Pistachio Psylla Research Articles

Unveiling the insecticidal efficiency of Viola ignobilis against Macrosiphum rosae and Agonoscena pistaciae: From chemical composition to cytotoxicity analysis

Currently, there is a growing preference for eco-friendly bioinsecticides over chemical insecticides due to their safety. Plant extracts have emerged as a promising solution for this purpose. Therefore, this study aimed to evaluate the insecticidal effectiveness of Viola ignobilis extract against two key pests of rose aphid (Macrosiphum rosae) and pistachio psylla (Agonoscena pistaciae). Significant compounds were identified using GC-MS and MALDI-TOF MS. Three bioassay methods were employed to assess the extract's insecticidal potential, and its cytotoxicity was tested on HEK293 cells. Results revealed that the highest insecticidal efficacy occurred at a concentration of 20 mg/mL after a 72 h exposure. The contact bioassay method displayed greater efficiency against M. rosae than A. pistaciae, while the oral bioassay demonstrated the highest efficiency against A. pistaciae. The extract also acted as a feeding deterrent, with indices of 77.47 ± 7.98 % and 87.98 ± 3.84 % for A. pistaciae and M. rosae, respectively. Furthermore, the insecticidal potency of the extract was assessed, resulting in LC50 values of 3.58 mg/mL and 6.77 mg/mL for the contact bioassay, and 0.87 mg/mL and 0.61 mg/mL for the oral bioassay against M. rosae and A. pistaciae, respectively. Importantly, the extract showed no detrimental cytotoxic effects on the HEK293 cell line within the tested concentration range, indicating its potential safety as a bioinsecticide. Overall, these findings highlight the potential of V. ignobilis extract as a promising candidate for further development in pest control.

Diatomaceous earth foliar spraying along with adjuvants in pistachio orchards associated with the common pistachio psylla, Agonoscena pistaciae.

The common pistachio psylla, Agonoscena pistaciae, is a serious global pest menacing pistachio orchards. Considering the dangers of using excessive chemical pesticides, it seems that using natural insecticides such as diatomaceous earth is a suitable way to lower the residual amount of highly hazardous pesticides. In this study, the effects of diatomaceous earth with different additives, including dipotassium hydrogen phosphate, polyurethane glue as a wood adhesive, and potassium silicate, were investigated in several concentrations over two years in orchard conditions. Although all treatments showed significant effects, the most effective treatments were (diatomaceous earth+dipotassium hydrogen phosphate) and (diatomaceous earth+polyurethane glue). Therefore, the use of diatomaceous earth combined with the additive materials mentioned can potentially be a safe method for the integrated management of the common pistachio psylla.

Release of the lady beetle (Oenopia conglobata L.) to control the common pistachio psylla

Common pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer (Hemiptera: Psyllidae), is a major pest of pistachio trees in Turkey, which can be difficult to control due to insecticide resistance. This study evaluated augmentative releases of larvae and adults of lady beetle, Oenopia conglobata L. (Coleoptera: Coccinellidae) for biological control of the psylla at densities of 25, 50, or 100 adults or larvae per tree in two pistachio orchards located in Turkey during 2016 and 2017. The pest population never reached the economic threshold in trees where 50 or 100 larvae or adults were released, whereas it exceeded the economic threshold in all other treatments (control and 25 larvae or adults release), locations-years except for Gaziantep in 2017. Higher release rates (100 larvae or adults per tree) reduced pest density by >50% on average, with efficacy ranging from 20% to 88%. The results indicate that augmentative releases of O. conglobata can result in additional generations of the predator in pistachio orchards. Although no differences were noted between releases of larval and adult stages of O. conglobata, release of large numbers of larvae in similar stages of development poses logistical challenges, rendering mass release of adults a more feasible approach. In conclusion, release of 100 adults per tree could be an effective biological control option for managing A. pistaciae in pistachio orchards.

