Among insect pests infesting stored dates, Plodia interpunctella Hubner (Lepidoptera: Pyralidae) is highly destructive in packinghouses or storages, leading to substantial losses. This study assessed the nutritional performances, digestive enzymes activity, and energy reserves of P. interpunctella larvae fed on various date fruits, including Dayri, Estemaran, Fersi, Halavi, and Zahedi varieties. Additionally, date fruits were analyzed to ascertain their secondary metabolite contents. Food digestibility (AD) showed a negative correlation with the efficiency of conversion of ingested (ECI) and digested food (ECD). Conversely, positive correlations were identified between food digestibility and relative growth (RGR), consumption rate (RCR), food consumed, and larval and pupal weight. The lowest RGR and RCR values were noted in P. interpunctella larvae fed on Estemaran and Fersi varieties, indicating the reduced suitability of these host plants for larval development. According to our findings, larvae fed on the Zahedi variety exhibited the highest larval, frass, and pupal weight, as well as food consumption. The lowest amylolytic and proteolytic activity was observed in P. interpunctella larvae fed on the Estemaran variety. Amylolytic activity in P. interpunctella showed a positive correlation with protein and glycogen contents, while a significant positive correlation was found between proteolytic activity and larval protein content. The low protein content in larvae fed on the Estemaran variety suggests its unsuitability for P. interpunctella feeding and growth. Conversely, the Dayri variety had the lowest phenolic content, indicating its suitability for larval development.

In this study life table parameters and predation activity of E. scutalis on a diet of T. turkestani were studied before the supply of Typha pollen (G0) and, after 10 (G10), 20 (G20), and 30 (G30) generations of being reared on cattail pollen (Typha latifolia L.). Our results showed that the longer the rearing of E. scutalis on cattail pollen before switching to T. turkestani, the most impact it had on the developmental duration of the predatory mite. The female adult longevity was the highest in G0. In the older generations (G20 and G30), adult pre-oviposition period (APOP) was shorter than in younger generations (G10). The adult females of G0 had the longest oviposition days. The intrinsic rate of increase (r) and finite rate of increase (λ) of E. scutalis were highest in G20. There was no significant difference in the parameters R0, r, λ, and T (mean generation time) before and after thirty generations of rearing on cattail pollen when exposed to T. turkestani. The proportion of male progeny produced by this predator was higher than that of females during both the early and late ages of the oviposition period. The predation rate of E. scutalis was not affected by the time of rearing on cattail pollen before switching to T. turkestani. Euseius scutalis consumed an average of 435.93 T. turkestani over its lifetime before the predator was reared on cattail pollen. This predation rate did not differ significantly after ten and thirty generations passed on a diet of Typha pollen. Overall, the findings of the current study indicated that E. scutalis long-term reared on cattail pollen could be a good candidate as a profitable predator on plants infested with T. turkestani.

Abstract Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is a polyphagous insect pest that causes serious damage to various food crops in storage. This study aimed to investigate the life-history and demographic parameters of P. interpunctella on 5 varieties of date palm fruits (Phoenix dactylifera L.), including Dayri, Estemaran, Fersi, Halavi, and Zahedi under laboratory conditions. Data were analyzed and compared using the age–stage, 2-sex life table. Plodia interpunctella completed its development on all date varieties. The shortest and longest pre-adult periods were recorded on Zahedi (38.47 days) and Estemaran (44.65 days) varieties, respectively. The net reproductive rates (R0) were 82.51, 59.05, 63.61, 102.27, and 114.86 offspring on Dayri, Estemaran, Fersi, Halavi, and Zahedi varieties, respectively. The intrinsic rate of increase (r) were 0.098, 0.085, 0.089, 0.109, and 0.113 day−1 on Dayri, Estemaran, Fersi, Halavi, and Zahedi varieties, respectively. The female fecundity ranged from 133.4 to 259.24 eggs on Estemaran and Zahedi varieties, respectively. The highest mean generation time (T) was obtained on Estemaran (47.984 days), and the lowest value of this parameter was obtained on Zahedi (41.722 days) variety. The results indicated that Zahedi and Halavi varieties were the susceptible hosts for P. interpunctella. In contrast, the Estemaran and Fersi were the most resistant varieties against P. interpunctella, which can be used for integrated management programs to decrease the damage of this pest.

