Amblyseius Swirskii Athias-Henriot Research Articles

Species Composition and Diversity of Mites Inhabiting Pomegranate Orchards at Assiut, Upper Egypt

Mites play an important role in the biological cycle of nature, as well as in the agricultural cycles of plants. They are considered to be very important for most plants, especially fruit orchards, which case both, qualitative and quantitative losses, they also cause different types of allergenic reactions among the fruit handles and farmers. A comprehensive survey of mites inhabiting pomegranate orchards at Assiut and its suburbs was conducted in the work herein. During the current work, colonies of the pomegranate false spider mite, Tenuipalpus punicae Pritchard & Baker and the mango spider mite, Oligonychus mangiferus (Rahman & Sapra) were recorded on pomegranate trees at Assiut governorate. The relative abundance of both mite species and their natural enemies was conducted. Based on previous studies, about 24 mite species in nine families were recorded in Egypt. In order to determine species composition of phytophagous and predacious mites on pomegranate trees, samples were taken from leaves, buds and fruits during 2018/2019 and 2019/2020 seasons. The citrus brown mite, Eutetranychus orientalis (Klein); T. punicae and the broad mite, Polyphagotarsonemus latus (Banks) seemed to be the most common phytophagous mites on pomegranate trees. On the other side, several predatory mite species were also recorded in the present work. Of these, Amblyseius swirskii Athias-Henriot; Euseius scutalis (Athias-Henriot); Typhlodromus (Typhlodromus) pyri Scheuten; Neoseiulus barkeri Hughes (Phytoseiidae), and Agistemus exsertus Gonzalez (Stigmaeidae), all were recorded in large numbers, especially on pomegranate leaves of all varieties. While Cheletogenes ornatus (Canestrini & Fanzago) and Cheletomimus bakeri (Ehara) (Cheyletidae) were recorded mostly on leaves and fruits. Quantifying the occurrence of various predacious mite species on pomegranate trees, may be of great importance to reduce the number of phytophagous ones. In separated subsequent studies, the efficacy of these predatory mites can be estimated as one of the biological control agents.

<p><strong>Resistant rose cultivar affects life table parameters of two-spotted spider mite and its predators </strong><strong><em>Phytoseiulus persimilis</em></strong><strong> and </strong><strong><em>Amblyseius swirskii</em></strong><strong> (Phytoseiidae) </strong><strong></strong></p>

Herbivores' host plant resistance may also affect performance of their predators. The effect of susceptible ('Yellow') and resistant ('Roulette') rose cultivars on demographic parameters of the two-spotted spider mite (TSSM), Tetranychus urticae Koch and its predators Phytoseiulus persimilis Athias-Henriot and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) was determined under laboratory conditions. The obtained data were analyzed using the two-sex life table theory. The development rate of different life stages of TSSM and its predators on the susceptible and resistant rose cultivars were significantly different. Total development time of juvenile stages of TSSM and A. swirskii on the resistant cultivar was longer than that on the susceptible one, although no significant differences were obtained in the case of P. persimilis. By using the two-sex life table, the intrinsic rate of increase (r) of TSSM on the susceptible and resistant cultivars was 0.205 and 0.143 day-1, respectively. In addition, the net reproductive rate (R0) of TSSM on the susceptible and resistant cultivars was 26.46 and 11.47 eggs per individual, respectively; however, the mean generation time (T) of TSSM on these cultivars was 15.92 and 16.92 days, respectively. Furthermore, the value of the intrinsic rate of increase (r) in P. persimilis on the susceptible and resistant cultivars was 0.217 versus 0.163 day-1as well as in A. swirskii on the mentioned cultivars was 0.147 versus 0.117 day-1, respectively. There was no significant difference between the values of the net reproductive rate (R0) in P. persimilis on the susceptible and resistant rose cultivars, but in A. swirskii the value of this parameter on the susceptible cultivar was significantly higher than that on the resistant one. The mean generation time (T) in both predators on the resistant cultivar was longer than the susceptible one. In conclusion, resistance of the rose cultivar negatively affected the population growth parameters of TSSM and its both predators.

