Ectomyelois Ceratoniae Research Articles

Adıyaman ve Siirt İlleri Nar (Punica granatum L.) Bahçelerinde Belirlenen Zararlı Böcek Türleri

This study was carried out in order to determine the insect pest species found at the orchards of Adıyaman and Siirt provinces. The studies were carried out in the Şirvan district of Siirt and Adıyaman’s the Central, Kahta and Samsat districts, where pomegranate production is intensively carried out through the years of 2017 and 2018. Samplings was carried out at the pomegranate orchards at least two weeks interval between April and October. Visual control, knock and insect rearing methods were used to obtain the insect species. According to the results from the study; a total of 42 insect species were obtained from the orders of Orthoptera (1), Thysanoptera (9), Hemiptera (18), Coleoptera (8) Lepidoptera (4) and Diptera (2). Among the identified pest species, Aphis punicae Passerini (Hemiptera: Aphididae) and Apomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) were determined as the main pest species. Dioryctria simplicella Heinemann (Lepidoptera: Pyralidae), Arcyophora dentula Lederer (Lepidoptera: Nolidae), Chrysobothris affinis (F.), Acmaeodera wethloi Obenberger (Coleoptera: Buprestidae) and Zaprionus indianus (Gupta) (Diptera: Drosophilidae) were determined for the first time in Turkey's pomegranate production areas.

Relationship between biochemical properties of some date varieties and nutritional requirements of Ectomyelois ceratoniae Zeller (1839)

Ectomyelois ceratoniae Z is one of the most dangerous insects in the world and Algerian phoeniciculture. The survival of this insect is based on the search for the appropriate dates varieties to its nutritional needs. In this paper, an experimental study was performed to determine these nutritional needs and the mechanisms to obtain them from dates. In this study, three susceptible varieties to the moth attack were chosen, the healthy and infested dates were separated to calculate on the one hand the attack rate and to carry out the qualitative analyzes. The results showed that the moth selects the appropriate dates to lay its eggs and feed the larvae based on the consistency of the dates and their high sucrose content. The content of the sucrose is reduced in attacked dates, resulting from their consumption after the enzymatic degradation by Invertase for the synthesis of simpler sugars (fructose and glucose) to be easily used by the larvae. The more the medium is very acidic (infested dates), the more the degradation of sucrose is important. The total sugar is also necessary to produce sufficient energy for the biological activities of the moth (growth).The use of these organic elements by the larvae leads to a reduction in the weight of the date and increases its fragility.

Efficacy of nanocapsules loaded with Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae) sex pheromone as evaluated in wind tunnel and field trapping experiments

Efficacy of nanocapsules loaded with Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae) sex pheromone as evaluated in wind tunnel and field trapping experiments

Natural insecticides from native plants of the Mediterranean basin and their activity for the control of the date moth Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae)

Natural insecticides from native plants of the Mediterranean basin and their activity for the control of the date moth Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae)

Field performance of the egg parasitoid Trichogramma cacoeciae Marchal (hymenoptera: Trichogrammatidae) following releases against Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) in two types of oasis in Tunisia

This study was carried out in two oases located in the south-west of Tunisia to investigate the efficacy of the oophagous parasitoid Trichogramma cacoeciae against Ectomyelois ceratoniae on date palm trees. The first oasis (Hezoua) is characterized by a cropping system divided into three levels of cultures. In the second oasis (Douz), orchards were based on the monoculture of the Deglet Noor cultivar. Parasitoids were released with three doses 26,000, 36,000 and 46,000 Trichogramma/ha. The impact of Trichogramma releases was evaluated by monitoring the egg parasitism, male catches of E. ceratoniae through pheromone traps, fruit damage during the whole season and fruit infestation at harvest. Trichogramma cacoeciae accomplished higher egg parasitism in Hezoua oasis (19.71 ± 1.02%) as compared to Douz oasis (8.43± 1.03%). Inundative releases of T. cacoeciae in the two oases resulted in varying degrees of pest control and they were not sufficient to limit economic losses.

