A neurotoxin found in venom from one of the world’s most venomous scorpions may offer a powerful, environmentally friendly solution to the growing problem of insect resistance to existing bioinsecticides.
A study carried out by researchers in China investigated the large-scale production of a protein called LqhIT2, which is derived from the venom of the deathstalker scorpion, Leiurus quinquestriatus hebraeus.
The protein specifically targets sodium ion channels in insects, disrupting their nervous systems and causing death. Because the protein has no known harmful effects on mammals, the researchers say their findings could pave the way for a new class of bio-insecticides, reducing agriculture’s dependence on synthetic chemical pesticides.
In a study published in Pest Management Science, the team from Zhejiang University utilised a yeast commonly used in industrial protein production to purify the scorpion venom protein, using batch fermentation.
Through that process, the researchers discovered they had created concentrations that were about 20 times higher than traditional methods of producing the neurotoxin, and much higher than levels previously reported in other insect neurotoxins.
“This is the first time we’ve seen rLqhIT2 produced at this scale with such purity,” the authors noted, emphasising that growing protein in yeast was preferable to older methods that use E. coli, which can contain endotoxins and contaminate the final product
Tackling resistance issues
The team said their findings are especially timely, not only because of concerns over the environmental impact of conventional pesticides, but also due to problems with resistance issues of bioinsecticides like Bacillus thuringiensis (Bt), particularly among Lepidopteran pests.
“Bt has been the cornerstone of biocontrol for decades,” said Dr Li Hua, lead author. “But it’s no longer enough. We need next-generation insecticides that are specific, effective and safe.”
Unlike Bt, which acts primarily through the insect gut, LqhIT2 works on pests’ nervous system, making it effective across a broader range of pest species. Lab tests showed it worked well against common pests like houseflies, locusts, and cockroaches, even in tiny amounts.
The team also tested rice plants that were modified to produce the protein. These plants caused pest larvae to eat less and grow more slowly, suggesting the approach could work when pests eat the crop, not just when they’re injected in the lab.
Another benefit is that the protein remained stable in hot conditions (80°C for 2 hours) and held up during production, which meant it should perform well outdoors.
However, once purified, the protein breaks down easily in the gut, meaning any leftover traces on food crops were likely to be safely digested by people and animals.
“Chemical insecticides persist in the environment – that’s part of the problem,” the researchers said. A biodegradable alternative like this could be a real breakthrough, the team added.
The researchers also believe the platform they developed to produce this protein could be used to express other neurotoxins in future. Further work is needed to assess large-scale field efficacy and ecological safety, but early indicators are promising, they said.
