جستجوی مقالات مرتبط با کلیدواژه « زمان دستیابی » در نشریات گروه « گیاهپزشکی »

A high searching rate is one of the most desirable traits of natural enemies. Different tests have been used to evaluate the searching behavior and efficiency of natural enemies, one of the most important tests among them is the functional response. In this study, the functional response of Habrobracon hebetor (Say) was investigated to different densities of 5th instar larvae of Meditteranean flour moth, Anagasta kuehniella (Zeller), fed on different food regimes. According to the obtained results, H. hebetor showed type II functional response on all treatments when mortality was considered just due to the number of parasitized larvae. When the combined number of parasitized and paralyzed larvae were considered, it showed type II on wheat flour + wheat husk and type III functional response on host larvae that used barely flour + wheat husk, corn flour + wheat husk, and wheat husk. The attack rate (a) of H. hebetor to parasitized larvae was 0.0549, 0.0504, 0.0526, and 0.0307 h-1 on wheat flour + wheat husk, barley flour + wheat husk, corn flour + wheat husk, and wheat husk, respectively. Accordingly, the handling time (Th) of H. hebetor was estimated as 5.9391, 5.3351, 5.1311, and 2.5789 hours that indicating H. hebetor spent less time for handling to larvae raised on the wheat husk. The results of this study could be used for the selection of the proper diet for H. hebetor mass rearing in insectariums.

AbstractThe functional response of ectoparsitoid wasp Anisopteromalus calandrae parasitizing the 4th instar larvae of the cowpea weevil, Callosobruchus maculatus was investigated over host plant and complex patch treatments in the laboratory. In the first group of experiments, the effect of two different host plants including cowpea Vigna unguiculata L. and chickpea Cicer arietinum was studied on the functional response of the parasitoid wasp. In the second series of tests, the influence of patch complexity was investigated using chickpea as the host plant.  According to the results of the logistic regression, the functional response for A. calandrae when attacking 4th instar larvae of C. maculatus on both chickpea and cowpea, and also in the complex patches of the host was type II. The search rates of the parasitoid were estimated 0.0488 and 0.0378 h-1, and the handling times were calculated to be 2.0962 and 2.1804 h in chickpea and cowpea treatments, respectively.  In the complex patch using chickpea seeds as host plant, the estimated search rate value for A. calandrae (0.0269 h-1) decreased in comparison with a simple patch (0.0488 h-1); however, the difference was not significant. These results can provide useful information for the biological control of the cowpea weevil in silos and store places.

It is necessary to investigate side effects of the pesticides on natural enemies of pests for integrated pest management (IPM) programs. Insecticides may impair physiological and behavioral traits of parasitoid wasps. This research was designed to study toxicity of actamiprid, pymetrozine and flonicamid on Aphidius matricariae Haliday (Hym.: Braconidae: Aphidiinae), a parasitoid wasp of Aphis fabae Scopoli (Hemi.: Aphididae). Furthermore, their sublethal effect were evaluated on the functional response of the parasitoid wasp of under laboratory conditions (25±1 0C, 65±5% R.H. and 16:8 (L: D) h).

A residual bioassay method was used to determine the toxicity of the insecticides on A. matricariae. Adult parasitoids were exposed to LC25 of the insecticides and distilled water as control on the glass vials and functional response study was done. After 24 h, randomly selected 6 alive mated females were transferred individually to cylindrical containers containing broad bean seedlings infested by densities of 2, 4, 8, 16, 32 and 64 of the third instar A. fabae nymphs. Each host density had fifteen replications. Aphids were left on the plants until mummification of the parasitized individuals. Functional response type was determined using logistic regression and its parameters were estimated by non-linear regression using SAS program.

The LC50 of values of actamiprid, pymetrozine and flonicamid were 3.07, 740.20 and 133.15 mg a.i./l, respectively. The results showed that acetamiprid was more toxic than pymetrozine and flonicamid to adult stage of A. matricariae. Functional response of the parasitoid on control and the insecticides treatments fitted the type II. Attack rate (a) in control, actamiprid, pymetrozine and flonicamid treatments were estimated 0.0432 ± 0.01, 0.0237 ± 0.003, 0.0414 ± 0.004 and 0.0398 ± 0.01 h-1 and handling time (Th) were 0.5170 ± 0.06, 1.4257 ± 0.13, 0.6133 ± 0.05 and 0.6816 ± 0.07 h, respectively. The attack rate (a) value of A. matricariae exposed to acetamiprid was significantly lower than that of control and other insecticides treatments. The highest value of handling time(Th) was observed in acetamipirid. Although, they were not significantly affected by pymetrozine and flonicamid. Maximum rates of parasitism (T/ Th) in control and mentioned insecticides treatments were estimated 46.42, 16.83, 39.15 and 35.21 aphids, respectively.