Isolation, Identification, and Biocontrol Potential of Entomopathogenic Nematodes and Associated Bacteria against Virachola livia (Lepidoptera: Lycaenidae) and Ectomyelois ceratoniae (Lepidoptera: Pyralidae).

Simple SummaryFor sustainable agriculture, there is a need to identify and evaluate more biocontrol agents, including entomopathogenic nematodes (EPNs). In this study, EPNs and their associated entomopathogenic bacteria symbionts (EPBs) were isolated and identified from 320 soil samples collected in Taif, Saudi Arabia. The biocontrol efficacy of EPNs and EPBs was also evaluated against third instar larvae of the pomegranate butterfly, Virachola livia, and the carob moth, Ectomyelois ceratoniae, two important insect pests of pomegranate, under laboratory conditions. Our results show that the EPNs Steinernema spp. were more virulent than Heterorhabditis spp. against the two pomegranate insects. In addition, the EPB Stenotrophomonas maltophilia CQ1, isolated from Steinernema spp., surpassed Pseudomonas mosselii SJ10, associated with Heterorhabditis spp., in their ability to kill V. livia or E. ceratoniae larvae. We conclude that either application of EPNs’ infective juveniles (IJs) or their associated EPBs could serve as potential biocontrol agents for V. livia and E. ceratoniae.Virachola livia (Lepidoptera: Lycaenidae) and Ectomyelois ceratoniae (Lepidoptera: Pyralidae) are the key pests of pomegranates in Saudi Arabia that are managed mainly using broad-spectrum pesticides. Interactions between the entomopathogenic nematodes (EPNs) Steinernematids, and Heterorhabditids, and their entomopathogenic bacterial symbionts (EPBs) have long been considered monoxenic 2-partner associations responsible for killing insects and, therefore, are widely used in insect pest biocontrol. However, there are limited reports identifying such organisms in Taif, Saudi Arabia. The current study aimed to identify the EPNs and their associated bacteria isolated from Taif, Saudi Arabia, and evaluate their biocontrol potential on third instar larvae of V. livia and E. ceratoniae under laboratory conditions. A total of 35 EPN isolates belonging to Steinernema (20) and Heterorhabditis (15) were recovered from 320 soil samples. Twenty-six isolates of symbiotic or associated bacteria were isolated from EPNs and molecularly identified as Xenorhabdus (6 isolates), Photorhabdus (4 isolates), Pseudomonas (7), or Stenotrophomonas (9). A pathogenicity assay revealed that Steinernema spp. were more virulent than Heterorhabditis spp. against the two pomegranate insects, with LC50 values of 18.5 and 13.6 infective juveniles (IJs)/larva of V. livia for Steinernema spp. and 52 and 32.4 IJs/larva of V. livia for Heterorhabditis spp. at 48 and 72 h post-treatment, respectively. Moreover, LC50 values of 9 and 6.6 IJs/larva (Steinernema spp.) and 34.4 and 26.6 IJs/larva (Heterorhabditis spp.) were recorded for E. ceratoniae larvae at 48 and 72 h post-treatment. In addition, the EPB Stenotrophomonas maltophilia CQ1, isolated from Steinernema spp., surpassed Pseudomonas mosselii SJ10, associated with Heterorhabditis spp., in their ability to kill V. livia or E. ceratoniae larvae within 6 h post-application, resulting in 100% mortality in both insects after 24 and 48 h of exposure. We conclude that either application of EPNs’ IJs or their associated EPBs could serve as potential biocontrol agents for V. livia and E. ceratoniae.

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.

