حسین اللهیاری

Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is an important generalist predator used to control several important crops' pests such as spider mites, whiteflies, and thrips. In this study, the lethal concentrations of Mentha piperita L. (Lamiaceae) and Laurus nobilis L. (Lauraceae) essential oils (EOs) were calculated on the adult stage of the Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). The side effects of EOs were investigated on the functional response of A. swirskii on F. occidentalis 1st instar larvae. The females of A. swirskii were exposed to sub-lethal concentrations (LC30 and LC50) of EOs for 12 h with the fumigant exposure method. In the control, the treatment was performed by using Triton X-100 (0.02). Treated predatory mites were selected randomly, and transferred to the experimental arenas containing 2, 4, 8, 16, 32, and 64 thrips. The predators were kept in the experimental arenas for 24 h at 25 ± 1 °C, 60 ± 10% RH, and a photoperiod of 16: 8 h (L: D). Results indicated that A. swirskii exhibited a type II functional response, regardless of EOs applications. The shortest (1.62 ± 0.046 h) and the longest (1.91 ± 0.049 h) handling times, were recorded in the control and the LC50 treatment of M. piperita EO, respectively. There was not a significant difference between attack rate coefficients (α) under sub-lethal concentrations. Based on the results, the two EOs have the potential to be used in F. occidentalis management, but their side effects on A. swirskii should be considered in IPM programs.

Cereal ground beetle Zabrus tenebrioides is the most important pest of wheat in Golestan province, which causes great damage to the crop in fields without crop rotation despite chemical control by spraying in the tillering stage. This research investigated the simultaneous effect of nutrition by fertilizing, planting density, and seed treatment by imidacloprid, on the infestation, the number of pest larvae, and the grain yield in rainfed wheat during 2020 to 2022. The research was conducted using a split split plot the main factor is fertilizing with two levels. The optimum level: 100 kg/ha is urea fertilizer, 75 kg/ha is phosphate fertilizer, and 25 kg/ha is potash fertilizer. The custom level: of 100 kg/ha is urea fertilizer. Sub factor is the planting density including 160, 180, and 210 kg/ hectare of seeds. Sub subfactor, imidacloprid including doses: 0, 1, 1.5, 2, and 2.5 g/100 kg seeds wheat. According to the results of the recent study and considering the environmental hazards and the importance of grain yield in relationship with the farmer's income - compared to the infestation and the number of pest larvae -thus, two treatments with the highest grain yield which have no significant difference based on the PLSD test at the 5% probability suggested: the planting density by 160 kg seeds per hectare with a concentration 1.5 gr pesticides per 100 kg seeds or planting density by 210 kg seeds per hectare with a concentration 1gr imidacloprid per 100 kg seeds with optimal nutrition by fertilizing.

Ants are eusocial insects of the family Formicidae and are one of the most successful insects in number and diversity. Despite their favorable impact on the ecosystem, they are sometimes regarded as serious pests due to damage to agricultural products and construction facilities. Baiting is a suitable alternative to many traditional ant control methods. In the present study, the effect of oral toxicity of fipronil, imidacloprid and borax on Tapinoma karavaievi workers was evaluated under laboratory conditions at 72, 96 and 120 hours after treatment and then the survival rate of workers treated with the LC50 of the studied compounds was compared in two weeks. According to the results, the highest oral toxicity in all three-time points was related to fipronil, imidacloprid and borax, respectively. In addition, the evaluation of the effect of pesticides on the survival of workers showed a faster control of workers treated with the LC50 of fipronil (2.46 mg ai L-1) compared to imidacloprid (32.61 mg ai L-1) and borax (2654.4 mg ai L-1). The results showed that 90% effectiveness of fipronil and imidacloprid occurred on days 7 and 11 after treatment, respectively, and it seems that 90% effectiveness of borax will probably take place in the third week after treatment. In general, the current study showed that all three studied pesticides have sufficient potential to control workers and the selection of the most suitable pesticide depends on considering the pesticide concentration, strategy of control and attention to the side effects of pesticides.