A predatory mite, Amblyseius swirskii, and plastic mulch for managing melon thrips, Thrips palmi, in vegetable crops

Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae), is a significant pest of vegetable crops and ornamental plants due to feeding and oviposition injury to vegetative and reproductive tissues. As an integrated approach, we evaluated the efficacy of a phytoseiid mite, Amblyseius swirskii Athias-Henriot, and different colored and UV-reflective plastic mulches for managing T. palmi in snap bean (Phaseolus vulgaris L.), cucumber (Cucumis sativus L.), yellow squash (Cucurbita pepo L.), eggplant (Solanum melongena L.), Jalapeño pepper (Capsicum annuum L.), and tomato (Solanum lycopersicum L.). The five mulch treatments evaluated were: “Shine N′ Ripe” (Metalized top and black bottom), “Can-Shine” (Metalized top and white bottom), “Black” plastic black-on-black (Can-Grow-XSB), black-on-white (Can-Grow XSB), “White” plastic; white-on-black (Can-Grow XSB), and bare soil with no mulch. The number of T. palmi adults and larvae in leaf samples collected from the middle third (stratum) of plants in each treatment was determined. In 2015 at 49 days after planting (DAP), curative release of 40–50 A. swirskii per plant did not suppress T. palmi effectively when the thrips population was high. There were no significant interactions between A. swirskii and crop or A. swirskii and mulch type on the number of T. palmi. However, in 2016 at 15 DAP, preventive release of A. swirskii, reduced the number of T. palmi in each of the mulch and crop treatments. Metalized mulch reduced the number of T. palmi early in the season when plants’ canopy did not shade the mulched area. These results suggest that use of metalized reflective mulch and A. swirskii, each have the potential to manage T. palmi at low population densities.

How Spiromesifen affects some biological parameters and switching behavior of predatory mite Amblyseius swirskii (Acari: Phytoseiidae) when feeding on different ratios of mixed preys

Two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and silverleaf whitefly, Bemisia tabaci (Gennadius) (Hem.: Aleyrodidae) are among the most destructive pests under greenhouse conditions which is primirarily countered using chemical pesticides. Due to insecticidal and acaricidal effectiveness of Spiromesifen (Oberon®), agricultural producers extensively used this chemical to control both whitefly and spider mite populations. In the present study, effects of recommended concentration of Spiromesifen on some biological and behavioral attributes of predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) feeding on different ratios of two-spotted spider mite and silverleaf whitefly were investigated. Different treatments were defined as 1 (150 immature stages of mite + 0 immature stages of whitefly), 2 (120 mite + 30 whitefly), 3 (90 mite + 60 whitefly), 4 (75 mite + 75 whitefly), 5 (60 mite + 90 whitefly), 6 (30 mite + 120 whitefly) and 7 (0 mite + 150 whitefly). According to the results, mortality percentage of adult individuals was not significantly affected by different ratios of prey. With increasing ratio of preys tested in experimental arena, feeding activity of predatory mite on both preys was increased. However, in the case of T. urtice, linear relation observed between the initial number of mite offered and number of mite eaten was more significant. Reproductive responses of female predators to different ratios of mixed preys had no specified trend. Furthermore, switching behavior was not detected in female predators. Our results have considerable role for increasing biological efficacy of A. swirskii in integrated management programs of different pests.

Next generation biological control – an introduction

Next generation biological control – an introduction

Diversity and infestation rate of mites associated with some birds in upper and lower Egypt

Survey, diversity and infestation rate of mites associated with five wild birds (Passer domestica niloticus, Columba livia, Streptopelia Senegalensis aegyptiaca , Pycnonotus barbatus and Corvus cornix) were carried out during two successive years in upper and lower Egypt provinces. The obtained data was recorded high numbers house sparrow, P. domestica niloticus (77.1%) were attacked by mite species followed by palm dove, S. Senegalensis aegyptiaca (75.5); C. cornix (70.2%); C. livia domestica (64.3%) and P. barbatus (61.9%). The total extracted mites was 24 species of 18 genera belonged to 16 family. The parasitic mites Blattisocius keegani Fox and B. tarsalis Berlese were the most prevalent between examined birds except, S. Senegalensis aegyptiaca while, Dermanyssus gallinae (DeGeer) was also, recorded on all examined birds except, P. barbatus. On the other hand, the mite species, Myialges falconis Fain, M. pici Fain, Ornithonyssus sylviarum(Canestrini & Fanzago), O. bacoti (Hirst), Megninia cubitalis(Megnin), Dermoglyphus columbae(Sugimoto), Paralges pachenemys(Megnin), Harpyrhynchus vercommni Megnin, Ornithocheyletia pingus Smiley, O. hallae Smiley, O. gersoni Smiley , Syringophilus minor (Berlese), Kleemannia plumose Oudemans, Amblyseius swirskii Athias-Henriot. were fewest prevalence between the examined birds species.