According to present results, acetamiprid negatively affected the attack rate (a), handling time (Th) and maximum attack rate (T/Th) of parasitoid compared to the control, pymetrozine and flonicamid treatments. Pymetrozine and flonicamid had lower side effects on A. matricariae in comparison with acetamiprid and they were suitable candidates for controlling of A. fabae in combination with A. matricariae. Although, studying side-effects of the insecticides on the mentioned parasitoid wasp in semi-field and field conditions are needed to obtain more applicable recommendations.

Phenacoccus solenopsis Tinsley is a polyphagous pest that has become a serious threat to agriculture in the tropical and subtropical regions of the world since the beginning of the twentieth century. Aenasius bambawalei Hayat is an endoparasitoid that parasitizes third instar nymphs of P. solenopsis. In this study, sublethal effects of spirotetramat and chlorpyrifos were investigated on the functional response of the parasitoid on the nymphs of P. solenopsis at 27± 1 ° C, 65± 5% RH, and a photoperiod of 14: 10 (L: D). The densities of 2, 4, 8, 16, 32, and 64 third instar nymphs of P. solenopsis were used in the experiments. The results of logistic regression showed type II functional response in all three treatments including control, spirotetramat, and chlorpyrifos. The search rate (a) of the wasp in control, spirotetramate, and chlorpyrifos treatments were calculated to be 0.2609, 0.1107, and 0.0556 h–1, respectively, which in spirotetramat, and chlorpyrifos were 57% and 78% less than control. Handling time (Th) in control, spirotetramat, and chlorpyrifos treatments were calculated to be 0.0187, 6.3352, and 9.3903 h, respectively. In spirotetramate and chlorpyrifos treatments, handling times were about 26% and 87% more than control. The handling rates of control, spirotetramate, and chlorpyrifos were 4.63, 3.28, and 2.55 host nymphs, respectively; which in spirotetramate and chlorpyrifos it was 31% and 45% less than in control. The results of this study showed that the insecticides of spirotetramate and chlorpyrifos had a negative effect on the functional response behavior of the parasitoid even at low doses and thus could disturb the biological control.

 The functional response is one of the important components of predator-prey interactions. It can be affected by different factors such as host plant quality. In this research, the functional response of the predatory gall midge Aphidoletes aphidimyza larvae to the nymphs of the melon aphid, Aphis gossypii reared on cucumber plants amended with different levels of nitrogen fertilizer (0, 100, 150 and 200 kg/ha) was investigated. The experiments were carried out at 25±1 °C, 60±5 % RH and a photoperiod of 16: 8(L: D). Different densities (2, 4, 6, 8, 12, 16 and 24) of mixed 2- and 3-d old nymphs of the aphid were separately offered to 4-d-old predator larvae. The numbers of killed preys were recorded after 18 h. Logistic and nonlinear regression analyses were used to determine the type of functional response and estimate of attack rate (a) and handling time (Th) parameters, respectively. At all treatments, the predator exhibited a type II functional response to change in A. gossypii density. The attack rate and handling time of the predator were ranged from 0.0623 to 0.1512 h-1 and 1.4646 to 1.8716 h, respectively. The highest value of attack rate and the lowest value of the handling time of A. aphidimyza were obtained at treatment of 200 kg/ha nitrogen. This study revealed that adding nitrogen to the soil in cucumber cultivation can improve the predatory ability of A. aphidimyza on A. gossypii. However, for understanding further details of the effects of different levels of nitrogen fertilizer on cucumber- A. gossypii- A. aphidimyza interactions, further studies need to be carried out.