Sugarcane yellow mite, Oligonychus sacchari McGregor (Acari: Tetranychidae), is one of the most important sugarcane pests in Khuzestan province, southwest Iran. This mite directly damages leaf cells by sucking chloroplasts and weakens the plant. In this study, the effects of two sugarcane by-products including molasses, vinasse, and a commercial formulation, Bino2 were investigated against O. sacchari on sugarcane, varieties CP69-1062 and CP57-614, under field conditions. Population densities of different life stages of the mite including eggs, nymphs, and adults were recorded immediately after the application and 3, 7, 10, 14, 21, and 28 days after spraying. The results showed that the population density of different life stages of mite decreased over time after foliar application. The sugarcane molasses showed the most significant effect in controlling the population of the pest. After that, vinasse and Bino2 had appropriate acaricidal potential compared to the control. For the CP69-1062 variety, the mean population density of mites in the control treatment was 55 per leaf, and in molasses, vinasse, and Bino2 treatments was 6.48, 26.7, and 15.48 per leaf, respectively. For the CP57-614 variety, the mean population density in the control treatment was 75 per leaf, and in the molasses, vinasse, and Bino2 treatments was 5.88, 28.77, and 22.59, respectively. The highest amount of Brix, Pol, and Purity in two varieties CP69-1062 and CP57-614 was related to the molasses-treated plots. The molasses, vinasse, and Bino2 have appropriate acaricidal potential and can be used in sugarcane yellow mite management programs. However, more studies are required to confirm the findings.

The predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is produced commercially for biological control of insects and mites on crop plants around the world. The aim of this study was to compare the effects of a diet of natural prey, Tetranychus turkestani Ugarov and Nikolskii (Acari: Tetranychidae), date palm pollen, or bee-collected pollen on A. swirskii development, reproduction, and life table parameters. Completely randomized, no-choice experiments were conducted in replicated experimental units, i.e., 3 x 3 cm plastic sheets inside Petri dishes. A life table analysis was also conducted. Results indicated that diet type did not affect A. swirskii preimaginal survival; it ranged from 97-100% on T. turkestani and both pollen diets. However, total development time was significantly shorter for A. swirskii females fed date palm pollen than T. turkestani or bee pollen. Adult females fed T. turkestani lived longer, had longer oviposition periods, and produced more eggs. The intrinsic rate of natural increase (0.396 d-1) was higher for A. swirskii fed date palm pollen than T. turkestani or bee pollen. The finite rate of increase, net reproductive rate, and gross reproductive rate did not differ significantly between A. swirskii fed date palm pollen or T. turkestani. Mean generation time (7.56 d) and population doubling time (1.043 d) were shorter for A. swirskii fed date palm pollen than T. turkestani or bee pollen. This study suggests that the T. turkestani diet or date palm pollen diet is suitable for A. swirskii. Date palm pollen has great potential as a cost effective diet to mass produce A. swirskii in the absence of natural prey. Future research could determine whether long-term rearing on date palm pollen reduces the ability of A. swirskii to locate, capture, and consume T. turkestani or other Tetranychus species on crop plants.

The tetranychid Tetranychus turkestani Ugarov and Nikolskii is a serious pest of many important crops around the world. Management of T. turkestani by augmentative biological control using predators such as the phytoseiid Amblyseius swirskii (Athias-Henriot) is envisioned as an environmentally safe alternative to acaricides. Foundational knowledge on T. turkestani – A. swirskii interactions in the laboratory are necessary to predict the outcome of A. swirskii augmentative releases in the field. In this study, the functional and numerical responses of adult A. swirskii females feeding on immature stages of T. turkestani were determined in the laboratory. Prey densities were 2, 4, 8, 16, 32, 64, or 128 individuals per Petri dish arena. The functional response of A. swirskii to prey showed a Holling's type II response. The attack rate and handling time estimates from the random predator equation were 0.1148/h and 0.3146 h, respectively, indicating that A. swirskii consumed 76.28 individuals per day at the maximum level. The number of eggs laid by the predator, i.e., the numerical response, increased as host density increased up to a maximum of 33.10 eggs per female; then oviposition rate leveled-off. This study suggests that A. swirskii is a suitable candidate for augmentative biological control of T. turkestani but follow-up experiments in greenhouses or open fields are necessary.

