Pest Of Palms Research Articles

Knowledge Level on Bagworm in Oil Palm and its Control Using Integrated Pest Management (IPM) Practices Among Independent Oil Palm Smallholders in Johor

Bagworm (Psychidae) and nettle caterpillars (Limacodidae) are among the major insect pests of oil palm in Malaysia. Bagworm from the species Metisa plana is the most destructive insect pests compared to nettle caterpillar in oil palm plantations. Outbreaks of bagworms were frequently occurred in various areas own by independent oil palm smallholders in Johor. At present, no scientific study has been conducted to indicate the level of knowledge among the independent oil palm smallholders on bagworm and its control, especially using the Integrated Pest Management (IPM) practices. Therefore, this study was conducted to determine knowledge level on bagworm and its control using IPM among 313 independent smallholders in three infestation areas in Johor, which are Mukim Chaah Bahru, Mukim Chaah, Mukim Paloh and Mukim Chamek. Data were collected by interview guided with a questionnaire consisting 23 questions regarding bagworm and its IPM practices. Most of the respondents are more than 51 years (61.1%), with 77.7% males and 22.3% females. They are mostly having primary (47.1%) and secondary (47.5%) school qualifications. This study found that most of the respondents have a basic understanding of bagworm in oil palm and its control measures using IPM practices, but their knowledge is still at a low level. Correlation analysis showed a significant relationship between the level of knowledge on bagworm and its control methods with race, education level and field management experience among the respondents. Therefore, more focus should be given by extension agents to enhance smallholder knowledge on bagworm management, especially in the potential and affected areas in Johor.

Proteolytic Activation of Bacillus thuringiensis Cry3Aa Toxin in the Red Palm Weevil (Coleoptera: Curculionidae).

The red palm weevil (RPW), Rhynchophorus ferrugineus (Oliver) is an important pest of palms that causes significant damage by boring into and feeding within palm stem tissues. Here, we studied the proteolytic process of Cry3Aa in the RPW to understand the mechanism of Cry toxicity. The bioassays showed that Cry3Aa toxin is weakly toxic to the RPW. Proteolytic activation assays indicated the Cry3Aa protein is digested into smaller fragments than the 55-kDa activated fragments under different conditions. In particular, at higher mass ratios of gut protease and Cry3Aa protein (5:1, 2:1, and 1:1, respectively), and at 36.9°C for 16 h in a solution of pH 8.6, the Cry3Aa protoxin is over-digested by the gut proteases of weevil larvae. Moreover, the zymogram analysis of the gut proteases revealed the RPW larvae harbors intestinal digestive enzymes mainly composed of serine proteases. This study describes the proteolytic activation process of Cry3Aa in the midgut of RPW larvae.

Phoretic mite infestations associated with Rhynchophorus palmarum (Coleoptera: Curculionidae) in southern California

The South American palm weevil, Rhynchophorus palmarum (Coleoptera: Curculionidae), established in San Diego County, California, USA sometime around 2014. Attached to the motile adults of this destructive palm pest, we identified three species of uropodine mites (Parasitiformes: Uropodina), Centrouropoda n. sp., Dinychus n. sp. and Fuscuropoda marginata. Two of these species, Centrouropoda n. sp. and Dinychus n. sp. are recorded for the first time in the USA and were likely introduced by R. palmarum. Several species of mites, primarily of Uropodina, have previously been recorded as phoretic on Rhynchophorus spp. In this study, we examined 3,035 adult R. palmarum trapped over a 2.5-year period, July 2016 to December 2018, and documented the presence of and species composition of phoretic mites and their relationship with weevil morphometrics (i.e., pronotum length and width). The presence and species composition of mites on weevil body parts changed over the survey period. No mites were found under weevil elytra in 2016 and mite prevalence under elytra increased over 2017–2018 due to an increased abundance of Centrouropoda n. sp per individual beetle. Mite occurrence levels were significantly correlated with reduced pronotum widths of male weevils only. The significance of this finding on male weevil fitness is unknown. Potential implications of phoretic mites on aspects of the invasion biology of R. palmarum are discussed.