Storage at low temperature for host availability at different times is a valuable way to increase the mass production of natural enemies for biological control programs. Usually, host cold storage is done at temperatures below the optimum temperature and can affect the adaptations of natural enemies. Egg parasitoids, Trissolcus agriope and Psix saccharicola from Scelionidae family are as biological control agents against important pest of pistachio, greenstink bug, Acrosternum arabicum. In this study, effect of host egg storage at 4 ± 1 °C on functional response of Trissolcus agriope and Psix saccharicola were evaluated at different densities (5, 10, 15, 20, 25, 30, 35, 50, 65, 80 and 95) under laboratory conditions. Logistic regression analysis revealed a functional response type III for T. agriope on both fresh and cold-stored eggs and type III and II for P. saccharicola on fresh eggs and cold-stored eggs, respectively. Although the type of treatment did not change the type of functional response in T. agriope but were reduced the type of response from III on fresh eggs to type II on cold-stored eggs in P. saccharicola. However handling time in both species were increased in cold-stored eggs treatment compared to fresh eggs treatment. Our results suggest that T. agriope can successfully parasitize cold-stored eggs of A. arabicum without considerable undesirable effects on its parasitism rates. However, this method may have negative effects on the performance of some other parasitoid wasp, including P. saccharicola.

One of the parameters used in natural enemies evaluation is functional response studies to predict the efficacy of the predator in biological control programs. The vine mealybug, Planococcusficus (Signoret) is an important vineyard pests in all parts of the world. Cryptolaemusmontrouzieri Mulsant, is a well–known natural enemy of mealybugs. The experiment was conducted under laboratory condition with 26±1°C with 70±5 % RH and 12:12 D:L photoperiod with four densities of adult females of vine mealybug, P. ficus, as host insect. Adult female and male and 3rd instar larval stage of C. montrouzieri and four densities (3, 5, 7 and 9, each with 10 replicates). The number of host killed after 24 hours were recorded. Determination type of functional response model and estimation of related parameters were carried out based on two–stage analysis method by using SAS software. A type 2 functional response was concluded under this experimental condition for all stages of predator using logistic regression with parameters estimated through nonlinear regression. The results for searching efficiency and handling time for 3rd instar larval, adult male and adult female of the predator were (0.6922 and 0.9549 hours), (0.4901 and 1.3542 hours) and (0.5977 and 1.0996 hours), respectively. Results showed that 3rd instar larvae of predator showed a better searching efficiency and lowest handling time rather than adults which is a fine character for a predator.

Background and Objectives Aphids are one of the major pests in ornamental plants may cause damage to plants directly by sucking their sap, and indirectly by injecting toxic salivary secretions, transmitting pathogens, attracting ants and favoring the development of sooty-mold. Crapemyrtle aphid, Tinocallis kahawaluokalani Kirkaldy, currently is considered the most serious pest of ornamental woody plant, Lagerstroemia spp. and produce large amounts of honeydew while feeding. T. kahawaluokalani causes premature drop of leaves, decline of summer flowering and reduces the commercial market. The multicolored Asian ladybird, Harmonia axyridis Pallas, is capable of eliminating T. kahawaluokalani populations on crape myrtle plants. There is no data about the predatory behavior of H. axyridis on T. kahawaluokalani. So, functional response of third and fourth larval instars, and females and males of H. axyridis to T. kahawaluokalani was studied in the laboratory condition. Materials and Methods Adults of H. axyridis and nymphs of T. kahawaluokalani were collected from Crapemyrtle plants in Mazandaran province (North of Iran). They were reared together on the Crapemyrtle leaves in the laboratory conditions (25± 2 °C, 60%± 10% RH and a photoperiod of 16:8 h L: D) h. Prey densities were 5, 10, 20, 30, 60, 80 and 120 aphids for third and fourth larval instars, and adult females and males. The number of prey consumed by each stage of the predator was recorded at each density after 24 hours. The type of the functional response was determined by logistic regression analysis (SAS/STAT, CATMOD pro cedure) of the proportion of prey killed (Ne) in relation to initial prey density (N0). The handling times and attack coefficients were estimated using Holling’s disk equation. Statistical analysis of the functional response was performed using the SAS software. Results In all the predator stages, according to the logistic regressions results, linear parameter, P1 was negative that shows a type II functional response. The response curve rises in a negatively accelerating manner to a plateau and the proportion of preys consumed by a predator decreases exponentially as the prey density increases. In highest densities, mean number of consumed aphids by third, fourth, and male and female adults were determined 50.5, 69.2, 75 and 83.9 aphids, respectively. Based on Rogers’s random equation, the lowest (0.0560 h-1) and the highest (0.1370 h-1) attack rates were obtained for third larval instar and adult female, respectively. Handling time was shortest (0.1821 h) in third larval instar and longest (0.2870 h) in female adult. Discussion Based on positive predatory characteristics including voracity and high searching efficiency of females, H. axyridis has high predation capacity and can be important in suppressing the T. kahawaluokalani populations.