<p class="Body">Sublethal effects of acetamiprid on biological aspects and life table of Amblyseius swirskii (Acari: Phytoseiidae) fed on Aleuroclava jasmini (Hemiptera: Aleyrodidae)

The whitefly, Aleuroclava jasmini (Takahashi) (Hemiptera: Aleyrodidae), is an important pest on paper mulberry Broussonetia papyrifera (L.) Vent. (Moraceae) plants in green spaces of Tehran, Iran. The predator mite Amblyseius swirskii Athias-Henriot is one of the most common species found in paper mulberry landscape and it is a major biological control agent of this pest. Knowledge of the impact of insecticides on predatory mites is crucial for integrated management programs of this whitefly. This study assessed, under laboratory conditions, the sublethal effect of acetamiprid on the life table parameters of A. swirskii fed on A. jasmini. The sublethal concentrations LC10, LC20 and LC30 were obtained based on a dose-effect test. Exposure to the sublethal concentrations of acetamiprid had significant effects on the total immature periods of both males and females. The total fecundity and oviposition period decreased with an increase in concentration. The estimated life table parameters indicated that sublethal concentrations of acetamiprid caused greater reduction in r, λ and R0 of A. swirskii compared to the control. Therefore, the use of acetamiprid to control of A. jasmini may have serious implications for integrated pest management programs that aimed at exploiting A. swirskii biological control in paper mulberry landscape.

Amblyseius swirskii Henriot ve Neoseiulus californicus’un (McGregor) (Mesostigmata: Phytoseiidae) Tetranychus urticae’nin Koch (Trombidiformes: Tetranychidae) yumurta ve nimf dönemleri arasındaki tercihi

Tetranychus urticae Koch (Trombidiformes: Tetranychidae), two-spotted spider mite, is a pest mite species that feed on a wide range of plants around the world. Neoseiulus californicus (McGregor) (Mesostigmata: Phytoseiidae) is shown as a predatory mite to be a very efficient biological control agent of T. urticae. Amblyseius swirskii Athias-Henriot (Mesostigmata: Phytoseiidae) is another phytoseiid mite species which can feed and reproduce on a wide range of food sources, including T. urticae. Information about the prey stage preference of a predator is valuable for evaluations of the potential of predatory mites to control of pests. We therefore analyzed the prey-stage preferences of A. swirskii and N. californicus to eggs and nymphs of T. urticae at 15:15, 10:20, and 20:10 egg: nymph ratios under controlled conditions (25±1 °C, 65±5% RH and 16-h light: 8-h dark photoperiod). The experiment was carried out on abaxial surfaces of bean leaf discs with a diameter of 2 cm. Starved (for 24 h), 2-3 days-old gravid females of A. swirskii and N. californicus were used in the experiment. One predatory mite was placed individually on each bean leaf disc infested with 15:15, 10:20 and 20:10 ratios of T. urticae egg: nymph. After 24 h of feeding, the numbers of prey consumed for each prey stage were recorded. From the results, it is clear that while N. californicus showed no preference between egg and nymphs of T. urticae. A. swirskii preferred nymphs to eggs of T. urticae.

Occurrence and Population Dynamics of Mites Associated with Citrus Trees at Menoufia Governorate

