Batrachedra Amydraula Research Articles

Factitious hosts for Goniozus omanensis (Hymenoptera: Bethylidae), a parasitoid of the lesser date moth Batrachedra amydraula Meyrick (Lepidoptera: Batrachedridae)

ABSTRACT The bethylid wasp Goniozus omanensis has been identified as a key natural enemy of Batrachedra amydraula Meyrick (Lepidoptera: Batrachedridae), an important pest of date palm. Efficient rearing of natural enemies can be an important part of biological pest control programmes but cultures of G. omanensis are challenging to maintain on B. amydraula. We evaluate two readily available species of Pyralid moths, Corcyra cephalonica and Galleria mellonella, as potential factitious hosts. We find that G. omanensis can develop on the larvae of either species, but the probability of failure is circa 75% overall. Both trialled host species were approximately equally suitable, but failures were typically during the early stages of brood production when presented with C. cephalonica and during the later stages when presented with G. mellonella. This suggests that C. cephalonica larvae may be more difficult to suppress and that G. mellonella larvae may be of lower nutritional value. The average production of adult parasitoids per host provided was approximately 1 and, given the observed female biased sex ratio, the average number of females was around 0.8. We suggest potential routes to improving the efficiency of rearing G. omanensis on these factitious hosts.

POPULATION DENSITY OF LESSER DATE MOTH ON MOST PROMINENT DATE PALM CULTIVARS AT KHAIRPUR MIRS

Pakistan is a more peculiar and hearty zone for almost all types of date palm cultivars but only District Khairpur Mirs of Sindh is regarded as “Khajeen jo dees”. The field survey-based research study was conducted at Taluka Kingri, District Khairpur during, 2017-18. The present study was sought on viz., Aseel, Nar-aseel, Fasly, Karbalian, Otakin, Daki-wari, Asul-kurh, Kashoo-wari, Asul-khurmo, Dedhi-wari, Lessoro, Begun-wari, Gajar-wari, Noori-wari and Nakul-kurh date palm varieties. All the novel already cultivated varieties were observed through random selection against the population density of Batrachedra amydraula. The pest data was taken every week from April, May and June months in both years of the study period. The pest data was gathered from 15 acres of cultivated Phoenix dactylifera orchards and prohibited to any insecticides. The maximum suspected pest infestation was found on Fasli cultivar whereas; the minimum infestation was recorded on Aseel. This commercial high-priced variety is found with high tolerance capability against salinity, drought, and upper range temperature conditions and hence recommended for cultivation. In the present study, it was frequently observed the appearance of the Batrachedra amydraula on all novel cultivars. The “Khajoor” is the cash crop and the main economic source of livelihood of this region but for a few decades, LDM has leads productivity reduction in terms of quantity and quality. The food security and socio-economic status of date palms are poorly documented in Pakistan. In this context for date palm crop security, more work should be carried on against population reduction of LDM.

Plant–herbivore–natural enemy trophic webs in date palm agro-ecosystems

Understanding the composition and dynamics of ecological communities is challenging because of the large number of organisms present and their numerous interactions. Among agricultural systems, intercropping considerably increases the complexity of communities compared to monocultures and alternative host plants can influence insect pest damage. Using literature records, we construct and analyse connectance trophic webs of date palm (Phoenix dactylifera) agro-ecosystems, including and excluding intercrops. Estimates of connectance (community complexity) are relatively low and little affected by consideration of intercrops. Plant–herbivore overlap is relatively high, suggesting that herbivores are typically not specialists. Herbivore–natural enemy overlap is greater when intercrops are considered, suggesting that diffuse apparent competition regulates pest populations. We pay particular attention to how trophic web structure might affect Batrachedra amydraula (Lesser date moth), an important economic pest. Records indicate it having 15 species of natural enemies and sharing 9 of these with other herbivores; these may maintain populations of natural enemies when the moth is seasonally rare, contributing to pest suppression. The estimated potential for apparent competition between the lesser date moth and other herbivores is higher when intercrops are considered. The consequent expectation of less severe infestations in plantations that are intercropped compared to monocultures matches empirically derived reports. Further, comparing results obtained from the literature on one country (Oman) and from 15 Middle Eastern countries, we find that community metric estimates are relatively little affected by the geographical scale considered. Overall, our results suggest that literature-based trophic web construction can provide an efficient and robust alternative, or in addition, to direct empirical methodologies and that the presence of intercrops will contribute to major pest suppression via indirect apparent competition.

