Effects of sublethal phosphine exposure on respiration rate and dispersal propensity of adult females of Tribolium castaneum

BACKGROUND Panonychus citri is a globally dominant citrus plant pest mite. Pesticide‐induced population resurgence is a concern for mite control. Exposure to sublethal concentrations of pesticides has stimulated reproduction and outbreak risks in many pests. Pyridaben, a mitochondrial electron transport inhibitor, has been frequently used worldwide in mite control. In the study, sublethal and transgenerational effects of pyridaben exposure on Pyr_Rs (resistant) and Pyr_Control (susceptible) strains were systematically investigated in both exposed parental generation (F0) and unexposed offspring generations (F1 and F2) by evaluating life‐table and physiological parameters. RESULTS After exposure to pyridaben, the fecundity of both strains was significantly reduced in F0 generation while significantly induced in F1 generation. Interestingly, these effects also stimulated the fecundity of the F2 generation in Pyr_Control strain while no significant effects occurred for Pyr_Rs strain. The intrinsic rate of increase (r) and finite rate of increase (λ) were significantly decreased only in F1 generation of Pyr_Control strain after exposure treatment. Meanwhile, the population projection indicated a smaller population size in F1 generation of Pyr_Control strain while a population increase for Pyr_Rs strain after sublethal treatment. Subsequent detoxification enzyme assays indicated that only P450 activities in F0 generation were significantly activated by LC30 exposure to pyridaben in both strains. Significant downregulation of reproduction‐related (Pc_Vg) genes was observed in the F0 generations of both strains. Significant upregulation of P450 (CYP4CL2) and Pc_Vg of the F1 generation in both strains suggested the presence of delayed hormesis effects on the reproduction and developed tolerance to pyridaben, although the effects did not last over a longer period (F2 generation). CONCLUSION These results provide evidence for transgenerational hormesis effects of low concentrations of pyridaben exposure that may lead to population increase and resurgence risks of resistant‐mites in natural settings by stimulating reproduction. © 2023 Society of Chemical Industry.

Section: Discussionmentioning

confidence: 99%

Sublethal and transgenerational effects of pyridaben exposure on the fitness and gene expression of Panonychus citri

Deng

Xia

Luo

et al. 2023

“…In the last couple decades, there has been increasing awareness that behavioral data should be taken into account when assessing risk from insecticides, but others have noted that such an approach will require a larger foundational set of data to predict longer‐term consequences on species 29 . Although there has been work carried out on examining the mechanisms of sublethal exposure in stored product entomology, 33 and characterizing sublethal changes after exposure, 23 few attempts have been made to predict sublethal changes before exposure. More recently, some have predicted that climate change may increase sublethal impacts of chemicals on a variety of species 34 .…”

Section: Discussionmentioning

confidence: 99%

Characterizing and predicting sublethal shifts in mobility by multiple stored product insects over time to an old and novel contact insecticide in three key stored commodities

Morrison

Arthur

Bruce

2021

BACKGROUND There has been a push to diversify integrated pest management (IPM) programs away from exclusive fumigant use in food facilities. Residual insecticides increasingly have been included among plans. In stored products, sublethal toxicity has been neglected in favor of evaluating direct mortality. Here, we evaluated the movement of Tribolium castaneum, Rhyzopertha dominica, Sitophilus oryzae and Sitophilus zeamais in response to aged residues of an existing (Diacon IGR+® with 11.4% methoprene + 4.75% deltamethrin) and novel (Gravista® with 2.85% methoprene + 1.2% deltamethrin + 33.3% piperonyl butoxide synergist) residual insecticide. RESULTS Using the maximum labeled rate and two exposure times for each species, we assessed distance moved and velocity on wheat, rice and corn. Assessments were made from commodity residues aged between 0 and 12 months (at 3‐month intervals). We found that after exposure, movement was reduced by 50–88% and equally by adults exposed to each insecticide formulation compared to untreated controls. After initial application, predicted distance moved increased from 4 to 14 m then 28 m in a 24 h period at 3 and 12 months post‐application, respectively. Effectiveness of each insecticide at suppressing movement generally declined by 9–12 month post‐application. CONCLUSIONS Given the quick and dramatic increases in sublethal movement after initial application, our results suggest that sanitation programs in post‐harvest environments are extremely important and it may be beneficial to pair chemical control with monitoring to prevent dispersal of affected insects to new areas of a facility. Published 2020. This article is a U.S. Government work and is in the public domain in the USA

“…35 Several studies have reported that sublethal insecticide exposure could directly stimulate the population of several pest insects and natural enemies such as melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), 36 brown planthopper, Nilaparvata lugens Stal (Hemiptera: Delphacidae), 37 black cutworm, Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae), 38 diamondback moth, Plutella xylostella Linnaeus (Lepidoptera:Plutellidae), 39 Habrobracon hebetor Say (Hymenoptera: Braconidae), 29 and Trichogramma parasitoids (Hymenoptera: Trichogrammatidae). 40,41 Even though a few studies have acknowledged the significance of the sublethal effects of insect pest species to fumigants, [42][43][44] there is a paucity of knowledge on this topic. Long-term exposure of sublethal phosphine influences life-history traits and could induce strong population growth and lead to severe infestations.…”

Section: Introductionmentioning

confidence: 99%

“…Even though a few studies have acknowledged the significance of the sublethal effects of insect pest species to fumigants, 42–44 there is a paucity of knowledge on this topic. Long‐term exposure of sublethal phosphine influences life‐history traits and could induce strong population growth and lead to severe infestations 42 .…”

Section: Introductionmentioning

confidence: 99%

Sublethal phosphine fumigation induces transgenerational hormesis in a factitious host, Corcyra cephalonica

Nath

Maurya

et al. 2023

BACKGROUNDThe rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) is a pest of stored grains and widely used as a factitious host during the mass rearing of several natural enemies of crop pests. Hormesis is well‐documented in pest insects, to some extent in natural enemies of pests.RESULTSWe report transgenerational stimulatory effects of the widely used fumigant, phosphine. The study reports the consequences of sublethal, low lethal and median lethal concentrations (LC5, LC25 and LC50) and untreated control for two sequential generations of the species (G1 to G2). In this study, we investigated the life‐history traits, nutrient reserves (protein, lipid and carbohydrate) and larval gut microbiome (using 16 s rRNA V3–V4 metagenomics sequencing) of C. cephalonica. Stimulatory effects were observed for various biological traits of C. cephalonica, notably adult longevity, emergence and increased egg hatchability when exposed to LC5 of phosphine. The total protein, lipid and carbohydrate contents of C. cephalonica also were found to be significantly increased by LC5 in both generations. The microbial diversity of LC5 treated larval gut was higher and found to be different from the rest of the treatments. This is the first report showing hormesis to a fumigant insecticide.CONCLUSIONOur findings increase knowledge on the interaction between hormesis, nutrient reserves and gut bacteria in C. cephalonica exposed to insecticides. Overall, the present study establishes phosphine‐induced hormesis at LC5 in the host C. cephalonica, which might help improve the quality of mass rearing of various natural enemies. © 2023 Society of Chemical Industry.