Preface... III List of participants... V Group photo... IX Contents... XI

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1 IOBC-WPRS Bulletin Vol. 93, 2013 Working Group Integrated Control of Plant-Feeding Mites. Proceedings of the Third Working Group Meeting at Český Krumlov, Czech Republic, September, Editors: Eric Palevsky, James Ridsdill-Smith, Phyllis Weintraub, Uri Gerson, Sauro Simoni, James McMurtry, Rostislav Zemek. ISBN [XIII pp.]. Contents Preface... III List of participants... V Group photo... IX Contents... XI Efficacy of onion extract and two synthetic acaricides against Tetranychus urticae on soybean in Georgia Tea Abramishvili, Nona Chkhaidze Abstract: The paper deals with control of spider mites in the soybean crop in east Georgia. The efficacy of an onion herbal extract and two acaricides, Vertimec and Masai, were studied in field trials. The results showed that the highest mortality (> 99%) ten days after the treatment was caused by Vertimec followed by Masai (98.8%) and the onion extract (75%). Lethal concentration LC50 for Vertimec, Masai and onion extract was estimated to be %, % and %, respectively. Substitution of synthetic acaricides with herbal extracts can be recommended for sustainable agriculture. Feeding behavior and cheliceral functional morphology of plant-feeding and non-plant feeding phytoseiids Einat Adar, Moshe Inbar, Shira Gal, Noam Doron, Zhi-Qiang Zhang, Eric Palevsky Effect of ground cover management on the biological control of spider mites in clementine mandarin orchards Ernestina Aguilar-Fenollosa, Mª Victoria Ibáñez-Gual, Sara Pascual-Ruiz, Mónica A. Hurtado, Josep A. Jacas Abstract: Tetranychus urticae is an important pest of citrus. To determine the effect of the management of the ground cover on the biological control of this mite, we have studied the dynamics of both Tetranychidae and Phytoseiidae mites in four commercial clementine mandarin orchards under three different cover management strategies: (1) bare soil, (2) resident wild cover and (3) a sown cover of Festuca arundinacea. Our results provide evidence that both natural enemies and plant resources play important regulatory roles. Cross breeding between the two spider mites, Tetranychus urticae Koch and Tetranychus cucurbitacearum (Sayed) in Egypt W. A. Attwa, A. Y. M. El-Laithy, E. M. El-Saiedy, S. E. Abd-Elrahaman, H. E. S. Sadek Abstract: The green two-spotted spider mite Tetranychus urticae Koch and the red mite T. cucurbitacerum (Sayed) were subjected to a study to shed light on their identity, based on their reproductive compatibility. Cross breeding produced fertile and normal hybrids for the F1 and F2

2 in relation to egg laying capacity and to the sex ratio of the offspring. Inheritance of female offspring color was maternal for the green form mite. Potential of Florida populations of Amblyseius largoensis (Acari: Phytoseiidae) as biological control agents of the invasive species Raoiella indica (Acari: Tenuipalpidae) Daniel Carrillo, Jorge E. Peña Abstract: Raoiella indica Hirst (Acari: Tenuipalpidae) is a phytophagous mite that recently invaded the Neotropical region. A predatory mite Amblyseius largoensis (Muma) (Acari: Phytoseiidae) has been found associated with R. indica in several areas recently invaded in the new world. A series of studies evaluated Florida (USA) populations of A. largoensis for potential control of R. indica by determining (1) the development and reproduction of A. largoensis feeding on R. indica and comparing its reproductive parameters to those obtained when feeding on other potential prey and pollen; (2) the prey-stage preferences of A. largoensis to R. indica; (3) the response of four populations of A. largoensis to R. indica and T. gloveri eggs and larvae; (4) the functional and numerical responses of A. largoensis to R. indica eggs, and (5) the effect of A. largoensis on R. indica densities using predator exclusion and predator release techniques. The results of these studies showed that (1) A. largoensis was able to feed, develop and reproduce on a diet consisting solely of R. indica showing improved reproductive parameters than when feeding on other prey and pollen; (2) A. largoensis showed preference for R. indica eggs