The response of a natural enemy to its host’ densities has been defined as “functional response”. It has been considered a feasible technique to measure the efficacy of biocontrol agents. We employed the concept to evaluate the functional response of adult female and male of Nesidiocoris tenuis under laboratory conditions by feeding on different densities (1, 2, 4, 8, 16, 32, 64, and 96) of Ephestia kuehniella and Tuta absoluta eggs in 7 replicates. The predators were kept unfed for 24 hours. Then the number of eaten prey was recorded after 24 hours. The results showed type III functional response for all tests based on logistic regression. The attack constants (b) of females and males fed on E. kuehniella and T. absoluta eggs were 0.0061 ± 0.0018, 0.0048 ± 0.0009, and 0.0093 ± 0.0037, 0.0042 ± 0.001, respectively. The estimated handling times (Th) for females and males on the respective preys were 0.3598 ± 0.0193, 0.2905 ± 0.0136, and 0.9032 ± 0.0511 and 0.5859 ± 0.0303 h. In conclusion, N. tenuis females had shorter handling time, greater attack rate and maximum daily consumption (73.86 eggs) compared with those of males. Therefore, results strongly support that female predators could be more effective in controlling T. absoluta.

It is necessary to investigate side effects of insecticides on natural enemies of pests. In this study, toxicity of spirotetramat, acetamiprid, pirimicarb and flonicamid was investigated on parasitoid wasp, Lysiphlebus fabarum (Marshall). Furthermore, sublethal effect of the insecticides were evaluated on the functional response of the parasitoid to densities of 2, 4, 8, 16, 32 and 64 of third instar nymphs of Aphis fabae Scopoli under laboratory conditions. Residual bioassay method was used to determine the toxicity of the insecticides on parasitoid adults. For functional response assay, mated females (

Botanical insecticides are one of the tools in integrated pest management programs. It is necessary to investigate their effect against pests and their side effects on natural enemies of pests. In this research, toxicity of two botanical insecticides, Dayabon® and Palizin® were investigated against third instar nymphs and adults of Aphis fabae Scopoli as well as pupal stage of its parasitoid wasp, Lysiphlebus fabarum (Marshall). Furthermore, effect of the insecticides were evaluated on the functional response of L. fabarum. All experiments were done under laboratory conditions. These insecticides were highly toxic for third instar nymphs of A. fabae with LC50 values of 750.2 and 636.3 ppm for Dayabon® and Palizin®, respectively. The LC50 values of the insecticides were 1302.04 and 1062.8 ppm, respectively, for adults. Mean adult parasitoid wasp emergence were 86.08 ± 3.2, 89.74 ± 2.55 and 91.33 ± 2.03%, respectively, for Dayabon®, Palizin® and control treatments at pupal stage. The insecticides had no adverse effect on fecundity of emerged females. According to International Organization for Biological Control, Dayabon® and Palizin® were classified as harmless insecticides. The results revealed the type II functional response in all experiments. Attack rate (a) of L. fabarum in control, Dayabon® and Palizin® treatments were 0.075, 0.050 and 0.056 h-1 and handling time (Th) were 0.459, 0.515 and 0.482 h, respectively. There were no differences in the functional response parameters between the treatments. These results suggest that Dayabon® and Palizin® are suitable candidates for control of A.fabae in combination with L. fabarum.

