Diet‐dependent intraguild predation between the predatory mites Neoseiulus californicus and Neoseiulus cucumeris

Based on the hypothesis that matching diets of intraguild (IG) predator and prey indicate strong food competition and thus intensify intraguild predation (IGP) as compared to non‐matching diets, we scrutinized diet‐dependent mutual IGP between the predatory mites Neoseiulus cucumeris and N. californicus. Both are natural enemies of herbivorous mites and insects and used in biological control of spider mites and thrips in various agricultural crops. Both are generalist predators that may also feed on plant‐derived substances such as pollen. Irrespective of diet (pollen or spider mites), N. cucumeris females had higher predation and oviposition rates and shorter attack latencies on IG prey than N. californicus. Predation rates on larvae were unaffected by diet but larvae from pollen‐fed mothers were a more profitable prey than those from spider‐mite fed mothers resulting in higher oviposition rates of IG predator females. Pollen‐fed protonymphs were earlier attacked by IG predator females than spider‐mite fed protonymphs. Spider mite‐fed N. californicus females attacked protonymphs earlier than did pollen‐fed N. californicus females. Overall, our study suggests that predator and prey diet may exert subtle influences on mutual IGP between bio‐control agents. Matching diets did not intensify IGP between N. californicus and N. cucumeris but predator and prey diets proximately influenced IGP through changes in behaviour and/or stoichiometry.     

Provision of astigmatid mites as supplementary food increases the density of the predatory mite Amblyseius swirskii in greenhouse crops,but does not support the omnivorous pest,western flower thrips

Astigmatid mites can be used as prey for mass rearing of phytoseiid predators, but also as a supplemental food source to support predator populations in crops. Here we evaluated the potential of six species of astigmatid mites (living or frozen) as alternative food for the predatory mite Amblyseius swirskii Athias-Henriot in greenhouse crops. All prey mites tested were suitable for predator oviposition. In general, oviposition was greater when prey mites were reared on dog food with yeast than when they were reared on wheat bran with yeast. Amongst prey items provided as frozen diet, larvae of Thyreophagus entomophagus (Laboulbene), Acarus siro L. and Lepidoglyphus destructor (Schrank) that had been reared on dog food with yeast, resulted in the highest oviposition rates of A. swirskii. T. entomophagus larvae as frozen diet resulted in the shortest preimaginal developmental time of A. swirskii. On chrysanthemum plants, we found that the greatest increase in predator density occurred when living mites of T. entomophagous were used as a food source. This increase was greater than when predators were fed cattail pollen, a commonly used supplemental food. Effects on predators of providing living A. siro and L. destructor, or frozen larvae of T. entomophagous as food, were comparable with provision of pollen. Use of supplemental food in crops can be a risk if it is also consumed by omnivorous pests such as western flower thrips, Frankliniella occidentalis Pergande. However, we showed that both frozen and living mites of T. entomophagous were unsuitable for thrips oviposition. Hence, we believe that provision of prey mite species increases A. swirskii density, supporting biological control of thrips and other pests in greenhouse crops.

     

Pollen as Food for the Predatory Mites Iphiseius Degenerans and Neoseiulus Cucumeris (Acari: Phytoseiidae): Dietary Range and Life History

Although all known phytoseiid mites (Acari: Phytoseiidae) are predators of mites or small insects, many readily feed and reproduce on pollen as well. This ability to feed on food from plant origin increases their survival during periods when prey is locally sparse, but might occur at the expense of the ability to utilize food as efficiently as specialized predators. In this study we compare two predatory mite species used as biological control agents against thrips, Neoseiulus cucumeris and Iphiseius degenerans, with respect to (1) the range of pollen species that may serve as food sources for a sustained oviposition; and (2) the life history and expected intrinsic growth rates on some suitable pollen diets. The results show that I. degenerans is, compared to N. cucumeris, able to utilize a larger proportion of approx. 25 pollen species tested, but does not show equally high ovipositional rates as N. cucumeris. Consequently, the highest intrinsic growth rate for I. degenerans (0.21 day ^–1) will be surpassed by N. cucumeris.     