followed by larvae, nymphs and adults; (3) the four populations of A. largoensis, all with different previous exposure to R. indica, were likely to accept and consume high numbers of R. indica eggs regardless of their previous feeding experience; however, A. largoensis showed plasticity in its response to R. indica larvae; (4) while feeding on R. indica eggs, A. largoensis females displayed a type II functional response with an increase in prey killed as prey density increased until a saturation level of approximately 45 R. indica eggs/day, a level at which oviposition by the predator was maximized (~ 2.36 A. largoensis eggs/day); (5) finally, a predator release rate of 1 A. largoensis female/ 10 R. indica adults reduced R. indica densities up to 50%. Overall, these results suggest that A. largoensis can play an important role in controlling R. indica populations in Florida. Population dynamics of major insect and mite pests and control on sweet pepper grown in net house in Egypt Ahmed Y. M. El-laithy, Elsaid M. A. Elseedy, Magdy. Y. El-kholi, Magda M. Abou-Ellela, Zdeňka Svobodová Abstract: Sweet pepper, Capsicum annuum L., is an economically viable vegetable crop. Its crop acreage is rapidly increasing under protected cultivation in Egypt. Dutch cultivars Dabka RZ, Zidenka RZ, Pasodoble RZ, Mazurka RZ yellow, 182 red cv., and 58 red cv. were included for fall plantations and summer plantations were Inspiration RZ and Taranto RZ. Predominant damage over the two seasons were due to the two-spotted spider mite Tetranychus urticae Koch and the Thrips tabaci Lindeman. The highest population density during the fall was recorded on Dabka RZ with T. urticae followed by moderate damage from onion thrips, T. tabaci. Infestation by the broad mite, Polyphagotarsonemus latus Banks was very rare. Light infestations were recorded with the whitefly Bemesia tabaci Gennadius on summer plantations. Infestation of summer pepper cultivars varied with respect to their fruit color; red was regularly more susceptible than yellow to T. urticae and moderately with B. tabaci, whilst infestation of the yellow fruit with T. tabaci color was vice versa. Functional response and mutual interference of Scolothrips longicornis (Thysanoptera: Thripidae) on two spotted spider mite Azadeh Farazmand, Yaghoub Fathipour, Karim Kamali Abstract: Scolothrips longicornis Priesner is a native predator insect in Iran and it is an active biological control agent in bean, cucumber and eggplant fields. The aim of this study was to determine functional response and mutual interference of the predatory thrips, S. longicornis

3 under laboratory conditions (25 C, RH 65% and a photoperiod of 16 h light: 8 h dark) fed on Tetranychus urticae Koch on cucumber. The functional response was measured by offering eggs and nymphs of T. urticae at seven densities (2, 4, 8, 16, 32, 64 and 128) to an adult female of thrips separately and the mutual interference was calculated by five densities (1, 2, 4, 8 and 16) of adult female predators on 250 nymphs of T. urticae. Both experiments were done during 24-h period. The values of the attack rate (a) and handling time (T h ) were estimated using the Royama- Rogers model. The logistic regression showed a type II response of the predator to different densities of eggs and nymphs of T. urticae. Both parameters (a, T h ) were very similar between eggs ( and h, respectively) and nymphs ( and h, respectively). The per capita searching efficiency decreased significantly from to with increasing predator density from 1 to 16 females. Also the per capita predation decreased significantly from to with increasing predator density from 1 to16. The results revealed the high predation potential of S. longicornis, which it can be used as a sufficient biological control agent on T. urticae. Interaction between beneficial organisms in control of spider mite Tetranychus urticae (Koch) Żaneta Fiedler Biological parameters and predatory capacity of Balaustium n. sp. (Acari: Erythraeidae) Luz Stella Fuentes Q., Karen Muñoz, Fernando Cantor The eriophyoid mite Aculops lycopersici induces pathogenesis thereby promoting the fitness of a competing herbivore on tomato Joris Glas Starvation influences female longevity and