Evaluation of the effect of calcium and nano calcium on Agonoscena pistaciae (Hem.: Aphalaridae) in pistachio orchards

Calcium (Ca) is necessary for the construction of cell walls and a wide range of physiological activities in plants. In this study Ca nanoparticles were produced from a solution containing Ca Sulfate by solvothermal method and were investigated in relation to varying fertilization of macroscales and nanoparticles of Ca on one of the important pistachios pests, the common pistachio psylla, Agonoscena pistaciae, fed on pistachio saplings of Ahmadaghaei rootstock (20-year-old) in pistachio orchard. The population density of A. pistaciae was tested using complete randomized blocks with three replications and four treatments: Ca, nano-Ca, pesticide (acetamiprid), and control (distilled water). The results revealed that the influence of feeding solution on nymph and egg populations differed significantly at the % 1 level, with acetamiprid having the highest measure of control on eggs and Ca having the lowest. In addition, acetamiprid boosted nymph abundance whereas Ca lowered it.

Preharvest Application of Sulfur as Pesticide on Fresh Hull and Kernel of Pistachio (Pistacia vera L.)

In recent years, sulfur has been shown to be effective in controlling pistachio psylla. In this study, the effect of sulfur foliar application as psylla pesticide on fresh fruit and kernel of three cultivars of pistachio was determined and compared with two commercial pesticides. Refinery micronized and mineral sulfur were applied at two concentrations of 30 and 60 kg/1000 L of water. The quality of fresh pistachio hulls and kernels were investigated. In ‘Fandoghi’ cultivar, all sulfur treatments reduced the kernel moisture. The firmness and water activity of hulls and kernels were significantly affected. All sulfur treatments decreased hull lightness in ‘Fandoghi’, while it increased in ‘Akbari’ and ‘Ahmadaghaei’ cultivars. Reduction of hull chroma was observed in some cases in all cultivars. Hue of hulls was not affected by the treatments. Lightness, chroma and hue values of the testa of kernels were not affected in ‘Fandoghi’ and ‘Akbari’. In ‘Ahmadaghaei’, refinery micronized sulfur increased the testa lightness and hue and decreased chroma probably because of the softer texture of hull in ‘Ahmadaghaei’ which breaks more easily during harvest practice. Sulfur treatments positively influenced appearance and general acceptance of ‘Ahmadaghaei’ fruits. The taste and aroma of pistachios were preserved in most of treatments. High concentration (60 kg/1000 L) of both sulfur types enhanced the ethylene production in ‘Ahmadaghaei’ which was almost same as the unripe fruit because sulfur treatments reduced the percentage of unripe fruit. In ‘Ahmadaghaei’, refinery micronized sulfur treatments increased the respiration rate.

Salicylic Acid Induced Resistance in Drought-Stressed Pistachio Seedlings Influences Physiological Performance of Agonoscena pistaciae (Hemiptera: Aphalaridae).

Induced host plant resistance is a potential approach to insect and disease management. Salicylic acid (SA) acts as a signal molecule to induce resistance in plants against sap-sucking insects. The effects of salicylic acid-induced resistance against common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer, were investigated in well-watered and drought-stressed pistachio, Pistacia vera L. cv. Akbari, seedlings. Agonoscena pistaciae exhibited a significant preference for plants treated with SA as compared with untreated controls or those subjected to drought stress. Plants subjected to both drought stress and SA treatment were equivalently colonized as compared with control plants but were more attractive than those subjected to drought stress alone. Psyllid mortality increased on plants subjected to simultaneous drought stress and SA treatment as compared with controls. Salicylic acid treatment mediated production of defensive enzymes in plants, including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), guaiacol peroxidase (GPX) and polyphenol oxidase (PPO), as well as that of other metabolites such as phenol, malondialdehyde (MDA), H2O2, free amino acids, and pigments via phenylpropanoid pathways under conditions of drought. Despite increases in activity of detoxification (glutathione S transferase, carboxylesterase) and antioxidative (SOD, CAT, APX, phenoloxidase, GPX) enzymes in psyllids, reduced survival of A. pistaciae on drought stressed and SA-treated plants was likely caused by excessive H2O2 and high phenolic content in treated plants. Based on our results, we postulate that salicylic acid-induced defense against A. pistaciae under drought conditions could be manipulated to enhance antibiosis against this key pest in pistachio orchards.