Responses of Amblyseius ovalis (Evans) (Acarina: Phytoseiidae) to natural food resouces and two artificial diets

Six phytophagous mites, maize pollen, and two artificial diets were fed to Amblyseius ovalis to evaluate their food suitability for the predator. The parafilm diet-chip of Hager and Tassan was adopted for artificial diet studies. The floating leaf method was the best among all tested methods, producing high survival, developmental, and reproductive rates of the predator. Offspring of A. ovalis fecding on artificial diets did not complete their life cycles. A. ovalis feeding on E. orientalis, O. mangiferus, ad O. taiwanicus developed into adult form faster than those feeding on other food resources. Predators feeding on the natural food, except those feeding on T. kanzawai, had much higher immatural survival rates, lower escape rates, and shorter developmental durations than those feeding on the artificial diets.All A. ovalis laid an average of two eggs per female per day after 2 days of preoviposition, except for those feeding on T. kanzawai which produced none. A. ovalis feeding on artificial diets showed a shorter oviposition period, lower daily and total reproductive rates, and shorter longevity. The complicated webbing life type of T. kanzawai inhibited the activities of A. ovalis, indicating that the predators may require nutrients other than T. kanzawai eggs to molt into adults and to reproduce. The functions varying the phytoseiid-tetranychid relationship during the predator's approach to the microhabitat of the prey were postulated from the predator's structures and the prey's life type. Most predator eggs were laid by 2–18 day-old females feeding on natural food resources. A. ovalis retained its high activity on the low webbing habitats of O. mangiferus and E. orientalis, and on maize pollen. The intrinsic rate of increase, mean generation time, and net reproductive rate of A. ovalis on each of nine tested food resources were evaluated from its life tables. The predator showed the highest intrinsic rates of increase when feeding on the prey of E. orientalis, O. mangiferus, and on maize pollen, and the lowest rates when feeding on the artificial diet even when the immatures had fed on the O. mangiferus and maize pollen. Consequently, the optimal food resources for A. ovalis appear to be O. mangiferus or O. oriintalis with supplements of maize pollen. When fed on these food resources, the predators demonstrated the highest rates of survival, longevity, fecundity, and intrinsic increase.     

Predatory mites avoid ovipositing near counterattacking prey

Attacking prey is not without risk; predators may endure counterattackby the prey. Here, we study the oviposition behaviour of a predatory mite(Iphiseius degenerans) in relation to its prey, thewesternflower thrips (Frankliniella occidentalis). This thrips iscapable of killing the eggs of the predator. Thrips and predatory mites - apartfrom feeding on each other - can also feed and reproduce on a diet of pollen.Because thrips may aggregate at pollen patches, such patches may be risky foroviposition by the predatory mites. We found that, in absence of thrips,predatory mites lay their eggs close to pollen, but further away when thripsarepresent. Predatory mite eggs near pollen were killed more frequently by thripsthan when they were deposited further away. The oviposition behaviour of thepredatory mite was also studied in absence of thrips, but in presence of thealarm pheromone of thrips. This pheromone is normally secreted upon contactwithpredators or competitors. When applied close to the pollen, predatory mitesoviposited significantly further away from it. When the alarm pheromone wasapplied away from the food source, most eggs were found near the pollen. Theseresults indicate that female predatory mites show flexible ovipositionbehaviourin response to the presence of their counterattacking prey.     

Grape downy mildew Plasmopara viticola, an alternative food for generalist predatory mites occurring in vineyards

Generalist phytoseiids are often observed for long periods on plants in the absence of prey, feeding on alternative foods and reaching high population levels. The persistence of generalist predatory mites on plants with a scarcity or absence of prey is a requirement for successful biocontrol strategies of herbivore mites. The importance of pollen as an alternative food for the support of generalist predatory mite populations is widely recognized. However, on grape the presence of pollen is often limited and thus other food sources should contribute towards generalist predatory mite persistence on perennial plants. Previous field observations reported the relationships between the population increases of generalist phytoseiids with late-season spread of grape downy mildew (GDM) Plasmopara viticola. In this study, we test the hypothesis that GDM could be a suitable food source for the predatory mites Amblyseius andersoni and Typhlodromus pyri. In the laboratory we compared the development times, oviposition rates and life-table parameters of predatory mites feeding on pollen or GDM mycelium and spores. Grape downy mildew supported the survival, development and oviposition of T. pyri and A. andersoni. Life-table parameters showed that GDM was a less suitable food source than pollen for both phytoseiid species and that it was more favorable for A. andersoni than for T. pyri. Implications for predator–prey interactions and conservation biological control in vineyards are discussed.     