fecundity of a commercial strain (Spical ) of Neoseiulus californicus (Acari: Phytoseiidae) Tetsuo Gotoh Effect of hot-water treatment on the two-spotted spider mite, Tetranychus urticae, and its predator, Neoseiulus californicus Tetsuo Gotoh, Yasuki Kitashima, Tatsuo Sato Species identification and genetic population characteristics of phytoseiid mites around chrysanthemum fields for conservation biological control of spider mites Norihide Hinomoto, Yoshinori Kunimoto, Yuzo Koyama The potential of Amblyseius swirskii as biocontrol agent for Aculops lycopersici on tomatoes Yvonne van Houten, Markus Knapp, Hans Hoogerbrugge, Karel Bolckmans Abstract: The tomato russet mite (TRM), Aculops lycopersici (Massee) is an important pest of tomatoes. So far no effective biological control strategy has been developed for this pest. The generalist phytoseiid predatory mite Amblyseius swirskii (Athias-Henriot) showed high oviposition rates when feeding on A. lycopersici as prey on tomato leaf discs and was therefore evaluated as potential biological control agent of russet mite on tomato plants. Amblyseius swirskii established and multiplied when it was released on small tomato plants that were heavily

4 infested with TRM. Thereafter, the efficiency of A. swirskii in TRM control was tested in a semifield experiment with bigger tomato plants. The predatory mites were released at two different intervals after infestation of the plants with A. lycopersici; i.e. 6 days and 20 days after the release of the TRM. In both cases the predatory mite density remained low throughout the experiment and the tomato russet mite density was not reduced as compared to the untreated control. The A. lycopersici reached a maximum density of 135 to 145 motile stages per leaflet seven weeks after infestation. In tomato crops phytoseiid predatory mites are usually less effective as biological control agents than on other plants, because tomato plants have glandular trichomes which negatively affect their performance. The density of trichomes is much lower on areas of the tomato plant that are heavily infested with A. lycopersici than on uninfested or slightly infested areas. The perspectives of predatory mites as potential biological control agents of A. lycopersici will be discussed. Integrated control of plant-feeding mites in the genomics era: what is genomics and what can, and can't, it do for you? Merijn Kant, Juan Manuel Alba, Joris Glas, Bart Schimmel, Antonio Orenes, Carlos Villarroel, Maurice W. Sabelis Life history of Typhlodromus athiasae as a predator of Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) under laboratory conditions İsmail Kasap, Serkan Pehlivan, Sultan Çobanoğlu Abstract: The biology of predatory mite Typhlodromus athiasae Porath and Swirski (Acari: Phytoseiidae), a predator of the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), was studied under laboratory conditions. All experiments were conducted on bean leaf discs in an incubator at 25 ± 1 C, 16 L:8 D photoperiod, and an average daily RH of 70 ± 10%. Observations on the immature stages were made twice daily and daily for the adults, in order to determine developmental time, survival and fecundity. The mean developmental time for females was 7.7 days and for males was 7.5 days, and mean adult longevity for females was 32 days. The mean total and daily egg production were 17.2 and 1.11 eggs, respectively. The net reproduction rate (R 0 ) was females/female, the intrinsic rate of increase (r m ) was female/female/day and mean generation time (T 0 ) was days. The the sex ratio was 0.68 female. Efficacy evaluation of the mycopesticide Naturalis (Beauveria bassiana strain ATCC 74040) against spider mites (Acari: Tetranychidae) in Serbia Dejan Marčić, Pantelija Perić, Slavka Petronijević, Mirjana Prijović, Tanja Drobnjaković, Slobodan Milenković Abstract: Biological efficacy of a B. bassiana-based product (trade name Naturalis, containing min. 2, viable conidiospores/ml; strain ATCC 74040) in spider mites control was investigated in two field trials and one greenhouse trial in Serbia. The product was applied twice at rates of 0.1% v/v (i.e. Naturalis-LR) and 0.15% v/v (i.e. Naturalis-HR), at 3-5 days intervals, and its efficacy