Coconut Pest Research Articles

Genomic identification of Oryctes rhinoceros nudivirus isolates, a biocontrol agent for coconut rhinoceros beetle

The coconut rhinoceros beetle (Oryctes rhinoceros, CRB) is a serious pest of coconut and oil palms. It is native to South and Southeast Asia and was inadvertently introduced to Samoa in 1909. It has invaded many other Pacific countries throughout the last century. Oryctes rhinoceros nudivirus (OrNV), a natural pathogen of CRB in its native range, was successfully introduced as a classical biocontrol agent and has effectively suppressed invasive CRB populations for decades. However, resurgence of CRB has been recorded, with new invasions detected in several Pacific Island Countries and Territories. Additionally, new populations of CRB are emerging in some invaded areas that have a degree of resistance to the virus isolates commonly released for CRB biocontrol. Here, we designed a fast and reliable tool for distinguishing between different OrNV isolates that can help with the selection process to identify effective isolates for management of new CRB invasions. A comparison of 13 gene/gene region sequences within the OrNV genome of 16 OrNV isolates from native and invaded ranges allowed us to identify unique Single Nucleotide Polymorphisms (SNPs). With these SNPs, we developed an assay using multiplex PCR-amplicon-based nanopore sequencing to distinguish between OrNV isolates. We found that as few as four gene fragments were sufficient to identify 15 out of 20 OrNV isolates. This method can be used as a tool to monitor the establishment and distribution of OrNV isolates selected for release as biocontrol agents in CRB-infected areas.

Characterization and screening of new Metarhizium isolates to control the coconut rhinoceros beetle in the Pacific islands

The coconut rhinoceros beetle (CRB; Oryctes rhinoceros) is one of the most destructive insect pests of coconut and oil palms in tropical Asia and the Pacific islands. Members of a new variant, known as CRB-G (clade I), have recently spread into the Pacific islands, causing significant damage. Biopesticides containing Metarhizium spp. are the strongest candidates for inundative biological control against the emerging CRB threat. Selection of the most virulent and robust isolate may determine the impact of this control option on the pest. In this work, CRB specimens with natural fungal infection were collected in Papua New Guinea (PNG) and Solomon Islands (SI). Putative entomopathogenic fungi were isolated and identified. These new isolates and some previously obtained from other Pacific countries were molecularly identified, characterized, and tested for virulence against CRB larval populations in PNG and SI in laboratory bioassays. Of the new isolates collected, four obtained from SI were identified as Metarhizium majus (conidia length ⁓11–15 μm), and four from PNG were identified as Metarhizium pingshaense (conidia length ⁓4–6 μm). The most virulent isolate was M. majus AgR-F717, which caused 100 % mortality in 20–23 days against a CRB variant from the CRB-S grouping (clade II) in laboratory bioassays carried out in PNG. Isolates of M. pingshaense did not show pathogenicity against CRB larvae. M. majus AgR-F717 was also the most virulent in laboratory bioassays using the mixed SI population (from both CRB-S and CRB-G groupings) and was selected for further evaluation using artificial breeding sites. Under field conditions, this isolate demonstrated its ability to infect CRB, dispersal up to 100 m from treated artificial breeding sites, and persistence in soil for at least four months. The new isolate AgR-F717 of M. majus has demonstrated potential as an augmentative biological control agent for CRB in PNG and SI.

