Effects of DEHP on the ecdysteroid pathway, sexual behavior and offspring of the moth Spodoptera littoralis

Abstract

Bis(2-ethylhexyl) phthalate (DEHP) is a widely produced plasticizer that is considered to act as an endocrine-disrupting chemical in vertebrates and invertebrates. Indeed, many studies have shown that DEHP alters hormonal levels, reproduction and behavior in vertebrates. Few studies have focused on the effects of DEHP on insects, although DEHP is found almost everywhere in their natural habitats, particularly in soils and plants. Here, we investigated the effects of DEHP on the sexual behavior and physiology of a pest insect, the noctuid moth Spodoptera littoralis. In this nocturnal species, olfaction is crucial for sexual behavior, and ecdysteroids at the antennal level have been shown to modulate sex pheromone detection by males. In the present study, larvae were fed food containing different DEHP concentrations, and DEHP concentrations were then measured in the adults (males and females). Hemolymphatic ecdysteroid concentrations, the antennal expression of genes involved in the ecdysteroid pathway (nuclear receptors EcR, USP, E75, and E78 and calmodulin) and sexual behavior were then investigated in adult males. The success and latency of mating as well as the hatching success were also studied in pairs consisting of one DEHP male and one uncontaminated female or one DEHP female and one uncontaminated male. We also studied the offspring produced from pairs involving contaminated females to test the transgenerational effect of DEHP. Our results showed the general downregulation of nuclear receptors and calmodulin gene expression associated with the higher concentrations of DEHP, suggesting peripheral olfactory disruption. We found some effects on male behavior but without an alteration of the mating rate.Effects on offspring mortality and developmental rates in the N+1 generation were also found at the higher doses of DEHP. Taken together, the results of the study show for the first time that larval exposure to DEHP can induce delayed endocrine-disruptive effects in the adults of a terrestrial insect as well as effects on the next generation. To date, our study is also the first description of an impact of endocrine disrupter on olfaction in insects.

Effect of Irradiation on Reproduction of Female Spodoptera litura (Fabr.) (Lepidoptera: Noctuidae) in Relation to the Inherited Sterility Technique

“…The GC-MS analysis of the pheromone gland extracts of the females showed different pheromonal components released by the moths at the onset of the scotophase. The pheromone components are functionally annotated and summarized in Table 2 [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. The pheromone components were classified into the following categories: (1) sex attractants, (2) sex pheromone precursors, (3) orientation pheromones, (4) ovipositor extensor/releasor, and (5) copulation releasor/terminator.…”

Analysis of the impact of three phthalates on the freshwater gastropod Physella acuta at the transcriptional level

“…DEP and DEHP, did not alter any of the mRNA levels. Researchers have described previously that both phthalates can alter the physiology of invertebrates 16 , 35 – 38 , including mollusks 39 – 41 . Other phthalates can also alter development and growth, which could be related to the endocrine-disrupting activity described for those chemicals.…”

Knockdown of ecdysone receptor in male desert locusts affects relative weight of accessory glands and mating behavior

“…Additionally, an endocrine disruptor of ecdysteroids caused olfactory disruption and affected mating behavior in the cotton leafworm, Spodoptera littoralis (Avilès et al, 2020). There are several possible causes for the observed delay in mating: 1) the SgEcR/SgRXR knockdown caused a delay in sexual maturation and therefore the display of male mating behavior was also delayed; 2) the knockdown affected locomotion; 3) the depletion of ecdysteroid receptor components directly affected male behavior, which was most likely occurring in the CNS.…”