Effectiveness of different management strategies against Ectomyeloïs ceratoniae Zeller (Lepidoptera: Pyralidae) in citrus orchards in Tunisia

ABSTRACT Ectomyelois ceratoniae (Zeller) is a cosmopolitan pest that affects many crops worldwide. The present study was performed to refine our knowledge about density and damage of this pest on Navel oranges in northern Tunisia and to evaluate the effectiveness of four alternative methods including, cultural control, mass trapping, Trichogramma cacoeciae (Marchal) releases and mating disruption. Results showed that E. ceratoniae populations increased from April to November. All trials were effective in decreasing E. ceratoniae populations on citrus fruits. The most effective management was mating disruption combined with T. cacoeciae release (30,000 Trichogramms/ha), with a reduction rate of E. ceratoniae of 62.8% after treatment. Mass trapping using delta traps combined with Trichogramma releases (25,000 T/ha) may be a promising alternative for limiting E. ceratoniae populations. It has also been shown that a density of 10 delta traps/ha can reduce the infestation rate of E. ceratoniae. Furthermore, control by successive T. cacoeciae releases at a density of 20,000 T/ha shows its effectiveness. Our results for improving management of E. ceratoniae in citrus orchards are highlighted and discussed herein.

Flying Activity and Seasonal Abundance of Carob Moth Ectomyelois ceratoniae Zeller and its Population Dynamics on Different Hosts in Lattakia, Syria

Arab, A., E. Al-Jouri, I. Okasha, D. Fayoud, R. Yousef and N. El-Ali. 2022. Flying Activity and Seasonal Abundance of Carob Moth Ectomyelois ceratoniae Zeller and its Population Dynamics on Different Hosts in Lattakia, Syria. Arab Journal of Plant Protection, 40(3): 201-208. https://doi.org/10.22268/AJPP-40.3.201208 The carob moth, Ectomyelois ceratoniae Zeller, is an important frugivorous pest worldwide. A study was carried out on pomegranate, citrus orchards and carob sites in Lattakia governorate during 2013-2014 to monitor the flying activity and seasonal abundance of the carob moth using synthetic pheromone traps (Russell IPM). The population dynamics of carob moth on pomegranate and navel orange fruits and carob pods were estimated. The results showed that the flying activity was between late March and early December. The highest monthly abundance of the insect was in June, in both years. The results also showed a medium significant correlation between temperature and insect flight activity and weekly catch rate, whereas the correlation with relative humidity was not significant. The highest infestation rate with carob moth was 40% on pomegranate, 37% on carob and 7% on navel orange in September 2013, whereas it was 36% on pomegranates, 30% on carob and 4% on navel oranges in September 2014. Keywords: Carob moth, Ectomyelois ceratoniae, seasonal abundance, pomegranate, orange, carob

Control Potentials of Three Entomopathogenic Bacterial Isolates for the Carob Moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae) in Pomegranates

Ectomyelois ceratoniae (Lepidoptera: Pyralidae) is the primary pest of pomegranates in Saudi Arabia and is mostly controlled using broad-spectrum pesticides. Providing environmentally sound choices to limit reliance on chemical management is a major challenge in the control of E. ceratoniae and, as a consequence, in the protection of pomegranate crops from its invasion. Entomopathogenic bacteria (EPB) symbiotically associated with entomopathogenic nematodes (EPNs) are well-known biocontrol agents of soil-dwelling or aerial pests. The bacterium symbiont (EPB) is the real insect-killing biocontrol agent, while the nematode (EPN) serves as a vector. We wondered whether the EPB vector, which is extremely vulnerable to adverse environmental conditions, like drought, high temperatures, and repellent soil microorganisms, could be omitted. We intended to evaluate the biocontrol potential of directly applied EPB cells and cell-free culture media (CFCM) on the larval instar E. ceratoniae. Xenorhabdus budapestensis DSM 16342 (EMA), X. szentirmaii DSM 16338 (EMC), and Photorhabdus luminescens ssp. laumondi (TT01) strains were used. After three days of exposure, the cells of EMA, EMC, and TT01 strains resulted in 100%, 88%, and 79.3% larval mortality rates, respectively. The applied EMA CFCM resulted in 53.7% larval mortality, indicating the presences of (at least) one extremely strong component produced by EMA. We concluded that the direct application of either the EPB cells or the CFCM must be a prospective alternative biocontrol of E. ceratoniae, especially to protect the important fruit (pomegranate, Punica granatum) cultivars. Especially, newly identified local EPB isolates could be applied as bio-pesticides for integrated management practices or organic pomegranate production.