Comparison of Biology and Reproductive Potential of Two Invasive Coconut Whiteflies, Aleurodicus rugioperculatus Martin and Paraleyrodes bondari Peracchi through an Age-Stage, Two-Sex Life Table Approach

Two invasive species of whiteflies, Aleurodicus rugioperculatus Martin and Paraleyrodes bondari Peracchi, have recently emerged as major pests of coconut (Cocos nucifera L.). Age-stage, two-sex life tables of these two whitefly species on coconut were compared to study their growth, development and reproductive characteristics. The results revealed that P. bondari exhibited a faster developmental time and longer oviposition period (11.46 ± 0.25 days), which resulted in higher values of net reproductive rate (R0 = 42.55 ± 4.71 offspring/individual), intrinsic rate of increase (r = 0.12 ± 0.01 per day), finite rate of increase (λ = 1.13 ± 0.01 per day), and gross reproduction rate (GRR = 56.18 ± 4.25 individuals/generation). Additionally, P. bondari had a lower mean generation time (T = 30.29 ± 0.19 days) when compared to A. rugioperculatus (T = 40.33 ± 0.21 days). The fecundity of P. bondari (72.94 ± 1.51 eggs/female) was significantly higher than that of A. rugioperculatus (53.81 ± 1.56 eggs/female). As a result, P. bondari exhibited a competitive advantage over A. rugioperculatus. These findings contribute to a better understanding of the bioecology of these two distinct invasive whitefly species, particularly in the context of interspecific competition within the same ecological niche.

Rugose spiralling whitefly, Aleurodicus rugioperculatus Martin infested host plant volatiles elicit a host locating behavior of aphelinid parasitoid, Encarsia guadeloupae Viggiani (Hymenoptera: Aphelinidae)

Parasitoids find their hosts by using cues released by herbivores and their host plants. In crop fields, these semiochemicals could be used for insect pest control by attracting and retaining natural enemies. The hymenopteran aphelinidae endoparasitoid, Encarsia guadeloupae (E. guadeloupae), selectively parasitizes rugose spiralling whitefly (RSW), Aleurodicus rugioperculatus Martin, an invasive pest of coconut in India, thus offering an effective way to improve RSW control under natural field conditions. However, the chemical interactions that occur in between the RSW infected host plants and E. guadeloupae were unknown. Hence, using olfactometer assays and chemical analyses, we investigated the volatile organic compounds (VOCs) mediating attraction of the parasitoid to RSW infested host plants. To investigate the attraction of the E. guadeloupae towards the healthy and RSW infected leaves of coconut (Cocos nucifera L), banana (Musa paradisiaca L) and custard apple (Annona squmosa L), we employed a six-arm olfactometer. The E. guadeloupae preferred the volatile compounds from RSW-infested host plants rather than healthy plants. A higher percent response rate of E. guadeloupae was observed in RSW-infected banana (35.83 %), followed by healthy banana (24.33 %), RSW-infested custard apple (16.33 %), and RSW-infested coconut (9.00 %) leaf volatiles, respectively. The volatile compounds emitted from RSW-infested and healthy plants have been studied using GC–MS with thermal desorption (TD). The results revealed more than 20 volatile compounds belonging to seven chemical classes were identified and characterized from infested plants by RSW. Of these, α-Ocimene, α-Pinene, 3-Carene, trans-α-Ocimene, and (E)-hex-3-ene-2, 5-diol were emitted at higher levels than other compounds its proven through PCA and Heat map analysis. These five compounds elicited the greatest attraction of E. guadeloupae towards RSW damaged plants. The synthetic blend of the above volatiles could be used as attractants to enhance the population of E. guadeloupae to manage RSW under field conditions.

Diversity of Bacterial Gut Microbiome of Oryctes rhinoceros Larvae and Their Potency as Source of Protease and Lipase Enzymes

<p><em>Oryctes rhinoceros </em>is an important pest of various coconut and palm species. Studies on the bacterial gut microbiome of <em>O. rhinoceros</em> larvae and their potential use as producers of industrial enzymes are still limited. This study aims to examine the diversity and abundance of bacterial microbiome in the gut of <em>O. rhinoceros</em> and their potential to produce protease and lipase. This study consisted of several stages, i.e., collection of <em>O. rhinoceros</em> larvae from coconut plantations; isolation of culturable bacteria from larval gut; protease and lipase enzyme activity assays; and partial characterization of culturable gut bacteria in terms of morphology, physiology, and biochemistry. There were seven bacteria that were isolated from the gut of <em>O. rhinoceros</em>, which were differentiated by their morphotype. The seven bacterial isolates also showed variations in physiological, and biochemical characteristics, and the larval guts were dominated by Gram-positive bacteria. The Shannon diversity index was 1.33, evenness was 0.682, richness was 7, and the abundance of each type of bacteria varied between 2x10<sup>5</sup> and 9.1x10<sup>10</sup>. Bacteria UBOG1, UBOG3, and UBOG5 were able to produce protease, but all seven bacteria were unable to produce lipase. Thus, bacterial isolates UBOG1, UBOG3, and UBOG5 are potential to be used in industry.</p>

