Middle East Journal of Agriculture Volume : 4 | Issue : 01 | Jan-Mar. | 2015 Research Pages: 67-76 ISSN 2077-4605 Taxonomical Revision of the Genus Colomerus Newkirk & Keifer (Acari: Eriophyidae) in Egypt 1Halawa, A. M., 1Ebrahim, A. A., 1Abdallah A. A. M. and 2Azza, A. Mohamed 1Fruit Acarology Department, Plant Protection Research Institute (PPRI), Agricultural Research Center (ARC), Egypt. 2Cotton and Field Crop Acarology Department, Plant Protection Research Institute (PPRI), Agricultural Research Center (ARC), Egypt. ABSTRACT To re-evaluate Columerus spp. in Egypt, mites were collected from vineyard orchards Vitis vinifera L. throughout all provinces of Egypt during years (2012 - 2014). Collected samples were examined microscopically by two methods, light microscopy using a Carl Zeiss compound and Analytical Scanning Electron Microscope. Twenty specimens were selected and divided into two sets based on the number of empodial rays (5 rays or 6 rays). The examined specimens showed that 95% from total specimens collected were found to belong to 5 empodial rays and only 5% to 6 empodial rays, either Colomerus vitis and Colomerus oculivitis separated from the same bud. In addition, three types of microtubercles were recorded, type I; elongate and more compact, type II; rounded and more wide spaced and type III; gradation from elongate to rounded. These types were observed randomly on the specimens that were identified (based on number of empodial rays only) as Co. oculivitis or (Co. cf. oculivitis) and Co. vitis or (Co. cf. vitis). Moreover, more than 50% of type I were associated with the specimens that has six empodial rays. The results also showed that the specimens with rounded microtubercles showed their absence from the beginning of the posterior seventh annuli, where eighth and ninth annuli were sparsely microtuberculate, while the specimens with elongate microtubercles were without microtubercles on the posterior sixth dorsal annuli. Type III represents few cases that showed gradation in the shape of microtubercles between type I and type II especially from the ventral side. Also, three types of cover flap for female genitalia were recorded; type I; included 10 ridges arranged in two uneven transverse rows, type II; included 13 ridges arranged in two distinct transverse rows and type III included more than 16 ridges arranged in a single row. Types I and II were observed randomly on many specimens (not associated with certain characters). on contrast, type III was very few and associated with specimens that have 6 empodial rays which has gradation microtubercles (elongats tend to rounded). There were highly significant length, width and distance differences within specimens for each set however there were strong correlations for variables comparatively in the two sets. The results in these study confirmed that the number of empodial rays are considered the main fixed characteristic for grapevine Colomerus specimen, while the microtubercles morphotype are considered problematic and inaccurate identification. In addition, it recommends two procedures based on the differentiating characters: A) Description of Colomerus species or strains from grapevine as a complex species (Colomerus vitis comp. sp.), based on the differentiating morphological characters. B) Dividing Colomerus species or strains from grapevine to 3 types depended on the more fixed characters, which are the empodial rays (5 and 6 rays) and microtubercles (elongate, rounded and gradation from elongate to round. Key words: Eriophyidae, Colomerus vitis, Colomerus oculivitis, electron microscope, taxonomy, grapevine. Introduction Grapevine (Vitis vinifera L.) is currently cultivated on a wide commercial scale throughout the temperate regions and it is successfully grown in Europe, the Balkans, Asia, Mediterranean, South Africa, South Australia, New Zealand, most of North America and many parts of South America (Bouquet et al., 2006; Arroyo-garcía et al., 2006; Mattia et al., 2008; Rosa et al., 2013). Thus, the grapes are considered the largest fruit crops in terms of trading between countries but the pests play an important role as a determining factor for this trading according to the International Standards for Phytosanitary Measures (ISPM). Several pests attack grapevine plants. Amongst are; the phytophagous mites, of which the most important are those belonging to eriophyid mites, since they frequently reach damage level in the vineyards (Duso and De Lillo, 1996). Eriophyid mites associated with grapevine belong to two genera, Calepitrimerus Keifer and Colomerus Newkirk & Keifer. Corresponding Author: Halawa, A. M., Fruit Acarology Department, Plant Protection Research Institute (PPRI), Agricultural Research Center (ARC), Egypt. 