In New Zealand, a small insect known as the tomato potato psyllid (TPP) has been impacting the quality of potato crops, leading to the production of what's colloquially termed as "zebra chips" due to their striped appearance and bitter taste. This issue is not a result of overcooking but is caused by the psyllid's transmission of bacteria to the potatoes. Canterbury, a significant potato-growing region, experienced a loss of 5.7% of its crop three years ago due to this pest, which represents a considerable area given the region's contribution to the country's overall potato production.
Research efforts led by Professor Clive Kaiser from Lincoln University have focused on combating the TPP with various control methods, including the introduction of a natural predator, the psyllid-eating pirate bug. These efforts have been crucial in addressing the threat posed by the psyllid, which originated from North America and found its way to New Zealand in 2008. The psyllid's ability to travel vast distances, potentially aided by trade winds, has been a significant factor in its spread.
Professor Kaiser's team has gained extensive knowledge about the TPP, including its life cycle, breeding habits, and the altitudes at which it flies. This expertise has informed strategies for managing the pest, such as adjusting pesticide application schedules to target the psyllid more effectively at vulnerable stages of its life cycle. A notable discovery involved finding a large number of psyllid eggs on African boxthorn plants, leading to the strategic deployment of pirate bugs to these areas.
The introduction of pirate bugs has seen a dramatic reduction in the incidence of TPP, with infected plants dropping to less than 0.01% of the crop in Canterbury. This biological control method has shown promise in maintaining the balance between the psyllid and its natural predators, suggesting a sustainable approach to managing this pest. Bioforce, a bioagent breeder, has been instrumental in supplying pirate bugs to support ongoing control efforts, helping ensure the continued production of high-quality, "zebra-free" potatoes.
Source: The Press