracts on reproduction and development of Drosophila melanogaster

Plant-derived substances, because of high biological activity, arouse interest of many scientists. Thus, plant extracts and pure substances are intensively studied on various insects as potential insecticides. In such studies, D. melanogaster is one of the most important model organisms. In our studies, we analysed the contents of two plant extracts and tested the activity of their main components against fruit flies and compared observed effects to effects caused by crude extracts. Then, we assessed the development of the next, unexposed generation. The chemical analysis of extracts revealed the presence of numerous glycoalkaloids and glucosinolates in Solanum nigrum and Armoracia rusticana extracts. These extracts, as well as their main components, revealed lethal and sublethal effects, such as the altered developmental time of various life stages and malformations of imagoes. Interestingly, the results for the extracts and pure main compounds often varied. Some of the results were also observed in the unexposed generation. These results confirm that the tested plants produce a range of substances with potential insecticidal effects. The different effects of extracts and pure main components suggest the presence of minor compounds, which should be tested as insecticides

Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture

Development of <i>D</i>. <i>melanogaster</i> fruitflies–effect of <i>S</i>. <i>tuberosum</i> extract.

<p>(a) exposed to the extract; (b) the next (non-exposed, F₁) generation.</p

Developmental parameters of non-exposed (F₁) generation of <i>D</i>. <i>melanogaster</i>.

<p>Parental generation exposed to <i>S</i>. <i>tuberosum</i>, α-chaconine or α-solanine.</p

Development of <i>D</i>. <i>melanogaster</i> fruitflies–effect of α-solanine.

<p>(a) exposed to α-solanine; (b) the next (non-exposed, F₁) generation.</p

Examples of the most frequent malformations and anomalies caused by exposition to tested extracts and metabolites in comparison with typical imagoes.

<p>(a) deformed wings (left, 0.5 μM α-solanine), (b) smaller black abdominal zone (black arrow, left, 50 μM potato extract), (c) smaller body size (right, 5 μM potato leaf extract), (d) deformed abdomen (right, 50 μM potato extract).</p

Development of <i>D</i>. <i>melanogaster</i> fruitflies exposed to <i>L</i>. <i>esculentum</i> extract.

<p>(a) exposed to the extract. (b) the next (non-exposed, F₁) generation.</p

Effect of <i>S</i>. <i>tuberosum</i> leaf extract, α-chaconine and α-solanine on parental (exposed) generation of <i>D</i>. <i>melanogaster</i>.

<p>Effect of <i>S</i>. <i>tuberosum</i> leaf extract, α-chaconine and α-solanine on parental (exposed) generation of <i>D</i>. <i>melanogaster</i>.</p

Development of <i>D</i>. <i>melanogaster</i> fruitflies–effect of α-chaconine.

<p>(a) exposed to α-chaconine; (b) the next (non-exposed, F₁) generation.</p