Oryctes elegans Perll is one of the most important pests of date palm trees. The present study was done to determine the probable role of this pest as a vector of Fusarium wilt disease in date orchards of Khuzestan province. Leaf wilt disease is one of the important diseases observed in date orchards of Khuzestan. Sampling was carried out from 24 date orchards in Abadan, Khorramshahr and Shadegan, which showed simultaneous infestation by O. elegans and fungal leaf wilt diseases. The collected samples included larvae and beetles of the date palm borer, leaves, petioles and fruit bunches of the tress. Fusarium proliferatum Matsush was isolated from collected samples with different percentages. To determine the disease transferring ability of the beetles, the experiments were carried out based on randomized complete design experiment with factorial test. Four densities; 3, 5, 7 and 9 of the beetles and four concentrations of the fungal suspensions 5×103, 5×104, 5×105 and 5×106 spores per ml were used. The frequency of isolated fungi from the insect specimens and plant materials confirmed transmission of fungus by the date palm borer. The results showed a positive and significant correlation between infested trees with Fusarium wilt disease and date palm borer. The pathogenicity test showed that insects in all four densities and all four concentrations were able to transfer the fungus and disease and in the densities of 7 beetles with 5×106 spores per ml and 9 beetles with 5×105 and 5×106 spores per ml caused drying of offshoots.

Background and objective Date palm Phoenix dactylifera L. is one of the income sources of cultural and economic importance in several countries. Leaf wilt disease is one of the important diseases observed in palm gardens in Khuzestan province. Disease symptoms are observed as asymmetrical leaves drying. Fusarium proliferatum is a common pathogen infecting numerous crops, including banana, carnation, cycads, date palm, garlic, mango, maize, onion, rice, and sesame plants. Materials and Methods To identify the causal agent(s), infected samples were collected from Abadan, Khorramshahr, and Shadegan cities and transferred to the laboratory. The samples were then disinfected and cultured on potato dextrose agar (PDA) plates. Fungi were purified by the single-spore technique. For molecular identification, the colonies were inoculated in potato-dextrose broth (PDB) and the grown mycelium mass was used for DNA extraction. Polymerase chain reaction was done with reaction initiators of Tef171F and Tef1997R to replicate a part of the tef1 region. Results BLAST search showed that the sequence of the studied isolate was 99.55% similar to both the confirmed isolate and the reference of F. proliferatum strain TOR-55. Phylogenetic analysis of the isolate with sequences related to type strains, using the maximum likelihood, confirmed that they belonged to this species. Pathogenicity test was followed by re-isolation from the inoculated plants. Discussion These results indicated that all four concentrations were able to infect trees and cause disease symptoms and pathogenicity. However, disease severity was higher at 5×105 and 5×106 spores per ml than the other concentrations of spores used here. The second two concentrations of spores were more effective in drying of leaflets and leaves.