Efficacy of Botanical Insecticides Against, Batrachedra amydraula on Phoenix dactylifera at Field Conditions

Efficacy of Botanical Insecticides Against, Batrachedra amydraula on Phoenix dactylifera at Field Conditions

المكافحة الحيوية لآفة الحميرة (Batrachedra. Amydraula/ mayrick) باستخدام الطفيل المحلي طفيل الجينوزس Goniozus omanensis

GONIOZUS OMANENSIS (Hym. Bethylidae) has been found to be the most common parasitoid of the lesser date moth, Batrachedra amydraula not only in Sultanate of Oman but also in neighboring Gulf states and other date palm growing parts of the world. It is one of the most important pests on date palm that is reported to cause more than 50% loss of the crop. Batrachedra amydraula, the lesser date moth is a species of moth of the Batrachedridae family reported from Bangladesh to western Saudi Arabia, Yemen, Israel, Iraq, and Iran, as well as most of North Africa. The larvae feed on Phoenix dactylifera. There are three generations per year in Sultanate of Oman. The first larvae appear in April and damage newly formed fruits. They are dormant from August to March of the following year, resting between the bases of the terminal fronds. Pupation takes place in March and adults emerge in April. Goniozus omanensis is primary parasitoid of lesser date moth Batrachedra amydraula. The present investigation involved successful rearing of parasitoid in the laboratory on larvae of Galleria mellonella and release in three date palm orchards as a bio-control agent against such a pest (one release, two releases, and three releases). The results showed that one release was sufficient to control 80% of the pest population in comparison with two (50%) and three releases (40%). About 0.1 % of pest was found from the bottom in comparison with emerging adults’ pests from infested fruits from the top of the palm.

Providing water sources to insectivorous bats for conservation biological control in arid date plantations

Balance between the high demand for agricultural production and the negative environmental impact of intensive agriculture requires the development of sustainable agricultural approaches. One such approach is conservation biological control (CBC), which aims at enhancing pest suppression by using natural enemies, such as predators and parasites. Insectivorous bats are considered as potential natural enemies for CBC of insect agricultural pests. Bats drink from open water sources and forage above them, hence we hypothesized that supplementation of artificial water pools adjacent to desert date plantations might promote the activity and species richness of insectivorous bats in this habitat, thereby contributing to pest suppression. We predicted that bats will be more attracted to the pools during summer, when other water sources are scarce, than during spring. In addition, we explored the effect of water supplements on the desert bat community structure. Eight pools were installed in a date plantation in the hyper-arid Arava valley, Israel. Bats were acoustically monitored during three experimental stages: 1) before filling the pools with water; 2) while the pools held water and 3) after emptying them. The lesser date moth (Batrachedra amydraula), a major date pest, was monitored using pheromone traps in parallel with the experimental stages. We found that the pools increased bat activity in summer, but not in spring, while species richness was not affected in either season. The local bat community structure was significantly altered while the pools held water, but not due to increased activity of synanthropic Mediterranean species at the expense of local desert species. The number of individuals of the lesser date moth near the pools decreased with the increase in bat activity. Our results support the idea that seasonal water supplementation enhances bat activity in arid farmlands with potential contribution to pest control and the actual contribution to pest suppression should be further quantified. We suggest that the integration of small artificial pools to promote agricultural pest predation by bats may help reduce crop loss and potentially contribute to the conservation of desert bat communities by adding water sources.

The Effect of the Hight of the Pheromone Traps Type Delta in Trapping and Forecasting the Emergence of the Lesser Date Moth, Batrachedra amydraula Meyrick and Evaluating the Sensitivity of Some Palm Varieties to Insect Injury