Coconut farmers’ knowledge of host and management approaches of rugose spiraling whitefly (Aleurodicus rugioperculatus Martin) in Bangladesh

Rugose spiraling whitefly (Aleurodicus rugioperculatus Martin) has become a major pest of coconut in Bangladesh. To assess farmers’ knowledge on host and management approaches of this pest, a survey of 240 farmers was conducted in eight districts of Bangladesh. Farmers noticed an expanding dispersion of this pest in Bangladesh since 2019. Among all the districts examined, Cox’s Bazar district was highly infested. Farmers mainly cultivated local coconut varieties in their homesteads. Forty percent (40%) of the farmers among all districts estimated that the pest reduced coconut yield to more than half. Only 1% of all farmers knew about all life stages of the pest. Consultation with extension officers significantly improved farmers’ knowledge of the pest. Summer was the peak season for the whitefly infestation. Farmers identified 22 hosts of the pest and almost four out of ten (40.4%) applied management methods against the pest. Among them, 22% used chemical methods, 42% used non-chemical methods, and 24% used both methods. Farmer’s types, purposes, and knowledge influenced their management approaches.

Pollen as sole food source for two generalist predatory mite species (Acari: Phytoseiidae)

Amblyseius largoensis and Typhlodromus ornatus (Acari: Phytoseiidae) are generalist predatory mites that naturally inhabit coconut plantations and other tropical crops. We assessed the suitability of two coconut pest mites, Raoiella indica (Acari: Tenuipalpidae) and Aceria guerreronis (Acari: Eriophyidae); the storage mite Tyrophagus putrescentiae (Acari: Acaridae); honey; and the pollens of castor bean, Ricinus communis, and cattail, Typha domingensis, and their mixture, as food sources for the mass rearing of A. largoensis and T. ornatus. Both pollens, supplied singly or mixed, generated the highest progeny production by both A. largoensis and T. ornatus, and were therefore selected for further life table studies. The pollen diets did not influence the survival of A. largoensis whereas there was higher survivorship of T. ornatus fed on the mixed pollen diet than on R. communis pollen alone. The maximum oviposition rate of both A. largoensis and T. ornatus occurred at the beginning of adulthood, irrespective of the pollen diet. Overall, the life table parameters indicated that the pollen of R. communis for A. largoensis, and R. communis with the mixed pollen diet for T. ornatus, were the best regarding population growth and reproduction. Collectively, our results indicate that A. largoensis and T. ornatus can survive and reproduce excellently when fed solely on R. communis or on the mixed pollen diet. In addition, these results point to the potential of pollen supplementation for the enhancement of the efficiency of these predators in conservation biological control.

Alternative Management of Raoiella Indica Hirst, 1924 (Acari: Tenuipalpidae) With Passion Fruit Seed Extract

