Climate Change in Pacific Northwest Lead To Expansion of Different Insect Species to Oak Savannas

According to a new study from Binghamton University, State University of New York, climate change has caused increasing temperatures in the Pacific Northwest, causing some insect species to expand their habitat into more northerly oak savannas.

Climate change on invasive species in the Western US

(Photo : David Clode/Unsplash)

Dylan Jones exhibited two pictures of oak leaves side by side. One, healthy and green, with the odd gall, a structure built by a herbivorous species of oak gall wasp.

The other leaf was yellowed and frayed, the victim of an insect population devoid of predators.

Warming temperatures in the Pacific Northwest have caused species such as Neurotereus saltatorius to expand their range into further northern oak savannas.

In the native area, you could discover a few of galls on a single leaf; in the extended range, you might find hundreds on a single tree, said Kirsten Prior, Assistant Professor of Biological Sciences. "This is rather common on Vancouver Island," as per ScienceDaily.

Jones, a Binghamton University PhD candidate in biological sciences and a Clifford D. Clark Diversity Fellow, is the primary author of a study on the issue that was just published in the Journal of Animal Ecology.

Prior, field technician Julia Kobelt, then-undergraduate Jenna Ross, and Assistant Professor of Biological Sciences Thomas Powell are among the co-authors of "Latitudinal gradient in species variety affords high niche options for a range-expanding phytophagous insect."

Oak savannas are grassy, shrubby environments with oaks as the major tree species. The oak in issue, Quercus garryana, prefers a dry climate.

As a result, Prior stated, oak savannas are frequently found in the rain shadow of the West Coast's mountain range.

Oaks, a varied and ecologically significant genus of trees found throughout North America, is home to a broad range of insect species, including oak gall wasps.

These wasp species produce galls, which can be rather spectacular in their many shapes, ranging from big apples to those with multicolored spikes resembling sea urchins.

Interestingly, Alfred Kinsey - yes, that Kinsey - investigated oak gall wasps before moving on to human sexuality.

"This group of animals has long fascinated biologists and hobbyists because they're quite charismatic," Prior said. "You may go to an oak and see at all these structures."

In addition to their herbivorous producers, these galls are home to a dazzling array of parasitoid wasps, one of the most varied and ecologically significant groups in the animal kingdom, the latter for their role in controlling insect pests.

Parasitoid wasps deposit their eggs in the gall, and their larvae consume the oak gall wasp larvae after hatching.

Oak gall wasps are abundant throughout North America, but their evolutionary relationships and even the identity of certain species are unclear.

A group of scientists from across the continent is striving to change that, and Jones and Prior are among them.

Read more: 6 Invasive Insects You Should Need To Kill Immediately According to Scientists

Insect disturbance and climate change

Because the temperature and other environmental variables influence forest insect populations, future climate change is likely to affect forest bug outbreaks, as per Climate Change Resource Center.

Larger and more frequent bug outbreaks may develop in certain circumstances, whereas repeating outbreaks may be halted in others.

Because forest insect populations are controlled by climatic factors, future climate change is likely to alter the outbreak dynamics of some forest bug species.

Larger and more frequent bug outbreaks may occur in certain circumstances, but repeating outbreaks may be interrupted or reduced in others.

Temperature fluctuations that directly affect insects, as well as diminished host tree resilience induced by precipitation changes, can all contribute to forest insect population development.

Alternatively, disruption of local adaptation to climate might result in the extinction of a limited population.

The role of biotic and abiotic causes on various forest insect population explosions is well understood.

According to the findings of this study, the impact of climate change on outbreaks would differ geographically as well as among various insect/host relationships.

Predicting the consequences of future climate change on insect-caused forest impacts will be difficult due to the intricacy of the food webs and host tree dynamics that most forest insects are a part of, as well as the uncertainty of climate projections.

Related article: Spotted Lanternfly: Indiana State Officials Warn About Invasive Insect Found in Tri-State