The effects of temperature on demographic parameters of the aphid parasitoid, Aphidius matricariae (Haliday), on lettuce aphid, Nasonovia ribisnigri Mosely, were studied at five constant temperatures, 15, 20, 22, 25 and 27 ± 1°C, 65 ± 5% RH and a photoperiod of 16L: 8D h. The life table parameters were estimated using age-stage, two-sex life table procedure. Moreover, the bootstrap method was used for estimating variance, mean and standard error of the population growth parameters, at studied temperatures. All estimated parameters were considerably affected by temperature. Accordingly, nymphs of N. ribisnigri could not settle and survive on the leaves at 27°C. Thus, mummies were not formed. Developmental time of the parasitoid wasp decreased with increasing temperature from 21.21 days at 15°C to 11.19 days at 25°C. The oviposition periods were 15.21±0.12, 9.47±0.10, 5.91±0.05 and 5.6±0.09 days at the temperatures of 15, 20, 22 and 25°C. Similarly, average number of mummies was 249.74±12.6, 192.72±12.8, 105.15±6.2 and 102.3±7.0, at the mentioned temperatures, respectively. The highest intrinsic rate of increase (r) and finite rate of increase (λ) were estimated to be 0.251 and 1.285 (d) at 20°C, respectively. However, there was no significant difference among the estimated values regarding intrinsic rate of increase and finite rate of increase at the temperatures of 20, 22 and 25°C. The highest value of net reproductive rate (R0) was 123.06 (offspring/individual) at 15°C and the shortest mean generation time (T) was 13.98 (day) at 25°C. According to the obtained results, the temperatures 20-25°C, can be considered as optimal temperature range for the biological control of the currant lettuce aphid by using A. matricariae.

Background and objectives The cotton aphid, Aphis gossypii, is an important pest on greenhouse crops such as the cucumber. Natural enemies have often been used successfully to control greenhouse pests. Among different pests, aphids because of their high reproductive rate are particularly difficult to control biologically. Materials and Methods In this study, the effects of separate and simultaneous application of the parasitoid wasp Lysiphlebus fabarum and the predator ladybird beetle Hippodamia variegata were studied to control A. gossypii on cucumber as an integrated pest management program. The replicates (n= 10) in all treatments included 10 cucumber plants in separate pots and were infected with five winged A. gossypii placed in a cage with a banker plant system of Vicia fabae-Aphis fabae. With the introduction of mummified aphids on a bean shoot (every two days), a pair of male and female adult ladybird beetles (every three days) or simultaneous application of both biocontrol agents, the numbers of aphids were counted in the three treatments. Results The results revealed that the parasitoid wasp L. fabarum alone was unable to control A. gossypii, but H. variegata performed better. The best performance was observed for simultaneous application of both biocontrol agents. Moreover, in the combined agents’ treatment, the number of A. gossypii on the both lower and upper cucumber leaves was not significantly different compare to other treatments that biological agentswere used seperatly. The number of mummified aphids did not differ between treatments at the end of the experiments. This is indicative of the tendency for ladybird beetles to feed on different growth stages of non-parasitized aphids compare to parasitized aphids containing immature stages of L. fabarum. Discussion The results indicate thatthe simultaneous application of both biocontrol agents is effective for the control of A. gossypii, although more research under greenhouse condition is needed.

The minute pirate bugs (Hemiptera: Anthocoridae) are an important group of natural enemies for biological control of many pests such as aphids, whiteflies, thrips, and spider mites. In this study, biodiversity of anthocorid bugs was studied in three geographical localities of Lorestan province (Khoramabad, Veisian, and Borujerd) during March 2014 to June 2016. A total of seven species, including Anthocoris pilosus (Jakolev‚ 1877), Orius albidipennis (Reuter, 1884), Orius laevigatus (Fieber, 1860), Orius minutus (Linnaeus, 1758), Orius niger (Wolff, 1811), Orius pallidicornis (Reuter, 1884) and Orius vicinus (Ribaut, 1923) were identified. We calculated the Shannon-Wiener index as 1.197, 0.939, and 0.898, the Simpson's index as 2.96, 1.75, and 1.75, and the Margalef's index as 0.66, 0.85, and 0.88 for anthocorid communities in Khoramabad, Veisian, and Borujerd, respectively. The biodiversity indices varied significantly in different seasons. The highest and the lowest diversity and abundance were recorded in summer and winter, respectively. The diversity indices were not statistically different between intensified (crop fields and orchards) and natural (rangelands and forests) habitats, though bugs in intensified habitats tended to have higher frequency and diversity than natural habitats. This study may provide useful information about species frequency and biodiversity of anthocorid bugs in Lorestan province.