Population dynamics and species composition of phytophagous and predatory mites in citrus orchards were determined from January to December 2016 at Shenofa locality, Shebin El-Kom, Menoufia governorate, Egypt. The survey revealed the occurrence of phytophagous mites as: Panonychus citri (McGregor), Eutetranychus orientalis (Klein) (Tetranychidae); Phyllocoptruta oleivora (Ashmed) (Eriophyidae); Brevipalpus californicus (Banks) (Tenuipalpidae) and Tydeus californicus (Banks) (Tydeidae), representing the most common phytophagous species found in citrus orchards. In addition, two predatory mite species of two families were recorded as: Amblyseius swirskii Athias-Henriot (Phytoseiidae) and Agistemus exsertus Gonzalez (Stigmaeidae) were found to be the most abundant predatory species inhabiting citrus leaves. The population fluctuation of phytophagous and predacious mites on studied citrus varieties was varied according to citrus varieties and sampling dates reaching its highest peak, in most cases, during September. Navel orange recorded the highest numbers of P. oleivora in comparison with other varieties of citrus (290.31 indiv. /10 leaves), while the highest number of P. citri and B. californicus were 85.63 and 45.3 indiv. /10 leaves on Balady orange. The obtained result indicated that the maximum and minimum temperature and relative humidity expressed as an insignificantly positive during 2016 season on the population of P. oleivora, E. orientalis, B. californicus, T. californicus, A. swirskii and A. exertus, but highly significance difference was obtained between population of P. citri only. Finally, it could be concluded that winter months are suitable for applying different biological control agents including predatory mites where pests are lowest in numbers and the optimum environmental factors are present as well.

Ecofriendly control approaches for Polyphagotarsonemus latus (Acari: Tarsonemidae) on tea (Camellia sinensis L.)

ABSTRACTPolyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) is a serious pest to a variety of agricultural crops including tea (Camellia sinensis (L.), Theales: Theaceae) worldwide. In this study, the potential of Amblyseius (Neoseiulus) californicus (McGregor 1954) and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) at two initial release ratios, 1:10 and 1:20 (predator: prey), and the effect of the garlic (Allium sativum L., Alliaceae) bulb extract, tobacco (Nicotiana tabacum L., Solanaceae) leaf extract and soft soap in the management of P. latus were assessed. The research was carried out on seedlings of Tuğlalı-10, Muradiye-10 and Gündoğdu Turkish tea clones in Rize province (Black Sea coast, Turkey) during two growing seasons in 2013 and 2014. For each clone, a completely randomized block design was used to compare the differences among the nine treatments and two controls (sprayed and unsprayed). 80 % Micronized Sulfur was used on the sprayed control plot. Results showed that A. swirskii and N. californicus may be effective in reducing P. latus densities at the initial predator: prey release ratios of 1:10 and 1:20 on tea plants under Rize conditions. The tobacco leaf, garlic bulb extracts and soft soap treatments were also found to be promising for controlling P. latus on tea plantation.

PCR-based species identification applied in Japanese pear orchards to survey seasonal proportion changes of phytoseiid mite species

For this study, we developed a PCR-based method to identify the ribosomal internal transcribed spacer (ITS) sequences of six phytoseiid mite species found in Japanese pear orchards: Neoseiulus californicus (McGregor), Neoseiulus womersleyi (Schicha), Neoseiulus makuwa (Ehara), Amblyseius eharai Amitai and Swirski, Gynaeseius liturivorus (Ehara), and Amblyseius swirskii Athias-Henriot. Using the method, we can show seasonal proportion changes of phytoseiid mite species composition in Japanese pear orchards. Genomic DNA extracted individually from phytoseiid mites collected in the orchards are subjected to PCR of the ITS sequences using a universal primer set of which nucleotide sequences are conserved among the six phytoseiid mite species. Then, DNA samples showing PCR products with the universal primer set are used for another PCR of the ITS sequences using species-specific primer sets designed for respective phytoseiid mite species. Species-specific PCR is conducted in order of decreasing dominance of phytoseiid mite species. The method, which specifically identifies the six phytoseiid mite species irrespective of their sexes and developmental stages, might be useful for researchers who are lacking adequate morphological identification skills and nucleotide sequencing systems at their institutions.

Farmers’ perception and control practices against the invasive red spider mite (Tetranychus evansi Baker & Pritchard) in Benin

Tetranychus evansi (Acari: Tetranychidae), is an important pest of solanaceous plants in Benin where it damages tomato (Solanum lycopersicum L.; Solanaceae), African eggplant (S. macrocarpon L.; Solanaceae), purple amaranth (Amaranthus cruentus L.; Amaranthaceae). The objective of the present study was to evaluate the intensity of T. evansi damage and impact of farmers' control practices in Benin. Two surveys were conducted between 2013 and 2016. The first survey revealed Tetranychus evansi as the only mite, causing production losses of 65% for African eggplant, 56% for tomato and 25% for purple amaranth. To protect the infested crops, growers sprayed various synthetic pesticides at high frequencies according to species cycle: 3, 6 and 12 times per month on purple amaranth, African eggplant and on tomato, respectively. Farmers reported that these compounds were largely ineffective against T. evansi. The second survey found 47 predatory mites of the family Phytoseiidae. The Amblyseiinae were the only group found in this study. An initial identification revealed Neoseiulus barkeri Hughes (Mesostigmata: Phytoseiidae) (77%), Neoseiulus sp. (19%) and Amblyseius swirskii Athias Henriot (4%).