Objective: The aim of this work was to evaluate the acaricidal potential of the passion fruit seed extract (Passiflora edulis) in controlling the red palm mite (R. indica). Theoretical framework: Raoiella indica is a pest mite of agricultural interest, considered one of the main pests of banana, coconut, date palm, and ornamental crops. Method: The experiment was conducted in a completely randomized design using passion fruit seed extract, with 7 repetitions and 12 R. indica individuals per repetition. The concentration tested was 1.0; 1.72; 2.95; 5.08; 8.73, and 15.0 %. The experimental units consisted of coconut leaf discs (4 cm in diameter) with moist cotton at the bottom of the Petri dish (10.0 x 1.2 cm) and around the disc to maintain turgidity and prevent the mites from escaping. The application was carried out using an airbrush, connected to a compressor calibrated with a constant pressure of 1.3 psi and 1 mL of solution per plate. The evaluation was conducted at intervals of 24, 48, and 72 hours following the extract's spraying. Results and discussion: Mortality was observed in the dose-response model, the concentration of 15 % showed mortality rates greater than 98.8 % of individuals. Amounts of phenolics of 10.242, tannins of 14.837, and flavonoids of 9.700 in mg g-1 were found, attributing the mortality of individuals to the presence of these compounds. It was concluded that the passion fruit seed extract has an acaricidal effect on R. indica in the laboratory. Implications of the research: Alternative pest management has grown substantially in recent years, given the demand for more sustainable products in the agricultural field. The use of botanical extracts is beneficial to the environment, as it does not promote soil and water contamination and can be an efficient method for controlling agricultural pests. Originality/value: This article adds value to research areas such as alternative management of agricultural pests, and sustainability and suggests a change in the environmentally conscious behavior of rural producers.

Uji Efikasi Berbagai Konsentrasi Insektisida Nabati Buah Majapahit (Aegle marmelos L. Correa) terhadap Mortalitas Hama Uret Tanaman Kelapa (Oryctes rhinoceros L.)

A type of insect that causes a decline in coconut production is the uret pest of coconut (Oryctes rhinoceros L.). The vegetable pesticide of the majapahit fruit is one of several techniques for controlling pests. This study was carried out from April to July 2022 at the Plant Protection Laboratory of the Department of Agricultural Production, Jember Country Polytechnic. The goal of this investigation was to determine the impact of the majapahit vegetable pesticide on the death of the uret pest of coconut plants. This study employed a non-factorial randomized block design (RBD) with four treatments and six replications, namely control, 50%, 60%, and 70% majapahit fruit extract.. The experimental data were examined using ANOVA; if the findings indicated a significant influence, a 5% stage LSD similarly check was carried out, along with the determination of LT50 using probit analysis. Mortality, physical changes, and LT50 are the key factors. The results showed that the majapahit fruit's natural insecticides had a significant impact on the death of the coconut plant's ureth pest, with the LT50 value at a concentration of 70% majapahit fruit extract reaching its lowest point in 178 hours.

Antimicrobial Potential of Rhynchophorus Beetle Larval Haemolymph Against Methicillin-Resistant Staphylococcus aureus and Neisseria gonorrhoeae.

<b>Background and Objective:</b> The emergence of methicillin-resistant community-acquired <i>Staphylococcus aureus </i>and antibiotic-resistant <i>Neisseria gonorrhoeae</i> has raised significant concerns. Efforts to combat resistance involve the exploration of novel alternative therapies, particularly those derived from insect components. <i>Rhynchophorus</i> sp., a coconut pest commonly found in Southeast Asia, has haemolymph that exhibits bactericidal properties<i>.</i> The objective of this study was to assess the potential of the haemolymph of <i>Rhynchophorus</i> sp., larvae as an antimicrobial agent against Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) and <i>Neisseria gonorrhoeae</i>. <b>Materials and Methods:</b> In this study, <i>Rhynchophorus</i> sp., larvae were gathered for the purpose of haemolymph extraction. These larvae were then divided into distinct groups, with one group subjected to immunization using <i>Escherichia coli</i>, while another group was left unimmunized. The study utilized the well diffusion method to evaluate antibacterial effectiveness. <b>Results:</b> Haemolymph fluid extracts from <i>Escherichia</i> coli-immunized <i>Rhynchophorus</i> sp., larvae, exhibited strong antibacterial activity, with an average value of 19.3±0.47 mm, against MRSA, more enhanced compared to unimmunized larvae. In contrast, haemolymph fluid extracts from <i>Escherichia coli</i>-immunized <i>Rhynchophorus</i> sp., larvae demonstrated a more moderate antibacterial activity, with a mean of 14.17±0.27 mm, against <i>Neisseria gonorrhoeae</i>, a level similar to unimmunized larvae. <b>Conclusion:</b> The haemolymph extracted from <i>Rhynchophorus </i>sp., beetles larvae exhibited antimicrobial effects against MRSA and <i>Neisseria gonorrhoeae</i>, particularly when it is enhanced through <i>Escherichia coli</i> immunization.