The greenhouse whitefly, Trialeurodes vaporariorum Westwood, is one of the most important pests in the world and Iran, which causes great damage to agricultural products annually. In this study, the effect of 50% lethal concentration (LC50) of mayonnaise and emulsifiable concentrate (EC) formulation (50 ml/lit) on life-table parameters of greenhouse whitefly was investigated using leaf-deaping method under laboratory conditions. The experiment was performed on second nymphs instar. The lowest number of eggs was related to mayonnaise treatment (38.92 eggs) which was less than EC (40.16 eggs) and control (97.39 eggs) treatment. The intrinsic rate of increase reduction (rm) of oil treatment showed the effect of oil on pest population dynamic.The intrinsic rate of increase of both formulations and control were 0.065 d-1 and 0.105 d-1, respectively. The finite rate of increase (λ) was also significantly lower for whitefly treated with oil 1.067 d-1 than whitefly in control 1.111 d-1. Furthermore, the net reproductive rate (R0) was 9.49 and 9.53 nymphs/female for mayonnaise and EC formulations which was less than control 26.97 nymphs/female, respectively. The highest generation time (T) was observed in EC oil .formulation with 34.26 d-1 and the lowest was recorded in control treatment with 31.12 d-1, respectively. According to the results of this study, EC and mayonnaise formulations can reduce reproductive capacity of greenhouse whitefly population.

The greenhouse whitefly, Trialeurodes vaporarium (Westwood), is an invasive insect pest of agriculture and horticulture worldwide. Imidacloprid as chemical pesticide has been used as a key pesticide for controlling sap-sucking pests and play a major role in controlling this pest. The main purpose of this study was investigation of resistance status of T. vaporarium to imidacloprid SC 35% (Confidor®) and cross resistance to Eforia® and Proteus® and effect of imidacloprid resistance on Encarsia formosa Gahan. Thirteen greenhouse whitefly populations were collected from greenhouses and fields and used for tests. Collected populations reared on cucumber plants under laboratory conditions at 25±2˚C, 70±10 % relative humidity and a photoperiod of 16:8 h (L: D). The LC50 values were estimated on the second instar nymphs for all populations using leaf dipping bioassay method. The VGR population showed highest LC50 that was 856.2 mg/L. The development of resistance to imidacloprid was confirmed for all tested populations with resistance factors ranging from 2.54 to 44.3. The most resistant strain showed cross resistance to Eforia® and Proteus®. There was no significant difference between LC50 values of E. formosa populations that collected form field, reared on the most resistant population and sensitive population of T. vaporarium. The LC50s were 388.7, 324.7 and 317.7, respectively. We discuss our results in regard to the evolve of imidacloprid resistance in T. vaporariorum populations and its implications for whitefly control.

This study has evaluated the age-specific functional response of the females of Nephus arcuatus Kapur, as the major predator of Nipaecoccus viridis (Newstead). The varying density of N. viridis eggs (2, 4, 8, 15, 40, 65, 90, and 115) were offered to 3 to 33 days of the lifespan of the female adults under laboratory conditions (30 ± 1 °C, 65 ± 5% RH and a photoperiod of 14L: 10D h). The age of female adults affected functional responses, its parameters (handling time (Th) and attack rates (a)), and predation rate by N. arcuatus. Females exhibited functional response type III during 16th, 24th and 28th days of their life. Conversely, the functional response during the other 30 days of female life changed from functional response type III to type II. The handling time decreased significantly from the 4th to 17th day as female age increases and then increased, whereas, the attack rates did not significantly change with higher age of the predator. The maximum attack rate values were found on the 12th, 14th, 15th, 17th, 18th, 20th and 25th days of female adults. The maximum mean predation rate was 156.6 eggs on the 17th and 18th days. Accordingly, the best time to use females of this predator in an inundative biocontrol agent is during the first 25 days of females' age, when the predator is more capable to attack the prey, especially when N. viridis is in the egg stage.

The two-spotted spider mite, Tetranychus urticaeKoch is one of the polyphagous pests that attack a wide range of crops. In recent decades, excessive application of synthetic acaricides has led toitsresistance to pesticidesand environmental pollution. However, considering the importance of the role of pesticides in controlling plant pests, it is impossible to cease using these compounds. In recent decades, new methods such as the use of plant extracts have been proposed that not only control pests but also have no residues and harmful environmental effects. Also, the use of plant extracts in combination with synthetic pesticides while controlling the pest, reduces the amount of pesticide usage. In this study, the efficacy of methanolic extracts of Zataria multifloraand Rosmarinus officinaliswasinvestigated individually and in combination withspirodiclofen and propargite to control two-spotted spider mites. Bioassay tests were performed using the leaf dipping method. Each treatment was performed in three independent biological replications and the mortality was recorded 24 h after exposure. The 50% lethal dose (LC50) of spirodiclofen and propargite as well as methanolic extracts of Z. multifloraand R.officinaliswere estimated to 1.89, 12.76, 1934.13, and 4382.07 mg/l, respectively. In addition, results of experiments related to mixing plant extracts with acaricides showedthat the combination of Z. multifloraextract with spirodiclofen and propargite caused a synergistic effect with a co-toxicity coefficient of 66.66 and 55.55, respectively. However, the combination of R.officinalisextract with spirodiclofen and propargite caused an antagonistic response with −77.78 and −80.56, respectively.

