In a small room at Lincoln’s Institute for Bioeconomic Sciences, Dr. Mark McDougall refocuses a laser so that the beam is centered on a piece of metal tape on a tomato leaf. He uses it to detect small movements.

What is the source of this movement? Tiny glasshouse whiteflies on the underside of leaves are trying to communicate in a kind of insect language that we can neither feel nor speak: the language of vibrations.

biological tremolology
Mark had never heard of this vibrational language until he completed his PhD on the subject. That study is called biotremology. But the idea completely fascinated him.

“I had no idea that vibration was just one part of how animals communicate. I had no idea it was so widespread around the world. This whole world of communication is basically completely unknown to us humans.”

© Craig Robertson / Institute of Bioeconomic SciencesDr Mark McDougall uses a laser vibrometer to study insect vibration calls in the lab

It is not only widespread, but also diverse. According to Mark, insects can create vibrations in all sorts of ways, just like different musicians in a band.

“Some insects just shake their bodies. Others, like grasshoppers, rub small plates on the inside of their bodies. But they can also be used to transmit vibrations through the stems of plants. Insects like termites bang their heads against the ground, sending vibrations throughout their nests.”

And it uses different patterns of vibrations to communicate different things. As a result, we are taken to this room, isolated from sound and vibrations. So Mark is trying to record and translate the language of greenhouse whiteflies and use that knowledge to fight back against whiteflies.

whitefly problem
Greenhouse whitefly is the most common whitefly species in New Zealand and is found year-round in greenhouse crops. They prefer plants in the nightshade family, such as tomatoes, eggplants, and capsicums, and plants in the cucurbit family, such as cucumbers and squash.

Adults are approximately 1.5 millimeters long and feed on plant sap during various stages of their life cycle, weakening plants and promoting the growth of sooty mold. If conditions are right, they can breed in large numbers and put a lot of stress on crops.

Tomato grower Pete Mundy knows this all too well. Pete, who is based in Christchurch’s Heathcote Valley, grows a variety of cherry tomatoes hydroponically in a hectare-sized greenhouse.

©Claire ConcannonPete Mundy allowed scientists to use his tomato-growing operation as a research testing site

Mr Pete has his own pest control methods to keep whitefly numbers in check, but he has also allowed researchers at the Institute of Bioeconomic Sciences to carry out a series of biotremology research tests on some of his plants.

Project leader Dr Lloyd Stringer says that’s because the point of the research is to find out whether this vibrational language can be used to deter pests in real-world settings. And he says the trial, supported by industry groups Tomato New Zealand and Vegetables New Zealand Incorporated, will help test practical limits from the start.

“For example, you might develop something here in the lab and think, ‘Oh, I have a great idea, this will work.’ You can also go to your glasshouse and say, ‘Oh, this won’t work. There’s no power plug every 5 meters.’ So… this helps us make sure we’re developing something useful and applicable without too much tweaking.”

© Craig Robertson / Institute of Bioeconomic SciencesDr. Lloyd Stringer, an entomologist at the Institute of Bioeconomic Sciences, is leading the research.

Tell the pest to get out
The first experiments in Peat’s greenhouse began in October 2025, using a single vibrating sound previously identified by Japanese researchers as deterring whiteflies from laying eggs.

A mini-shaker was attached to a metal beam inside the greenhouse, and vibrations were transmitted down the wire to the plants every 15 minutes. The trial ran for six weeks, with entomologist Dr Rachel Horner counting the number of whitefly eggs on the leaves of both control and treated plants each week.

However, when they crunched the numbers, the researchers found no significant differences between the control and vibration zones, although there appeared to be a slight trend towards reduced spawning in the treatment plants.

Lloyd said there are a lot of variables. For example, there was wide variation in whitefly numbers across greenhouses and at different times during the trial, making it difficult to determine the effects. Additionally, there are questions about how “loud” the vibrations need to be for whiteflies to respond, and how far the vibrations travel through the plant.

© Craig Robertson / Institute of Bioeconomic SciencesGreenhouse whitefly feeds on plant sap, weakening plants and promoting the growth of sooty mold.

Follow-up testing will include increasing the frequency of vibrations, and we are also working with a Christchurch company to develop bespoke equipment to increase the vibration area.

The idea of ​​using biotremology for pest control is not new, but the practical issues and cost of creating the necessary vibrations in the growing environment have long hindered its use, says Dr. Lloyd Stringer.

For growers like Pete Mundy, the promise of adding another non-chemical tool to their pest management toolbox is very appealing, and for Dr. Lloyd Stringer, the time is right to give it a proper try.

“Technology is here…we need to do it now!”

sauce: RNZ