The sugarcane stem borer, Sesamia cretica Lederer, is one of the most economically important pests of sugarcane in Khuzestan province, southwest Iran. The egg parasitoid Telenomus busseolae Gahan significantly affect S. cretica population in the field. Host age is an important factor of host acceptance and suitability for egg parasitoids. We examined the ability of T. busseolae to parasitize and develop in S. cretica eggs of different ages. In a no choice laboratory experiment, we measured the effect of host age (12, 36, or 60h old) on parasitism rate and offspring fitness characteristics such as survival, development time, sex ratio, size, and progeny longevity and fecundity. Results revealed that the suitability of host eggs decreased as host age increased. Exposure of parasitoids to 12h old eggs resulted in higher percentage parasitism, higher acceptance, higher survival and larger body size of parasitoid progeny. Progeny that emerged from 12h old eggs had also higher longevity and fecundity than those emerged from other host ages tested.

1. The fitness impacts of two levels of superparasitism were compared in a sexual and an asexual strain of Lysiphlebus fabarum (Marshall) developing in black bean aphids.2. Asexual females were larger than sexuals, had higher eggs loads, and better adult emergence in two of three treatments, but parasitised fewer available aphids in 24 h (80% fewer when foraging alone).3. Superparasitism resulted in wasps that were larger than those emerging from singly parasitised aphids, and asexual females had larger ovaries, without delayed development. In contrast, sexual wasps took about 2 days longer to develop in superparasitised hosts, and females had smaller ovaries with lower egg loads.4. The growth of host aphids bearing asexual larvae was not reduced relative to healthy aphids, except when heavily superparasitised, whereas sexual larvae reduced aphid growth in all treatments.5. Elimination of supernumerary larvae was virtually complete at 4.5 days after parasitism by sexual females, but no elimination occurred among asexual larvae. The evolution of diminished aggression in asexual larvae may be facilitated by greater genetic similarity, without necessarily leading to gregarious development, assuming the extended life of supernumeraries somehow improves survivor fitness.6. Sons of virgin sexual females developed faster than sons of mated females, implicating parental effects that slowed development of the latter.7. It is concluded that asexual females of this strain use superparasitism to improve host quality, and thus the fitness of their daughters, whereas females of the sexual strain prioritise offspring number.

As an agricultural modernization, gamma irradiation is an important method for enhancing crop yield and quality. Nevertheless, its use can alter other plant traits such as nutrition and resistance to different biotic/abiotic stresses that consequently affect plant–insect interactions. A tritrophic system was utilized based on two canola mutant lines produced through gamma irradiation (RGS 8–1 and Talaye 8–3). Plutella xylostella (L.), as a worldwide pest of Brassicaceae and Cotesia vestalis (Holiday) as a key biocontrol agent of P. xylostella were examined for the potential indirect effects of canola seed irradiation on the experimental insects’ performance when acting on the respective mutant lines. This study showed that physical mutation did not affect plant nitrogen and herbivore-damaged total phenolics; however, phenolic compounds showed greater concentration in damaged leaves than undamaged leaves of both mutant and control plants. The relative growth rate and pupal weight of P. xylostella reared on RGS 8–1 were significantly higher than those reared on the control RGS. There was no significant difference by performance parameters of the parasitoid, C. vestalis, including total pre-oviposition period, adult longevity, adult fresh body weight of males and females, pupal weight, forewing area, and total longevity of both sexes on tested canola cultivars in comparison with their mutant lines. Life table parameters of C. vestalis on mutant lines of both cultivars, RGS and Talaye, were not significantly different from their control treatments. Comprehensive studies should be conducted to find out the mechanisms under which gamma rays affect plant–insect interactions.