Life history parameters of a commercially available Amblyseius swirskii (Acari: Phytoseiidae) fed on cattail (Typha latifolia) pollen and tomato russet mite (Aculops lycopersici)

Development, oviposition, and survival of a commercially available predatory mite, Amblyseius swirskii (Athias-Henriot), were investigated to determine the life history parameters when they consumed a diet of cattail (Typha latifolia L.) pollen or tomato russet mites (Aculops lycopersici [Massee]) at 25 ± 0.5 °C and 70 ± 10% RH. Both diets were favorable for development, oviposition, and survival of A. swirskii. Amblyseius swirskii reared on mite prey showed improved performance as compared to pollen. Females laid a total of 26.8 and 38.1 eggs on the pollen and mite diets, respectively. The mortality of female A. swirskii was very low during the first 20 days on both diets, and the cumulative Weibull models that were used to describe age-specific survival and fecundity of female showed a good fit to the data. The net reproductive rate (R₀), intrinsic rate of increase (r_m), and finite rate of increase (λ) of A. swirskii were higher on russet mites than when fed on the pollen diet due to their shorter immature development period and higher oviposition rate. The intrinsic rate of increase (r_m) of the predatory mite was 0.185 and 0.201 on the pollen and mite diet, respectively. The mean generation time (T) and the population doubling time (D_t) were not significantly different for A. swirskii on the two diets. Our results provide life history information for a commercially available A. swirskii using two favorable diets and can be used to compare population growth under other diet sources.     

Rearing, release and establishment of imported predatory mites to control citrus rust mite in Israel

Citrus rust mite, Phyllocoptruta oleivora (Ashmead), is a major pest of citrus in Israel. Five species of predatory mites: Amblyseius herbicolus Chant, Euseius victoriensis (Womersley), Euseius elinae (Schicha), Typhlodromus rickeri Chant and Euseius stipulatus (Athias-Henriot), were imported to improve the biological control of the pest. Mite rearing and sampling methods were developed and improved, and the predators were released. Recovery in some citrus orchards was recorded, but only E. victoriensis became established in the north of Israel.     

Influence of diet on life table parameters of <Emphasis Type="Italic">Iphiseius degenerans</Emphasis> (Acari: Phytoseiidae)

Studies on the reproduction, longevity and life table parameters of Iphiseius degenerans (Berlese) were carried out under laboratory conditions of 25 ± 1 °C, 75 ± 5% RH and 16L:8D h. As food sources for the predatory mite, Ricinus communis L. pollen, all stages of the spider mite Tetranychus urticae Koch, Frankliniella occidentalis (Pergande) larvae, and Ephestia kuehniella Zeller eggs were selected. All diets were accepted as food by the adult mites. Female longevity ranged from 29.5 to 42.4 days, the highest value was recorded on a diet of Ephestia eggs. The highest percentage of females escaping the experimental arena was observed on the diet consisting of thrips larvae. The highest oviposition rate (1.9 eggs/female.day) was recorded when the predator was fed on spider mites on an artificial substrate. For other diets, oviposition rates ranged from 1.0 to 1.3 eggs/female.day. The intrinsic rate of natural increase (r _m) of I. degenerans varied between 0.015 and 0.142 females/female.day. The diet consisting of castor bean pollen resulted in the highest population growth whereas the diet on spider mites brushed off onto a bean leaf arena resulted in the slowest population growth. This can be explained by the inability of the predator to cope with the webbing of T. urticae, and the high escape rate of the progeny when reared on spider mites. The percentage of females in the offspring ranged from 40 to 73%.This revised version was published online in May 2005 with a corrected cover date.     

Within‐patch oviposition site shifts by spider mites in response to prior predation risks decrease predator patch exploitation

