Monitoring and population changes of Tuta absoluta (Meyrick, 1917) on tomato under greenhouse conditions in an arid expanse of south-eastern Algeria

The population changes of Tuta absoluta was surveyed during three growing seasons in greenhouse tomatoes in Biskra. Introduced in 2009 for the first time, it seems to be well established on tomato crops in Biskra; while their natural enemies remained lacking, due possibly to pesticides overuse. All pest stages were present on tomato plants during the three cropping seasons. Important numbers of males were captured during the first growing season and the least during the third growing season. The first adults’ flight spread out between October and December. Adults’ flight significantly rose at the end of the plant cycle due to increased temperatures in all cultivation seasons. This can provide information on the infestation levels for the following cultivation years. The numbers of immature were low during the three cultivation seasons. March, April and May seem more favorable to the different leaf miner instars development for the three cropping seasons. This was due probably to temperature rising.