Energetic costs of resistance in the Agonoscena pistaciae Burckhardt & Lauterer, 1989 (Hemiptera: Aphalaridae), against spirotetramat, acetamiprid and hexaflumuron

Abstract: The common pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer, 1989 (Hemiptera: Aphalaridae), is a key pest found in pistachio orchards in Iran. This pest has a high potential for developing resistance to insecticides due to its short life cycle and high reproductive potential. Intensive application of insecticides leads to excessive selection pressure followed by resistance to synthetic insecticides in some psylla populations. In this research, effects of four concentrations of three extensively used insecticides (spirotetramat, acetamiprid, and hexaflumuron) on energy resources (like sugar, lipid, glycogen, and protein contents), energy consumption, and cellular energy allocation were investigated in resistant and susceptible populations of the common pistachio psylla in the Kerman province of Iran. Energy resource contents in the susceptible population (133 331.2 mj/insect) were significantly more than in the resistant population (96 253.5 mj/insect), whereas energy consumption in the resistant population (38 630.4 mj energy/h/insect) was higher than in the susceptible population (31 276.8 mj energy/h/insect). Additionally, cellular energy allocation in the resistant population (2 400.9 mj energy/h/insect) was higher than in the susceptible population (2 126.13 mj energy/h/insect). Therefore, stress (especially toxicants) causes variations in metabolism, which influences the growth and reproduction of the pest.

Evaluation of effect of biorational insecticides on horticultural indices of the pistachio trees infested with the pistachio psylla, Agonoscena pistaciae

Field experiments were conducted during 2016–2017 on pistachio trees (Pistacia vera L., Anacardiaceae) in Kashan pistachio orchards to assess the effects of some insecticides on horticultural characteristics of the pistachio trees infested with the pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer. This research was conducted in the ten-year-old pistachio orchards (Akbari variety) of Kashan, Iran. The treatments were included palizin®, pistagaurd ®, kaolin (Surround®) 5%, kaolin 10%, movento® (registered chemical insecticide to compare) and control. Spraying was carried out three times a year, with one-month interval (4th of July, August and September). The results showed that in 2016, the effect of treatment in terms of twig length was significant. In terms of number of healthy buds was not significant and in terms of number of lost buds was highly significant. The number of unhealthy flower buds was positively affected by application of kaolin, pistaguard and palizin in 2016. However, no significant effect was recorded in 2017 for all tested pesticides. Kaolin 5 or 10%, was the only pesticide with positive effect on yield traits. These results provide support the potential use of this technology as an alternative pest management tool against pistachio psylla.

Determining the Efficiency of Mass Trapping of Yellow Sticky Traps in Different Wavelengths Agains Pistachio Psyllid in Siirt Province [Agonescena Pistaciae Burc. and Laut. (Hemiptera: Psyllidae)

This study was conducted in gardens contaminated with pistachio psylla in Siirt Province between 2007 and 2010. It has been found that pistachio psylla forms the highest populations in the pistachio gardens in the Central District of Siirt Province, and in particular, causes important damages in young leaves in mid-June and in the maturing period of fruits in mid- and late-August. Efficiency in certain counts of yellow sticky trap coded 1016 B, of which efficiency and attraction power are considered significant, was observed in the study. It was concluded in the study that these traps are important for reduction of the population of the pest in cases where the population is small. It was found that traps would provide positive contribution if combined with other methods of fight and used in 4 traps for each tree and 7-day periods of hanging.