Aphids are tiny soft-body insect pests which damage the host plant directly through sap feeding and indirectly by transmission of plant viruses. Pomegranate green aphid, Aphis punicae is a common pest of pomegranate gardens in Iran. In some years, the aphid dramatically damages under the suitable conditions in that they can grow and reproduce. Lady beetles are small, brightly colored insects and belong to family Coccinellidae. These predators obtain necessary resources for their survival and reproduction from a variety of habitats. Menochilussexmaculatus (Col.: Coccinellidae) is one of the major predators of pests reported in the gardens of Iran. The zigzag beetle is a general entomophagouscoccinellid that feeds upon soft body insects such as aphids. The adults of M sexmaculatus are bright yellow in color with black vertical zigzag lines. The adults and larva prey upon all stages of aphids. The study of the predation efficiency of M. sexmaculatus would increase its chances to be used as a biological control agent M. sexmaculatus is an efficient predator of many aphid species, e.g. the mustard aphid, LipaphiserysimiKalt. The zigzag, beetle widely distributed and feed on aphid species in India, Pakistan, Borneo, Jawa Indonesia, and the UK. The Philippines, Islands of Bali, France, Sumatra and South Africa. In this paper, we evaluated the effect of temperature on some biological parameters of M. sexmaculatus by feeding on pomegranate green aphid, A.punicae. Menochilussexmaculatus is an effective predator to be used as a bio-control agent but the major challenge is its mass rearing and augmentation
The colony of M. sexmaculatus was established from about 100 adult beetles collected from a pomegranate orchard (GPS coordinates 30°23'42.31'' N and 55°56’51.11’ E) at Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran, in October 2013.. Adults were held In a ventilated plastic box (25.0 x 20.0 x 10.0cm) and fed by pomegranate green aphids in a climate-controlled growth chamber set to 25 ± 2 °C, 65 ± 5% RH and 16L: 8D photoperiod. The functional response of different stages of M.sexmaculatus to different densities of 3rd and 4th nymphal stages of pomegranate green aphid were studied at temperatures of 20, 22.5, 25, 27.5 and 30 (±1)°C, for adult females (10-days old) in temperatures of 25 and 27.5(±1)°C for 3rd and 4th larval stages, at 65 ± 5 RH and 16:8 L: D photoperiod. The densities of 2, 4, 8, 16, 32, 64, 100, and 128 3rd and 4th nymphal stages of aphid for 3rd and 4th larval stages and densities 8, 16, 32, 64, 100 and 128 for female and male adults. Females of lady beetle were used and the average feeding at any density was recorded after 24h. Type of functional response was determined using logistic regression and the searching efficiency (a) and handling time (Th), were estimated by nonlinear regression. All the data in the Excel 2007 program was set. Curves and graphs were plotted using Excel 2007 software.
Type of the functional response of the all predator stages across all temperatures was type II. The results showed that the temperature is effective on functional response of predator, and searching efficiency of predator increased at temperatures of 22.5°C to 27.5°C. The maximum and minimum value of the searching efficiency were0.14 h-1 at 27.5°C and 0.0582 h-1 at 22.5°C and of handling time were 0.26 h at 20°C and 0.0182h at 22.5°C for adult females respectively.
Conclusion In general, the lady beetle at temperature of 27.5°C and in stages of 4th larval and adult would have the highest predatory efficiency. Application of this predator was interested in biological control programs of pomegranate green aphid. The data indicated that the M. sexmaculatus may be a useful candidate for the biological control of A. punacaein pomegranate gardens.

The functional response is the most basic form of predator-prey interaction and describes the relationship between the number of prey attacked and the initial prey density. Hyperaspis polita Weise (Col. Coccinellidae) is one of the most important predators of some species of mealybugs and is collected from some parts of Iran especially Khuzestan province. In this research, the functional response of the fourth instar larvae, females and males of this predator to varying densities of female cotton mealybug Phenacoccus solenopsis Tinsley was assessed in a growth chamber (30±1˚C, 65±5% R.H. and photoperiod of 14:10 (L:D) h). A cubic logistic regression between the proportion of prey killed and initial prey densities was performed to determine the shape (Type II or Type III) of functional response. Based on the logistic regression, functional response type II were determined for all predator stages. The attack rate (a), handling time (Th), and theoretical maximum predation rate (T/Th) were estimated using Roger's model to be 0.0196±0.0029 h-1, 3.3262±0.4551 h, and 7.2 prey/d for fourth instar larvae, 0.0131±0.00238 h-1, 3.4765±0.7419 h, and 6.9 prey/d for adult females and 0.0195±0.00528 h, 12.013±0.2624 h-1, and 1.99 prey/d for adult males respectively. According to our results, the fourth instar larvae and the adult females of H. polita can be applied as an effective biological control agent against P. solenopsis.

Study of behavioral parameters and functional response of predators is an important process in selecting these agents for biological control programs. In case of simultaneous use of these predatory insects with entomopathogens, behavioral reactions of predator may be altered. In this study, type of functional response of the predator, Orius niger (Hem.: Anthocoridae) was determined on the healthy adult female mite, Tetranychus urticae (Acari: Tetranychidae) and on the Beauveriabassiana-treated mites atthe four time intervals 0, 24, 48 and 72 hours at different densities of 5, 10, 20, 30, 40, 50 and 60 at 25 ± 1 ° C, 65 ± 5% RH and 16:8h (L:D) photoperiod. The results showed functional response of this predatory bug on untreated mites was type III while it was type II in other treatments. Comparison of searching efficiency and handling time in control with fungus treatments at various time intervals was only non-significant between control and 0 hour in searching efficiency and between control and 24 hours in handling time post-inoculation. The maximum attack rate (T/Th) in two treatments of 48 and 72 hours was reduced and was significantly different from other treatments; concomitantly handling time of predator was increased. These results suggest the effect of entomopathogenic fungus on behavioral reactions of predatory bug, O. niger.

