The Essential Role of Insects and the Challenges They Face

Insects are an omnipresent part of our environment—whether it’s an ant scurrying across a sidewalk, a bee flitting from flower to flower, or a butterfly dancing through the air. These small creatures play a critical role in our ecosystems by pollinating plants, breaking down waste, controlling pest populations, and forming integral links within food chains.

The Decline of Insect Populations

Despite their importance, human activities are contributing to a steep decline in insect populations across the globe. A recent study highlighted that the United States has lost over 20% of its butterfly populations in the last two decades. Unfortunately, this alarming trend is not isolated; many studies reveal that insect populations are diminishing at a staggering rate of 1% to 2% per year.

Understanding the Causes

As part of the international research group Status of Insects, we conducted a comprehensive review of 175 recent studies to uncover the reasons behind this insect decline. Our findings indicate hundreds of interconnected causes, most of which can be traced back to human activities.

Major Contributing Factors

The decline in insect populations is driven by several key factors:

• Intensive Agriculture: The expansion of agricultural lands reduces natural habitats and exposes insects to harmful chemicals.
• Climate Change: Alters habitats and affects the lifecycle of various insect species.
• Pollution: Various forms of pollution, including light and chemical pollutants, threaten insect survival.
• Invasive Species: Non-native species can outcompete native insects for resources.
• Habitat Loss: Urbanization and land development lead to significant loss of natural habitats.

Many insects face multiple stressors simultaneously, which compounds the threats they encounter.

Urban Challenges for Insects

In urban areas, insects such as moths face unique risks. As cities expand, their habitats shrink, and they are further impacted by invasive plant species and pollution—particularly light pollution. Moths, which are naturally drawn to light, may become prey to predators that also hunt in these artificially lit spaces, consuming energy resources they would typically use for vital activities such as pollination.

Additionally, moths contribute to plant growth control during their caterpillar stage and serve as a food source for various bird and bat species, forming a crucial part of the urban ecological network.

Threats in Agriculture

Intensive agricultural practices represent one of the most significant threats to insect populations. The expansion of farms leads to habitat loss for native pollinators like bees, compounded by high levels of pesticide use. Insecticides, designed to target pests, also severely impact beneficial insects such as bees, while herbicides eliminate the plants that provide food sources for them. Often, commercial farms rely on honeybees for pollination, but these non-native species can introduce diseases to local bee populations.

Water Pollution and Aquatic Insects

While much attention focuses on terrestrial insects like bees and butterflies, aquatic insects are also under threat. Dragonflies, for example, have a juvenile stage that is wholly aquatic, making them vulnerable to reduced water levels, pollution, and rising temperatures from climate change.

A Holistic Approach to Conservation

To effectively address the decline of insects, conservation efforts must encompass all these risks. Well-meaning actions, such as reducing pollution or managing invasive species, will be futile without restoring habitats. Revitalizing ecosystems can lead to broad benefits and enhance insect resilience against various threats.

Despite the fact that there are more insect species on Earth than any other animal or plant group, public focus is primarily on pollinators, leaving many other insects in need of attention and protection.

How to Support Insect Populations

To foster healthy insect populations, it’s crucial to create high-quality habitats. This involves:

• Planting a diverse array of native plants that offer both nectar and foliage for herbivorous insects.
• Providing nesting opportunities, such as bare soil or leaf litter.
• Limiting artificial lighting at night and reducing pesticide use.

The challenges to reversing insect population declines are significant, but there are various strategies—both large and small—that individuals, communities, and organizations can adopt to contribute positively to insect conservation.

This article is republished from The Conversation under a Creative Commons license.