Siirt İlinde Antepfıstığı Psillidi [Agonoscena pistaciae Burck. and Laut.) (Hemiptera: Aphalaridae)]'nın Yayılışı ve Populasyon Dinamiğinin Belirlenmesi

Bu çalışma 2015-2017 yıllarında Siirt İlinde Antepfıstığında zararlı Antepfıstığı psillidi [Agonoscena pistaciae Burck. and Laut.) (Hemiptera: Aphalaridae)]’nın yayılışı ve populasyon seyrini belirlemek amacıyla yürütülmüştür. Yayılış alanını belirlemek için Siirt İlinin Merkez, Aydınlar, Eruh, Kurtalan, Pervari, ve Şirvan ilçelerinde 24 köyde toplam 66 fıstık bahçesinde gözlem ve inceleme yapılmıştır. Zararlının popülasyon seyrini belirlemek için ise 2016-2017 yıllarında Siirt Merkez ilçede 4 bahçede çalışmalar yürütülmüştür. Yayılış alanını belirlemek için darbe yöntemi ve göz ile inceleme yöntemi, mimf ve yumurta yoğunluğunu belirlemek için ise göz ile inceleme yöntemi kullanılmıştır. Örneklemeler 1-2 haftalık aralıklarla yapılmıştır. Çalışma sonucunda A pistaciae tüm ilçelerde yayılış gösterdiği ve kontrol edilen tüm bahçelerin bulaşık olduğu belirlenmiştir. Kışlanmış erginler nisan ayının ortasında, ilk yumurtalar nisan ayının son haftasında ve birinci dönem nimflere ise nisan sonu mayıs başında belirlenmiştir. Kış geçirecek ergin formları eylül ayı ortasından itibaren görülmüştür. A pistaciae’nın ergin, nimf ve yumurta yoğunluğunun mayıs sonu ve haziran başında biraz arttığı, ancak ağustos sonlarından kasım ortalarına kadar ergin, nimf ve yumurta yoğunluğunun yüksek olduğu tespit edilmiştir. Birçok bahçede ekonomik zarar eşiğini aştığı görülmüştür. Mayıs sonu- haziran başı ve temmuz sonu-ağustos ortasından sonra yapılacak kontrollerde eğer bileşik yaprak başına 20-30 nimf tespit edilirse bir yada iki kimyasal uygulama yeterli olacaktır.

Functional response of Oenopia conglobata contaminata (Coleoptera:Coccinellidae) to Agonoscena pistaciae (Hemiptera: Psyllidae) at two different temperatures

Oenopia conglobata contaminata, is an important predator of the most important pistachio pest, Agonoscena pistaciae, in Iran. The functional response of the adult, third and fourth larval instars of O. conglobata contaminata fed on the common pistachio psylla, A. pistaciae, was studied at 22° and 25 °C (65 ± 5%RH and 16 L: 8D). Different psylla densities of 10, 20, 40, 80, and 160 were used. The data were fitted a type II functional response in all the stages. There was a significant difference in the attack rate and handling time of the predator in all stages at 22 °C and 25 °C. The maximum attack rate (T/Th) occurred at 25 °C. The lowest and highest attack rates were 0.046 and 0.154 for adult of the predator at 22 °C and 25 °C, respectively. The handling time decreased significantly as the temperature increased from 22 °C to 25 °C in all treatments. The results suggest that the efficiency of the Oenopia conglobata to control the pistachio psylla is high at 25 °C. On the other hand, the predatory beetle O. conglobata contaminata reacted to increasing temperature by enhanced search rate and activity.

Movento effects on learning and hippocampal brain-derived neurotrophic factor protein of adult male rats.

Spirotetramat is a toxic commercially known as Movento used to control pistachio psylla pests. In the present study, the effects of Movento on passive avoidance learning of rats and their ability to explore the novel object in the novel object recognition test were investigated. The changes in the concentration of hippocampal brain-derived neurotrophic factor (BDNF) proteins were evaluated, too. Male Wistar rats were gavaged at different dosages of the Movento (50, 100, 250, 500, 1000, 1250, and 1500 mg/kg) or saline for 7 days (administered every 2 days). We showed that Movento caused 50 and 100% mortality at the dose of 1250 and 1500 mg/kg, respectively. At the dose of 1000 mg/kg, Movento significantly decreased locomotor activity (P < 0.05). These rats also displayed a significant decrease in the number of training trials in the shuttle box and the ability to recognize a novel object compared with the control group (P < 0.01). The BDNF protein level of hippocampus also showed a significant decrease in the Movento (1000 mg/kg) compared with the control group (P < 0.01) while the number of pancellular necrosis pyramidal CA1 cells increased significantly in the Movento group (P < 0.001). We concluded that exposure to Movento can decline sensory, motor, and learning in rats.

