Lebensdauer des räuberischen Marienkäfers Serangium parcesetosum Sicard (Col., Coccinellidae) mit natürlicher und künstlicher Nahrung

The little known ladybird, Serangium parcesetosum SICARD (Col., Coccinellidae) seems to be an important predator of whiteflies. It has found attacking Bemisia tabaci (GENN.) (Hom., Aleyrodidae) (KAPADIA & PURI 1992), Aleurolobus barodensis MASK (PATEL et al. 1996), Aleurothrixus floccosus MASKELL (ABBOUD & AHMAD 1998), Bemisia argentifolii BELLOWS and PERRING (LEGASPI et al. 2001) as well as Dialeurodes citri (ASHMEAD) (YIGIT et al. 2003). However, in Germany the laboratory studies demonstrated that S. parcesetosum is a promising predator of B. tabaci (AL-ZYOUD & SENGONCA 2004; SENGONCA et al. 2004; AL-ZYOUD et al. 2005a, b; SENGONCA et al. 2005). One of the important features for a successful predator is to live for a long period on the prey species and also not feed on the plant in the prey absence. Long longevity accomplished by voraciously feeding of S. parcesetosum adults resulted in a successful control of B. argentifolii (ELLIS et al. 2001). To use this predator successfully in controlling the whiteflies, especially B. tabaci and Trialeurodes vaporariorum WESTWOOD (Hom., Aleyrodidae), it was important to investigate its natural and artificial nutritional sources. However, such knowledge of S. parcesetosum is still insufficient or completely lacking in the literature. Therefore, the present work was directed to study the longevity of S. parcesetosum on natural nutritional sources such as B. tabaci and T. vaporariorum as well as on certain artificial nutritional sources at two different temperatures in the laboratory.Der in der Literatur nur wenig bekannte Marienkäfer Serangium parcesetosum SICARD (Col., Coccinellidae) scheint, ein spezialisierter Prädator der Weißen Fliegen zu sein. Untersuchungen über die Lebensdauer eines Prädators sind eine der wichtigsten Parameter für seine erfolgreiche Verwendung in der biologischen Bekämpfung. Solche Informationen über S. parcesetosum sind bisher in der Literatur allerdings nur unzulänglich bekannt bzw. fehlen vollständig. Folglich war das Ziel dieser Arbeit, bei zwei unterschiedlichen Temperaturen im Labor zu untersuchen, wie lang S. parcesetosum mit Bemisia tabaci (GENN.) bzw. Trialeurodes vaporariorum WESTWOOD (Hom., Aleyrodidae) als Beute sowie mit bestimmten künstlichen Nahrungen überleben kann. Die Ergebnisse zeigten, dass beide Geschlechter von S. parcesetosum auf Baumwolle mit B. tabaci als Beute, mit Ausnahme der Männchen bei 30°C, signifikant länger mit allen anderen Nahrungen lebten. Bei beiden Temperaturen war die Lebensdauer der Weibchen, mit allen untersuchten Nahrungen, signifikant länger als die der Männchen. Sie schwankte bei beiden Geschlechtern von durchschnittlich 94,3 (♂♂) bis 175,4 (♀♀) Tagen bei 18°C bzw. 50,3 (♂♂) bis 92,4 (♀♀) Tage bei 30°C mit den getesteten Nahrungen. Die adulten Weibchen und Männchen von S. parcesetosum konnten für eine beträchtliche Zeit mit künstlichen Nahrungen überleben. Bei beiden Temperaturen war die durchschnittliche Überlebensdauer beider Geschlechter bei einem Angebot von 10%iger Honig-Emulsion als Nahrung signifikant länger als nur mit Baumwollblättern bzw. ohne ein Angebot an Nahrung

Efficiency of GCSC-BtA, as a new type of biocide, on different agricultural arthropod pests and its side-effect on some predators

