How Climate Change Influences Insect Color and Reproduction

By: Sam Watanuki | Published: Jul 15, 2024

Insects exhibit a fascinating relationship between their body color and the surrounding temperature. Darker-colored insects, like the ambush bug, can warm up faster in the chilly mornings, gaining a reproductive advantage.

This ability to warm up quickly allows them to be active while others are still sluggish from the cold.

Temperature's Role in Insect Evolution

According to a review article in Ecology and Evolution, temperature has a significant impact on insect coloration.

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A photograph of a thermometer

Source: Freepik

As temperatures rise, insects tend to produce less melanin, leading to lighter and brighter hues. This adaptation helps them stay cooler since lighter colors reflect more sunlight.

Butterflies and Climate Change

The Mead’s sulphur butterflies in the North American mountains are showcasing a striking transformation.

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painted lady butterfly

Source: Didier Descouens/Wikipedia

According to a 2016 study, their once vibrant, shimmery sulphur yellow wings are turning paler as temperatures rise, showing the direct influence of climate on insect pigmentation.

Ladybugs and Melanin Reduction

Between the 1980s and the 2000s, the two-spotted ladybug has also shown a shift in coloration.

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ladybug

Source: Francisco Welter-Schultes/Wikipedia

It became increasingly rare to find black ladybugs with red spots, as they adapted to warmer climates by becoming red with black spots. This change is a direct response to the rising temperatures.

Inconsistent Patterns in Color Change

Herberstein’s team discovered that color change patterns in insects are not always straightforward.

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Asian Longhorned Beetle

Source: Dutch government/Wikipedia

A study on Mead’s sulphur butterflies, examining specimens from 1953 to 2013, found that in some areas, their wings became richer and darker over time, contradicting the expected trend.

Walking Stick Insects and Temperature

A 2018 study found that a species of walking stick insect became greener and darker as temperatures rose.

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The sunlight shining through tree branches in the daytime.

Source: Jessica Sysengrath/Unsplash

This surprising adaptation was observed as researchers collected samples from higher altitudes, showing a complex interaction between temperature and coloration.

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Planthoppers and Elevation

Planthoppers also demonstrated an unusual pattern of color change. As temperatures increased and researchers sampled them at higher elevations, these insects became darker.

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A photograph of the sun during a hot day

Source: Wikimedia

This finding adds to the understanding that insect color adaptation is influenced by multiple factors, including altitude.

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The Role of Melanin Beyond Heat Regulation

Melanin plays various roles in insects, beyond just regulating body temperature. It is involved in immunological defenses and protection against ultraviolet radiation.

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Scenic View Of Lake During Sunset

Source: Nicole Avagliano/Pexels

This multifunctionality complicates the understanding of how insects will continue to adapt to climate change.

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Climate Change and Insect Mating

The impact of climate change on insect reproduction is still uncertain. Rising temperatures could affect the ability of insects to find mates, as color is crucial for attracting partners and species recognition.

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A photograph of a thermometer in a garden

Source: Freepik

Changes in coloration might disrupt these essential behaviors.

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Dragonflies and Color Loss

Michael Moore, an integrative biologist, observed in 2021 that male dragonflies were losing their wing color patterns in hotter climates.

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A four-spotted chaser, Libellula quadrimaculata on an emergent plant

Source: Aiwok/Wikipedia

This loss could potentially hinder their ability to attract mates, highlighting a significant concern for insect populations in a warming world.

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The Complexity of Insect Adaptation

“There isn’t a one-size-fits-all rule,” says Moore. The relationship between climate change and insect coloration is complex and varies across species and regions.

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A photograph of a researcher at his desk

Source: Freepik

Ongoing research is crucial to understanding how these adaptations will affect insect populations in the long term.

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Future Directions in Research

Scientists are continuing to study how climate change influences insect color and reproduction.

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researcher in lab coat using microscope

Source: DC Studio, Freepik

Understanding these dynamics is vital for predicting how insect populations will fare in the face of global warming.

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