White Grub (<i>Leucopholis coneophora</i> Burmeister) Management in Mid-Hill Region of Meghalaya

White grubs are one of the most damaging soil insect pests inflicting economic losses in groundnut cultivation in India. The white grub Leucopholis coneophora (Burmeister) is a polyphagous pest of coconut and intercrops. However, in the mid-hill region of Meghalaya, the occurrence of this species was recorded, which calls for an investigation. Also, there is a need to develop location-specific and easily adoptable climate-ready technologies before it attains pest status. In this context, a field experiment was conducted to evaluate the efficacy of few insecticides and bioformulations with different methods of application. Results showed that seed treatment with imidacloprid 17.8SL @ 3ml/ kg seeds proved to be the most effective by exhibiting the lowest grub incidence (0.17 grubs/ 12 sq m plot) and minimum plant infestation (1.82%). For bioformulations, field spraying with Metarrhizium anisopliae (1x108 spores/ml @5ml/ l) was found to be superior over Beauveria bassiana at the same dose. These results will aid in formulating an ecofriendly IPM strategy for white grubs in this climate-resilient region of India.

Assessment of bio-formulations of indigenous strains of Bacillus thuringiensis, Metarhizium robertsii and Metarhizium majus for management of the rhinoceros beetle, Oryctes rhinoceros L., in field

BackgroundAmong all the coconut pests, rhinoceros beetle causes acute and serious damage to coconut palm. Management of this pest is very difficult due to its nocturnal activity, and also, it damages the emerging leaf inside the bud. Management of rhinoceros beetle using entomopathogens will be of great importance as it is economical and ecofriendly. Studies were carried out to decipher the biocontrol potential of indigenous entomopathogenic bacterium (Bacillus thuringiensis) and entomopathogenic fungi (Metarhizium robertsii and M. majus) against Oryctes rhinoceros in the field, individually as well as in combination, by soil drench as well as by topical spray method.ResultsThe study showed that B. thuringiensis strain NBAIR-BTAN4 showed 24.8% mortality at 5th week in soil drench method and 24% mortality in topical spray method. M. robertsii showed 24% mortality at 5th week in soil drench method as well as topical spray method. Similarly, M. majus showed 24% mortality in soil drench method and 23.2% in topical spray method at 5th week. In combination, NBAIR-BTAN4 + M. robertsii showed 40.8 and 44% in soil drench and topical spray method at 5th week, respectively. Combination of NBAIR-BTAN4 + M. majus showed 44.8 and 40.8% in soil drench and topical spray method at 5th week, respectively. Combination of NBAIR-BTAN4 + M. robertsii + M. majus showed 52.8 and 57.6% mortality at 5th week in soil drench and topical spray method, respectively.ConclusionThe present study showed application B. thuringiensis in combination with M. robertsii and M. majus is effective in management rhinoceros beetle in coconut orchard. Study also indicated that soil drench method is more promising strategy than topical spray method in managing larval population of the beetles and also confirmed that B. thuringiensis, M. robertsii and M. majus are compatible and they seemed to have a synergistic effect in controlling the pest in coconut orchard.