A new type of biocide GCSC-BtA, named from "Germany-China Scientific Cooperation-Bacillus thuringiensis-Abamectin", was successfully developed by conjugating delta-endotoxin of Bacillus thuringiensis (B.t.) with Abamectin from Streptomyces avermitilis through conjugator EDC for control of different agricultural arthropod pests. The laboratory results of efficiency of biocide GCSC-BtA to four different arthropod pests and its side-effect on two species of predators are presented in this paper. The results showed significant differences in the mortalities of Tetranychus cinnabarinus (BOISD.) (Acari, Tetranychidae), Frankliniella occidentalis PERGANDE (Thys., Thripidae), Aphis fabae SCOPOLI (Hom., Aphididae) and Cameraria ohridella DESCHKA ET DIMI´C (Lep., Gracillariidae) caused by treatment of 0.6250 mg/ml of formulated product of GCSC-BtA, B.t., Abamectin and Cypermethrin. GCSC-BtA treatment caused higher mortalities of 86.37%, 94.82%, 94.15% and 93.23% in T. cinnabarinus, F. occidentalis, A. fabae and C. ohridella, respectively. Mortalities caused by Abamectin treatment were 73.92%, 63.3%, 86.52% and 73.48%, and by Cypermethrin treatment were 44.29%, 57.28%, 97.68% and 51.26%, respectively. B.t. could only kill C. ohridella with 87.62% mortality. Pesticidal treatment gave variations in mortalities of Orius strigicollis POPPIUS (Het., Anthocoridae) and Stethorus cantonensis PANG (Col., Coccinellidae) predators at p < 0.01, where 0.6250 mg/ml GCSC-BtA caused 21.76% and 32.42% mortalities, while the same rate of products of Abamectin with 73.26% and 87.67% as well as Cypermethrin with 86.43% and 93.83% mortalities, respectively. It is concluded that the biocide GCSC-BtA has increased efficacies as well as host ranges of B.t. and Abamectin, but displayed safer to some predators

Möglichkeiten zur biologischen Bekämpfung des Zwiebelthrips Thrips tabaci LINDEMAN (Thys., Thripidae) durch verschiedene, entomopathogene Pilze aus Thailand

The onion thrips, Thrips tabaci LINDEMAN (Thys., Thripidae) is an important pest of field and greenhouse crops around the world. It causes damage directly through feeding and indirectly through the transmission of lethal plant viruses. It is difficult to control this pest with insecticides because of its small size and cryptic habits (LEWIS 1997). Entomopathogenic fungi are currently being investigated for the control of many important insect pests on various crops around the world, and some are commercially available. There are many studies on the efficacy of several entomopathogenic fungi on thrips. CARL (1975) reported that Neozygites parvispora (MACLEOD, TYRRELL & CARL) REMAUDIERE and KELLER has been found frequently on T. tabaci but under field conditions the fungus was less successful than in the greenhouse. In addition, Entomophthora thripidum SAMSON, RAMAKERS & OSWALD was found infecting T. tabaci in Netherlands, but in field trials the fungus failed to suppress thrips populations below the economic acceptable level (SAMSON et al. 1979). In laboratory studies, T. tabaci was susceptible to Verticillium lecanii (ZIMMERMANN) VIÉGAS, Beauveria bassiana (BALSAMO) VUILLEMIN, Metarhizium anisopliae (METSCH.) SOROKIN and Paecilomyces fumosoroseus (WIZE) BROWN & SMITH (GILLESPIE 1986, FRANSEN 1990). VESTERGAARD et al. (1995) and BROWNBRIDGE (1995) showed that B. bassiana, M. anisopliae and V. lecanii were more active against the western flower thrips, Frankliniella occidentalis (PERGANDE) than P. fumosoroseus or Paecilomyces farinosus (HOLM ex S.F. GRAY) BROWN & SMITH. HALL et al. (1994) and SAITO (1991) suggested that Hirsutella sp., P. fumosoroseus and B. bassiana may be useful in the management of the melon thrips, Thrips palmi KARNY. EKESI et al. (1998) stated that B. bassiana and M. anisopliae are highly pathogenic to the legume flower thrips, Megalurothrips sjostedti (TRYBORN). In the glasshouse, V. lecanii has been used successfully to control T. tabaci on cucumber (GILLESPIE 1986).VACANTE et al. (1994) noted that N. parvispora caused up to 60 per cent mortality in motile developmental stages of F. occidentalis and reduced the insect populationdensity. Under greenhouse conditions, M. anisopliae was found to be effective in reducing the population growth of F. occidentalis on cucumber (AZAIZEH et al. 2002). Whereas, MANIANIA et al. (2001) observed that M. anisopliae had the potential to control F. occidentalis on chrysanthemum. The studies of MANIANIA et al. (2003) indicated that M. anisopliae had a potential to control T. tabaci in the field. Akanthomyces, Aschersonia, Cordyceps, Hypocrella, Hynennostilbe and Torrubiella were never observed to control thrips. Therefore, this study was conducted to investigate the pathogenicity of different entomopathogenic fungi from Thailand against T. tabaci larvae under controlled climatic conditions in the laboratory.Thrips tabaci LINDEMAN (Thys., Thripidae) ist ein weltweit verbreiteter Schädling mit einem breiten Wirtspflanzenspektrum an verschiedenen Freiland und Gewächshauskulturen, dessen Bekämpfung durch die geringe Größe und ihre versteckte Lebensweise erschwert wird. Entomopathogene Pilze sind wichtige Krankheitserreger zahlreicher Insektenarten und infizieren Individuen verschiedenen Alters und verschiedener Entwicklungsstufen. In der vorliegenden Studie wurden 41 Isolate von 25 entomopathogenen Pilzarten aus 11 Gattungen (Akanthomyces, Aschersonia, Beauveria, Cordyceps, Hirsutella, Hymenostilbe, Hypocrella, Metarhizium, Paecilomyces, Torrubiella und Verticillium) auf ihre Pathogenität gegenüber T. tabaci-Larven untersucht. Bis auf Hymenostilbe sp., Torrubiella spp., Hypocrella discoidea und Cordyceps pseudomilitaris stellten sich alle Pilze als Pathogen für T. tabaci heraus. Zwischen den Isolaten wurden hoch signifikante Unterschiede festgestellt. Die Mortalität variierte je nach Pilzart, Pilzgattung und Isolat. Fünfzehn Isolate, 7 von Beauveria, 4 von Metarhizium, 3 von Paecilomyces und 1 von Cordyceps, wiesen die höchste Pathogenität gegenüber T. tabaci-Larven auf