Introduction: Lysiphlebus fabarum Marshall (Hymenoptera: Braconidae: Aphidiinae) is a common aphidiine parasitoid in central Europe, where it attacks more than 70 species of aphids. Although both unisexual (thelytokous) and bisexual (arrhenotokous) strains of L. fabarum have been reported in Iran, the former appear to be more widely distributed. Aphid control in Iran relies heavily on pesticides in both field and greenhouse settings, whereas any availability of new biological control agents such as L. fabarum would likely aid in reducing pesticide use. One of the most important aspects of implementing a parasitoid as a biological control agent is to determine the best density of parasitoid in the host access, in mass rearing. Parasitoid wasps display a wide array of strategies to dispose of host resources. Superparasitism is parasitism of a host by parasitoids of the same species. In solitary parasitoids, superparasitism almost occurs when hosts are limited or parasitoid density in a patch is high. Acceptance or rejection of a host usually depends on a female parasitoid’s ability to distinguish parasitized and unparasitized hosts. Previously, superparasitism was thought to be a maladaptive strategy, wasteful of both eggs and time, while it is now recognized as adaptive in a number of situations, e.g. under conditions of low host availability, as a mechanism for overwhelming the immune response of hosts. Materials and Methods: In the present study, stock colonies of the unisexual and bisexual strains of the parasitoid were established from materials collected from Zanjan province and Khuzestan province fields, respectively. Both populations of the parasitoid were collected from parasitized black bean aphids feeding on the broad bean, Vicia fabae L. A stock colony of black bean aphids was established with material collected from bean fields in Khuzestan province. The synchronous cohorts of both strains of L. fabarum were produced at 21±1 ºC, 50–60% r.h., and L14:D10 photoperiod, and then introduced (one day old) separately into 40 2nd instar nymphs in different densities (1, 5, 10, 15 and 30). The females were removed after 24 hours and parasitized aphids were dissected three days after parasitism to determine the number of wasp larvae in each host. As well as, in another experiment the super parasitized aphids were dissected in three consecutive days (3.5, 4.5 and 5.5) to determine the process of competitors’ elimination. Results and Discussion: According to results, in both strains, wasp densities affected on parasitism rates. In the bisexual strain, females parasitized more aphids in 20 and 30 densities treatments than one density treatment, while this rate did not differ significantly between 1, 5, 10 and 15 densities treatments. In the unisexual strain, single females significantly parasitized fewer hosts than other treatments, but there was no difference between other densities treatments. When in each density, percentage parasitism was compared between two strains, in the density of one female, bisexual females parasitized significantly higher than unisexual ones, in contrast to the density of 30, which significantly more larvae were counted in hosts of the unisexual strain than bisexual ones. In other densities, there was no significant difference between two strains. In the second experiment, which the rate of superparasitism was compared in different densities, in bisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The number of larvae did not differ significantly between other densities treatments. In the unisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The most rate of superparasitism was observed in 20 and 30 density treatments. When in each density, the rate of superparasitism was compared between both strains, in 1, 5 and 10 densities, bisexual females superparasitism significantly higher than unisexual ones, in contrast to the density of 30 females, which significantly more larvae were counted in hosts of the unisexual strain than the hosts of bisexual ones. In association with the process of competitors’ elimination, bisexual strain larvae eliminated rival larvae over time (in three consecutive days, including days 3.5, 4.5 and 5.5), as the numbers of larvae were decreased in densities of 5, 20 and 30 females. While in unisexual strain, elimination of rival larvae was not observed over time. Conclusion: Wasp densities affected by parasitism rates and the rate of superparasitism in both strains. In mass rearing, the best density of wasps can be defined as the density that most available hosts are parasitized with a minimum of superparasitism, because superparasitism can depredate the time and eggs of female foragers. The results showed that densities of one and 5 females (for 40 individuals of 2nd instar nymphs) can be suggested as the proper densities of females in bisexual and unisexual strains, respectively. The results of this study can be useful in mass rearing and release of both L. fabarum strains.