Olfactory Sensilla and Olfactory Genes in the Parasitoid Wasp Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae).

Simple SummaryParasitic wasps are the major natural enemies of many organisms, and therefore they are broadly used in the biological control of numerous agricultural and horticultural pests. For example, Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) is a tiny natural egg parasitoid of various agricultural pest insects, including Plutella xylostella, Helicoverpa armigera, Spodoptera frugiperda and Ectomyelois ceratoniae. However, how T. pretiosum seek and localise host insect eggs is still not clear. The olfactory system is critical in guiding insect behaviours, including mating, feeding and oviposition, which play pivotal roles in the interactions between parasitoid wasps and their hosts. This project aimed to investigate T. pretiosum major olfactory tissue (antennae) and the olfactory genes, including odorant binding proteins (OBPs) and odorant receptors (ORs). T. pretiosum adult antennae were examined under scanning electron microscopy, and four types of olfactory sensilla were observed. Using T. pretiosum genome, 22 OBPs and 105 ORs were identified, which were further compared with olfactory genes of other Hymenoptera insect species. The expression patterns of OBPs between T. pretiosum male and female adults were examined to identify female- or male-specific OBPs. This study enriches our knowledge of T. pretiosum olfactory system and will help better use it in the integrated pest management (IPM) for many insect pest species.Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) is a tiny natural egg parasitoid of several agricultural pest insects, which has been widely used in the biological control for Plutella xylostella, Helicoverpa armigera, Spodoptera frugiperda and Ectomyelois ceratoniae. However, limited studies have been conducted on T. pretiosum olfactory system, which is critical in regulating insect behaviours. In this study, T. pretiosum adult antennae were investigated under ascanning electron microscopy (SEM). Four types of olfactory sensilla were observed, including chaetica sensilla (CS), trichoid sensilla (TS), faleate sensilla (FS) and placoid sensilla (PS). Using T. pretiosum genome, 22 putative odorant binding proteins (OBPs) and 105 odorant receptors (ORs) were identified, which were further compared with olfactory genes of Apis mellifera, Nasonia vitripennis and Diachasma alloeum. The expression patterns of OBPs between T. pretiosum male and female adults were examined by quantitative real time PCR (qRT-PCR) approaches. Three female-specific OBPs (TpreOBP19, TpreOBP15 and TpreOBP3) were identified, which may play crucial roles in T. pretiosum host-seeking and oviposition behaviours. This study enriches our knowledge of T. pretiosum olfactory genes and improves our understanding of its olfactory system.

Effect of Two Essential Oils From the Asteraceaes Family Against Ectomyelois Ceratoniae Zell. (Lepidoptera, Pyralidae): Case Of Artemisia Herba-Alba Asso. And Artemisia Compestris L.