El-Filahy, M.H.A. and M.Sh. Mansour. 2023. The Effect of the Hight of the Pheromone Traps Type Delta in Trapping and Forecasting the Emergence of the Lesser Date Moth, Batrachedra amydraula Meyrick and Evaluating the Sensitivity of Some Palm Varieties to Insect Injury. Arab Journal of Plant Protection, 41(3): 226-232. https://doi.org/10.22268/AJPP-41.3.226232 During the 2021-2022 season field study conducted in Anbar governorate to determine the population dynamics of Batrachedra amydraula using pheromone traps (Alpha scenes Inc. West Linn) and the effect of trap height on number of male insects traped. In addition, host preference and sensitivity of date palm varieties to infestation with the insect was also evaluated. The results obtained showed that the first appearance of the insect was at the end of the third week of March with an average of 2 insects/trap at a temperature of 16.5°C and 51.5% RH. The number of insects caught in the trap reached a peak during the first week of June at an average of 139 insect/trap, at a temperature of 32°C and 42% RH. The insect count then decreased after the third week of June to zero insects/trap until the third week of July. Field experiments also showed that the traps height had an effect on the number of insects caught. The average number of total insects caught in traps at 1.5 m was 45.5, whereas the average number of insects caught in traps placed at 2.5 m was 20.5. The results also showed that the highest total infestation rate in the Khistawi variety was 36.89%, followed by Zahdi (18.83%). The infestation rate of the variety kheyara was the lowest (12.61%). The results also showed the average larval density of the insect Batrachedra amydraula was the highest on the khestawi variety with total average injury severity of 0.14%, followed by zahdi variety with an average total injury severity of 0.05%. Therefore, by combining the infestation rate and average number of the insect larvae, it can be concluded that the Khistawi variety was the most sensitive to the insect, and the variety Kheyara was the most tolerant. In addition, the use of pheromone traps was instrumental in reducing the injury caused by the insect, and using resistant/tolerant varieties can effectively contributes to the reduction of the infestation rate of the insect to become below the economic injury level. Keywords: Date palm, Phoenix dactylifera L., Lesser date moth Batrachedra amydraula, Pheromone traps, Variety sensitivity

Biological Activity of some Control Agents and Trichogramma evanescence on the Bioactive of Batrachedra amydraula M. (Batrachedridae:Lepidoptera) on Date Palms in Iraq

Field studies were conducted in each of the governorates of Basra, Maysan and Dhi Qar and Babylon and included a field survey for the presence of the bug Batrachedra amydraula and the sensitivity of some date palm cultivars to the infection of the mentioned insect and evaluating the efficiency of direct spraying of different concentrations of some control agents in reducing the rates of infection with the bug on immature fruits in date palm, Where nano silver (AgNPs), Alsystin, Trichoderma viride, and Trichogramma evanescence were used. Whereas, the treatment of the field survey in the province of Basra recorded the highest percentage of the B. amydraula on the date palm amounted to 53.79%. While the lowest percentage was recorded in the Dhi Qar, it amounted to 43.66%. The cultivar Al-Zuhdi also recorded the highest sensitivity to the infection of the mentioned insect by 51.29%, and the lowest sensitivity was recorded for Al-Halawi cultivar with a rate of 44.66%. Whereas nano silver were the most effective among all other factors. Where the infection of the bitch was reduced by 6.00% compared with the control treatment, which amounted to 55.03%, while the biological fungus T. viride had the least effect with a total infection rate of 18.40% compared with the control treatment, which gave a total infection rate of 55.03%. The interaction treatment between nano silver and the insect growth regulator cysteine also contributed to a higher reduction in the rates of total infection by an average of 5.60%, while the combination of interaction between the bio control fungus T. viride and the biological growth regulator Alsystin gave the least reduction in the total infection rates by an average of 29.70%. The egg parasitoid Trichogramma evanescence effectively contributed to reducing the infestation of the B. amydraula by influencing the percentage of eggs presence, where the treatment (3 capsules/palm) gave the highest reduction in the total infection rates at an average of 6.54% compared to the control treatment, which gave a total infection rate of 55.03%, While the treatment (1capsule/palm) gave the least reduction in the total infection rates, with an average of 11.87%, compared with the control treatment, which gave 55.03% of the total infection rates.