In egg‐laying animals with no post‐oviposition parental care, between‐ or within‐patch oviposition site selection can determine offspring survival. However, despite the accumulation of evidence supporting the substantial impact predators have on oviposition site selection, few studies have examined whether oviposition site shift within patches (“micro‐oviposition shift”) reduces predation risk to offspring. The benefits of prey micro‐oviposition shift are underestimated in environments where predators cannot disperse from prey patches. In this study, we examined micro‐oviposition shift by the herbivorous mite Tetranychus kanzawai in response to the predatory mite, Neoseiulus womersleyi, by testing its effects on predator patch exploitation in situations where predatory mites were free to disperse from prey patches. Adult T. kanzawai females construct three‐dimensional webs on leaf surfaces and usually lay eggs under the webs; however, females that have experienced predation risks, shift oviposition sites onto the webs even in the absence of current predation risks. We compared the predation of eggs on webs deposited by predator‐experienced females with those on leaf surfaces. Predatory mites left prey patches with more eggs unpredated when higher proportions of prey eggs were located on webs, and egg survival on webs was much higher than that on leaf surfaces. These results indicate that a micro‐oviposition shift by predator‐experienced T. kanzawai protects offspring from predation, suggesting adaptive learning and subsociality in this species. Conversely, fecundity and longevity of predator‐experienced T. kanzawai females were not reduced compared to those of predator‐naïve females; we could not detect any costs associated with the learned micro‐oviposition shift. Moreover, the previously experienced predation risks did not promote between‐patch dispersal of T. kanzawai females against subsequently encountered predators. Based on these results, the relationships of between‐patch oviposition site selection and micro‐oviposition shift are discussed.     

Biological control of broad mites (<Emphasis Type="Italic">Polyphagotarsonemus latus</Emphasis>) with the generalist predator <Emphasis Type="Italic">Amblyseius swirskii</Emphasis>

The broad mite is a serious pest of a variety of crops worldwide. Several phytoseiid mites have been described to control these mites. However, broad mites are still one of the major pest problems on greenhouse pepper in South-eastern Spain. The generalist predatory mite A. swirskii is widely used against other pests of pepper plants such as thrips and whiteflies, the latter being a vector of broad mites. We assessed the potential of A. swirskii to control broad mites. The oviposition rate of A. swirskii on a diet of broad mites was lower than on a diet of pollen, but higher than oviposition in the absence of food. Population-dynamical experiments with A. swirskii on single sweet pepper plants in a greenhouse compartment showed successful control of broad mites.     

Pollen,mould mites and fungi: improvements to mass rearing ofTyphlodromus doreenae andAmblyseius victoriensis

Populations ofTyphlodromus doreenae Schicha on 18×14 cm arenas using pollen ofTypha orientalis Presl. as food, increased from an estimated 50–150 to 1,000–1,600 motiles per arena in the presence of mould mites,Tyrophagus putrescentiae (Schrank) and the fungusRhizopus stolonifer (Ehrenberg ex. Fr.) Lind.T. putrescentiae in association withR. stolonifer, developed pigmentation and were preyed on byT. doreenae which also became pigmented. UnpigmentedT. putrescentiae were not attacked byT. doreenae which remained pale coloured.T. doreenae died when supplied with the fungus alone. Bean plants dusted with pollen ofT. orientalis from a talcum powder dispenser supported a large population (7–12 stages/leaf) ofAmblyseius victoriensis (Womersley). These improvements to mass rearing ofT. doreenae andA. victoriensis are discussed with respect to their potential for commercialisation.     

Development and survival ofOrius albidipennis andO. levigatus (Het.: Anthocoridae) on various diets

The effect of various diets on nymphal development and survival of two predaceous anthocorid bugs,Orius albidipennis (Reuter) andO. laevigatus (Fieber) was investigated in the laboratory. Five different diets were compared: eggs ofEphestia kuehniella Zeller; eggs ofE. kuehniella plus mixed flower pollen; only mixed flower pollen; pollen from sweet pepper (Capsicum annuum L. cv. Mazurka) flowers; and sweet pepper plants. A high percentage of predators successfully completed nymphal development on those diets containing lepidopterous eggs. When fed on sweet pepper pollen, the survival percentages were 65% forO. laevigatus and 38% forO. albidipennis. No nymphs of either species completed the nymphal stage on mixed flower pollen or on sweet pepper plants. Development was significantly faster on diets containing eggs ofE. kuehniella. Results are discussed in relation to the capability of the bugs to survive periods of prey scarcity and to the optimization of release strategies for these predators in the greenhouse.     