Water hardness and acidity are the important properties that can influence the performance of pesticides. The effect of water hardness and pH on the efficacy of insecticides on second instar nymph of Bemisia tabaci was determined by leaf dip method. In the first experiment, well water samples at 1869, 645, and 265 mg L-1 hardness, standard, and deionized water with malathion, acetamiprid, and spiromesifen used for bioassay. In another experiment, the effect of water pH at four levels 4, 6, 7, 9 on the toxicity of the above three insecticides was investigated. Increasing water hardness reduced the performance of the experimental insecticides. LC50 values showed that the toxicity of malathion, acetamiprid, and spiromesifen was 40, 157, and 84 times less in water with 1869 mg L-1 hardness than deionized water. The efficiency of malathion, acetamiprid, and spiromesifen was 13, 65, and 39 times less in water with 645 ppm hardness than deionized water. Pesticides were less effective at pH 9 compared to other pH levels. Malathion efficacy was 11.41 and 7.16 times better when it was diluted in water with pH 6 and 7 than pH 9. Acetamiprid provided 10.72 and 5.89 times greater toxicity when applied at pH 7 and 6 respectively than water with pH 9. Spiromesifen in deionized water with pH 7 and 6 has exhibited 5.51 and 3.82 times better efficacy compared to the water at the pH level of 9. Overall, the performance of insecticides reduced at hardness levels above 265 ppm and in alkaline pH.

Water acidity is an important property that can influence the performance of pesticides Acidic or alkaline water pH can negatively influence the solubility, uptake, biological activity and hydrolysis of the pesticide molecule. The effect of water pH on the efficacy of insecticides on second instar nymph of Bemisia tabaci was determined by leaf dip method. The experiment was conducted with deionized and standard water at 4 pH levels 4, 6, 7, 9 and three insecticides as malathion, acetamiprid and spiromesifen. Based on LC50 values, there was a significant difference between the toxicity of insecticides at different pH levels. All pesticides were less effective at pH 9 compared to other pH levels. The lethal dose ratio LC50 of standard to deionized water for malathion at pH 6, acetamiprid and spiromesifen at pH 7 was statistically different. The toxicity of insecticides was affected by water type at the mentioned pH levels. Malathion performance in deionized water at pH 6 was 2.82 times higher than standard at the same pH. For acetamiprid was observed that toxicity in deionized water at pH 7 was 2.55 fold more than standard. The results also revealed that spiromesifen in deionized water with pH 7 and 6 has exhibited 2.1 and 1.85 times better efficacy compared to the same pH levels in standard D. Overall, this study showed that experimental insecticides in a specific pH have a relevant effect on Bemisia tabaci.

Background and objectives Understanding the functional response of a predator to its prey and its parameters including attack rate and handling time, are one of the basic methods in applied biological control for evaluation of the efficiency of a predator. Nephus arcuatus is one of the most important biological control agents of Nipaecoccus viridis. Material and Methods In this study, a laboratory study has been conducted to evaluate the stage-specific functional response of larval stages and adult females and males of N. arcuatus to varying densities of N. viridis 2nd instar nymph. Experimental conditions were based on optimal temperature for N. arcuatus activities, 30±1ºC, 65±5% RH, and 14L:10D photoperiod. Results and Discussion The shape of functional response curve and the functional response parameters were determined respectively by logistic regression and nonlinear least square regression. The 1st instar, 2nd instar larvae, adult males as well as adult females exhibited a type II functional response. Attack rate (a) and handling time (Th) were estimated to be 0.1139 h-1 and 11.4117 h for the 1st instar, 0.3237 h-1 and 4.7013 h for 2nd instar larvae, 0.2233h-1 and 1.4711 h for adult males, and 0.2836h-1 and 1.0198 h for adult females, respectively. In contrast, the 3rd instar and 4th instar larvae of N. arcuatus exhibited a type III functional response. Constant b and handling time were estimated to be 0.0195 and 1.7396 h for the 3rd instar, and 0.00774 and 0.4912 h for 4th instar larvae, respectively. Our results indicated that estimated attack rates did not change significantly between different stages of N. arcuatus with similar functional response curve. In contrast, the handling times of N. arcuatus to its prey increased as the larval age of this predator increased, also females had longer handling time than adult males. Based on the maximum predation rate (T/Th), the 4th instar larva was the most voracious stage (48.56 prey/d) followed by the adult female (23.53 pey/d) and male (16.32 egg/d) N. arcuatus. These findings suggest that the voracity of all stages of N. arcuatus toward N. viridis hold good promises for a use of especially simultaneously 4th instar larvae, and adult males and females of N. arcuatus in a biological control program against N. viridis in orchards and on ornamental plants.

