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Dispersal of eriophyoid mites is crucial for the successful colonization of new plants. Literature suggests that their long-distance dispersal is through aerial transfer. During dispersal, eriophyoids might be captured in vapor or fine drops of water (perhaps most likely in clouds) where they might be protected against water loss and desiccation, but where they would have no food and be exposed to low temperatures and oxygen concentrations. Considerable resistance of these mites to these stressful environmental conditions is expected and has only partly been confirmed experimentally. The aim of the bioassays conducted here was to assess the survival of five eriophyoid species off their host plants, with poor oxygen availability under two temperature regimes. The bioassays were carried out on live mites dipped into two media used as microenvironments: (1) vaseline oil (used also as control treatment), and (2) water solution of Tween 80 (0.2%) and cycloheximide (50 mg/l). The bioassays were performed at 5 ± 1 and 25 ± 1 °C. The survival of mites was assessed weekly (5 °C) or daily (25 °C) by counting live and active specimens. The following species were subjected to the bioassays: Aceria caulobia (a stem gall mite), Aceria ficus (a vagrant mite), Cecidophyopsis hendersoni (a vagrant mite), Colomerus vitis (protogyne/male population and deutogyne morphs; a leaf gall mite) and Phytoptus avellanae (a bud gall mite). The survival rate of the mites was higher at 5 °C than at 25 °C under both experimental conditions. At 5 °C, the survival of almost all species was higher in the water solution (up to 6-7 weeks) than in vaseline oil (3-5 weeks). Longer survival was found for A. caulobia and P. avellanae (gall-making species) than for C. hendersoni and A. ficus (vagrant species). As expected, the deutogynes of C. vitis survived longer than its protogynes. The current results suggest that individuals of some of the tested species are well suited for withstanding cold, starvation and low oxygen rates, which could be found at higher atmospheric layers, within the clouds, allowing them an effective long-distance dispersal.

Confocal laser scanning microscopy (CLSM) methods are still rarely used by acarologists although they are very appropriate for studying minute arthropod pests, especially eriophyoid mites. In this paper, the female reproductive system of phytoptines, including the bud mite Phytoptus avellanae, the well-known pest of hazelnut, was studied using CLSM and resulted in new interpretations of the functioning anatomy of phytoptid genitalia. Comparison of cuticle-lined internal genitalia, based on novel CLSM-based 2D and 3D imaging, and multivariate analysis of morphometric measurements, show that two basic types of internal genitalia can be found within Phytoptinae: one type in phytoptines associated with monocotyledoneous hosts (especially Cyperaceae and Asparagaceae), and another one in those associated with various dicotyledoneous hosts. Phytoptines from monocots (genera Oziella and Acathrix and Phytoptus "caricis" sp. group) possess a spherical distal part of the spermathecal tube and a semitriangular transverse genital apodeme, whereas phytoptines from dicots (genus Phytoptus "avellenae" sp. group) possess an elongate distal part of the tube and a trapezoidal apodeme. These differences in the internal genitalic anatomy were used for modifying the diagnosis of phytoptine genera (Phytoptus, Oziella and Acathrix), and reorganizing the Phytoptinae, resulting in new synonymies: 11 species were transferred from genus Phytoptus "caricis" sp. group to the genus Oziella.

Hazelnut big bud mite, Phytoptus avellanae Nalepa, is one of the most harmful pests of Corylus spp. (Corylaceae) worldwide. Herein, we show that this species represents a complex of two cryptic species: one that lives and reproduces in buds causing their enlargement ('big buds') and drying, whereas the other is a vagrant living on leaves, under bud scales and in catkins, based on phylogenetic analyzes of mitochondrial cytochrome c oxidase subunit I (COI) DNA and the nuclear D2 region of 28S rDNA sequences. A molecular assessment based on mtCOI DNA and nuclear D2 28S rDNA revealed consistent differences of 16.8 and 3.5 % between the two species, respectively. Molecular analysis also revealed that atypical flattened nymphs (Tegonotus-like nymphs sensu Keifer in Mites Injurious to Economic Plants, University of California Press, Berkeley, pp 327-562, 1975) with differently annulated opisthosoma, which appear in the life cycle of P. avellanae s.l., belong to the 'vagrant' lineage, i.e. vagrant cryptic species. Light microscopy images of Tegonotus-like nymphs molting into males and females are presented for the first time. Our results suggest that the name P. avellanae comprise two species. Big bud mite should keep the name P. avellanae, and the vagrant cryptic species should be re-named after a proper morphological description is made.

