[Selection of diets of the barn owl Tyto alba and the long-eared owl Asio otus in el Mâalba agricultural region in Algeria]

The diet of a barn owl and long-eared owl in a farmland area of El Maalba, East of Djelfa [34 degree 41' N; 3 degree 15' E] was determined by pellet analysis. The results showed that rodents [RA = 72.6%] were the most numerous prey in the diet of Tyto alba. The most consumed preys were Gerbillus campestris [RA = 26.0%], Meriones shawii and Rhizotrogus sp. [RA = 15.1%] for each species. The diets of long-eared owl showed that rodents were the most numerous preys [70.4%]. Gerbillus campestris [RA = 22.5%], Passer sp. [RA = 16.9%] and Meriones shawii [RA = 15.5%] were the most consumed. The comparison between the diet of these raptors and the availability of prey showed that Meriones shawii was the most preferred prey by the barn owl and long-eared owl

[Place des ravageurs des cultures dans le regime alimentaire des rapaces nocturnes dans une region steppique a Ain el-Hadjel]

The study of the diet of three species of nocturnal raptors in the area of Ain El- Hadjel [Algeria], resulted in the determination of 23 agriculture-pest prey species. The study shows that the ravagers invertebrates make 31.9% of the Little Owl diet of which Rhizotrogus sp. [R.A. = 18.7%] and Messor structor [R.A. = 12.1%] are the most consumed preys. On the other hand, the ravagers vertebrates appeared to be more looked for by the Barn Owl [R.A. = 67,5%]. They are most represented by Meriones shawii [R.A. = 41.4%] and Gerbillus sp. [R.A. = 11.4%]. As for the Desert Eagle Owl [R.A. = 42.7%], it also prefers Meriones shawii [R.A. = 9.1%] and Gerbillus gerbillus [A.R. = 9.1%]. Feeding on these kind of preys, these raptors are regarded as auxiliaries to the farmer

[Effect of the varroa destructor on alar morphometry and on the immune system components of the apis mellifera intermissa]

Varroa destructor is a major enemy of honeybees. It was found in Algeria in 1981 in the apiary Oum Theboul El Kala [East Algeria]. This parasite spread rapidly from there. In order to study the impact of the Varroa destructor on wing morphometry and the immune system components of the honeybee, samples of healthy worker honeybees and parasitized nurses were collected from the apiary of Oued Aissi [Tizi-Ouzou] located in the North of Algeria. This parasite significantly affected the length and the width of the fore wings, the angles 31, 33 and 34. No significant effect [P>0,05] was detected for the angles 32, 35 and 36. The immune pathogen effect of the Varroa destructor on the nurse honeybees was expressed by a significant reduction [P=0,001] in the total number of hemocytes [THC], which is one of the most frequently used measures for immune system components

[Daily attacks of three barley Hordeum vulgare L.plots by the hybrid sparrow Passer Domesticus X.P. hispaniolensis in the eastern Mitidja]

This study shows the daily distribution density of the Passer domesticus x P. hispaniolensis in three plots in Boudouaou. This investigation was conducted during two months [April, May] in 2003. This period of time corresponds to the growing up and maturation of Hordeum vulgare L. During April, the average of hybrid sparrows found in plots 1, 2 and 3 is 50.77, 36.10 and 17.24 respectively. The same trend was also observed in May. During the period of study, it is found that the number of sparrows identified in the three plots, was higher in the morning than what it was in the afternoon