Often dismissed as mere nuisances, flies play an essential role in the ecosystem as key pollinators, ranking among the most plentiful on our planet.
A recent study conducted by a research team from Penn State sheds light on the alarming risks that rising global temperatures pose to these crucial insects.
Study Insights on Pollinators
Published in the Journal of Melittology, the research investigates how various species of bees and flies native to tropical and subtropical regions in the Americas cope with heat.
The findings reveal that flies are particularly vulnerable to increasing temperatures compared to bees, which can thrive in hotter conditions and adapt to a wider array of habitats.
Margarita López-Uribe, an Early Career Associate Professor of Entomology specializing in pollinator health at Penn State, spearheaded the research.
She stressed the indispensable roles both flies and bees play in pollinating wild plants and vital crops alike.
López-Uribe further highlighted the threats these insects face—from habitat loss and pesticide exposure to disease and the compounding challenges of climate change.
The study underscores the significant contribution of flies to pollination.
While bees are often thought of first, flies follow closely in their wake, particularly in their importance to crop and natural habitat pollination.
These insects are pivotal for maintaining biodiversity within ecosystems, helping to reproduce a variety of plant species that provide food and shelter for many organisms.
Notably, flies are the primary pollinators of cocoa trees, crucial for chocolate production.
Economic Impact of Pollinators
A report from 2020 indicated that the 105 major crops reliant on insect pollination contribute over $800 billion to the global economy, encompassing a host of popular and nutritious foods such as fruits, vegetables, and nuts.
The current study reaffirms that particular groups of flies, especially hoverflies and blowflies, consistently rank just behind bees as essential pollinators.
López-Uribe pointed out the need to acknowledge and appreciate the contribution of flies to pollination—their ecological roles often go unnoticed, yet their vulnerabilities parallel those of bees.
Insects, being ectothermic or cold-blooded, struggle to maintain optimal body temperatures, making them particularly susceptible to rising heat levels.
To better understand the response of different pollinator species to climate change, the researchers evaluated the “critical thermal maximum” (CTMax) for various bees and flies.
This metric reflects the highest temperature these insects can endure before their mobility is affected.
The results demonstrated that bees typically tolerate much hotter conditions; their average CTMax is 2.3 degrees Celsius higher than that of flies.
The study also revealed that bees foraging during the cooler parts of the day exhibit greater heat tolerance, while geographical variations in heat resistance were noted among species.
Future Implications for Flies
Interestingly, during the COVID-19 pandemic, the research team adapted by collecting data remotely.
They relied on international students from Penn State and partner institutions to study insect species in their home countries, allowing them to gather valuable information without needing to travel extensively.
The analysis showed that species from high-altitude tropical regions, like Cajicá in Colombia, had lower CTMax values than those from subtropical areas, such as California and Texas.
This suggests that insects in cooler mountain environments could be more vulnerable to even minor increases in temperature.
López-Uribe warned that in alpine and subarctic regions, flies are often the primary pollinators.
As climate change unfolds, these vital pollinators may be at risk of disappearing, posing serious consequences for local ecosystems and biodiversity.
The findings advocate for greater recognition of the pivotal roles that flies and bees play in nature and our food systems, emphasizing the need for protective measures to ensure their survival.
Source: ScienceDaily