Intensive pest control against mites and Drosophila on small fruits in protected cultivation
In recent years, damage caused by the tarsonemid mite in raspberry plantations in protected cultivation has increased in southern Italy. This was confirmed by technician Carmine Lanaro, reference point for Bioplanet in Campania and specialist in small fruits. To combat this mite, the use of beneficial insects is essential. “We have developed a strategy based on two predatory mites, Ambliysius andersoni and Ambliysius cucumeris,” said Lanaro.
“Since we started the preventive biological control campaign at the end of September, we have effectively restricted the reproduction of the tarsonemid mite. Our two pest predators are generalists, but hit the target very successfully and together show very good results.
“This is very reassuring as there is no effective chemical control. Therefore, the use of beneficial insects is critical not only for organic growers but also for those who grow in an integrated system.”
Additionally, Drosophila suzukii in both raspberries and strawberries is another problem that has emerged in recent months. “In this case, pest control begins outside the greenhouses with the spread of the parasitoid Trichopria drosophilae. This year there was hope of a lower Drosophila population due to weather conditions, but that was not the case. The insect is now endemic and we need to act consistently and in a timely manner every year, “Lanaro said.
Trichopria exhibits pronounced sexual dimorphism, with the female being larger than the male, which has long and bristle antennae that are used in an elaborate mating ritual. The female searches the ground for newly formed Drosophila pupae and lays an egg there, especially in the larvae that are still in it.
The Trichopria larva will then completely devour the Drosophila in its pupa until it mutates into an adult who exits through a circular hole. Each female Trichopria can infect up to a hundred Drosophila, with a development cycle of three weeks, which enables a continuous generation sequence with a slowdown only in the coldest months.