Behavioral changes of biocontrol agents after exposing to pesticides have an important role in success of IPM programs. In the current study lethal and sublethal effects of abamectin, acetamiprid and indoxacarb as the widely used insecticides were investigated on adults of mirid bug, Nesidiocoris tenuis and its behavior on Tuta absoluta eggs. Experiments were performed in the laboratory conditions (25±1ºC, 60±10% R.H. and 16:8 (L:D) photoperiod). Effects of sublethal concentration of insecticides were evaluated during 24 h period using dried residues of insecticides on tomato leaf. The values of LC50 for abamectin, acetamiprid and indoxacarb against N. tenuis were 33.40, 36.55 and 204.43 and of LC30 were 20.42, 30.38 and 181.53 µl a.i./L, respectively. All insecticides decreased attack rate of the predator; however, the most effective one was indoxacarb. On the other hand, indoxacrab and acetamiprid caused significact increase in handling time of predator while the most effective was indoxacarb. Abamectin showed the lower behavioral effects among the tested insecticides. According to total effect index (E) in IOBC category, acetamiprid (85%) and indoxacarb (77%) were harmful against N. tenuis predatory bug, while, abamectin (38%) was considered as slightly harmful.

The strawberry spider mite, Tetranychus turkestani (Ugarov & Nikolski) is one of the most important pests of agricultural crops in Iran. Orius albidipennis (Reuter) is also an active predator of spider mites in agricultural ecosystems in Iran. One of the characters which is used for the evaluation of predators is their response to the different densities of prey (functional response). Functional response of different developmental stages of this bug by feeding on adult female T. turkestani was investigated at 25 ± 1 ºC, 60 ± 5% RH and a photoperiod of 16:8 (L:D) h under laboratory condition. The experiments were carried out in a petri (10 cm diameter) on a bean leaf with the densities of 5, 10, 20, 30, 50 and 70 adult female mites. Mean maximum feeding rate of first, second, third, fourth and fifth nymphal stages as well as female and male adults of this bug were 9.6, 23, 34.8, 39.2, 48.1, 56.4 and49.1female adult T. turkestani, respectively. Functional response of all developmental stages (except for fourth nymphal stage) was of the Holling’s type II. Fourth nymphal stage showed Holling’s type III. Based on the Rojer’s equation, estimated attack rates of O. albidipennis were0.0654, 0.0678, 0.075, 0.0098, 0.1834, 0.1691 and0.165 and estimated handling times were 2.3048, 0.8259, 0.4684, 0.6585, 0.3666, 0.2484 and 0.3336 h for the first, second, third, fourth, fifth, female and male adult, respectively.

The greenhouse whitefly, Trialeurodes vaporariorum is an important pest in vegetable and ornamental crop, especially in greenhouse condition. The predatory mite Amblyseius swirskii has been evaluated as a potential biological control agent for whiteflies. Functional response and mutual interference of adult female of this predator fed on young instars (first + second instar) of greenhouse whitefly were studied in laboratory conditions (25±1 °C, 70±10 % RH, and a photoperiod of 16:8 h L:D). The experiments were carried out on leaf disks in petri dishes with 10-15 replicates. SAS program was used to determine the type of functional responses and estimate the functional responses parameters. Our results revealed that adult females of A. swirskii exhibited type II functional responses on different densities (2, 4, 6, 8, 12, 20, and 30) of prey. The rate of searching efficiency and handling time were estimated as 0.142 ±0.022 h-1 and 2.310±0.110 h, respectively. Nicholson’s model and linear regression were used to determine the per capita searching efficiency and interference coefficient, respectively. The per Capita searching efficiencies of this predator decreased significantly with increasing predator densities and the value of interference coefficient of this predator fed on 40 density of greenhouse whitefly was -0.167. The rate of predation increased as the host density increased from 2 to 30 and subsequently the predator density decreased from 6 to 1. Therefore, different host–predator ratios could affect the efficacy of A. swirskii.