Effects of different diets on biological parameters of the predatory mite Amblyseius swirskii (Acari: Phytoseiidae)

ABSTRACTThe predatory mite, Amblyseius swirskii Athias-Henriot is one of the natural enemies of agricultural pests such as the spider mite, Tetranychus urticae (Koch). Pollen, as a food supplement or alternative food source, has a considerable impact on the efficiency of the predatory mite in the biological control programme. In this study, the effect of six distinct diets (one consisting solely of the eggs of T. urticae and the others being pollen of apricot, soybean, sesame, walnut, and date, each mixed with the eggs of T. urticae) on the biological parameters of A. Swirskii was studied. Development from egg to adult, oviposition day, and daily mortality were investigated in 65 replications for each type of food. The results demonstrated that A. swirskii was able to adapt to each of the six tested diets and growth development was considerable with each. Comparisons of the biological parameters among these diets showed that the average generation length, from egg to adult, had significant differences at the 5% level. The fertility life table parameters showed no significant differences between treatments for rm (the rate at which a population increases in size in the absence of density-dependent forces impacting the population)‚ λ (sustained increase in population in one day compared to the previous day), and R0 (number of progeny of the substituted females per person in one generation). The results showed that the oviposition and survival times of A. swirskii were greatly enhanced by the pollen diets so that a much greater efficiency of this predatory mite in biological control programmes was achieved.

Orius albidipennis (Rueter) as an effective biocontrol agent against Tetranychus urticae Koch on pepper crops in greenhouse in Egypt

The present study was carried out in greenhouses, on sweet pepper crops, during the winter plantations 2015–2016 and 2016–2017 in a commercial farm located at Berkash district, Giza, Egypt. During the first season, three acariphagous biocontrol agent species, the predatory mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) (at a rate of 2 individuals/m2), and two of predatory insect, Macrolophus caliginosus Wagner (at a rate of 1 individual/m2) and Orius albidipennis (Reuter) (at a rate of 1/2 individual adults/m2), were applied to control Tetranychus urticae. The obtained results showed that T. urticae was controlled successfully using A. swirskii and O. albidipennis. Releasing of A. swirskii and O. albidipennis caused 26 and 24% yield increases, respectively, as compared to control treatment. During the second season of 2016–2017, the efficiency of O. albidipennis at a rate of 1/2 per m2 was compared to three recommended pesticides, for controlling T. urticae. The obtained results revealed that applying O. albidipennis proved to be the most efficient control method against T. urticae on sweet pepper, with the lowest remaining pest density of T. urticae (2.9 mites/leaf); while with chemical control, the remaining density of T. urticae reached 20.13 mites/leaf at the end of the season. Thus, results demonstrated that the released insect predator, O. albidipennis, was the most effective method to control T. urticae under greenhouse conditions for two reasons. On the one hand, it resulted in a 31.36% yield increase, and on the other hand, it could reduce the chemical application, to improve food safety and environmental pollution reduction.

CONFIRMATION OF PRESENCE OF A PREDATORY GALL MIDGE, Feltiella acarisuga, (Vallot, 1827) AND STAPHYLINID PREDATOR Oligota oviformis Casey, 1893 OF A TWO SPOTTED SPIDER MITE (Tetranychus urticae, Koch, 1836) IN SLOVENIA

The two spotted spider mite, Tetranychus urticae C. L. Koch, 1836 is one of the most important pests of greenhouse crops worldwide. Due to its polyphagic range of hosts and rapid development it forms great populations and as such represents a suitable host/prey for lots of natural enemies usable in biological control. Most commonly used predators of Tetranychid mites are predatory mites (Phytoseiulus persimilis Athias-Henriot, 1957, Amblyseius swirskii Athias-Henriot, 1962 ,…), but among most voracious predators is the larva of a predatory gall midge, Feltiella acarisuga (Vallot, 1827) that was found also in greenhouses of the Biotechnical Faculty in Ljubljana on eggplant leaves in 2017. Besides the predatory gall midge also another predator, staphylinid Oligota oviformis Casey, 1893 beetles and larvae were found in great numbers. After positive identification of F. acarisuga found naturally in Slovenia, it can be added to the list of indigenous species of natural enemies and thus can be used in biological control programs in greenhouse crop protection against spider mites.

