Lethal, sublethal and transgenerational effects of the novel chiral neonicotinoid pesticide cycloxaprid on demographic and behavioral traits of Aphis gossypii (Hemiptera: Aphididae)

Abstract

Aphis gossypii Glover (Hemiptera: Aphididae) is a key pest in cotton crops, notably owing to its increasing resistance to commonly used pesticides. Such resistance prompts for the development of integrated pest management (IPM) programs that include novel pesticides being effective against the aphid. In the present study, we assessed lethal and sublethal effects of cycloxaprid, a novel chiral neonicotinoid pesticide developed in China, on A. gossypii. The lethal concentration at 50% (LC ) value of cycloxaprid on A. gossypii was estimated, using the dipping method, at 7.73 mg/L. The impact of a sublethal concentration (LC ) and a lethal concentration (LC ) of cycloxaprid on A. gossypii population growth and feeding behavior (using electrical penetration graph technique [EPG]), and its transgenerational effect were further assessed. Adult longevity and fecundity significantly decreased after exposure to LC or LC of cycloxaprid. Cycloxaprid with sublethal concentrations (especially LC ) had negative effects on phloem ingestion by A. gossypii. Additionally, the offspring of the adults exposed to LC of cycloxaprid had shorter nymphal development duration and adult longevity than the control, and those from LC and LC treatments had lower adult fecundity and net productive rate. We demonstrated that cycloxaprid is a pesticide showing both lethal and sublethal activities, and transgenerational effects on A. gossypii; it may be useful for implementation in IPM programs against this aphid pest.

Sublethal and transgenerational effects of dinotefuran on biological parameters and behavioural traits of the mirid bug Apolygus lucorum

“…Many insect species also have lower survival rates in their immature stages, including A. lucorum 41 , R. padi 43 , B. tabaci 15,44 , Euschistus heros 16 , and A. gossypii 45 . Additionally, the reduction in fecundity were also observed in A. lucorum with LD 40 of cycloxaprid 18 , A. gossypii exposed to LC 10 and LC 40 of cycloxaprid 34 , A. glycine with 0.20 mg L −1 of imidacloprid 42 , and N. lugens treated with imidacloprid and dinotefuran 46 . This phenomenon could attribute to the reduction in vitellogenin (Vg) and the expression level of Vg mRNA significantly decreased by 43.8% in F1 generation of A. lucorum whose parents were treated with LD 15 of sulfoxaflor 41 .…”

“…Additionally, imidacloprid significantly extended the nymphal development duration of M. persicae 17,23 and R. padi 43 . In contrast, a reduction in nymphal development duration was reported in A. lucorum 41 , B. tabaci 15 , A. gossypii 24,34 , and A. glycines 42 . And the reduction in preadult duration may attribute to the lower egg duration at both LC 10 and LC 30 of dinotefuran in F1 generation of A. lucorum (Fig.…”

“…EPGs analysis demonstrated that the feeding behaviour of A. lucorum did not differ between dinotefuran treatments and the control, indicating that these two concentrations will not increase crop injury when this pest moves to other plants. In contrast, many studies have reported negative effects of insecticides on the feeding behaviour of A. gossypii 24,34 , M. persicae 23,35 , S. avenae 25 , and R. padi 27,36 . Cira et al 26 found that H. halys adults that www.nature.com/scientificreports www.nature.com/scientificreports/ survived from sulfoxaflor exposure produced significantly fewer feeding sites than those in the control.…”

“…Fortunately, the biological meaning of the feeding waveforms in a few species of mirid bugs was recently clarified in several studies 29,32,33 . Additionally, EPGs were also applied to reveal the impacts of neonicotinoid insecticides on the feeding behaviour in Aphis gossypii 24,34 , Myzus persicae 23,35 , Sitobion avenae 25 , and R. padi 27,36 . Cui et al 25 found that cycloxaprid significantly increased the total length of non-probing periods and inhibited the phloem ingestion of S. avenae.…”

Assessment of ecological risks of agrochemicals requires a new framework.

“…A multitude of impairments have been observed with many pesticides tested at sub-lethal levels under laboratory conditions, with some of them negatively affecting the reproductive abilities of the species tested. Examples include the lower fecundity of the pea aphid (Acyrthosiphon pisum) exposed to sublethal concentrations of Margosan-O extracts (active ingredient, azadirachtin) [66] and that of the cotton aphid (Aphis gossypii) exposed to cycloxaprid [67], both of which can help reduce the populations of those pests and achieve their effective long-term control. However, similar negative effects can be observed in beneficial, predatory and parasitoid arthropod species, such as the decrease in fecundity of predatory Coleomegilla maculata lady beetles after exposure to commercial formulations of 2,4-D and dicamba herbicides [68] and reduced ovipositions of Eriopis connexa lady beetles exposed to the insecticides teflubenzuron and cypermethrin [69]; the severe reduction in fecundity of predatory thrips (Scolothrips longicornis) exposed to abamectin [70]; or the reduced fecundity of the generalist predatory bug Orius armatus exposed to spinosad [71], amongst many others.…”