The Effect of Formone Traps and Their Integration with Chemical and Biopesticides in the Fight Against the Humera Bug Batrachedra Amydraula Meyrick on Date Palms

The study was conducted during the 2021 season at the Fallujah palm plant to evaluate the effectiveness of some biopesticides Uphold Sc360, Benzostar %5 wDG (Emamectin benzoate) and Bio-T(Bacillus thurengiensis var. Kurestaki) and complement them with formone traps on the minor date moth Batrachedra amydraula and their effect on productive properties (taste weight/kg). The integration transaction between chemical and biopesticides and formone fisheries outperformed other transactions and recorded the highest homicide rate of, %84.626 while the other transactions varied with the homicide rate, 16,725 73,361, 64,441% and % 37.79 for trap transactions and integration with the pesticide Uphold and complete with the pesticide Benzostar respectively. The results showed that there are differences in the moral percentage of death resulting from the duration of exposure to the pesticide, where the killing rate after the duration of exposure of 14 days was the highest and amounted to, %7.457 while the moral percentage of homicide for the duration of exposure to the pesticide after 3 days was the lowest and recorded. %35.808. The pesticides used also clearly affected the productive characteristics of the palm with an moral taste weight (10.42 9.25, 9.92, 10.92, kg compared to the control treatment of 7.25 kg and the weight of the total yield of the transactions 99.75, 91.875, 102.375, 99.75, 105, 98.99, 105, 92.5, 5 92.625 and 109.25 kg compared to the control treatment which amounted to 79.75 kg.

Evaluation of Different Insecticides Against Lesser Date Moth, Batrachedra amydraula Meyrick, 1916 (Lepidoptera: Batrachedridae) under Field Conditions

Evaluation of Different Insecticides Against Lesser Date Moth, Batrachedra amydraula Meyrick, 1916 (Lepidoptera: Batrachedridae) under Field Conditions

Studying the effect of environmental conditions in the seasonal abundance of lesser date moth (Batrachedra : Amydraula : Meyrick) on date palm, Phoenix dactylifera L. in Central and Southern Iraq

A field study was conducted for the 2019/2020 season, which included a field survey to determine the infestation percentages and determine the sensitivity of some date palm varieties to the infestation with the lesser date moth (B.amydraula M.). Besides, determining the date of insect appearance and its population density is based on temperatures, relative humidity, and thermal accumulation. The study showed that infestation with the lesser date moth includes all areas planted with palm trees and the infestation percentages range between medium and severe, especially in dense orchards, and according to the prevailing environmental conditions. Basra Governorate / Abu Al-Khaseeb district gave a severe infection in the total infestation percentage of 67.00%, while the lowest infestation percentage was recorded in Babylon Governorate, Al-Madhatia district, at a percentage of 17.66 %, which considered a weak infection. The study also gave a clear indication that all date varieties were infested with lesser date moths at varying percentages, where the Al - Zahdi cultivar recorded the highest infestation percentage of 58.71%, while Al - Halawi cultivar recorded the lowest infestation percentage amounted to 39.97%. The study recorded the first appearance of the insect adults at the beginning of the second week of March in both Basra and Babylon governorates, with a population density of (2.80, 2.80) insect/in2 respectively at an average temperature (14.26, 15.20) ºC, respectively, and average humidity of (49.86, 51.67) % respectively. The study showed that the insect has three overlapping generations during the year, starting from the beginning of March to the beginning of March of the next season, as the duration of the first and second generations was one month each, while the duration of the third generation extends to approximately nine months. The insect has three peaks in which the insect population density increases significantly. In Basra, the increase reached its peak at the beginning of the second week of April and during the second week of May and June, with a population density of (7.71, 7.39 and 6.88) insect/in2 respectively, and an aggregate temperature of (445.20, 665.52 and 814.65) thermal units, respectively. However, in Babylon, the seasonal abundance of the insect reached its peak at the end of the first week of April and the second week of May and during the third week of June, with a population density of (6.71, 6.40, and 6.60) insect/in2 and a thermal accumulation of (358.08, 418.56 and 586). 08) thermal unit.

Population Fluctuations of the Major Lepidopteran Insect Pests of Date Palm at Al-Wahat Al-Baharia Region, Egypt.

<b>Background and Objective:</b> Several insect pests infest the date palm and its fruit in the field and storage causing economic damage and affecting the tree productivity from one year to another and from one location to another due to the pest's status in the field. Therefore, this study aimed to estimate the seasonal fluctuation of the important insect pests, <i>Arenipses sabella</i>, <i>Batrachedra amydraula</i> and <i>Ephestia</i> sp. during the 3 successive years in the date palm fields at Al-Wahat Al-Bahareia region in Egypt. <b>Materials and Methods:</b> Three light traps were used to capture insects for 3 years, 2018, 2019 and 2020. The survey was done every 2 weeks for the three above-mentioned insects. Each year was divided into five periods according to the production of date palms. Also, the correlation coefficient was estimated between the population fluctuations and meteorological data. <b>Results:</b> In all three seasons, the number of all these insects increased gradually from the beginning of January till the fruiting period (end of July). Then, the numbers decreased gradually starting from August till the end of the year. The correlation coefficient for all estimated pests was more than R = 0.7 except for <i>Ephestia</i> sp. with the humidity (R = 0.6049). <b>Conclusion:</b> All studied lepidopteran insects are presented during the whole year and fluctuated with the highest peak at the fruiting period. Moreover, the increase in temperature and decrease in humidity is correlated with the high numbers of these insects. This study could help control these pests with different methods according to their estimated populations of them.