Efficacy of two predatory phytoseiid mites in controlling the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) on cherry tomato grown in a hydroponic system

Thrips is one of the most harmful insect groups attacking many field and vegetable crops. Predatory mites, especially those in family Phytoseiidae, are considered as good bioagents to control thrips where application of chemical pesticides can be decreased. This work was conducted to evaluate the efficacy of the two phytoseiid mites, Amblyseius swirskii (Athias-Henriot) and Neoseiulus cucumeris (Oudemans), in controlling the western flower thrips (Frankliniella occidentalis, Pergande) on cherry tomato plants in a hydroponic system. The results indicated that both predatory mites were effective in decreasing populations of adults and larvae of F. occidentalis at all of the chosen periods. The mixed effect of A. swirskii plus N. cucumeris (AS + NC) was higher in reducing thrips populations than that when each of them was used alone. Larvae of F. occidentalis were decreased on leaves of tomato plants from 11.2 and 14.5/leaf in the control treatment (no predatory mites) to 4.27 and 3.73/leaf due to the combination of AS and NC after 7 and 15 days, respectively. On the other hand, larvae of F. occidentalis attained levels of 8.75 and 12.83/five flowers when no predatory mites were applied compared to 2.46 and 1.20/five flowers when adults of AS plus NC were used after 50 and 60 days of releasing, respectively. This study demonstrated that the combination of AS and NC resulted in higher reductions in F. occidentalis without any competition between them.

Reciprocal intraguild predation between Neoseiulus barkeri and Amblyseius swirskii (Mesostigmata: Phytoseiidae): Does experience affect anti-intraguild predation behaviors?

In order to increase their inclusive fitness, animals predominantly probe their changing environment for predation cues to adopt appropriate antipredator strategies and decrease the costs of defensive behavior. Intraguild predation (IGP) occurs when a predator kills and consumes individuals of another predator which is its competitor for a shared prey. IGP is prevalent among predatory mites of the family Phytoseiidae which are used as biological control agents of agricultural pests worldwide. Phytoseiid mite mothers usually display antipredator behaviors to avoid or reduce IGP risk of their juveniles. When facing a novel IGP risk, experience may enable the mothers to display more efficient antipredator responses. We studied the effect of experience on reciprocal antipredator behaviors of an indigenous predatory phytoseiid mite, i.e., Neoseiulus barkeri Hughes, and an exotic one, i.e., Amblyseius swirskii Athias-Henriot, as biological control candidates for integrated pest management strategies in Iran. First, we determined the occurrence of IGP and mutual risk of the predators within the guild; IGP occurred reciprocally and A. swirskii was the stronger IG predator. Second, in choice situations between a patch with only shared prey and a patch with shared prey plus IGP risk cues, we scrutinized patch choice, oviposition site selection and ability to counterattack by females of each species that had either experienced the IGP risk or not. The experience did not affect patch choice and oviposition behaviors of the species whereas it elicited an increase in their predation on IG predator juveniles. We suggest that the presence of IG predator juveniles and cues may not significantly modify the distribution of the IG prey species. The reinforced counterattack behavior in experienced females showed that both species were able to tune their antipredator behavior after exposure to IG predators. Consequences of the antipredator behaviors in experienced IG prey females on distribution and possibilities of the coexistence of the study species are discussed.

