# Toxic and Environmental Effects of Neonicotinoid Based Insecticides
## 6 Neonicotinoids' (\"Nicotine-Like Insecticides') Effects on Pollinators (i.e., 'Bees')  
The word neonicotinoids means 'new nicotine-like insecticides' in the literal sense. Similar to nicotine-based pesticides, neonicotinoid-based pesticides are addictive to organisms and act on various receptors of the nervous system [31]. A study was conducted in which bees were given two bowls of water, one laced with sugar, and another laced with neonicotinoid. After the bees ingested a small dosage of neonicotinoids, they preferred the neonicotinoid-laced water instead of the sugar water, thus proving their addictive properties [36]. Neonicotinoids affect the nerve synapse of insects by acting on certain receptors, which leads to fatality. However, the toxicity of neonicotinoids is much higher when ingested by invertebrates (i.e., insects, worms, etc.) compared to higher organisms such as birds. The lethal dosage for honeybees is much lower than that of mammals since only less than 0.023 \(\upmu\)g is needed to kill a honeybee, which is one of the best pollinators in the agricultural industry [29]. Although the lethal dosage is higher for other organisms, such as birds, fish, etc., the toxic effects of neonicotinoids can bio-accumulate. Bioaccumulation occurs through extended periods of pesticide exposure or through ingesting other neonicotinoid-affected organisms that are lower in the food chain [29]. When neonicotinoids were first introduced into the farming industry, they were thought to have low toxicity to beneficial insects. However, in recent years, it was recognized through studies that bees and other beneficial insects are negatively affected by contact with nectar and pollen that are laced with neonicotinoid-based pesticides. Low-level exposure to neonicotinoids may not result in immediate death for beneficial insects, but the toxins reduce the insects' ability to function correctly. For example, when natural pollinators such as bees are exposed to neonicotinoids, their ability to forage nectar may be reduced. Also, bees may cease to remember the locations of flowers or the way back to their hives [31]. [PERSON] and [PERSON] [37] reported that neonicotinoids currently make up of about 30% of insecticide sales worldwide, and due to their adverse impacts on pollinators such as honeybees and bumble bees, neonicotinoids are being banned in the EU. Since it is crucial to understand the mechanism underlying neonicotinoid actions on pollinators as well as on other pests, they researched the molecular mechanisms of neonicotinoid actions at an atomic level and proposed relevant research topics for further studies for pest management. In a recent study, [PERSON] et al. [38] presented the existing research on other herbicides, fungicides, and insecticides which come with a range of environmental concerns, such as the effects of insecticides on non-target organisms such as bees. Their study also focused on non-neonicotinoid insecticides and non-honeybees. Furthermore, neonicotinoids caused alterations in the bees' immune systems, causing the bees to be susceptible to viral infections that healthy bees normally have immunity to. Aside from bees, neonicotinoids also have a negative impact on other wildlife, such as birds and aquatic invertebrates. Neonicotinoids cannot be completely broken down into harmless chemicals by the natural ecosystem or even with chemical treatment methods. Residues of neonicotinoid pesticides can come from soil and seeds, which lead to residues in plants. Neonicotinoids can also affect pollen, nectar, surface water, etc. [2]. In addition to environmental effects, neonicotinoids, when applied as seed treatments, become more and more dilute in plants as they grow. The pesticides become ineffective after a specific duration depending on the type of vegetation, and the effects of the pesticides often do not last until harvest. This means that vegetation is potentially susceptible to pests before it is harvested.