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.

The common pistachio psyllid (CPP: Agonoscena pistaciae) is the key pest of pistachio orchards in Iran. At the moment, insecticides despite their known adverse effects on human health and environment, are the only and the last option for controlling CPP in most cases. However, selection pressure of insecticides has resulted in establishing highly resistant populations of CPP. Nowadays, volatile organic compounds (VOCs) of plants presenting opportunities for sustainable plant protection. In this regard, VOCs of pistachio trees (Ohadi and Kaleh ghoochi cultivars) were collected by headspace method in the pistachio orchards and identified chromatographically (GC–MS). VOCs, including monoterpenes, esters, acids, alcohols, aldehydes, and aromatics, were identified in both cultivars, numbering 43 in the Ohadi cultivar and 37 in the Kaleh ghoochi. The quantitatively dominant constituents were (E)-β-Ocimene (32.5%), limonene (14.8%) and methyl benzoate (12.1%) in the Ohadi cultivar and (E)-β-Ocimene (29.2%), limonene (20.1%) and α-Thujene (6.6%) in the Kaleh ghoochi. To study whether olfactory cues elicit responses in adult CPP, the odor of pistachio leaves (Ohadi cultivar) were offered in a Y-tube olfactometer to field-collected populations. Significant positive responses to volatiles of leaves were found in both males (P<0.03) and females (P<0.001). These data may be useful in semiochemically-based management strategies in the pistachio orchards such as mass trapping or deter of CPP or attraction of natural enemies.

The predatory bug, Nesidiocoris tenuis is an effective biocontrol agent against Tuta absoluta and Trialeurodes vaporariorum in tomato greenhouses. The life table parameters of the predator were compared using Ephestia kuehniella and T. absoluta eggs on tomato leaflets under laboratory conditions. The data analysis was performed using age–stage two-sex life-table theory. The mean premature periods of the predator were 24.15 ± 0.23 and 29.58 ± 0.47 days feeding on E. kuehniella and T. absoluta eggs, respectively. Furthermore, the female and male longevities were 46.58 ± 3.9, 42.64 ± 4.17 and 47.39±0.72, 43.62±0.73 days on the above-mentioned eggs, respectively. Total fecundity of N. tenuis feeding on E. kuehniella and T. absoluta eggs was 79.08 ± 14.91 and 66 ± 3.53 eggs/female, respectively. Eventually, the population growth parameters were estimated: intrinsic rate of increase (r) 0.078 ± 0.009 and 0.084 ± 0.006 day-1, finite rate of increase (λ) 1.082 ± 0.01 and 1.087 ± 0.006 day-1, net reproductive rate (R0) 17.88 ± 5.55 and 22.42 ± 4.46 offspring/individual, gross reproductive rate (GRR) 66.41 ± 17.91 and 56.85 ± 6.62 offspring/individual, and mean generation time (T) 36.10 ± 1.04 and 37.24 ± 0.70 days, on the respective prey. However, there was not any significant difference between predators reared on E. kuehniella and T. absoluta eggs considering demographic parameters. In an applied conclusion, N. tenuis can be mass reared on E. kuehniella eggs and then be released against T. absoluta, especially in greenhouse environments, without any concern over possible decline on its demographic potential.

