New data on aphid fauna (Hemiptera, Aphididae) in Algeria

Abstract A survey of aphids was carried out during the period 2008-2011 in different regions of Algeria by collecting and identifying aphids and their host plants. Aphids were collected from 46 host plants. Forty-six species were reported including thirty-six species which were recorded for the first time in this country and thirty species which were recorded for the first time in the Maghreb (North Africa). This study extends the number of known Algerian aphid to 156 species.


Material and methods
The regions choosen for sample collection belonged to different bioclimatic stages. The regions of Annaba, Tarf and Algiers are located on the Mediterranean coast and are characterized by a humid and sub humid climate. Other regions (Guelma, Constantine, Setif and Oum El Bouaghi) are located on the high plateaus and high plains, where cereal crops are cultivated (semi arid climate). Khenchela, Batna and Biskra are located on the slopes north and south of the Saharan Atlas. Their natural vegetation is dominated by steppe plants. Ouargla and Ghardaia are located almost in the center of the Algerian Sahara (arid climate). Their natural vegetation is composed of desertic plants (Fig. 1).
This study, conducted between 2008 and 2011, considers only the new aphid species of Algeria and the species already mentioned but without specified host plants. Specimens were collected from wild and cultivated plants, tree and shrubs bearing aphid colonies. The aphids were preserved in 75% ethyl alcohol until their prepara- tion for slide-mounting. They were identified using the keys of Eastop (1994, 2000), Nieto Nafria et al. (2002,2005) and Remaudière et al. (1985). The nomenclature used was that proposed by Remaudière and Remaudière (1997). The aphid preserving techniques are mainly based on the method of Hille Ris Lambers (1950). The majority of the studied and identified specimens were deposited in the insect collection of the Department of Agronomy, University of Batna (Algeria) and a minor part of aphids were deposited in the collection of the National Institute of Agronomic Research (INRA) at the CBGP in Montpellier, France.

Discussion
With 46 species, this survey constitutes the most important contribution to the knowledge on aphid diversity in Algeria. Organization of the similar local studies would to play an important role in the applied entomological studies and may add more species to Algerian aphid fauna. There is a very large volume of literature about all the major pest aphid species and two factors that have the greatest influence on intraspecific variation in aphids: the life cycle and the host plant. Among the species inventoried, Aphis illinoisensis is the aphid that has the greatest agricultural importance. This invasive aphid was reported for the first time in the Mediterranean from southern Turkey in 2002, and identified as a new possible threat to the respective grape-growing areas (Remaudière et al. 2003). A general historical set of invasive grape aphid detection is as follows: 2002 in southern Turkey (Remaudière et al. 2003), 2005 in Crete -Greece (Tsitsipis et al. 2005(Tsitsipis et al. ), 2007 in Israel ( Barjadze and Ben-Dov 2011), 2009in Tunisia (Ben Halima-Kamel and Mdellel 2010. In Algeria this aphid was detected for the first time in 2007 in several regions of viticulture (Laamari and Coeur d´Acier 2010). Greenidea ficicola is considered as another invasive species. It was encountered for the first time in 2007 on Ficus nitida in Tunisia (Ben Halima-Kamel 2009). In Algeria it was collected in April, 2008.
A total of 34 aphid species were collected on the steppe plants specific of the Saharian Atlas. This mountain range forms the boundary between the northern (Mediterranean area) and southern (African area) of Algeria. It is home to many endemic plants, which may harbour very specific and uncommon aphid species. All aphid species reported as new to Algeria and North Africa were found in this transition area (Batna, Biskra and Khenchela regions).

Conclusion
In this study, 36 aphid species were reported for the first time in Algeria, increasing the number of species known to be present in this country to 156. Given the high level of climatic and plant diversity in Algeria, the expansion of prospect activities to a larger number of plant species and environments would undoubtedly provide a more accurate picture of the Algerian aphid fauna and would increase the number of species known to be present in this country. Furthermore, prospect studies in the Sahara and steppe zones, which are know to have a highly endemic flora, might lead to the description of species new to science.