Neonicotinoid pesticide applications affect pollinator abundance and visitation, leading to implications for sunflower production (Helianthus annuus L.)

Abstract

Pesticides are considered a risk to pollinators; however, little is known about the possible effects of their injudicious use on pollinators, including the ecosystem services provided to crops and wildflowers. Recently, great attention has been paid to the effects of neonicotinoids pesticides on pollinators and their potential role in harming the health of bees all over the world. Sunflowers, being self-incompatible plants, rely on insects, primarily bees, for effective cross-pollination and successful seed-set. Ensuring the presence of sufficient pollinators in the field is crucial for facilitating pollen movement between flowers and promoting optimal seed development. However, the reliance on insect-mediated cross-pollination also makes sunflowers susceptible to pest attacks, which can negatively impact seed production. To mitigate these potential threats and achieve increased seed yields, careful consideration is given to the judicious use of pesticides. Striking the right balance between providing adequate pollinators and implementing appropriate pest management strategies is vital for maximizing sunflower crop productivity. To reveal such potential impacts of neonicotinoid insecticides, we undergo the current study that aimed to estimate flower visitation and pollination in a sunflower crop by applying three neonicotinoid insecticides i.e. imidacloprid, clothianidin, and thiamethoxam, including the control group for two years i.e. 2020, and 2021. In all experimental plots, we quantified floral visitors for fourteen days at three different times (8 am, 12 pm, and 5 pm). Floral visitors were divided into three groups, Apis bees, Non-Apis bees, and butterflies. After the maturation period, the achenes from each capitulum were separated and brought for weight. We discovered that this study confirmed the adverse effect of neonicotinoids pesticides on sunflower production.

Our research revealed that the use of imidacloprid, clothianidin, and thiamethoxam had a negative impact on the visitation of Apis bees, with reductions of 19%, 18.5%, and 23% respectively, as compared to the control group during the year 2020. Furthermore, these pesticides also caused a decrease in the visitation of Non-Apis bees by 15%, 15%, and 17% respectively. The visitation of butterflies was also affected, with reductions of 17.4%, 14.6%, and 15.8% for imidacloprid, clothianidin, and thiamethoxam respectively. Based on our research conducted in the year 2021, the use of imidacloprid, clothianidin, and thiamethoxam caused a reduction of 22.5%, 24%, and 25.5% respectively in the visitation of Apis bees, as compared to the control group. Similarly, non-Apis bees experienced a decrease in visitation by 19.5%, 23.5%, and 25% respectively for imidacloprid, clothianidin, and thiamethoxam, compared to the control group. The visitation of butterflies was also affected, with reductions of 18.2%, 22.2%, and 26% respectively for imidacloprid, clothianidin, and thiamethoxam, compared to the control group. Our findings suggest that the use of these pesticides affected the diversity of floral visitors and contributed to a decline in the number of fruit during the year 2020 and 2021.

Moreover, the abundance of floral visitors, the mass of fruits, and the quantity of oil in the seeds were significantly lower after treatment with neonicotinoid pesticides, thus evidencing its negative effect on sunflower productivity.

Keywords:

• Sunflower
• Abundance
• Pollinators
• Neonicotinoids
• Pesticide toxicity
• Productivity

Public Interest Statement

Our research sheds light on the potential impacts of neonicotinoid pesticides, commonly used in agriculture, on the pollination process and productivity of sunflower crops. Sunflowers heavily rely on pollinators, such as bees and butterflies, for successful flower visitation and fruit production. Through comprehensive field studies, we found that the use of neonicotinoid pesticides—specifically imidacloprid, clothianidin, and thiamethoxam—resulted in a significant reduction in the visitation of both Apis and non-Apis bees, as well as butterflies.

The negative effects were observed in terms of decreased flower visitation, lower fruit mass, and reduced oil quantity in sunflower seeds. These findings raise concerns about the potential harm inflicted on pollinator populations and the subsequent impact on crop productivity. Our research emphasizes the need for responsible pesticide use and highlights the importance of protecting pollinators for the overall health and sustainability of agricultural ecosystems.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Author contributions

MSS conceived and designed the experiments, collected the bees, and analyzed the data. MFA contributed the materials, review the article, MAJ conducted the experiments and AS helped in data analysis and review the article.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/23311932.2023.2258773

Additional information

Funding

The author(s) received no specific funding for this work.

Notes on contributors

Muhammad Shoaib Saleem

Muhammad Shoaib Saleem I am an experienced Research Scientist and Entomologist, currently holding the position of entomologist at the Department of Plant Protection (DPP), Government of Pakistan. Within my role, I actively participate in diverse areas such as planning, plant quarantine, locust expertise, and pesticide registration processes. With a strong academic background and completing PhD in Plant Protection, specializing in the impact of pesticides on the health, behavior, and ecology of pollinators, specifically focusing on honeybees and integrated pest management of vegetable insect pests, I possess a comprehensive understanding of entomological research and its practical implications. My research activities extend beyond the confines of academia as I actively engage in broader projects and issues pertaining to sustainable pest management strategies, pesticide risk assessment, and the conservation of pollinator populations. The research discussed in this paper aligns with my overarching objective of contributing to evidence-based decision-making processes, promoting the development of environmentally friendly agricultural practices, and ensuring the long-term sustainability of crop production.