Induced defense responses of a plant to herbivory can influence interactions of that plant with subsequent organisms that use it as a food source. In this study, we conducted several experiments in order to understand whether preference and performance of Trialeurodes vaporariorum, Tetranychus urticae, and Aphis gossypii are affected by the previous herbivory of conspecific on the cucumber plant; and whether these effects are local or systemic. Longevity, fecundity, and pre-imaginal development period were measured as performance criteria. About A. gossypii; longevity andfecundity, about of T. urticae; fecundity and pre-imaginal development period, and about T. vaporariorum fecundity negatively affected by the previous herbivory of conspecifics. Results indicated that herbivory of these pests can induce resistance in cucumber, and can affect preference and performance of conspecifics. Results of performance experiments variedfrom negative to neutral depending on the performance criteria and the studied level (local or systemic). No positive effect was observed in studied interactions. According to results, all three herbivores tested here were able to induce resistance in cucumber and affect the preference of conspecifics. However, whitefly was unable to detect the previous herbivory of conspecifics, although these plants negatively affected whiteflies. According to results of preference experiments, it can be concluded that T. urticae was much more accurate than others at detection of the induced plants. Effect of induced defense on herbivore performance is not always aligned with the preference of the herbivore. Conducting both performance and preference experiments not only revealed the effect of induction of plant defense, but also showed the sensitivity of the herbivore at detection of changes in plant and ability to choose the appropriate host.

Thrips are important greenhouse pest that cause transmitting viruses in addition to direct damage. Functional response is an important factor in selection of natural enemies for the biological control of pests. The general predator Amblyseius swirskii and entomopathogenic fungus are the most important natural enemies of western flower thrips (WFT) Frankliniella occidentalis in most area. The functional response of the predatory mite, A. swirskii was examined on either untreated or Beauveria bassiana (isolate JEF-007) treated larvae of the WFT after three time intervals: 0, 24 and 36-h treatments. The functional response were studied in the laboratory condition (25±1 ºC, 70±10 % RH and photoperiod of 16:8 h (L: D)), and densities of 2, 4, 6, 8, 10, 12, 16 and 20 larvae per Petri dish, over 24h. The data were good fit to Rogers-II functional response model for all of untreated and B. bassiana-treated insects. Comparisons of the results of functional response parameters in different treatments indicated that the handling time on western flower trips 24 hours after infection had significantly different with the control but there were no significantly different among treatments control, 0 hour after infection and 36 hour after infection of the fungus.

Ephestia kuehniella eggs are among protein rich sources for mass production of the predator Nesidiocoris tenuis. It has been used as an alternative prey for the predator establishment in the tomato greenhouses. Comparing the predation rate of N. tenuis on E. kuehniella and Tuta absoluta eggs, a factorial experiment based on completely randomized design (CRD) was conducted and performed under laboratory conditions. Results indicated that predator sex and prey species significantly affected the rate of predation. The predation values of the female predatory on E. kuehniella and T. absolutaeggs were 58±4.83 and 77.50±4.83, respectively, showing a significant difference (P

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hem., Aleyrodidae) is a cosmopolitan and polyphagous insect that attack a wide range of crops. In this study, the biological parameters of parasitoid wasp, Eretmocerus delhiensis Mani (Hym., Aphelinidae) on T. vaporariorum were evaluated. The experiments were conducted at 25±1°C, 65±5% RH and a photoperiod of 16: 8 h (L: D) in growth chamber. Based on the results of our studies, all of parasitoid progeny were female and there was no male progeny. Adult emergence, pre-oviposition, oviposition and post-oviposition period, developmental time and longevity of female parasitoid were 71 %, 15.03±0.32, 0.46±0.06, 4.2±0.12, 1.04±0.08, and 5.71±0.13 and 20.74±0.5 days, respectively. Also, other parameters such as; daily fecundity, total fecundity, daily host feeding, and total host feeding were 3.04±0.11 and 17.43±0.17 eggs 1.07±0.05, and 6.40±0.35 nymphs, respectively. Regression analysis revealed that host feeding had a significant effect on oviposition of this parasitoid. Therefore, the parasitoid wasp E. delhiensis not only parasitize their hosts but also kill them through host feeding. These results suggest E. delhiensis has the potential to be used as a biological control agent in greenhouse whitefly management.

In this study the effects of natural grain-based media on the sporulation and germination of conidia and blastospores of Metarhizium anisopliae were investigated. Experiments were conducted with factorial arrangement in a completely randomized design with nine treatments and three replications. The obtained results showed that there was significant difference in the yield of conidia among different treatnents, two weeks after inoculation, (F= 4.66, df= 7, 16, p

Greenhouse whitefly and two-spotted spider mite are two important pests on greenhouse crops. The polyphagous predatory mite Amblyseius swirskii preys on both of these pests. In this research, predation of the predatory mite on different stages of both pests, prey stage preference of pests, prey preference and switching behavior of predator between preferred stage of greenhouse whitefly and two-spotted spider mite were investigated in laboratory conditions (25 ± 1°C, 70 ± 10% RH and 16L: 8D hour photoperiod). The preference index for each experiment was calculated by Manly’s β index. Results showed that, young instars (first and second instars) of greenhouse whitefly and non-sessile stages of spider mites (larvae, protonymph and deuonymph) were preferred stages. Comparison of the mean preference index between young instars of greenhouse whitefly and protonymphs of two-spotted spider mite showed that this predator showed a significant preference to T. urticae. The variation in different ratio of preys had no effect on predatory mite preference so switching didn’t observed in A. swirskii.