Study of mating effect, hosts range and competition with the parasitoid Bracon hebetor on some behavioral and biological aspects of larval parasitoid Goniosus sp

Laboratory studies was conducted to investigate effect of mating behavior on egg laying, host selection and competition with Bracon hebetor. The results showed that no differences in mating and egg laying behavior between mated and unmated females. number of egg laying were 90.67 egg per female of unmated and mated females respectively. However unmated female produce only males progeny.The parasitoid showed response to the larvae of different lepidopterous insects such as. Mediterranean flour moth, potato tuber warm, greater wax moth, tomato leafminer, Angoumois Grain Moth and lesser date moth. The parasitoid did not respond to the larvae of Corn stem borer and cotton bollworm (tomato fruitworm) .The results of competition study between the parasite Goniozus sp and B. hebetor indicates that the first parasite was more competitive and parasitism on the larvae of the host where the percentage of parasitism was 72.22% of the total larvae, while, the percentage of parasitism was 27.77% for the parasite B.hebetor.

Management of Date Palm Pests: Lack of Commercial Input

According to Statista, the global date market was valued at about $13.4 billion in 2019 and is forecast to reach $16.25 billion by 2025. However, this valuable crop is threatened by numerous pests. In fact, the date palm is associated with 132 species of insect and mite pests, which feed on the leaves, roots, trunk, and fruits on the palm, as well as stored dates. The most economically important pests include the red palm weevil, (Rhynchophorus ferrugineus), old world date mite (Oligonychus afrasiaticus), lesser date moth (Batrachedra amydraula), Dubas date bug (Ommatissus lybicus), green pit scale (Palmaspis phoenicis), carob moth (Ectomyelois ceratoniae), date palm longhorn beetle (Jebusaea hammerschmidti) and almond moth (Cadra castellan). It has been estimated that effective curative approaches for red palm weevil infestations alone could result in savings as high as $104 million. Several research groups are working to find effective solutions to control these pests, but as yet no commercial biocontrol products are registered or available for curative control of the palm beetle and larvae. Therefore, a more robust Integrated Pest Management(IPM) system is needed to reduce the pest damage. Commercial formulations include root treatments, insecticide-based capsules that are injected into the trunk, or foliage/fruit sprays. However, chemical insecticides should not be the only solution to the management of date palm pests, especially those concealed inside the trunk or beneath palm tissues, making them difficult to target. This is primarily because chemical insecticides frequently just kill the target pest's natural enemies, while the pests themselves remain protected within the date palm. Several approaches are used but it has also been shown that resistance against a range of commonly used chemical insecticides (profenophos, imidacloprid, chlorpyrifos, cypermethrin, deltamethrin, spinosad, lambda-cyhalothrin, phosphine) develops after extensive use. Resistance ratios as high as 79-fold have been reported, compared with susceptible control pests. Researchers have reported significantly improved populations of natural enemies of target pests in date palm plantations when chemical insecticide use is reduced. Around 90 species of beneficial predators and parasitoids have so far been reported, suggesting that biological control with microbials could be incorporated into a synchronised IPM programme.

Deterministic and Stochastic Fractional Order Model for Lesser Date Moth

In this paper, a deterministic and stochastic fractional order model for lesser date moth (LDM) using mating disruption and natural enemies is proposed and analysed. The interaction between LDM larvae, fertilized LDM female, unfertilized LDM female, LDM male and the natural enemy is investigated. In order to clarify the characteristics of the proposed deterministic fractional order model, the analysis of existence, uniqueness, non-negativity and boundedness of the solutions of the proposed fractional-order model are examined. In addition, some sufficient conditions are obtained to ensure the local and global stability of equilibrium points. The occurrence of local bifurcation near the equilibrium points is investigated with the help of Sotomayor’s theorem. Numerical simulations are conducted to illustrate the properties of the proposed fractional order model with respect to the intrinsic growth rate of the LDM larvae, natural enemy’s mortality rate, predation rate, sex pheromone trap parameter, fractional order and environmental noise. The impact of mating disruption on lesser date moth is demonstrated. Also, a numerical approximation method is developed for the proposed stochastic fractional-order model.

