Impact of the secondary plant metabolite Cucurbitacin B on the demographical traits of the melon aphid, Aphis gossypii

Abstract

Cucurbitacin B is a natural triterpene present in plants of Cucurbitaceae family, which are among the host plants for melon aphid, Aphis gossypii. In present study we characterized the effects of two cucurbitacin B concentrations on the biological parameters of adults (F0) and of juveniles and adults of their progeny (F1). The results showed that cucurbitacin B at 25 ppm significantly reduced the adult longevity and fecundity of both F0 and F1 generation. Exposure of F0 generation to 25 ppm though reduced the demographic traits of F1 including the intrinsic rate of increase r (day−1), generation time T (day), finite rate of increase λ (day−1), however, only net reproductive rate R0 (offspring/individual) decreased significantly. While 100 ppm reduced not only the longevity and fecundity of F0 generation but also the longevity of F1 generation. Fecundity of F1 was not affected by 100 ppm of cucurbitacin B, however, R0 (offspring/individual) and T (day) of F1 generation were lower than the control population. These results support the hypothesis that high contents of cucurbitacin B caused negative impact on melon aphid and could be used as a lead for classical selection of resistant varieties of plants that are main hosts for the melon aphid.

Impact of low lethal concentrations of buprofezin on biological traits and expression profile of chitin synthase 1 gene (CHS1) in melon aphid, Aphis gossypii

“…The pre-adult period and mean generation time ( T ) were increased due to different physical and chemical processes when treated with buprofezin. Similar effects at the demographical level have been presented in various other reports 29,30,65,66 . Previous reports suggested that exposure to sublethal concentrations of buprofezin can suppress the population growth of S .…”

“…furcifera via impact on their survival and reproduction 29,30 . Additionally, adverse effects at the demographical level have been reported in melon aphid at 25 and 100 ppm of cucurbitacin B 65 . Moreover, sublethal concentrations of imidacloprid and pirimicarb decreased the longevity and population growth of A gossypii 67 .…”

“…All adult aphids were removed after 24 hours while the offspring were allowed to grow on plants for eight days without any insecticide application. At this time, the newly-born nymphs passed all developmental stages and became apterous adults 65,66 .…”

Effects of Sublethal Doses of Methyl Benzoate on the Life History Traits and Acetylcholinesterase (AChE) Activity of Aphis gossypii

“…Due to various physical and chemical processes, the pre-adult and mean generation time (T) increased after exposure to MB. In a few other studies on A. gossypii, similar effects were reported at the demographic level [12,55].…”

Predation and reproduction of the generalist predator Nabis pseudoferus preying on Tuta absoluta

“…For comparison, we ran the same bioassays using adults of the common pest cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), as prey. This insect is highly polyphagous, found in greenhouse and field vegetables, fruit crops, and ornamentals (Blackmen & Eastop, 2000; Capinera, 2001; Yousaf et al, 2018). Its direct feeding causes leaf chlorosis and deformity, as well as sticky honeydew which provides a growth medium for sooty mold which reduces the plant’s photosynthetic capacity; the aphid also transmits various plant‐pathogenic viruses (Yuan & Ullman, 1996; Alford, 1999; Capinera, 2001; Pinto et al, 2008; Campolo et al, 2014).…”