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hem.: Aleyrodidae) is a polyphagous and key pest that causes damaging to wide range of crops. The parasitoid wasp, Eretmocerus delhiensis Mani (Hym.: Aphelinidae) is a syn-ovigenic and thelytokous species that parasitizing greenhouse whitefly nymphs. In order to evaluation parasitoid wasp, Eretmocerus delhiensis Mani (Hym.: Aphelinidae) in control of greenhouse whitefly demography parameters of E. delhiensis on greenhouse whitefly on tomato cultivar Super-Chief at temperature 25±1°C, 65±5 % RH and a photoperiod 16:8 h (L: D) in growth chamber were studied. For calculation of population growth parameters Age- Stage, Two-Sex Life table was used. The result showed that oviposition period, longevity and fecundity for this parasitoid were 4.2±0.12 d, 20.74±0.5 d and 17.43±0.17 offspring respectively. Based on results of the life table, demography parameters consisting of net reproductive rate (R0), gross reproductive rate (GRR) were 12.11±0.94 and 31.43±1.85 offspring per female, intrinsic rate of increase (rm), finite rate of increase (λ), were 0.16±0.0059 d-1, 1.17±.007 d-1 and mean generation time (T) and doubling time (DT) of E. delhiensis were 15.66 d and 4.354/d respectively. Based on our results, this parasitoid is a promising candidate for greenhouse whitefly control.

Diamondback moth, Plutella xylostella (L.) (Lep.: Plutellidae), is the most destructive insect pest of cruciferous crops throughout the world. Crucifer production has been seriously affected by developing resistance of P. xylostella populations to a wide range of insecticides. In population studies, the knowledge of herbivore's population growth on different host plants is of prime importance. In the present study, the influence of host-plant species including rapeseed cv. Okapi, cauliflower cv. Arizona and Chinese cabbage cv. Hero on P. xylostella life-history parameters was studied in the laboratory condition (25±1°C, 70±10% RH and 16L:8D h photoperiods). The parameters longevity, the intrinsic rate of natural increase (rm), net reproductive rate (R0), mean generation time (T) and finite rate of increase (λ) were measured on these host plants. Differences between host plants for fertility life table’s parameters were analyzed using the Birch and Jack-knife methods. The results showed that there were significant differences for the studied parameters between host plants. The lowest and highest rate of P. xylostella regeneration occurred on rapeseed (63.67(♀♀/♀/generation)) and Chinese cabbage (86.08(♀♀/♀/generation)), respectively. Generation period of P. xylostella on rapeseed and Chinese cabbage was estimated 23.78 and 18.1 days, respectively. The lowest rate of finite population increase was obtained on rapeseed, 1.191(♀♀/♀/day), and the highest on Chinese cabbage, 1.279(♀♀/♀/day). The maximum and minimum time needed for doubling P. xylostella population were found on rapeseed (3.965 days) and Chinese cabbage (2.814 days). The highest and lowest intrinsic rates of population were on Chinese cabbage and rapeseed with 0.246 and 0.174 (♀♀/♀/day), respectively.

Germ-line transformation of insects is now widely used for analyzing gene function and for the development of genetically modified strains for various purposes. There is not enough information on the embryonic development of some brain parts in insects. In order to study the genetic control of embryonic brain development, we established some transgenic lines to identify some genes involved in embryonic brain development. The genome has been sequenced and transgenic approaches are established for this model organism. Transposable element piggyBac was used as a vector for the transformation of T. castaneum. Tc-vermilion line- a Tribolium eye-color mutant- was also used for the microinjection of the donor vector. The donor vector contained the Tc-vermilion gene under the control of 3xP3 promoter, resulting in black eyes as a marker of their identity. In the present study, several transgenic lines bearing the regulatory regions of some importantgenes were generated. Additionally, transgenic lines for tracing of neuroblast development from the onset to the respective fully developed structure in the brain were established. Taken together, valuable tools which allow investigations of the complex genetic network needed for embryonic brain development in T. castaneum were established.Furthermore, the system will allow identification of genes and their functions in Tribolium brain formation.