67 Middle East J. Agric. Res., 4(1): 67-76, 2015 Twenty-seven species assigned to genus Colomerus, have been described from all continents, except Antarctica (Chandrapatya et al., 2014). Several of these species are known to attack ornamental plants, only three species have been reported from major crops, Colomerus vitis (Pagenstecher, 1857) and Colomerus oculivitis (Attiah, 1967) were reported from grapevine (Vitis vinifera L.) and Colomerus novahebridensis (Keifer, 1977) from coconut (Cocos nucifera L.) (Chandrapatya et al., 2014). Colomerus vitis is considered the most economically damaging of eriophyid mite associated with vineyards (Pagenstecher, 1857; Duso and de Lillo, 1996; Bernard et al., 2005; Linder et al., 2006; Walton et al., 2007; Luchian et al., 2008; Tomoioaga and Comsa, 2010). This species has been placed originally in the genus Phytoptus (Pagenstecher, 1857) then in Eriophyes (Nalepa) and finally in Colomerus (Newkirk and Keifer, 1971). Although three strains of Co. vitis (bud, leaf erineum and leaf curl) were reported based on behaviors and symptoms, no morphological differences between them were recorded, this led to believe that they may belong to a cryptic species complex (Craemer and Saccaggi, 2013). Co. oculivitis first described in Egypt was located in Bagour (Nile Delta) by Attiah 1967 and recently in Saudi Arabia by Al-Atawi and Halawa, 2011. It causes symptoms on grapevine similar to C. vitis in addition to reddish discoloration of leafs and eventual desiccation. In recent publications, Craemer and Saccaggi (2013) and Chandrapatya et al. (2014) reported that the mentioned species (Co. vitis and Co. oculivitis) were recorded from imported grapevine material from various countries to South Africa; many of these were identified as Co. oculivitis or morphologically closely related, despite South Africa and exporting countries being free from this species. Accordingly, they claimed their uncertainty in relation to the reliable separation of Co. vitis and Co. oculivitis. Owing to the high variability of characters considered important in the characterization of those species, except for the number of empodial rays (5 in Co. vitis and 6 in Co. oculivitis) which was discrete and unambiguous distinguishing character. Meanwhile, they reported that Colomerus spp. from grapevine worldwide could be inaccurately categorized to specific species, given the possible unrivalled variation in the number of empodial rays in those species. As far as known, Co. oculivitis was described originally from Egypt. Thus, the main aim of the present study is comprehensive re-evaluation of Colomerus spp. in Egypt, based on the taxonomical characters reported by Attiah (1967) (number of rays in the feather claw, shape and density of microtubercles, number of ribs on the female genital coverflap and Leg I and II measurements). Materials and Methods Mites: collected – mounted Mites were collected from vineyard orchards Vitis vinifera L. throughout all the provinces of Egypt during two years (2012 - 2014). Samples included leaves, fruits, buds and branches and were individually placed in tightly-closed plastic bags and transported in the same day to the Fruit Acarology Department, Plant Protection Research Institute (PPRI), Agricultural Research center (ARC). Mites were removed using a fine hairbrush under dissection stereomicroscope; some of them were cleared and mounted on micro-slides by using Keifer medium according to Keifer (1975), then dried at 40°C for one week (Zhang, 2003) and finally examined under a Carl Zeiss compound microscope. Other individuals collected from the same samples were morphologically described directly using Analytical Scanning Electron Microscope (Model: JEOL JSM- 639OLA). Identification to a specific genus was made using the key to the world genera by Amrine et al. (2003) and the species identification was done using published descriptions of Colomerus species from grapevine. Specimens Twenty specimens were selected and divided into two sets based on the number of empodial rays (5 rays or 6 rays). There were ten specimens (females) belonging to empodial 6 rays (A set) and other ten specimens (females) belonging to empodial 5 rays (B set). Measuring method In this study, the lengths, widths and distances of ten pairs of setae, body, shield and legs were measured. Twenty-nine variables from each set (A and B) were selected for this study. The measuring process used in this study followed that reported by Huang et al. (1991) as methods to confirm the symmetries between individuals in the two groups. All measurements in this study were given in micrometers (µm). Analytical methods Results of morphological analysis of grapevine Colomerus species assessment were collected and tabulated in table (1), then analyzed