Tracking potential biosecurity incursions using publicly available images: A case of coconut rhinoceros beetle

AbstractThe coconut rhinoceros beetle, Oryctes rhinoceros (L.), (CRB) is a major pest of coconut and oil palms that causes significant damage in the Asia/Pacific region. Traditional methods for surveillance and detection of CRB involve in‐person inspections, but these are expensive to carry out and were made impossible by travel restrictions during the COVID‐19 pandemic. In this paper, a method to remotely detect possible CRB incursions and assess damage levels using publicly available images is described. The method involves searching for pictures of palms and identifying those with the distinctive V‐shaped cuts in fronds characteristic of CRB feeding. The method was validated by examining palm images from known outbreak areas and those free from the pest. We found evidence of CRB damage in the previously unreported site of Dili, Timor Leste and possible evidence of CRB in the Solomon Islands even before it was first reported in 2015. Potential limitations and broader applications of this approach are also discussed.

A Conceptual Framework for a Modern Science of Integrated Pest Management for Pests and Diseases of Coconut

The integrated pest management (IPM) approach was introduced to alleviate the negative effects of synthetic pesticide use in any agroecosystem. Initially, IPM is proposed as a multidisciplinary environmentally-sensitive approach that utilizes biological, cultural, genetics, mechanical, physical, and other artificial techniques to manage the pest population. The IPM concept has evolved with various reported history as well as definitions and has been adopted to solve pest problems in different agroecosystems including coconut. This paper revisits the different approaches of IPM in coconut pests as well as the conceptual framework for IPM introduced by Stenberg (2017) and the new integrated pest management paradigm for modern age conceptualized by Dara (2019) to come up with a holistic IPM framework for the efficient control of pests and diseases of coconut for adoption of coconut-producing countries in the region.

Preface

The emerging pest and disease incursions in coconut growing countries result in great economic yield losses and negative impact to the industry, biodiversity loss, and disrupted native and agricultural system.Repeated use of the same active ingredient of pesticide to control pests and diseases could lead to pest and disease resistance. The inevitable effect of climate change, other environmental factors, and the destruction of natural enemies could trigger the incursion and migration of devastating pests and diseases. The massive planting and replanting could create homogeneity in coconut farms, predisposing these to disease infection and pest infestation. The concurrent reported outbreaks of Brontispa in Southeast Asia, Coconut Rhinoceros Beetle, Guam type (CRB-G) in Guam, and Asia-Pacic countries, Coconut Scale Insect in the Philippines, Lethal Yellowing in Jamaica, and Mexico, Bogia Coconut Syndrome in Papua New Guinea, Sexava, Rhyncophorus in Indonesia, and the recognition of the need to develop international biosecurity protocols for safe germplasm exchange have prompted the International Coconut Community (ICC) to hold the 1st IPM symposium.We know that pests and diseases reduced the ability of the industry to fully benefit from the market opportunities. In the face of this situation ICC Sessions and Ministerial meetings as the highest authority and the ICC recommended the ICC Secretariat to convene an IPM symposium to help countries overcome low coconut production due to pests and diseases.The general objective of the symposium is to establish an international IPM network system and synergy to protect the coconut producers & industries and conserve the coconut genetic resources and diversity from the adverse impact of pests and diseases through expertise and experience sharing.The specific objectives of the symposium are:1. To bring together key members of the scientific community for an interactive discussion on emerging issues and advances related to IPM, that will help enhance and develop IPM extension and research on invasive coconut pests and diseases2. To craft ecologically sound, science-based, and sustainable pest and disease management approaches based on IPM practices across countries.3. To create an international platform/network among coconut growing countries to strengthen the development of IPM strategies, pest and disease risk assessment, and inter-country collaborations that will address the research gaps and challenges of managing invasive pests/diseases losses and negative impact on the industry, biodiversity loss, and disrupted native and agricultural system.List of Editor-in-Chief, Managing Editor, Associate Editor, Scientific Committee of IPM Symposium Proceedings are available in this Pdf.