was compared to abamectin (a microbiological acaricide), and acrinathrin and clofentezine (chemical acaricides), applied once at their label rates. The trial against two-spotted spider mite (Tetranychus urticae) on pepper was conducted in a commercial greenhouse at Padinska Skela locality (N '; E '), where Naturalis was applied twice at 5-day intervals, and the efficacy was assessed 8 and 18 DAT1 (= days after the first treatment). In the assessments, lower and higher rate of Naturalis achieved high efficacy (> 97%) in T. urticae control. Abamectin and acrinathrin also showed high efficacy (> 99%). The trials against summer population of European red mite (Panonychus ulmi) were conducted in commercial apple orchards at Morović (N '; E ') and Slankamen (N '; E ') localities, and acaricides were applied at 75 BBCH growth stage. In Morović, the second treatment with Naturalis was three days after the first treatment, and the efficacy was assessed 6, 17, and 27 DAT1. Naturalis-LR achieved 78.6%, 85% and 90.6% efficacy, respectively, and

5 Naturalis-HR achieved 74.4%, 95.8%, and 95.5% efficacy, respectively, while abamectin efficacy was 89%, 99.3%, and 97.5%. In Slankamen, the second treatment with Naturalis was four days after the first treatment, and the efficacy was assessed 11 and 24 DAT1. Efficacy of Naturalis-LR was 65.6% and 54.2%, and of Naturalis-HR it was 89% and 75.8%. Abamectin achieved 83.4% and 82.6% efficacy, while the efficacy of acrinathrin was 91.1% and 94.5%. Clofentezine efficacy was only 53.1% and 66.2%, which is probably the consequence of intense selection pressure on P. ulmi population at this locality in the previous years. The obtained results indicate that application of mycopesticide Naturalis can provide an efficacy in spider mite control which is comparable to the efficacy of standard acaricides. The results are discussed in the light of possible improvement of spider mite management by alternative use of this mycoacaricide as a control measure. Revision of the life style system of phytoseiid mites Jim A. McMurtry, Gabriel J. De Moraes Relationship between T. urticae numbers in samples and the proportion of infested rose leaflets in Colombian rose crops Karen Muñoz, Fernando Cantor, José Ricardo Cure Abstract: In Colombia there are almost 7000 hectares of flower production and the floriculture sector generates employment for over 150,000 families. In this area of the economy roses are the main flowers produced and exported. However, production is limited by the attack of pests among which the two-spotted spider mite Tetranychus urticae Koch stands out. According to recent information, 30-50% of the budget destined to pesticides in Colombian rose crops are acaricides. To reduce the use of these acaricides it is important to improve the monitoring plans for this mite using methodologies that allow reducing the invested time without significantly diminishing the reliability of the estimates. This is possible if a specific relationship between density and spatial distribution of the population can be established. In this way, the mean population density could be estimated from the proportion of sampling units occupied by the mites. This relationship had been established for many authors in different countries and for different crops but it had never been tested in the Colombian rose production system. For this reason, a mathematical model was evaluated to find the relationship using data from T. urticae samplings on a commercial rose crop. During 18 weeks, T. urticae were counted on leaves of the lower stratum of rose plants corresponding to 56 squares (each square has 50 plants). Mites were counted on five to seven leaflets of three leaves for each square. It was found that the mite population had an aggregated distribution and the mathematical model tested can describe a relationship between the numbers counted and the proportion of sampling units occupied by the mites. More studies are needed to develop this relationship in order to help farmers to formulate an adequate monitoring plan. From sampling to decision: The costs and benefits of information in Integrated Pest Management Gösta Nachman Influence of temperature and host plant on the developmental time and fecundity of two-spotted spider mites in laboratory conditions Hajar Pakyari Abstract: Environmental variables, such as temperature, play a key role in the time required for development of Tetranychus urticae Koch. Developmental time and fecundity of T. urticae were examined at 15, 20, 25, 30 and 35 C on cucumber, soybean and bean plants. Developmental time of T. urticae was the least at 35 C (5.36 d) and 30 C (6.01 d), while at 15 C it took d. As to the host plants involved, T. urticae developed the fastest on beans (8.38 d), followed by cucumber (9.24 d) and soybean (10.01 d). Fecundity was highest at 30 C (86.80