Cold tolerance and supercooling points of two ladybird beetles (Col.: Coccinellidae): Impact of the diet

Ladybird beetles have successfully been used to control different pests. Cheilomenes sexmaculata (Fabricius) and Oenopia conglobata contaminata)Menetries((Coleoptera: Coccinellidae) are two dominant and efficient predators of the common pistachio psylla, Agonoscena pistaciae (Hem.: Psyllidae) in Iran. In the current study, the impact of two diets, i.e., nymphs of A. pistaciae and eggs of Ephestia kuehniella Zeller (Lep.: Pyralidae), were investigated on the cold hardiness, supercooling point (SCP), and lethal temperature of different life stages of the coccinellids. The results suggested that the eggs of E. kuehniella are a suitable diet for both predators. In general, beetles of O. conglobata contaminata were more cold tolerant than those of C. sexmaculata. The SCP of the adults of C. sexmaculata, feeding on psyllid was about −15 °C, whereas the SCP of the beetles, feeding on the eggs of flour moth, was about −19 °C. However, the diets had no significant effects on the SCP of O. conglobata contaminata. For both ladybird beetles, eggs were the most sensitive stage, and adulthood was the most tolerant developmental stage. No eggs survived at zero and subzero temperatures. The survival of C. sexmaculata increased from 6.25% for adults fed on psyllids to 13.75% for those fed on flour moth eggs after 24 h exposure to cold at −4 °C. The survival of O. conglobata contaminata adults after exposure to cold at −4 °C for 24 h raised from 28.75% for adults fed on psyllids to 42.50% for those fed on flour moth eggs. Regardless of the diet, both beetles were considered to be chill-intolerant insects as the most mortality occurred above the SCP.

Inferring Biological Control Potential of Adult Predatory Coccinellids Using Life History Traits and Putative Habitat Preference.

Aspects of the nutritional ecology and life histories of five predatory coccinellids (Coleoptera: Coccinellidae)-two arboreal predator species, Oenopia conglobata contaminata (Menetries) and Adalia bipunctata (Linnaeus), and three herbaceous dwelling predator species, Coccinella undecimpunctata aegyptica (Reiche), Exochomus nigripennis (Erichson), and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae)-were compared when fed either Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae), the key psylla pest of pistachio trees, or Aphis gossypii Glover (Hemiptera: Aphididae), a common aphid on herbaceous plants in pistachio orchards. The putative habitat preferences of four of the five coccinellids studied were consistent with their performance on the major herbivore present in those two habitats in terms of net reproductive rate. Oenopia conglobata contaminata and Ad. bipunctata showed higher net reproductive rates when fed on pistachio psylla prey, whereas C. undecimpunctata aegyptiaca and E. nigripennis had better reproductive output on aphid prey. Moreover, E. nigripennis was the most specialized of these generalist predators, eating more and reproducing better when fed aphids. Hippodamia variegata was relatively unaffected by the diet offered, suggesting greater ability to switch among herbivore prey and perhaps better potential as a biocontrol agent with abilities to exploit Ag. pistaciae without large life history tradeoffs.

Variation in Insecticidal Susceptibility of Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae), and its Coccinellid Predator, Oenopia conglobata L. (Coleoptera: Coccinellidae)