Acarofauna associated with coconut fruits (Cocos nucifera L.) in a crop area from Pará state, Amazon, Brazil

Aceria guerreronis Keifer and Steneotarsonemus furcatus De Leon are phytophagous mites that attack coconut fruits. These mites establish their colonies under the bracts in the perianth where they feed, causing necrosis and a loss of fruit quality and commercial value. Phytoseiidae is considered the most important family for the control of pest mites. With 256 species documented, the Phytoseiid fauna in Brazil is highly diversified. They are distributed across all Brazilian biomes, including the Amazon, Caatinga, Cerrado, Pampa, Atlantic Forest, and Pantanal. Regardless of the fact that the Amazon biome occupies an estimated 49% of the Brazilian territory, its acarofauna remains unexplored. In this region, coconut is one of the most cultivated crops, although the variety of mites in this crop in the Amazon is yet unclear. This information is essential since there are potential predatory species that can play an important role in the biological control of coconut pests. Thus, the present study investigated the diversity and seasonality of mites in coconut fruits in the Eastern Amazon production region throughout the year. Data were collected monthly and analyzed to determine the diversity and seasonality. The faunistic indices were calculated using the program ANAFAU, and the abundance and diversity of phytoseiids were analyzed using the software EstimateS. As the fruit ages, the quantity of injured fruits increases. The mites collected belonged to the families: Oribatida (20), Rhodacaroidea (14), Eriophyidae (473,904), Phytoseiidae (147), Tarsonemidae (133), Ascidae (122), Bdellidae (110), Tydeidae (59), Cunaxidae (7), Eupodidae (7), Cheyletidae (5), Blattisociidae (4), and Cryptognathidae (1). Throughout the collection period, A. guerreronis and S. furcatus were detected on fruits with and without damage, with A. guerreronis being the most prevalent. Predatory mites of the Phytoseiidae family were sampled from 12 collections, totaling 147 specimens distributed across eight species. Amblyseius aerialis (Muma) was the predominant predator species. The peak population of A. guerreronis and S. furcatus occurred in different periods, although both species were sampled during periods of high precipitation, suggesting adaptation to the climatic conditions of the region. Temperature was strongly correlated with mites of the Phytoseiidae family. The occurrence of these mites was more common in months with higher temperatures. The mite A. aerialis was discovered in 12 evaluations, with a greater occurrence in October 2019 and August 2020. Understanding the diversity, abundance, and population fluctuations of pest mites and their natural enemies in coconut plants is critical for developing integrated pest management strategies.

Invasion of Rugose spiraling whitefly (Hemiptera: Aleyrodidae) across Bangladesh coastal region causes widespread damage to coconut plants.

Rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin, a native pest of coconut in Central America, has recently been introduced to South-East Asia. Little is known about the spread of RSW in Bangladesh, the effect this pest has on coconut plants, or the full range of its plant hosts. To fill this knowledge gap, we conducted surveys across the southern coastal coconut producing region of Bangladesh. Coconut plant damage from RSW was high throughout all the areas surveyed, and this was correlated with the population density of RSW. Areas, such as Khulna, which had the highest population density of RSW, had the highest level of RSW leaf damage. Coconut plants with an infestation of RSW had significantly fewer leaves and fruits. The coconut fruits were also smaller, both in terms of size and weight, and contained less water and lighter endosperm compared to non-infested plants. This highlights the need for the management of RSW in coconut growing regions. We also report 39 new host plant species for RSW from 22 plant families, including the economically important mangrove plant Nipa palm, Nypa fruticans Wurmb.

Comparative assessment of Pest damage identification of coconut plant using damage texture and color analysis.