6 eggs) and lowest at 15 C (56.57 eggs). The fecundity of female mites increased with temperatures up to 30 C, but at 35 C it decreased (69 eggs). The host plants influenced female fecundity to a limited extent; the average number of eggs on bean, soybean and cucumber was 77, 69 and 69, respectively. Factors affecting dispersion of Brevipalpus phoenicis (Acari: Tenuipalpidae) from citrus fruits Jorge E. Pena, Ignacio Baez, Katia Santos Molecular detection of Tetranychidae prey in Phytoseiidae predators occurring in citrus by Multiplex PCR Consuelo Pérez-Sayas, Tatiana Pina, Maria Antonia Gómez-Martínez, Josep Jacas, Monica Hurtado Is the quality of pollen affecting the biological control of Tetranychus urticae by phytoseiids in clementine mandarins? Tatiana Pina, Poliane Sá Argolo, Alberto Urbaneja, Josep A. Jacas Population ecology of Halotydeus destructor in pastures T. J. Ridsdill-Smith, R. H. Smith, J. Read and C. C. Pavri Abstract: High populations of Halotydeus destructor, averaging 20,000 mites/m 2, are found in pastures over large regions of Australia, although abundance is patchy. Impact of this pest on pasture productivity is seen by substantial reductions in clover seed yield and in seedling survival. Mites feed in small aggregations of 3-38 individuals on a leaf, and aggregations are found in small patches (1-2 m) under tall pasture. High populations are also found in large patches (80 x 160 m) in pastures, which are considered to result from high levels of egg laying when food resources are favourable. Analysis of time series provided evidence for direct and delayed local density dependence. The delayed density dependence had a lag of weeks (two generations). As winter progresses the locations of the large aggregations change from generation to generation. Mantel correlations indicate travelling waves of high population density whose peaks moved through the study site with time. Travelling waves could result from ecological interactions or seasonal forcing, or both. Introduction of exotic predatory mites for pest control in Japan and its risk of non-target effects Yukie Sato, Atsushi Mochizuki How the belowground may drive an aboveground tri-trophic system Peter Schausberger, Daniela Hoffmann Laboratory evaluation of toxicity and repellence of four microbial control agents on two phytoseiid species Sauro Simoni, Silvia Guidi, Franca Tarchi, Donatella Goggioli, Mabrouk Bouneb Abstract: In laboratory trials, the toxicity and indirect harmful effects of 4 fungicides used in biological control strategies were evaluated on detached strawberry leaves (var. Selva), on the phytoseiids Phytoseiulus persimilis and Neoseiulus californicus, commonly used for the control of tetranychids. The microbial control agents tested were Bacillus subtilis strain QST 713 (Serenade Max ), Ampelomyces quisqualis isolate M-10 (AQ 10 WG), Trichoderma harzianum

7 strain INAT 11 and Bacillus amyloliquefaciens strain D747 (Amylo-X ). The effects of these agens were tested on one commercial strain of P. persimilis, and on two different strains of N. californicus, one reared on Tetranychus urticae and the other on Quercus pollen. No adverse effects were recorded on female adult mortality, egg mortality, development of deutonymphs. Nor was the first oviposition of the predators affected by the fungicides. Furthermore, within three hours of exposure, no significant interference with the behaviour of the predators, such as repellence and first choice in location, was observed between treated and untreated control leaves. However, in choice-tests, the predators seemed to prefer