The common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer is a key pest throughout all pistachio producing regions of Iran. Pest management depends primarily on the application of chemical insecticides. The lack of compatibility between natural enemies and pesticides is the main concern to ecologists in the integrated management of psylla. The susceptibility of the fifth instar nymphs of A. pistaciae from five populations of the Kerman province and third instar larvae of the lady beetle species, Oenopia conglobata L., were examined against three commonly used insecticides: acetamiprid, spirotetramat and hexaflumuron, using the spraying tower method. Probit regression analysis was conducted on mortality data at various insecticide concentrations using the POLO-PLUS program to estimate LC50 values. Resistance ratio data revealed that usage of pesticides has led to resistance in the psylla population of Rafsanjan. The results showed that the Rafsanjan psylla population (with LC50 values of 40.55, 43.65 and 95.10 mg a.i. L-1, for acetamiprid, spirotetramat and hexaflumuron, respectively) was the most resistant and the Anar population (with LC50 values of 11.92, 24.13 and 81.06 mg a.i. L-1 for acetamiprid, spirotetramat and hexaflumuron, respectively) was the most susceptible based on the LC50 ratios of insecticides. The LC50 values of acetamiprid, spirotetramat and hexaflumuron for the coccinellid predator O. conglobata in the Rafsanjan population were estimated to be 8.76, 5218.33 and 2268.81 mg a.i. L-1, respectively. The predator was more susceptible to acetamiprid and more tolerant to spirotetramat and hexaflumuron than the psylla A. pistaciae.

Insecticidal effect of plant extracts on common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae)

The common pistachio psylla, Agonoscena pistaciae (Hemiptera: Aphalaridae) is one of the most detrimental pests to pistachio trees. Nowadays various pesticides are used to control the common pistachio psylla, but extensive pesticide spraying against this pest over a period of several years has overpowered its natural enemies. The plant’s byproducts come as an alternative ecologically more compatible in substitution to the synthetic insecticides. This work aims to evaluate the insecticidal potential of herbal extracts of fruit peels of Citrus sinensis and Citrus reticulata, seeds of C. sinensis and Rubia tinctorum, and leaves of Lawsonia inermis against common pistachio psylla. Five concentration 40, 47, 56, 67 and 80 µl/ml, of these plant extracts were sprayed on the fifth instar nymphs of common pistachio psylla by Potter Spray Tower under laboratory conditions (26 ± 2 °C, 60–70% RH and a photoperiod of 16L: 8D h). Results showed significant differences among the treatments of the plant extracts and between the concentrations. The LC50 values of C. sinensis peels, C. reticulata peels, C. sinensis seeds, R. tinctorum seeds and L. inermis leaves were 62.04, 38.84, 43.60, 59.01 and 33.99 µl/ml, respectively. Also, all extracts showed the greatest mortality effect in 80 µl/ml concentration. According to these results, these plant extracts may use as herbal pesticides chemical control programme of common pistachio psylla.

Influence of temperature on the functional response of the predatory bug, Anthocoris minki pistaciae (Hemiptera: Anthocoridae), a predator of Agonoscena pistaciae (Hemiptera: Psyllidae)

AbstractThe common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), is one of the most destructive pests of cultivated pistachio trees in Iran. A locally available anthocorid predator, Anthocoris minki pistaciae Wagner (Hemiptera: Anthocoridae) was evaluated as a biological agent candidate for the control of this pest. The functional response of this predatory bug was investigated at temperatures of 20, 25, 27.5, and 30 °C, relative humidity of 50–60%, photoperiod L:D of 16:8 h and at densities of 2, 4, 8, 20, 40, 60, 80, and 100 nymphs of A. pistaciae during a 24-h period. A type II functional response model was fitted at all tested temperatures. The results indicated that the instantaneous attack rate for the predatory bug ranged from 0.15 to 0.36 nymphs per hour and estimated handling times were 0.41, 0.35, 0.42, and 0.27 h at 20, 25, 27.5, and 30 °C, respectively. Based on asymptotic 95% confidence intervals, searching efficiency didn’t differ significantly from 2...

Effects of pyriproxyfen and imidacloprid on mortality and reproduction of Menochilus sexmaculatus (Coleoptera: Coccinellidae), predator of Agonoscena pistaciae