Potential of the predatory mite Phytoseius finitimus (Acari: Phytoseiidae) to feed and reproduce on greenhouse pests

Phytoseiid mites of the genus Phytoseius are natural enemies of tetranychid and eriophyid herbivorous mites mostly found on hairy plants where they feed on prey, as well as on pollen. Nevertheless, the nutritional ecology and the role of these predators in biological pest control are only rarely addressed. In the present study, we evaluated the potential of Phytoseius finitimus to feed and reproduce on three major greenhouse pests, the two-spotted spider mite, the greenhouse whitefly and the western flower thrips. Additionally, we estimated the effect of cattail pollen when provided to the predator alone or in mixed diets with prey. Contrary to thrips larvae, both spider mite larvae and whitefly crawlers sustained the development of P. finitimus. In addition, females consumed more spider mite eggs and larvae, as well as whitefly crawlers than thrips larvae, but laid eggs when feeding on all prey. When provided alone, cattail pollen sustained the development and reproduction of the predator. The addition of pollen in mixed diets with prey reduced prey consumption, though it increased the predator’s egg production. We discuss the implications of our findings for biological pest control.     

Juvenile prey induce antipredator behaviour in adult predators

It is generally assumed that the choice of oviposition sites in arthropods is affected by the presence of food for the offspring on the one hand and by predation risk on the other hand. But where should females oviposit when the food itself poses a predation risk for their offspring? Here, we address this question by studying the oviposition behaviour of the predatory mite Amblyseius swirskii in reaction to the presence of its counterattacking prey, the western flower thrips Frankliniella occidentalis. We offered the mites a choice between two potential oviposition sites, one with and one without food. We used two types of food: thrips larvae, which are predators of eggs of predatory mite but are consumed by older predator stages, and pollen, a food source that poses no risk to the predators. With pollen as food, the predators preferred ovipositing on the site with food. This might facilitate the foraging for food by the immature offspring that will emerge from the eggs. With thrips as food, female predators preferred ovipositing on the site without thrips. Predators that oviposited more on the site with thrips larvae killed more thrips larvae than females that oviposited on the site without food, but this did not result in higher oviposition. This suggests that the females killed thrips to protect their offspring. Our results show that predators display complex anti-predator behaviour in response to the presence of counter-attacking prey.     

Assessing the Effects of Bt Maize on the Predatory Mite Neoseiulus cucumeris

The investigation of Neoseiulus cucumeris in the context of the ecological risk assessment of insect resistant transgenic plants is of particular interest as this omnivorous predatory mite species is commercially available and considered important for biological control. In a multitrophic feeding experiment we assessed the impact of Bt maize on the performance of N. cucumeris when offered spider mites (Tetranychus urticae) reared on Bt (Bt11, Syngenta) or non-Bt maize (near isogenic line) and Bt or non-Bt maize pollen as a food source. Various parameters including mortality, development time, oviposition rate were measured. Spider mites were used as a prey for N. cucumeris, since these herbivores are known to contain similar levels of Cry1Ab toxin, when reared on Bt maize, as those found in the transgenic leaf material. In contrast, toxin levels in pollen of this transgenic cultivar are very low. No differences in any of the parameters were found when N. cucumeris was fed with spider mites reared on Bt and non-Bt maize. Pollen was shown to be a less suitable food source for this predator as compared to spider mites. Moreover, subtle effects on female N. cucumeris (9% longer development time and 17% reduced fecundity) were measured when fed with pollen originating from Bt maize as compared to non-Bt maize pollen. Our findings indicate that the predatory mite N. cucumeris is not sensitive to the Cry1Ab toxin as no effects could be detected when offered Bt-containing spider mites, and that the effects found when fed with Bt maize pollen can be assigned to differences in nutritional quality of Bt and non-Bt maize pollen. The significance of these findings is discussed with regard to the ecological relevance for risk assessment of transgenic plants.     

Pest species diversity enhances control of spider mites and whiteflies by a generalist phytoseiid predator

To test the hypothesis that pest species diversity enhances biological pest control with generalist predators, we studied the dynamics of three major pest species on greenhouse cucumber: Western flower thrips, Frankliniella occidentalis (Pergande), greenhouse whitefly, Trialeurodes vaporariorum (Westwood), and two-spotted spider mites, Tetranychus urticae Koch in combination with the predator species Amblyseius swirskii Athias-Henriot. When spider mites infested plants prior to predator release, predatory mites were not capable of controlling spider mite populations in the absence of other pest species. A laboratory experiment showed that predators were hindered by the webbing of spider mites. In a greenhouse experiment, spider mite leaf damage was lower in the presence of thrips and predators than in the presence of whiteflies and predators, but damage was lowest in the presence of thrips, whiteflies and predators. Whitefly control was also improved in the presence of thrips. The lower levels of spider mite leaf damage probably resulted from (1) a strong numerical response of the predator (up to 50 times higher densities) when a second and third pest species were present in addition to spider mites, and (2) from A. swirskii attacking mobile spider mite stages outside or near the edges of the spider mite webbing. Interactions of spider mites with thrips and whiteflies might also result in suppression of spider mites. However, when predators were released prior to spider mite infestations in the absence of other pest species, but with pollen as food for the predators, we found increased suppression of spider mites with increased numbers of predators released, confirming the role of predators in spider mite control. Thus, our study provides evidence that diversity of pest species can enhance biological control through increased predator densities.     