leaves treated with T. harzianum to those treated with B. subitilis and B amyloliquefaciens, and finally with A. quisqualis. The possible implications of exposure to these substances over longer periods are discussed. Conservation biological control in vineyards: impact of four pesticide adjuvants and the insecticide spirotetramat (Movento) on a key predatory mite Menelaos Stavrinides, Nicholas J. Mills, Kent M. Daane Spider mite suppression in herbs by Phytoseiulus persimilis and Neoseiulus californicus Michaela Stolz, Michael Gross Abstract: Since few years the Austrian consumers could choose among a great variety of fresh herbs in supermarkets. However, a short look in the plant protection product register reveals, that the possibilities for the producers to suppress pest species in herbs by beneficials are strongly limited. The prime reason for this indication gap is the lack of efficacy data on potential beneficials against thrips, spider mites or white flies in herbs. Here, we evaluated the suppression potential of Phytoseiulus persimilis and Neoseiulus californicus against the two-spotted spider mite Tetranychus urticae on lemon balm plants. Three treatments were conducted in separate greenhouse compartments: (1) T. urticae, (2) T. urticae + P. persimilis, (3) T. urticae + N. californicus. Spider mite population development and biomass of the plants after finishing of the experiments were compared among treatments. Although both predator species were able to suppress the spider mites within 9 weeks, spider mite densities decreased earlier in the treatment with P. persimilis. Additionally, the biomass of the plants treated with P. persimilis was higher than that in the treatments without P. persimilis. Two conclusions can be deduced from these results for practical aspects of biological spider mite control in herbs: first, both phytoseiid mite species can be used for spider mite control in herbs, however, P. persimilis, highly specialized preying on spider mites was more efficient than the generalist N. californicus. Second, a suppression of spider mites after 9 weeks is not acceptable in practice because of high crop loss. Consequently, the ratio spider mites: beneficials was too high in our experiments. The optimal release rates of the beneficials in herbs will be determined in experiments under practical conditions. Social familiarity enhances antipredation success of Phytoseiulus persimilis threatened by the intraguild predator Amblyseius andersoni Markus Andreas Strodl, Peter Schausberger The influence of different maize varieties and treatments on the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae) Zdeňka Svobodová, Rostislav Zemek, Oxana Habuštová, Hany Mohamed Hussein, František Sehnal Abstract: Laboratory experiments were carried out to assess the life-table parameters of the twospotted spider mite, Tetranychus urticae (Acari: Tetranychidae) on leaves of four maize varieties: (1) transgenic Bt maize variety MON expressing Cry3Bb1 for control of Diabrotica spp., and protein CP4 EPSPS for a toleration of glyphosate-based herbicides, (2) isogenic variety

8 treated with or without soil insecticide, (3) KIPOUS and (4) PR38N86. The latter two maize varieties were used as independent references. The leaves used in the experiments were collected in the field after flowering. The content of Cry protein was verified with an immunological ELISA test. Newly emerged larvae were individually placed on the upper surface of leaf discs placed on water saturated cotton in plastic Petri dishes. Survival of juveniles, developmental time and female fecundity was examined daily until the mites died. The longevity of adults was the longest and females oviposited the highest amount of eggs on Bt maize though not significantly different from spider mites reared on the isogenic variety. Similarly, no statistically significant differences between mites reared on the Bt variety and those reared on the isogenic variety were found in life table parameters. On the other hand, life table parameters of T. urticae on the soil insecticide-treated isogenic variety were significantly worse compared to those on the other varieties. We can thus conclude that the obtained results do not indicate