The effect of two insecticides, imidacloprid and pyriproxyfen, were investigated on some biological parameters of ladybird beetle Menochilus sexmaculatus (F.) (Coleoptera: Coccinellidae) under laboratory condition. The ladybird beetle were exposed to insecticides by ingestion of the common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae) (prey). For imidacloprid, maximum field recommended concentration (MFRC) (1/1 MFRC = 140 ppm), 1/2 and 1/4 MFRC were tested. For pyriproxyfen dilutions of 1/1 MFRC (50 ppm), 2/1 and 1/2 MFRC were used after 24 h. The 100% mortality was observed with imidacloprid in all tested concentrations, whereas no mortality was observed by pyriproxyfen even at the highest concentration (2/1 MFRC). Because of the high mortality observed with imidacloprid, lower concentrations of 1/10, 1/20 and 1/40 MFRC were tested and all predators were killed 3, 7 and 10 days after treatment, respectively. At 1/100 MFRC, no eggs were laid but prey consumption was continued for two weeks. At 1/1 and 2/1 MFRC of pyriproxyfen, ingestion of prey was reduced by 18% and 23%, respectively. At 1/1 and 1/2 MFRC of pyriproxyfen, fecundity and fertility of the coccinellid predator was decreased to 43% and 24.5%, respectively. Imidacloprid at 1/100 MFRC caused significant reduction on fecundity but had no detrimental effect on fertility of the produced eggs. Therefore, unlike the pyriproxyfen that had not acute toxicity, the imidacloprid was extremely toxic to coccinellid at MFRC. However, pyriproxyfen was able to affect on feeding ratio and reproduction of M. sexmaculatus.

Evaluation of Three Neonicotinoid Insecticides Against the Common Pistachio Psylla,Agonoscena pistaciae,and Its Natural Enemies

The common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), is a key pest in pistachio orchards in Iran. Chemical control is a common method to manage this pest. Compatibility between natural enemies and pesticides is a primary concern in programs of integrated pest management of the psyllid pest. In this research, susceptibility of fifth instar nymphs of Ag. pistaciae and fourth instar larvae of the two most common predators of this pest, Adalia bipunctata L. (Coleoptera: Coccinellidae) and Coccinella undecimpunctata aegyptiaca Reiche, to acetamiprid, thiamethoxam, and imidacloprid was investigated. Probit analysis of concentration-mortality data was conducted to estimate the LC50 value. The results showed that thiamethoxam with an LC50 value of 56.35 mg a.i./L was more toxic to fifth instar nymphs of Ag. pistaciae in comparison to acetamiprid (60.75 mg a.i/L) and imidacloprid (138.21 mg a.i/L). Imidacloprid with an LC50 value of 218.89 mg a.i/L compared to acetamiprid (222.65 mg a.i/L) and thiamethoxam (232.37 mg a.i/L) had more lethal effects on fourth instar larvae of Ad. bipunctata. However, on the fourth instar larvae of C. undecimpunctata aegyptica, acetamiprid with an LC50 value of 263.44 mg a.i/L was more toxic than thiamethoxam (296.62 mg a.i/L) and imidacloprid (447.82 mg a.i/L). The laboratory findings showed that the three tested insecticides were more toxic to the common pistachio psylla than to its natural predators. Thiamethoxam was the most toxic against Ag. pistaciae. However, its toxicity to the predators was lower than imidacloprid and acetamiprid. This result suggests that thiamethoxam is the best insecticide for control of Ag. pistaciae in combination with predatory lady beetles.

Temperature-Dependent Development of the Five Psyllophagous Ladybird Predators of Agonoscena pistaciae (Hemiptera: Psyllidae)

Abstract The temperature-dependent development of five psyllophagous ladybirds, Adalia bipunctata (L.), Coccinella undecimpunctata aegyptica (Reiche), Exochomus nigripennis (Erichson), Hippodamia variegata (Goeze), and Oenopia conglobata contaminata (Menetries) (Coleoptera: Coccinellidae), was studied on the common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), in the laboratory. The lower developmental thresholds for total development (egg to adult) of the predators ranged from 10.9 (O. c. contaminata) to 14°C (C. u. aegyptica). The lowest and highest degree-day (DD) requirement values for total development of the studied cocinellids were estimated for C. u. aegyptica (166.67 DD) and E. nigripennis (344.83 DD), respectively. The optimum temperature for development of the studied ladybirds, calculated using third-order polynomial and Lactin models, was in the range of 27.5–30°C. This study showed that all the five psyllophagous ladybirds successfully complete their development in a wide range of temperatures from 17.5 to 30°C, indicating their high potential for use in biological control programs against A. pistaciae.