Life history of insect herbivores is unclear after feeding on mutant lines of many crops. To shed light, demographic parameters of Plutella xylostella on three canola cultivars ("Zar", "RGS", "Talaye") and their physical mutation-derived lines ("Zar 9-9", "RGS 8-1", "RGS 10-2", "RGS 8-13" and "Talaye 8-3") were determined under greenhouse condition. Methods of life table including the female age specific life table and the age-stage, two-sex life table were applied. According to two-sex life table, there was no significant difference between demographic parameters of P. xylostella on "Talaye" and "Zar" in comparison with their mutant lines, but significant differences were observed between these parameters on mutant lines of "RGS". Having suitable cultural traits, "RGS 8-1" was more susceptible than the other two mutant lines and its control cultivar "RGS" in terms of population growth of the pest. According to the two-sex life table, the net reproductive rate (R-0), intrinsic rate of increase (r), and finite rate of increase (lambda) were the highest on RGS 8-1 (98.63 offspring per individual, 0.208 and 1.231 day(-1), respectively). Also, population projection showed the rapid growth of the pest on the latter line. There was a little difference between the same population parameters estimated by two methods of life table. Investigating some consequences of plant breeding using radiation techniques on insect fitness not only leads plant breeders to do more unfailing selections but also provides some enlightenment in pest management programs effectively when plantation of such crops is prioritized.

Nephus arcuatus Kapur is an important predator of Nipaecoccus viridis (Newstead), in citrus orchards of southwestern Iran. This study examined the feeding efficiency of all stages of N. arcuatus at different densities of N. viridis eggs by estimating their functional responses. First and 2nd instar larvae as well as adult males exhibited a type II functional response. Attack rate and handling time were estimated to be 0.2749 h−1 and 5.4252 h, respectively, for 1st instars, 0.5142 h−1 and 1.1995 h for 2nd instars, and 0.4726 h−1 and 0.7765 h for adult males. In contrast, 3rd and 4th instar larvae and adult females of N. arcuatus exhibited a type III functional response. Constant b and handling time were estimated to be 0.0142 and 0.4064 h for 3rd instars, respectively, 0.00660 and 0.1492 h for 4th instars, and 0.00859 and 0.2850 h for adult females. The functional response of these six developmental stages differed in handling time. Based on maximum predation rate, 4th instar larvae were the most predatory (160.9 eggs/d) followed by adult females (84.2 eggs/d). These findings suggest that N. arcuatus is a promising biocontrol agent of N. viridis eggs especially for 4th instar larvae and adult females.

Fumigant toxicity and persistence of asafetida, geranium, and walnut essential oils were investigated against adults of Rhyzopertha dominica (F.). The experiments were conducted at 28 +/- 2 degrees C, 65 +/- 5% RH in continuous darkness. Fumigant toxicity of the essential oils was higher in the empty glass vials than when wheat was treated with the oils. Asafetida oil was more toxic than the two other tested plant species. The essential oil of asafetida was persisted 7 days with 65.71h half-life time; while the half-life time of geranium and walnut essential oils was 43.39 and 49.37h, respectively. The present study suggests that asafetida oil may be potential use as stored products protectant.

In this study, the efficiency of essential oils from asafoetida, Ferula assa foetida L.,geranium, Pelargonium hortorum L.H. Bailey and walnut leaves, Juglans regia F. was investigated on nutritional indices of Rhyzopertha dominica (F.) adults. Wheat grains were treated with different concentrations of the oils. The nutritional indices: relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and feeding deterrence index (FDI) were measured at 28 ± 2 °C, 65 ± 5% R. H. in continuous darkness. RGR, RCR and ECI deceased as the concentration level was increased. While, FDI percent increased significantly as the concentration level increased. Asafoetida oil had the most efficiency on nutritional indices and 28.61 ppm of the oil was enough to decrease RGR, RCR and ECI% to 0.032 mg/mg/day, 0.444 mg/mg/day and 6.994%, respectively. FDI percent of adults exposed to 6.5 ppm of asafoetida oil was 13.31% which increased upto 64.62% at the concentration of 28.61 ppm. In the second experiment, the effect of tested essential oils was evaluated on F1 progeny reduction of R. dominica. Walnut and asafoetida leaves essential oils significantly suppressed progeny production by (59.92%) and (53.2%) respectively.