Toxicities of 26 pesticides against 10 biological control species

To determine selective effectiveness for specific pesticides on biological control species we evaluated the contact toxicity of 16 insecticides, 2 acaricides, 3 fungicides, and 5 biopesticides. Targeted species included 3 predatory mites (Phytoseiulus persimilis Athias-Henriot, Amblyseius swirskii Athias-Henriot, and Neoseiulus californicus McGregor), 5 hymenopteran parasitoids (Diglyphus isaea Walker, Aphidius colemani Viereck, Encarsia formosa Gahan, Eretmocerus eremicus Rose and Zolnerowich and E. mundus Mercet), and 2 hemipteran predators (Orius laevigatus Fieber and Nesidiocoris tenuis Reuter) in laboratory condition. In addition, residual toxicity was evaluated on P. persimilis, E. formosa, and O. laevigatus. For contact toxicity, five insecticides (spinetoram, spinosad, lepimectin, chlorfenapyr, and dinotefuran+spinetoram) showed high toxicity to predatory mites. Most pesticides tested were highly toxic to all hymenopteran species except for D. isaea which showed low susceptibility to 11 pesticides. Bistrifluron+flubendiamide and B. valismortis were less toxic to A. colemani, and only B. valismortis was safe to both E. mundus and E. eremicus. Insect growth regulators (methoxyfenozide and bistrifluron), chlorantraniliprole, and bistrifuron+flubendiamide were not toxic to hemipteran predators. Fungicides and biopesticides were safe to hemipteran predators except for two biopesticides (B. subtilis and P. fluorescens). Most pesticides had low residual toxicity to P. persimilis, with the exception of chlorfenapyr whose toxicity persisted over 7days. One insecticide (cyantraniliprole), 2 acaricides (spiromesifen and fenpyroximate), 1 fungicide (metrafenone), and 4 biopesticides (B. subtilis, P. polymyxa, P. fluorescens, and B. valismortis) showed a much lower residual toxicity to E. formosa. Eight insecticides, 2 acaricides, 3 fungicides, and 5 biopesticides showed low residual toxicity to O. laevigatus.

Control of Tomato leaf curl New Delhi virus in zucchini using the predatory mite Amblyseius swirskii

The tobacco whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), is a serious pest of vegetables in many horticulture systems. It vectors the Tomato leaf curl New Delhi virus (ToLCNDV) which causes considerable damage in zucchini crops. Both pest and the disease are well established in field and greenhouse crops in the southeast of Spain, the largest vegetable growing area in Europe. The predatory mite Amblyseius swirskii Athias-Henriot (Arachnida: Phytoseiidae) is known to effectively manage B. tabaci populations in crops such as sweet pepper and cucumber, feeding on eggs and crawlers of this pest. However, there are no reports on the effectiveness of predatory mites against tobacco whitefly in zucchini crops. The potential to reduce whitefly populations as well as the spread of ToLCNDV in zucchini was evaluated by the pre-installation of A. swirskii in seedlings. Results showed that the number of adult whiteflies and deposited eggs on zucchini plants were significantly lower on plants with the phytoseiid predator, showing a significant negative impact of A. swirskii on B. tabaci colonization and reproduction but not on the primary infection with ToLCNDV. However, the pre-release of the predatory mites resulted in a strong decrease in eggs and subsequently emerging adults of whiteflies relative to plants without predators, and a significant reduction in secondary spread of the virus.

Natural diets versus factitious prey: comparative effects on development, fecundity and life table of Amblyseius swirskii (Acari: Phytoseiidae)

Using the most suitable alternative diets that are easily available and less expensive than the natural diets may give rise to reduce the rearing costs of natural enemies. Alternative or additional food used for this purpose should be in accordance with the food spectrum of the respective mite species. To our knowledge no information is accessible on the comparison between natural diets and factitious prey for Amblyseius swirskii Athias-Henriot. Therefore, the objective of this study was to evaluate the nutritional value of three natural diets including almond pollen, maize pollen and Tetranychus urticae Koch, as well as four factitious prey comprising eggs of Ephestia kuehniella Zeller, Tyrophagus putrescentiae (Schrank), decapsulated and encapsulated cysts of Artemia franciscana Leach for A. swirskii. The data would seem to suggest that developmental time of individuals fed on pollens was shorter than that of those fed on factitious prey. The gross and net reproductive rate, intrinsic and finite rate of increase of the individuals consumed factitious prey were lower than those of mites fed on natural food diets, for the simple reason of shorter developmental time and higher oviposition rate of this predator on the latter. In conclusion, our results showed that natural foods were more favorable than factitious prey and among them almond pollen and maize pollen were the most suitable for A. swirskii, and thus it should be taken into account for application in its mass production, and supporting its population in greenhouse or field conditions when used in an augmentative approach.