Comparative studies on the suitability of two aphelinids, Aphelinus asychis WALKER and Aphelinus varipes FÖRSTER (Hym., Aphelinidae), for the biological control of Aphis gossypii GLOVER (Hom., Aphididae)

Die Gurkenblattlaus Aphis gossypii GLOVER (Hom., Aphididae) ist ein weltweit verbreiteter, polyphager Schädling, dessen Wirtspflanzenspektrum verschiedene Feld- und Gewächshauskulturen wie z. B. Malvaceen (Baumwolle, Hibiskus) und Curcurbitaceen (Gurken, Melonen, Zucchini) umfasst. In Europa stellt die Gurkenblattlaus einen wichtigen Schädling an Gurkenkulturen im Unterglasanbau dar (VAN SCHELT 1993) und sie tritt vermehrt auch an anderen Gewächshauskulturen auf (VAN STEENIS 1992). Aufgrund der Resistenzentwicklung von A. gossypii gegenüber zahlreichen chemischen Insektiziden gewinnt die biologische Bekämpfung unter Verwendung von Nützlingen zunehmend an Bedeutung. Bisher wurden der Parasitoid Aphelinus colemani VIERECK (Hym., Braconidae) und die räuberische Gallmückenlarve Aphidoletes aphidimyza RONDANI (Dipt., Cecidomyiidae) zur Bekämpfung dieser Blattlausart verwendet, jedoch mit nur mäßigen Erfolgen (VAN STEENIS 1994, VAN STEENIS & EL- KHAWASS 1995). TAKADA (2002) berichtet, dass die zwei Parasitoide Aphelinus asychis WALKER und Aphelinus varipes FÖRSTER (Hym., Aphelinidae) ein Potential zur biologischen Bekämpfung von A. gossypii an verschiedenen Gewächshauskulturen in Japan besitzen. Das Ziel der vorliegenden Studie war daher zu untersuchen, welcher dieser zwei Parasitoide zur biologischen Bekämpfung von A. gossypii an Gurken besser geeignet ist. Dazu wurden in Laborversuchen einige biologische Parameter wie Entwicklung, „host feeding“-Verhalten und Parasitierungsleistung beider Arten ermittelt und verglichen.The cotton aphid is a phytophagous cosmopolitan species and an important pest on cucumber in European greenhouses. Because of increased insecticide resistance and destruction of natural enemies through the use of pesticides current research is directed towards the development of management. systems that use biological control methods. The present laboratory study was designed to compare two aphelinids, Aphelinus asychis WALKER and Aphelinus varipes FÖRSTER, according to some life table characteristics parasitizing the cotton aphid, Aphis gossypii GLOVER. The traits studied were developmental time, adult emergence rate, host feeding and parasitation. The results showed that both species were able to complete their development with exclusively this host. Moreover, they can host feed and parasitize successfully on A. gossypii-nymphs. Developmental duration from egg to mummification and from mummification to emergence of adults were 7,1 days and 6,9 days for A. asychis and 9,1 days and 10,3 days for A. varipes, respectively. Adult emergence rates were higher for A. asychis (75%) than for A. varipes (53%). Comparison of the impact on A. gossypii of both parasitoids indicated that A. asychis was more effective than A. varipes. In total A. asychis killed an average of 17,1 and A. varipes an average of 4,8 A. gossypii-nymphs/day. Consequently, A. asychis seems to be a promising natural enemy which could contribute to a successful biological control program for A. gossypii. However, it´s biology, ecology and control efficiency need further information