The Influence of Bunches Thinning and Pesticides on Some Traits and the Rate of Infection with Lesser Date Moth in Date Palm

The experiment was carried out in one of the private palm orchards infested with the lesser date moth (Batrachedra amydraula Meyrick) in the village of AL-Bualay AL-Jassim 8 km northwest of Ramadi during the season 2020, with the aim of studying the influence of bunches thinning and pesticides on some of physical and chemical and productivity and rate of infection with lesser date moth on date palm. The results revealed that the thinning factors C1(6 bunch) and C2 (8 bunch) date palm-1 reduce rate of infestation of the lesser date moth after 14 days of spraying pesticides at rates of 20.80 and 23.10% compared to the control treatment (28.30%). The pesticide A2 (Matrixine plus) outperformed in reducing the rate of infection after 7, 14, 21 days with an average of 6.34, 16.10, and 26.10% respectively, these rates were increased in the control treatment (11.88 and 31.30 and 61.90%) respectively. On the other hand, treatments 6 and 8 bunch outperformed the control treatment in terms of fruit setting, increased ripening rate and reduced khalal ratio, with rates of (76.33 and 73.78%), (50.00 and 50.11%), and (50.00 and 50.00%) respectively. The results confirmed that there were no significant differences between the thinning treatments on the total yield between treatments and their interactions. When using the pesticide A2, it caused a significant increase in the rate of ripening and a decrease in the percentage of khalal with rates of 56.22 and 43.78% respectively. The results indicate outperformed of the thinning treatment C2 and pesticide treatment A2 in phosphor, nitrogen, and potassium percent in fruits with an average of (0.0806,0.0820%), (0.4022,0.3989%), and (0.6856,0.6933%) respectively. These values decreased in the control treatment by rates of (0.0766 and 0.0750%), (0.3767 and 0.3767%), and (0.6422 and 0.6356%) respectively.

Effect of interaction between pheromone traps and plant seeds of harmal, Peganum harmala, on lesser date moth, Batrachedra amydraula (Merck), in Basra Province

The lesser date moth, Batrachedra amydraula Merck is one of the most important pests affect date palm fruits, which cause great losses to the yield, whether in quantity or quality. This study was conducted in Basra province / Al-Qurna district to study the effect of harmal plant seeds on the numerical density, percentage and severity of infection caused by lesser date moth on the date palm trees. The results showed that the highest number of lesser date moths’ population density was appeared in the fogging treatment (111.3 / trap), while the lowest was in the fumigation treatment (64.3 / trap). The lowest percentage of infection by lesser date moth was in the aqueous extract treatment of (29.7%), while the highest was in the fumigation treatment (31.4%). In the first period, the treatment of aqueous extract gave the best results, as the percentage of infection was (17.8%). The lowest rate of infection severity was also in the treatment of aqueous extract (2.2 / 5 fruit), while the highest was in the fogging treatment (6.5 / 5 fruit). In the third period, both treatments of fumigation and fogging gave the best results, as the infection severity was (0/5 fruit) compared to the control for the same period of (8.9 / 5 fruit). The treatment of aqueous extract gave the best results in reducing the severity of infection by lesser date moth, while the treatment of fogging gave the best results in reducing the number density of lesser date moth.

