In Tunisia, the use of the egg parasitoid trichogrammatid wasps to cope with several economic pests is gaining increasing attention. Trichogramma bourarachae (Pintureau & Babault) is among the Trichogramma wasps naturally present in Tunisia and regarded as a potential natural enemy to be used in biological control programs of many lepidopteran pests that cause economic losses. The propensity of T. bourarachae to cold storage with and without diapause induction was studied. The effect of this technique on its emergence rate and parasitic activity was investigated. The study showed that wasps of T. bourarachae treated at the induction temperature of 15°C for 5 days can be stored at 4 ± 1°C for more than 30 days without significant loss of their performances. By using this prestorage temperature, T. bourarachae could keep its emergence capacity (77.5%) up to 60 days of cold storage at 4 ± 1°C. However, its parasitic activity decreased significantly (37.16%) after 45 days of cold storage. These results are promising for its mass production, transport, and release in the framework of national campaigns to control several agricultural pests of economic importance.

This study was carried out to evaluate two biological methods for the control of Ectomyelois ceratoniae (Lepidoptera: Pyralidae) which is considered to be the most important pest species in Tunisia. Mass trapping through 14 traps (water and delta) baited with sex pheromone, and Trichogramma cacoeciae releases with two doses: 25,000 Trichogramma (T)/ha (D1) and 50,000 T/ha (D2) were tested separately. Field trials were conducted during 2016 in oases cultivated by date palm trees and pomegranates. In this experiment the infestation rates for delta traps, water traps and control were 17.6, 32.9 and 87.3%, respectively. Therefore, mass trapping with 14 delta traps was the most effective on pomegranate fruits. After inundative releases of T. cacoeciae (D1: 25,000 and D2: 50,000 T/ha), the results revealed an impact of this parasitoid in inhibiting carob moth eggs hatching, and a significant reduction of the infestation rate of pomegranate fruits between 19.1 and 22.7% for both doses compared to control plot with 87.3%. However, these trials (mass trapping and Trichogramma releases) applied on date palm trees were not sufficient to limit economic losses.

The pomegranate butterfly Deudorix (=Virachola) livia Klug 1834 (Lepidoptera: Lycaenidae) was encountered for the first time infesting dates (Phoenix dactylifera, variety Deglet Nour) in the oasis of Gafsa, Southern Tunisia in September 2011. Larvae of D. livia only caused damage on date fruits at the phenological stages kimiri (green fruits) and khalal (yellow fruits). The average infestation rate of dates was 10%. In addition, 7.1% of the infested fruits dropped to the ground. Damage caused by this insect on dates is described, the current situation in Tunisia is provided and possible control methods in Tunisia are briefly discussed. Although this pest has previously been reported in Tunisia on pomegranate this is the first report of D. livia on dates in the country.

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