The current work was done Artemisia herba-alba and Artemisia compestris essential oils harvested from the Eastern Algerian Sahara, their insecticidal characteristics against the eggs and adults of the date moth Ectomyelois ceratoniae. Indeed, two treatment modes were used; by contact application on eggs and by inhalation against adults. It appears from the results that the hatch rates were less than the hatching rate recorded in the control (96% ±00.00). The hatching rate reported on eggs treated by the highest dose (160 μl/ml) of Artemisia herba-alba and Artemisia compestris essential oils are 16.66 ± 08.81 and 37.77 ± 13.47 respectively. Statistical treatment results by the Chi-square test (χ2), attest that the treatment by A. herba-alba and Artemisia compestris essential oils at the same dose (160 μl/ml) affect significantly (χ2 = 35.62, p = 0.00 and χ2 = 21.17, p = 0.00 respectively) the hatching rate compared to the control. The sensitivity of adults to essential oils is expressed by 100% mortality rates obtained after 10 min of treatment by the highest doses (80 μl/ml and 160 μl/ml) of A. herba-alba essential oils, the same mortality rates (100%) were notified with the same doses (80 μl/ml and 160 μl/ml) after 20 min and 15 min of treatment by Artemisia compestris essential oils respectively. The dose-dependent mortality data revealed that there was a significant difference between the five doses of A. herba-alba essential oil tested except at the last treatment time (20 min) for which it was appeared p = 0.571, while for A. compestris essential oil, a significant difference was recorded with p varying between 0.00 and 0.003. The lowest LD50 value (0.09 μl/ml and 16.71 μl/ml) were noted during the longest treatment time (20 min), while the highest LD50 value (75.85 μl/ml and 263.7 μl/ml) were found during the shortest time (5 min) of A. herba-alba and A. compestris respectively. J. Bio-Sci. 29(2): 09-17, 2021 (December)

Suitability of Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) as host for two local Trichogramma species (Hymenoptera: Trichogrammatidae) and possible implications on biological control programs

In this study, laboratory tests were conducted to evaluate the suitability of Ectomyelois ceratoniae (Zeller) eggs as host for the development of two Trichogramma species: Trichogramma cacoeciae (Marchal) and Trichogramma bourarachae (Pintureau and Babault) (Hymenoptera: Trichogrammatidae) collected in Tunisia and reared on Ephestia kuehniella Zeller eggs. We also studied effects of five different temperature regimes (15, 20, 25, 30 and 35°C) on the biological traits of these two parasitoids. Results showed that eggs of E. ceratoniae were more suitable for the development of T. bourarachae. The number of parasitized eggs (15.46±2.04) as well as the emergence rate (95.78±5.10) was significantly higher compared to T. cacoeciae. For both Trichogramma species, the highest parasitism rate was observed at 30°C. At 35°C, the mean number of parasitized eggs (32.06±13.32) and the longevity (4.03±0.56) of T. bourarachae females were significantly higher compared to T. cacoeciae. The developmental time of both Trichogramma species was shorter at higher temperatures. The emergence rates were similar and relatively high in all tested temperature ranging from 80.48% to 97.92% for T. bourarachae and from 92.03% to 99.33% for T. cacoeciae.

The influence of calyx removal and fruit bagging on carob moth, Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae), infestation in pomegranate

Carob moth [Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae)] is a serious pest of pomegranate orchards in several parts of the world, including Turkey. Insecticides are often not a viable option to manage this pest as the larvae are protected inside the pomegranate fruit. This study evaluated the potential of fruit bagging (B), calyx removal (RC) and fruit bagging after calyx removal (BRC) for managing carob moth during 2016–2018 in two districts of Şanlıurfa Province, Turkey. Fifty trees were randomly selected from each location when pomegranate fruits reached the size of a walnut, i.e., approximately 3–5 cm diameter (end of May to start of June). Two fruits were marked for each method on each selected tree, whereas two fruits were reserved for control treatment. All fruits were examined during mid-August and late-September to determine carob moth infestation. The tested methods significantly (p < 0.01) differed for carob moth damage at both locations during each year. All the methods successfully controlled carob moth compared to control treatment. Infestation rate was 0%, 3.75% 23.75% and 57.25% for BRC, B, RC and control treatments, respectively. Covering pomegranate fruits with net bags has potential as an environment-friendly alternative management method for carob moth. Fruit bagging after calyx removal can give 100% control of the pest without any damage to the fruit. Nonetheless, future studies are needed to explore whether bagging can protect fruits from abiotic stresses and other pests.