Bringing Sexy Back: Unauthorized Film Editing, Copyright, and How Removing Reproductive Acts Violates Reproduction Rights

The Multicolored Asian Ladybird, Harmonia axyridis, is an extremely successful invasive species. Here we suggest that, in addition to many other traits, the dorsal spines of its larvae contribute to their success, as suggested by behavioral observations of agonistic interactions between H. axyridis and European coccinellids. In coccinellids, the role of dorsal spines in these interactions has been poorly studied and they could be a physical protection against intraguild predators. Dorsal spines of second instar H. axyridis larvae were removed with micro-scissors, which resulted in spineless larvae after molting (spineless group). These larvae were then exposed to starved Coccinella septempunctata larvae. Two control categories were also submitted to interactions: H. axyridis larvae with all their spines (control group) and with their spines, but injured by pin stings (injured group). Spine removal at the second instar did not hamper H. axyridis development. The bite rate by C. septempunctata was significantly higher on the spineless H. axyridis and more dorsally located compared to the control and injured groups, while no bite rate difference was observed between the injured and the control group. Our results suggest that in addition to behavioral and chemical defenses, the dorsal spines play a significant protective role against bites. Therefore, spines in ladybirds could be considered as a morphological defense against intraguild predation. In H. axyridis, these defenses might contribute to its success in food resources already exploited by other guild members and thus further facilitate the invasion of new areas.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Anatomical and palynological characteristics of Salvia willeana (Holmboe) Hedge and Salvia veneris Hedge endemic to Cyprus

In this study, anatomical and palynological features of the roots, stems, petiole and leaves of Salvia willeana (Holmboe) Hedge and Salvia veneris Hedge, Salvia species endemic to Cyprus, were investigated. In the anatomical characteristics of stem structures, it was found that the chlorenchyma composed of 6 or 7 rows of cells which was beneath the epidermis of S. veneris, whereas S. willeana did not have such a tissue. While the transverse section of the leaf of S. veneris had either a single large vascular bundle or a two-lobe vascular bundle in the midrib, there was only a single large vascular bundle in that of S. willeana. While there were 2-or-3-piece vascular bundles in the center and threepiece vascular bundles at the corners of the petiole of S. veneris, there was a single large vascular bundle in the center and two vascular bundles at the corners of the petiole of S. willeana. It was determined that pollens belonging to both taxa had hexazonocolpate, subprolate, semitectate structure and showed bireticulate ornamentation. However, the number of lumina in the secondary reticulum of S. willeana was fewer than ten while it was more than ten in S. veneris

Suitability of two predatory mites as a biological control of Frankliniella occidentalis(Pergande) (Thysanoptera: Thripidae)

