Sex-change to combat one of Australia's worst pests

In a unique way to combat one of Australia's worst pests, scientists are planning to create a male-only line of the dreaded Queensland fruit fly to save the country's 7 billion dollar horticulture industry.
Scientists at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) are combining micro sensing, sterile insect technology and new insect trapping systems to protect the farms from one of Australia's most economically damaging pest.
Although only 8mm in length the Queensland fruit fly, or Q-fly, is a highly mobile insect capable of infecting a wide range of major fruit and vegetable crops, including stone and tropical fruits.

The spread of Q-fly in Australia's eastern states is threatening the country's AUD 6.9 billion horticultural industry, which relies on both domestic and international trade, researchers said.
Until recently, farmers located in areas where Q-fly is present have used agri-chemicals - such as dimethoate and fenthion - to prevent and manage incursions.
However, after a long period of review, the Australian Pesticides and Veterinary Medicines Authority has recently restricted the use of these insecticides.

According to CSIRO researcher Dr Paul De Barro, increased Q-fly numbers can also threaten status of pest free areas.
"We believe that our sterile insect technology (SIT), through development of a male-only line of Q-fly, will offer a new environmentally friendly, sustainable and cost effective approach to assist in managing this damaging pest," De Barro said.

"SIT is a scientifically proven method for suppressing or eradicating fruit fly populations and managing their potential impacts in horticulture production areas," said De Barro.
This biological control method has already been used with great success around the world and in South Australia to combat the Mediterranean fruit fly. However, the development of male-only sterile Q-fly is a first.
"Despite all our knowledge of fruit flies, we do not actually know where they go to breed. When you're looking to deploy sterile male flies to disrupt the mating cycle this information is a critical piece of the puzzle," De Barro said.

By using micro sensing technology on Q-flies, CSIRO will be able to answer that question and, most importantly, understand where to deploy sterile Q-flies and also how to make better use of other management options such as new trapping systems and pheromone baits.
"It will tell us how many sterile flies we will need to release and most importantly, when to release them," De Barro said.
Combining SIT with other sensor technologies represents a game-changing opportunity as it not only provides us with information about how the Q-fly interacts with its natural environment, but offers real opportunities to reduce the cost of current monitoring networks for fruit fly," said De Barro.