Insect Communities May Face Significant Disruption and Disorder Due to Climate Change

What occurs when climate change is introduced into the equation is the potential for the emergence of new species worldwide, as various organism groups become distinct and follow separate evolutionary paths.

In the publication “Contrasting effects of warming in diverging insects,” which was recently released in Ecology Letters, Thomas H.Q. Powell, an assistant lecturer of biological sciences at Binghamton University, State University of NY, and his research team aim to address this very question.

During the 1850s, the apple maggot fly, a significant pest in agriculture, began to split into two separate populations in the Hudson Valley. One population continued to rely on the fruit of native hawthorn trees in the region, while the other adapted to a new food source: apple trees, which were originally introduced to North America by English colonists.

Entomologist’s Historical Observations and Confirmation of Real-Time Species Origin

“The entomologist who first observed this actually corresponded with Darwin, speculating that it could potentially be an instance of species origin occurring in real time. It wasn’t until researchers in the late 20th century revisited this system that we discovered he was correct,“ explained Powell, an entomologist and assistant professor of biological sciences at Binghamton University, State University of New York.

Due to the hawthorns’ fruiting schedule occurring three to four weeks later than apples, the reproductive cycles of the two populations shifted accordingly.

Consequently, this shift has implications for several species of parasitic wasps that rely on the apple maggot fly as a food source. It highlights the intricate balance that underlies ecosystems.

To conduct their experiment, the researchers raised populations of flies and parasitic wasps that fed on either apple or hawthorn trees.

These populations were subjected to two sets of conditions: one reflecting the average seasonal temperatures of the past decade and the other representing warmer conditions projected for the next 50 to 100 years. The experiment’s outcomes have significant implications for insect biodiversity, as noted by Powell.

Interestingly, despite being in the same geographical area, the two fly populations responded quite differently to the temperature shift. The flies living on hawthorn trees demonstrated greater resilience, possibly due to a higher level of genetic diversity.

On the other hand, the life cycles of apple flies became out of sync with their host plants, jeopardizing their survival and potentially interrupting the speciation process.

Resilience of Parasitic Wasps to Heat, but Potential Consequences of Disrupted Life Cycles

In contrast, the heat did not impact the life cycles of the parasitic wasps. However, if their life cycles become mismatched with those of their prey, it could have severe consequences.

While natural adaptation might eventually restore some balance in disrupted ecosystems over the long term, there are significant limitations to rapid evolution. Factors such as fragmented habitats and limited genetic variability constrain organisms’ ability to respond effectively to changing environmental pressures.

Powell emphasized that it’s not just the disruption of evolution caused by climate change, but also the rapid evolution of the flies that affects their vulnerability to climate change.

This finding suggests that even flies from the same habitat that have been evolving since the 1800s may respond differently to future conditions. Consequently, the ecological timing of insect communities could undergo widespread chaos in the coming decades.

Read the original article on Phys.

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