Coconut cultivation is a promising agricultural activity. But to keep the coconut plants pest-free, the detection of various pest damage in coconut plants is of utmost importance for the cultivators. The processes that the cultivators use to detect pest damage in coconut plants are conventional methods, experts' views, or some laboratory techniques. But these procedures are not adequate in the detection of coconut damage identification. In this study, 16 different color and texture features are reported for 1265 coconut pest damage images by extracting the color and texture features of the damage images in the color and grey domain after the damage segmentation using the thresholding technique. The Gray Level Co-occurrence Matrix (GLCM) and Gray Level Run Length Matrix (GLRLM) techniques are applied to extract the texture features of the damages and two Artificial Neural Network (ANN) architectures are reported to classify the extracted data features of the damages into 5 different classes such as Eriophyid_Mite, Rhinoceros_Beetle, Red_Palm_Weevil, Rugose_Spiraling_White_fly, and Rugose_in_Mature with an average testing accuracy of almost 100% respectively. To compare the results with the other machine learning techniques, the Support Vector Machine(SVM), Decision Tree (DT), and Naïve Bayes (NB) are also introduced for damage identification where the SVM methods also report almost 100% accuracy on the fuse features of GLCM and GLRLM. The results of the ANN and SVM are compared by finding the confusion matrix, precision, recall, and f-1 score of the ANN model with the DT and NB classifier. The ANN and SVM outperform in all matrices and they can be used as the base model for further study of coconut pest damage identification using deep learning techniques.

Performance and population prediction of Opisina arenosella on four species of palm plants

AbstractOpisina arenosella Walker (Lepidoptera: Oecophoridae) is a major pest of coconut, Cocos nucifera L. (Arecaceae), but also of other palm plant species. Information on its life history on hosts other than coconut is missing. Age‐stage two‐sex life tables and a population prediction model were used to assess the development, survival, reproduction, and population growth potential of O. arenosella populations bred from four palm plants: C. nucifera, Livistona chinensis (Jacq.) R.Br. ex Mart., Roystonea regia (Kunth) O.F. Cook, and Elaeis guineensis Jacq. The results revealed that O. arenosella could complete a generation on all four hosts. Still, they showed relatively high fitness on L. chinensis, second to that on C. nucifera, with the shortest generation time (egg to pupa, 71.1 days), higher stage survival (egg: 0.89; larva: 0.74; pupa: 0.56), fecundity (176.3 eggs), and population growth potential. On L. chinensis, net reproductive rate, R0, was 35.1, gross reproduction rate, GRR = 88.8, intrinsic rate of increase, r = 0.049 per day, finite rate of increase, λ = 1.050 per day, mean generation time, T = 72.1 days, and doubling time, DT = 14.1 days. Based on 10 eggs, the population prediction model showed that larval populations on L. chinensis could develop to the third generation in 180 days and reached the peak value (9870.2 larvae) on day 158. Besides coconut, all three palm plant species can support O. arenosella to complete the life cycle. The outcomes of this research may be beneficial in formulating pest management strategies for palm crops.

Spatial patterns of the leaf crown borer Eupalamides cyparissias (Cramer, 1775) (Lepidoptera: Castiniidae) in coconut (Cocos nucifera L.) tropical region.

The leaf crown borer Eupalamides cyparissias (Cramer, 1775) is an important pest of coconut (Cocos nucifera L.) and other palms (Arecaceae) of economic importance, attacking the base of leaves, inflorescences, and infructescences, increasing fruit abortion. The objective of this study was to evaluate the spatial correlation of the infestation rate of E. cyparissias in coconut plantation blocks in the Brazilian Amazon, from January to December 2019, in the city of Santa Izabel, Pará, Brazil. The study area is a farm subdivided into 157 blocks of a commercial plantation of the green dwarf coconut. The Local Moran's Index was used to evaluate the existence of spatial autocorrelation of the E. cyparissias infestation rate in the 157 blocks with neighboring blocks. The infestation rate was calculated by the ratio between the number of plants attacked by the borer and the total number of plants in a block. There is a significant correlation of the symptomatology of the attack by E. cyparissias in the blocks of the experimental area, which indicates an aggregated pattern of distribution. There is no significant correlation between the attack by the borer and the age of the coconut tree; however there is a significant correlation between the attack by the borer and proximity to forest areas. These results indicate that forest regions are foci of infestation by the borer in coconut plantations.