Mit dem vorliegenden Beitrag wurde versucht, die Eignung der Raubmilbenarten Amblyseius cucumeris (Oudemans) und Neoseiulus barkeri Hughes (syn. nov. Amblyseius mckenziei) zur biologischen Bekämpfung des Schadthrips Frankliniella occidentalis (Pergande) zu ermitteln. Beide Raubmilbenarten konnten sich mit der genannten Beute nicht vollständig entwickeln. Bereits als Protonymphe verstarben die meisten Raubmilben, ohne nennenswert Nahrung aufgenommen zu haben. Adulte Raubmilbenweibchen erreichten eine beute- und artenunabhängige durchschnittliche Lebensdauer von 34,0-34,5 Tagen, die Männchen dagegen von 18,5-19,4 Tagen. Die täglichen Fraßleistungen schwankten zwischen null und drei Thripslarven. Die durchschnittlichen Gesamtfraßleistungen betrugen für A. cucumeris-Weibchen 58,8 Thripslarven, für die Männchen 19,0, für N. barkeri-Weibchen 48,2 und für die Männchen 19,7 Thripslarven. N. barkeri-Weibchen legten mit F. occidentalis als Beute keine Eier ab, A. cucumeris-Weibchen durchschnittlich 11 ,0 Eier, somit aber wesentlich weniger als mit Tetranychus cinnabarinus als Beute in der Kontrolle (42,5 Eier). Die Entwicklung der Folgegeneration war außerdem stark eingeschränkt. Nur aus ca. 33 % der Eier schlüpften Larven, und nur etwa 75 % der Larven entwickelten sich zu Protonymphen. Dabei erreichte jedoch keine Raubmilbe das Adultenstadium. Insgesamt werden beide Raubmilbenarten als nicht geeignete Räuber von F. occidentalis beurteilt.Experiments were conducted on the suitability of the predatory mites Amblyseius cucumeris (Oudemans) and Neoseiulus barkeri Hughes as a biological control of Frankliniella occidentalis (Pergande). Both species of the predatory mites could not develop completely feeding on this prey. Most mites had already died in the protonymphal stage, hardly having fed on the thrips larvae. Average longevity extended 34.0-34.5 days for females but however only 18.5- 19.4 days for males irrespective of the species or the prey. The daily consumption varied between zero and three thrips larvae. Total consumption of thrips larvae was 58.8 for A. cucumeris females , 19.0 for A. cucumeris males, 48.2 for N. barkeri females and 19.7 for N. barkeri males. N. barkeri females did not show any reproduction activity, A. cucumeris females produced an average of 11.0 eggs during oviposition. In contrast, 42.5 eggs were produced by the A. cucumeris females in the control group preying on Tetranychus cinnabarinus. Development of the second generation was restricted. Larvae hatched from only 33 % of the eggs and only 75 % of the larvae moulted to the protonymphal Stage. None of these protonymphs reached the adult stage. As a result both species of the predatory mites were regarded as non-suitable predators of F. occidentalis

Aphids (Homoptera: Aphididae) on Winter Wheat: Predicting Maximum Abundance of Metopolophium dirhodum

In Central Europe, the most abundant aphid infesting the leaves of small grain cereals is Metopolophium dirhodum (Walker) (Homoptera: Aphididae). Annual variation in its seasonal dynamics was evaluated using a 25-yr series of standardized weekly censuses of winter wheat plots. M. dirhodum made up >50 % of the aphids on the foliage. Date of immigration (8 May–3 July), length of period of population increase (0–9 wk), and date of attaining maximum abundance (28 May–22 July) varied greatly. For the prediction, we regressed maximum numbers/tiller on numbers recorded in the first week after heading. The regression of maximum abundance on nonzero aphid counts revealed a critical number of ≥1.50 aphids/tiller, which if exceeded resulted in a harmful maximum abundance of ≥10 aphids/tiller at the peak. Zero aphid counts resulted in 10% of cases with a harmful maximum abundance. Using this regression for prediction will result in 18% of the recorded cases being false negatives and 9% false positives. Parallel annual variation in the average maximum numbers of M. dirhodum, Sitobion avenae (Fabricius) (Homoptera: Aphididae), and Rhopalosiphum padi (Linné) (Homoptera: Aphididae) indicated the following factors that affected their abundance: temperature in winter and host plant quality. The predictions apply only in areas where M. dirhodum is holocyclic and aphids do not overwinter in wheat stands

Studles on the apple clearwing moth, Synanthedon myopaeformis (Borkh.), in Nordrhein

In der vorliegenden Arbeit wurden die Verbreitung, Flugaktivität und der Larvenbefall von Synanthedon myopaeformis (Borkh.) im nordrheinischen Apfelanbau untersucht. Die Ergebnisse haben gezeigt, daß S. myopaeformis im gesamten Apfelanbaugebiet weit verbreitet ist. Die Flugaktivität der Falter erstreckte sich über etwa dreieinhalb Monate von Ende Mai bis Anfang September. Dabei wurden in den Jahren 1985 und 1986 in Meckenheim durchschnittlich etwa 400, in Bornheim etwa 320 Falter pro Pheromonfalle gefangen. Im Vergleich dazu befand sich der ermittelte Larvenbefall auf einem recht niedrigen Niveau. Die höchsten Werte wurden in einer Apfelanlage in Meckenheim mit durchschnittlich 1,0 (1985) und 6,4 Larven und Puppen pro Baum (1986) festgestellt. Das Alter der Bäume konnte als ein Einflußfaktor auf die Höhe des Larvenbefalls ermittelt werden, während die Apfelsorte nur eine untergeordnete Rolle spielte.Studies were conducted on the distribution, flight activity and attack of the larvae of Synanthedon myopaeformis (Borkh.) in Nordrhein apple orchards. The results have shown that S. myopaeformis is widely distributed in Nordrhein. Flight activity of the moths lasted about three and a half months from the end of May until the beginning of September. In 1985 and 1986, 400 and 320 moths were captured with sexual traps in Meckenheim and Bornheim, respectively. Attack of the larvae showed very low whea compared to flight activity. The greatest number of larvae and pupae per tree (1,0 = 1985 and 6,4 = 1986) were found in an apple orchard in Meckenheim. The age of the apple trees influenced the level of infestation whereas cultivar was of minor importance