Determination of economic injury level of date palm lesser moth, Batrachedra amydraula (Lepidoptera: Batrachedridae) on six commercial date cultivars in Iran

شب پرة کوچک خرما Batrachedra amydraula Meyrick (Lepidoptera: Batrachedridae) و سایر کرم ­های میوه­ خوار خرما از مهم­ترین آفات میوة خرما می ­باشند که موجب خشک شدن و ریزش خرما می­شوند. در این پژوهش ارتباط بین تراکم جمعیت کرم میوه خوار خرما و میزان آسیب ناشی از آن و کاهش شاخص ­های عملکرد خرما روی شش رقم تجاری نخل خرما در استان­ های خوزستان، بوشهر، هرمزگان، کرمان، و سیستان و بلوچستان طی سال­های 1396 و 1397 بررسی شد. هزینه مدیریت تولید در دو حالت کاربرد کنترل شیمیایی و بیولوژیک و قیمت محصول در هر منطقه بر اساس پیش بینی میانگین شش ماهه محاسبه شد. نمونه برداری­ها از انتهای اردیبهشت تا اوایل شهریور به فاصله هر 10 روز یک بار انجام شد. از هر درخت چهار خوشه از چهار جهت مختلف جغرافیایی درخت انتخاب و از هر خوشه، تعداد 25 عدد میوه (از نظر سالم و آلوده بودن) مورد بررسی قرار گرفت. در نهایت از مدل نورتون برای محاسبه EIL در شرایط کنترل بیولوژیک و کنترل شیمیایی استفاده شد. بر اساس نتایج، هزینه کنترل بیولوژیک کمتر از کنترل شیمیایی بود. بالاترین هزینه در هر دو روش مربوط به هزینه خرید مواد کنترل کننده بود. بالاترین میزان آسیب وارده به محصول (علائم تغذیه) در اثر واحد جمعیت آفت مربوط به رقم مضافتی و کمترین آن مربوط به رقم کبکاب بود. همچنین بالاترین میزان خسارت محصول در اثر واحد آسیب (زیان ناشی از تغذیه) آفت مربوط به رقم ربی و کمترین آن در رقم سایر مشاهده شد. در کلیه ارقام مورد مطالعه، سطح زیان اقتصادی در سال 1396 کمتر از سال 1397 در هر دو روش کنترل شیمیایی و بیولوژیک بود. از طرفی هزینه در روش کنترل بیولوژیکی در هر دو سال و در کلیه ارقام مورد مطالعه پایین­ تر از روش کنترل شیمیایی بود. بالاترین سطح زیان اقتصادی در سال 1397 مربوطه به رقم سایر و در روش کنترل بیولوژیک (1/ 1546 لارو-روز) و کمترین آن مربوط به رقم ربی و در روش کنترل شیمیایی (81/13 لارو-روز) بود.

Mathematical Modelling of Lesser Date Moth Using Sex Pheromone Traps and Natural Enemies

In this paper, a mathematical model for lesser date moth is proposed and analyzed. The interaction between the date palm tree, lesser date moth, and natural enemy has been investigated. The impact of sex pheromone traps on lesser date moth is demonstrated. Some sufficient conditions are obtained to ensure the local and global stability of equilibrium points. The occurrence of local bifurcation near the equilibrium points is performed using Sotomayor’s theorem. Theoretical results are illustrated using numerical simulations.

HPSI of date palm (Phoenix dactyliferaL.)varieties/ genotypes against fruit borers, Batrachedra amydraulaand Arenipses sabellain hot arid region

Host plant resistance is an important component for management of the fruit borers, Batrachedra amydraula and Arenipses sabella owing to difficulties associated with its chemical and biological control. A total of 32 date palm varieties/ genotypes were evaluated for screening against the fruit borers in hot arid region. The results showed that the percentage of fruit infestation of fruit borers, B. amydraula and A. sabella on tested varieties/ genotypes of datepalm varied significantly. Pooled data showed that the Migra, Tayer, Javantri and Medjool were found highly tolerant varieties/ genotypes with fruit infestation (5.32%, 8.40%, 8.40%, 8.78% of B. amydraula and 4.33%, 5.27%, 5.62%, 5.52% of A. sabella, respectively). Whereas, the varieties/ genotypes Zahidi, Suriya, Khasab and Khuneizi had fruit infestation (29.88%, 28.33%, 28.27%, 27.05% of B. amydraula and 20.67%, 19.83%, 17.40%, 19.95% of A. sabella, respectively) and declared as highly infestation varieties/ genotypes to the fruit borers. Lower values of host plant susceptibility indices based on fruit infestation (HPSI) were recorded on resistance varieties/ genotypes, Migra, Tayer, Javantri and Medjool (31.63%, 49.97%, 49.97%, 52.25% of B. amydraula and 40.16%, 48.81%, 52.05%, 51.13% of A. sabella, respectively) which could be used as a source of resistance for developing date palm varieties/ genotypes resistant to fruit borers.