A Glimpse inside the Bubbly World of SpittlebugsMarch 25, 2019
Research on Spittlebugs using PreSens O2 Microsensors in the New York Times Science News
In February Dr Matthews from the University of British Columbia and two of his students, Kephra Beckett and Anna Robertson, published their findings on the respiratory strategies of spittlebugs in the Journal of Experimental Biology. The publication was selected as the editors' choice for the month and caught the attention of science writer James Gorman, who reported about it in the New York Times.
Spittlebug nymphs feed on xylem sap, using their copious liquid excreta to create a wet foam in which to hide. This bubble nest provides the nymphs with a moist, temperate microenvironment in which to live and feed while developing into adult froghoppers, as well as protecting them from predators. Sounds cozy, but things are a little different for spittlebugs at the campus of the University of British Columbia. Before you know it, somebody might be poking a microsensor into your self-built home to check its oxygen level.
The spittlebugs' frothy nests made Dr Matthews, who specializes in respiratory adaptations in animals, wonder: how do the insects inside breathe? Do they use the air trapped inside the bubbles or poke their abdomen through the foam in order to breathe? Together with students Beckett and Robertson, he addressed this question using PreSens' oxygen microsensors. Using a micromanipulator they performed transect measurements inside the bubble nests in the field as well as in the laboratory, and used PreSens sensor spots to determine the insects' rates of O2 consumption. They showed that the nymphs preferred to snorkel in the foam, breathing atmospheric O2 directly using the tip of their abdomen. However, when the spittlebug was ready to molt into the adult froghopper, it first retreated into a single large bubble in the foam nest. The level of O2 in this bubble chamber was below atmospheric, indicating that the newly emerged froghopper was indeed consuming the O2 within the bubble.
Pretty much everybody has seen this white, spittle-like foam on plants in gardens and parks before, but most people know very little about the insects creating it. Therefore, the NYT article by Mr Gorman "Inside the Spittlebug's Bubble Home" probably fount not only scientifically interested readers. If you like to know more about the results Dr Matthews and his team have published, you can find the article on the Journal of Environmental Biology website, where it also is the editors' choice this month: "Studies on the gas exchange in the meadow spittlebug, Philaenus spumarius: the metabolic cost of feeding on, and living in, xylem sap", Journal of Experimental Biology (2019) 222, jeb 191973