Population growth model of the carob moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae) under field conditions

The carob moth, Ectomyelois ceratoniae Zeller, is the most important pest on pomegranate fruits and has several overlapping generations per year in Iran. This paper investigated the use of a mechanistic model for describing the effect of the control strategy on the size of the total population of the carob moth. The analytical solution of mechanistic model was written in the form of a logistic probability density function by Matis et al. (2006). The logistic probability density function fits this carob moth data very well for control and treatment fields (r2=0.91 and 0.95). The parameters of the model are the predicted peak size, Nmax, the predicted time of peak, tmax, and an approximate per capita birth and death rate, all of which are important in practical application. In general, this paper demonstrates the utility of analyzing carob moth population data using mechanistic models and their underlying rate parameters.

EFFECT OF BIOCHEMICAL METABOLITES OF DATES ON NUTRITIONAL PERFORMANCES OF CAROB MOTH, (ECTOMYELOIS CERATONIAE ZELLER (LEPIDOPTERA: PYRALIDAE))

The carob moth, Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) is considered as one of the most redoubtable pests threatening the production of date fruit, (Phoenix dactylifera L.), in Algeria. . In this research, nutritional indices and energy reserves of E. ceratoniae in response to feeding on three date varieties (Deglet Noor, Mech Degla and Ghars) were studied at 28 ± 1°C, relative humidity of 65 ± 5% and a photoperiod of 16:8 (L:D) hours. Biochemical and physical characteristics date varieties of were determined, and a correlation was made with nutritional responses of E. ceratoniae. Significant differences were observed in nutritional yield and energy contents of E. ceratoniae across various date varieties. The relative intake rate (TRI) of the larvae of E. ceratoniae showed a very highly significant difference between the three varieties studied. The highest relative intake rate was observed in larvae fed by the Deglet Nour variety, while the lowest TRI was recorded in the Ghars variety.

Effectiveness of mass trapping and Trichogramma cacoeciae (Hymenoptera: Trichogrammatidae) releases against Ectomyelois ceratoniae (Lepidoptera: Pyralidae) in Tunisian oases

This study was carried out to evaluate two biological methods for the control of Ectomyelois ceratoniae (Lepidoptera: Pyralidae) which is considered to be the most important pest species in Tunisia. Mass trapping through 14 traps (water and delta) baited with sex pheromone, and Trichogramma cacoeciae releases with two doses: 25,000 Trichogramma (T)/ha (D1) and 50,000 T/ha (D2) were tested separately. Field trials were conducted during 2016 in oases cultivated by date palm trees and pomegranates. In this experiment the infestation rates for delta traps, water traps and control were 17.6, 32.9 and 87.3%, respectively. Therefore, mass trapping with 14 delta traps was the most effective on pomegranate fruits. After inundative releases of T. cacoeciae (D1: 25,000 and D2: 50,000 T/ha), the results revealed an impact of this parasitoid in inhibiting carob moth eggs hatching, and a significant reduction of the infestation rate of pomegranate fruits between 19.1 and 22.7% for both doses compared to control plot with 87.3%. However, these trials (mass trapping and Trichogramma releases) applied on date palm trees were not sufficient to limit economic losses.

Insect and avian threats to the industrial production of balanites fruit in Eritrea