any significant effect of the Cry3Bb1 toxin on measured life table parameters of T. urticae. Variation in host colonization ability of three populations of the wheat curl mite, Aceria tosichella Keifer Wiktoria Szydło, Anna Skoracka Mites memorize direction of wind carrying chemical cues after signal loss due to wind shifts Merijn van Tilborg, Peter Roessingh, Junji Takabayashi, Maurice Willem Sabelis Predation of Typhlodromus longilaterus Athias-Henriot (Parasitiformes, Phytoseiidae) females on eggs and juveniles of the tetranychid mites Tetranychus urticae (Koch) and Panonychus citri (McGregor) (Acariformes, Tetranychidae) Haralabos Tsolakis, Milko Sinacori, Salvatore Ragusa Abstract: Typhlodromus longilaterus is a generalist phytoseiid mite described by Athias-Henriot in 1957 and commonly found in Israel on spontaneous herbaceous plants. As very little is known about this species, the present study reports preliminary results on the predation capacity of phytoseiid females on eggs and juveniles of two tetranychid mites very common in the Mediterranean area, Tetranychus urticae and Panonychus citri. After 24 hours the phytoseiid females preyed on 15% of offered eggs of both tetranychids, while the prey ratio was higher on T. urticae eggs after this period (33.4% and 33.5% vs 20.8% and 16.2% after 2 and 3 days for T. urticae and P. citri respectively). The phytoseiid showed its preference also for nymphs of T. urticae preying on 44-50% of nymphs offered, while the predation range was lower on nymphs of P. citri (from 30.3 to 36.3%). Antipredation strategies of Phytoseiulus persimilis larvae depend on the level of intraguild predation risk Andreas Walzer, Peter Schausberger Impacts of sustainable greenhouse production systems on Tetranychus urticae and Phytoseiulus persimilis Sacha White, Nieves Garcia, Esteban Jose Baeza Romero, Laura Pirondini, Dave Skirvin

9 Typhlodromus pyri (Phytoseiidae) research and implementation in IPM of fruit orchards and vineyards in the Czech Republic Miloslav Zacharda, Rostislav Zemek Abstract: A simple shake-and wash technique for monitoring mites was developed. A faunal survey documented twenty-five species of phytoseiids. Typhlodromus pyri was abundant only in some of commercial sprayed orchards and vineyards, or was absent. The residual leaf-dip tests indicated considerable differences in susceptibility of T. pyri strains to azinphos-ethyl (Gusathion A). Local resistant populations of T. pyri were revealed. The seasonal history of T. pyri was described and data on population dynamics, number of generations, feeding, mating and reproductive habits as well as seasonal distribution within the apple tree canopy were collected. It was documented that communities of predatory phytoseiid mites and spider and eriophyid mites were influenced by specific type of chemical treatment. The long-term residual efficacy of 16 pesticides to the predatory phytoseiid mite T. pyri was evaluated in laboratory bioassays. Consequently specific spraying program against noxious tortricid moths and fungi in orchards and vineyards was set up to be compatible with T. pyri. A residual leaf-dip test proved a different innate susceptibility of susceptible and resistant strains of T. pyri, Euseius finlandicus, and Phytoseius echinus to azinphos-ethyl. E. finlandicus was the most susceptible whereas a susceptible strain of T. pyri the most tolerant. Esterase and glutathione S-transferase activities gave a good correlation between susceptibilities of these strains to azinphos-ethyl and activities of glutathione S-transferases. In summer, resistant populations of T. pyri were transfered to the predatory mite-free vineyards and orchards on one-yr shoots of apple or vine whereas in winter textile carrier strips with hibernating females were used. Life tables of overwintered females and their progeny of T. pyri fed on Tetranychus urticae and Cecidophyopsis ribis were constructed. Also powdery mildew affected parameters of development and proved to be important alternative food for T. pyri. Towards a description of the bacterial community associated with the bulb mite Rhizoglyphus robini Claprede Renate Zindel, Maya Ofek, Einat Zchori-Fein, Dror Minz, Eric Palevsky, Alexandre Aebi