Laboratory studies on the development, longevity and reproduction of four Amblyseius predatory mite fed with Tetranychus urticae Koch (Acari: Tetranychidae) and Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)

In der vorliegenden Arbeit wurden Laboruntersuchungen zur Entwicklungsdauer, Mortalität sowie zur Lebensdauer und Reproduktion der Adulten Raubmilben Amblyseius andersoni (Chant), Amblyseius califomicus (Mc Gregor), Amblyseius cucumeris (Oudemans) und Amblyseius degenerans (Berlese) (Acari: Phytoseiidae), bei Ernahrung mit zwei unterschiedlichen Beutearten, durchgeführt. Als Beute dienten adulte Tetranychus urticae Koch (Acari: Tetranychidae) und Frankliniella occidentalis- Larven (Pergande) (Thysanoptera: Thripidae). Die Ergebnisse zeigten, dass die Beute einen starken Einfluss auf die Entwicklung einiger Raubmilbenarten ausübte. A. californicus und A. degenerans, die mit T. urticae ernährt wurden, entwickelten sich bis zum Adult, wohingegen die Individuen, die F. occidentalis als Beute bekamen, sich nicht entwickeln konnten. So starben alle Individuen von A. californicus im Nymphenstadium und aus den Eiern von A. degenerans, deren Parentalgeneration mit F. occidentalis ernährt wurde, schlüpften keine Larven. Bei A. andersoni und A. cucumeris konnte dies nicht beobachtet werden. Sie entwickelten sich unabhängig von der Beute in annähernd derselben Zeit. Dennoch erreichen die Mortalitätsraten bei beiden Raubmilben ca. 17 % bei Ernahrung mit T. urticae und ca. 50 % mit F. occidentalis. Auch die Lebensdauer und Reproduktion der adulten Raubmilben wurde von der Art der Nahrung stark beeinflusst. Es zeigte sich, dass die Lebensdauer der Raubmilben A. andersoni und A. cucumeris durch F. occidentalis als Beute signifikant vermindert wurde. Die tägliche Eiablage von A. andersoni, A. californicus und A. degenerans war bei Ernährung mit F. occidentalis signifikant niedriger als die mit T. urticae als Beute.The present laboratory study dealt with the development, longevity and reproduction of four predatory mites namely; Amblyseius andersoni (Chant), Amblyseius californicus (Mc Gregor), A111blyseius cucumeris (Oudemans) and Amblyseius de gene rans (Berlese) (Acari: Phytoseiidae) fed on Tetranychus urticae Koch (Acari: Tetranychidae) and Frankliniella occidental is-larvae (Pergande) (Thysanoptera: Thripidae) as prey. Results revealed that the prey species had a strong impact on the development of the predatory mites tested. A. californicus and A. degenerans were able to successfully achieve their full development when fed on T. urticae but not on F. occidentalis. Where all A. californicus individuals died during nymphal stage, while the eggs, laid by adult A. degenerans females fed on F. occidentalis, did not hatch. On the other hand, A. andersoni and A. cucumeris were able to achieve full development regardless of the species of both preys offered. However, the percentage mortality of both predatory mites during development was about 17 % and 50 % when they were fed on T. urticae and F. occidentalis, respectively. The longevity and reproduction of the predatory mites tested, were also strongly affected by the prey species offered. The longevity of A. andersoni and A. cucumeris was significantly reduced when both predatory mites were fed on F. occidentalis. The number of eggs laid daily by A. andersoni, A. californicus and A. degenerans was significantly reduced when the predatory mites had been fed on F. occidentalis compared to that with T. urticae