Balanites fruit pulp and seed kernel contain considerable amount of steroidal saponins, which are used as raw material for the production of pharmaceutical drugs. However, insect and avian pests are the key limiting factors in balanites production. This study was conducted to record the causal insect and avian pests and level of their infestation. Balanites fruits fallen on the ground were collected at regular intervals for two fruiting seasons at Keren, Eritrea. The fruits were put in polybags and stored at room temperature. The emerging insects were counted and percent infestation was calculated. The insects identified were balanites stone borer, Eublemma (= Eupsoropsis) robertsi (Lepidoptera: Erebidae) and carob moth, Apomyelois (=Ectomyelois) ceratoniae (Lepidoptera: Pyralidae). Eublemma robertsi larva consumed the kernel and bored into the stone with one exit hole (ca. 3 mm) at pre-pupal stage whereas A. ceratoniae larvae infested and contaminated fruit pulp with faecal waste. More than 70% of fruits collected during October and November were infested by E. robertsi and oviposition of 1–3 eggs were found on 73% of examined fruits. Damage from A. ceratoniae was unnoticeable in field-collected fruits but larval infestation was observable after one month of storage. The speckled mousebird, Colius striatus (Coliiformes: Coliidae), was the most frequent avian visitor, which not only nibbled on fruits attached to branches but also caused drop of fruits to the ground. Fruit damage caused by birds ranged 58 to 95% during the two fruiting seasons.

The Influence of Fertilization on Pomegranate Susceptibility to Infestation by Ectomyelois ceratoniae

ABSTRACT Carob moth, Ectomyelois ceratoniae Zell (Lep.: Pyralidae), is the most important pest in Iranian pomegranate orchards and imposes tremendous annual economic loss to the pomegranate producers. A two-year study was conducted to investigate the effects of the utilization of different fertilizers on the carob moth infestation of pomegranate cv. ‘Bajestani’. Fertilizer programs significantly affected fruit infestation. The highest infestation rate was recorded in unfertilized plants (38.07%, 31.44% in the first and the second years, respectively). Among different treatments, chemical and humic fulvic-containing fertilizers proved to be the most efficient treatments for controlling carob moth. A Significant correlation was observed between carob moth infestation and various fruit and tree-related attributes. The peel hardness and its hardness-associated nutrients (Ca, K and Si), as well as total phenolic content of fruit juice, were among the factors that showed a high negative correlation with carob moth infestation. According to our results, a combination of organic and Si, Ca, and K-containing fertilizers has great practical potential in the management of pomegranate orchards to reduce the carob moth damages.

Performance of Habrobracon hebetor (Say) (Hymenoptera: Braconidae) parasitizing Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae) on different pomegranate cultivars

Habrobracon hebetor (Say) (Hymenoptera: Braconidae) is an important ectoparasitoid for biological control of several lepidopteran insect pests. The present research evaluated plant-herbivore-parasitoid interactions with H. hebetor and Ectomyelois ceratoniae (Zeller) on five commercial cultivars of pomegranate (Punica granatum L.), including Esfahani-Daneghermez and Malase-Danesyah (relatively resistant), Gabri and Tafti (moderately susceptible) and Shahvare-Danesefid (relatively susceptible) under controlled conditions as follows: 30 ± 1 °C, 60 ± 5% RH with a photoperiod of 14:10 (L:D) h. Significant differences were observed in the demographical parameters of H. hebetor on different pomegranate cultivars. The shortest immature development time of parasitoid wasp was detected on Shahvare-Danesefid cultivar, and the longest period was on Malase-Danesyah and Esfahani-Daneghermez cultivars. Fecundity rate was the highest on Tafti and Shahvare-Danesefid cultivars and the lowest on Malase-Danesyah. Furthermore, there were no significant differences among pomegranate cultivars in the gross reproductive rate (GRR) and net reproductive rate (R0) parameters of H. hebetor. The highest value of intrinsic rate of increase (r) was observed on Shahvare-Danesefid (0.249 d−1), and the lowest was on Malase-Danesyah (0.196 d−1). Significant positive or negative relationships were observed between the life history parameters of H. hebetor and the biochemical traits of pomegranate cultivars. Shahvare-Danesefid cultivar was found to be a more appropriate host than other cultivars to develop H. hebetor. These results may provide fundamental data to further understand pomegranate-carob moth-parasitoid wasp relationships. Most importantly, our findings indicated that dynamic variations in the quality of host plant affected the performance and multitrophic communications behavior of H. hebetor.