4th International Symposium on Hazelnut -- JUL 30-AUG 02, 1996 -- ORDU, TURKEY WOS: 000071757700070 Damage types caused by two forms of Phytoptus avellanae Nal. ("gall" and "vagrant" forms) and Cecidophyopsis vermiformis Nal., all of which are commonly found in the hazelnut cultivars in the Blacksea Region, were investigated by periodic sampling. Our results show that the gall form of P. avellanae feeds exclusively on generative buds and causes formation of big buds; whereas the vagrant form of P. avellanae does not cause big bud formation, but feeds intensively on both vegetative and generative buds, on catkins and on young fruit clusters which eventually fall. On the other hand, C. vermiformis itself does not cause formation of big buds, but feeds in big buds created by P. avellanae, and not all big buds are infested with C. vermiformis, Big buds with only P. ave(lanae inside have been termed "spring big buds". Due to intensive feeding and reproduction by C. vermiformis, infested big buds prematurely open and fall down at the end of summer, thus leading to the formation of "summer big buds". The nymphs and adults migrate to spring big buds after the summer big buds dry and form "winter big buds". In addition, C. vermiformis rarely infests vegetative and generative parts which may fall if infestation becomes too heavy. Int Soc Hort Sci, Working Grp Nuts

6th International Congress on Hazelnut -- JUN 14-18, 2004 -- Tarragona Reus, SPAIN Ozman-Sullivan, Sebahat/0000-0001-5240-8110 WOS: 000233635700054 The big bud mites Phytoptus avellanae Nal. and Cecidophyopsis vermifomis Nal. cause significant yield loss in hazelnut (Corylus avellana L.) orchards. Determination of effective pesticides and the proper timing of their application against big bud mites were studied in the Samsun province of Turkey. Two field trials were conducted from 1994 to 1997. The migration period of the mites (April-May) was covered each year. Nine pesticides (Sulphur WP, Azinphos-methyl EC, Azinphos-methyl WP, Dimethoate EC, Bromopropylate EC, Amitraz EC, Quinomethionate WP, Carbosulfan EC and Methidathion EC) were evaluated at their registered application rates as alternatives to the standard pesticide Endosulfan EC. Sulphur 80% WP was as effective (83.25%) as Endosulfan 35% EC (83.35%) for the control of big bud mites. A single application of Sulphur 80% WP (400 g/100 L) at the end of April or beginning of May, just before the peak period of mite migration from old big buds to new buds, was very effective in keeping mite and big bud numbers low.

4th International Symposium on Hazelnut -- JUL 30-AUG 02, 1996 -- ORDU, TURKEY Ozman-Sullivan, Sebahat/0000-0001-5240-8110 WOS: 000071757700065 During 1992-1994 we have investigated in detail the life cycles of the two forms of Phytoptus avellanae Nal. ("gall" and "vagrant" forms) and of Cecidophyopsis vermifomris Nal. which cause serious worldwide damage in hazelnut cultivars. Selected hazelnut plantations from the Blacksea Region of Turkey were visited every 2-3 days during the migration period, once every two weeks during the winter months and weekly for the rest of the year and samples were collected. The gall form of P. avellanae has a single nymph form and a simple life cycle. In spring, nymphs migrate from old big buds to healthy buds where feeding and reproduction continues until the following spring. Since the entire population is stationary within the same bud throughout the year, generations overlap. The vagrant form of P. avellanae has a different and rather complex life cycle and two forms of nymphs are present. The vagrant form feeds not only on big buds but also on vegetative and generative parts such as leaves, male and female flowers and completes its life cycle even in the absence of big buds. C. vermiformis also has a complex life cycle with two migration periods in spring and autumn. It lives inside the big buds created by P. avellanae and its generations overlap. C. vermiformis is rarely found on male and female flowers and vegetative buds. Int Soc Hort Sci, Working Grp Nuts

4th International Symposium on Hazelnut -- JUL 30-AUG 02, 1996 -- ORDU, TURKEY Ozman-Sullivan, Sebahat/0000-0001-5240-8110 WOS: 000071757700067 Phytoptus avellanae Nal. and Cecidophyopsis vermifomris Nal. commonly infest hazelnut plantations in the Blacksea Region. This study was performed on Tombul and Uzunmusa cultivars with periodic sampling during 1992-1994, in Samsun. Population fluctuations of the two species were investigated on big buds which contained either eggs, nymphs, adults of both species together or P. avellanae only. Although the numbers of P. avellanae in newly infested buds are very low in early summer, they reach maximum population levels during the following spring. C. vermiformis inside the summer big buds reaches the maximum population level in early autumn while C. vermiformis inside the winter big buds reaches the maximum population level in spring. In summer big buds infested by both species, the two populations are approximately equal in early summer whereas C. vermiformis becomes the dominant species from the end of July onwards. In winter big buds, although the number of C. vermiformis entering the big buds is low in autumn, C. vermiformis is usually the predominant population in spring. Int Soc Hort Sci, Working Grp Nuts