Effects of potential food sources on biological and demographic parameters of the predatory mites Kampimodromus aberrans, Typhlodromus pyri and Amblyseius andersoni

Kampimodromus aberrans, Typhlodromus pyri and Amblyseius andersoni are generalist predatory mites important in controlling tetranychid and eriophyoid mites in European vineyards. They can persist by exploiting various non-prey foods when their main prey is absent or scarce. A comparative analysis of the effects of various prey and non-prey foods on the life history of these predators is lacking. In the laboratory, predatory mites were reared on herbivorous mites (Panonychus ulmi, Eotetranychus carpini and Colomerus vitis), a potential alternative prey (Tydeus caudatus) and two non-prey foods, i.e. the pollen of Typha latifolia and the mycelium of Grape downy mildew (GDM) Plasmopara viticola. Developmental times, survival, sex ratio and fecundity as well as life table parameters were estimated. Kampimodromus aberrans developed faster on E. carpini, C. vitis or pollen than on P. ulmi and laid more eggs on pollen than on prey. Low numbers of this predator developed on GDM infected leaves. Tydeus caudatus was not suitable as prey for any of the three predatory mites. Kampimodromus aberrans showed the highest intrinsic rate of population increase when fed on pollen. Developmental times of T. pyri on prey or pollen were similar but fecundity was higher on pollen than on P. ulmi. Typhlodromus pyri had higher intrinsic rates of population increase on C. vitis and pollen than on P. ulmi; E. carpini showed intermediate values whereas GDM resulted in the lowest r ( m ) values. Development of A. andersoni females was faster on pollen and C. vitis than on P. ulmi and GDM. Fecundity was higher on pollen and mites compared to GDM. Life table parameters of A. andersoni did not differ when predators were fed with prey or pollen while GDM led to a lower r ( m ) value. On a specific diet A. andersoni exhibited faster development and higher fecundity than T. pyri and K. aberrans. These findings improve knowledge on factors affecting the potential of predatory mites in controlling phytophagous mites in European vineyards.     

Initial Screening of Little Known Predatory Mites in Brazil as Potential Pest Control Agents

The objective of this study was to evaluate the oviposition rate and the survivorship of some of the most common predators on plants of the natural vegetation of southeastern Brazil, when confined with different food sources. Forty-four laboratory tests were carried out, each corresponding to a different combination of predator species and food source. The predators tested were: Phytoseiidae—Amblyseius acalyphus, Euseius citrifolius, Iphiseiodes zuluagai, Metaseiulus (Metaseiulus) camelliae, Typhlodromips cananeiensis; Stigmaeidae—Agistemus floridanus, Zetzellia malvinae; Tydeidae—Pronematus sp. For most predators, the highest oviposition rate and survivorship were obtained when the prey was one of the tenuipalpid mites, Brevipalpus phoenicis or Tenuipalpus heveae. With the exception of A. floridanus, the predators had low oviposition rate and survivorship on Calacarus heveae relative to their respective rate on other food sources. Predators had also generally low oviposition rate and survivorship when feeding on Tetranychus urticae, Oligonychus gossypii or Frankliniella sp.     

Laboratory studies on the feeding habits,post-embryonic survival and oviposition of the predaceous mitesAmblyseius chilenensis Dosse andAmblyseius hibisci Chant [Acarina: Phytoseiidae on various kinds of food substances

The predaceous mitesAmblyseius chilenensis Dosse andAmblyseius hibisci Chant were introduced to Israel from Riverside, California. In the laboratory studies were conducted on the feeding, post-embryonic survival and oviposition rate of these mites on 17 kinds of food substances, such as mites, insects and pollen.