Susceptibility of Demotispa neivai (Coleoptera: Chrysomelidae) to Beauveria bassiana and Metarhizium anisopliae entomopathogenic fungal isolates.

The potential of Beauveria bassiana and Metarhizium anisopliae isolates obtained from naturally infected oil palm pests was evaluated to control Demotispa neivai as an alternative for organophosphate insecticide use in oil palm crops in Latin America. Two B. bassiana (Bb-0018 and Bb-0025) and two M. anisopliae (Ma-0002 and Ma-0003) isolates were tested against D. neivai adults for hydrophobicity, virulence, survival, adhesion to host cuticle, and mortality in semi-field conditions. Concentration-mortality bioassays demonstrate that isolates had lethal effect on D. neivai adults with Bb-0025 [median lethal concentration (LC50 )=3.45 × 107 conidia mL-1 ] and Bb-0018 (LC50 =3.75 × 107 conidia mL-1 ) being the most effective followed by Ma-0003 (LC50 =3.38 × 108 conidia mL-1 ) and Ma-0002 (5.33 × 108 conidia mL-1 ). Adult survival was 99% without exposure to fungal isolates, decreasing to 21.65% in insects exposed to Ma-0002, 19.41% with Ma-0003, 20.13% with Bb-0018, and 0.17% with Bb-0025. Mortality of D. neivai adults caused by the entomopathogenic fungal isolates was similar in both laboratory and semi-field conditions. Also, vegetative growth of the entomopathogenic fungal isolates was found in infected D. neivai adults in the field. Our data suggest that the tested entomopathogenic fungal isolates are effective against D. neivai with potential to be used as biological control agents contributing to the decrease of the use of chemical insecticides to control this oil palm pest. © 2021 Society of Chemical Industry.

Bioassay of Some Indigenous Entomopathogens for Controlling Rhynchophorus ferrugineus, Olivier in Saudi Arabia.

<b>Background and Objective:</b> The red palm weevil is a dangerous date palm pests that cannot be controlled with chemical pesticides only. As a result of the justified concerns of the negative use of synthetic insecticides on human health and the environment. So on, candidate eco-friendly micro-organisms isolated from KSA agri-ecosystems were evaluated in controlling RPW. <b>Materials and Methods:</b> Some indigenous entomopathogenic fungi and bacteria were isolated from naturally infected RPW larvae and adults and evaluated as alternative control methods. <b>Results:</b> The infection of RPW larvae with entomopathogenic fungi and bacteria under natural conditions was higher than in adults. <i>Beauveria bassiana </i>was the most prevalent followed by <i>Aspergillus </i>sp., <i>Metarhizium anisopliae</i>, <i>Mucor</i> sp., <i>Cladosporium chlorocephalum</i>. In contrast, both <i>Bacillus</i> <i>thuringiensis</i> and <i>Bacillus popilliae</i> formed 73.9 and 26.1%, respectively. From the 7th day, mortalities (%) increased gradually and recorded the highest mortalities with 21st days after treatment and recorded 93.33, 66.70, 53.36, 46.69 and 60.00% when treated with <i>B. bassiana</i>, <i>M. anisopliae</i>, <i>C. chlorosphalum</i>, <i>Mucor</i> sp. and <i>Aspergillus</i> sp., respectively. <b>Conclusion:</b> Although there was evidence indicating midgut damage and feeding inhibition among larvae that survived the treatments, instead of lower activity of <i>B. thuringiensis</i> against <i>R. ferrugineus</i> immature stages may refer to that, Both species of <i>Bacillus</i> were more virulent as the days 15-21 post-treatment.

Parasites rather than phoronts: Teratorhabditis synpapillata nematodes reduce lifespan of their Rhynchophorus ferrugineus host in a life stage-dependent manner.

Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) red palm weevils are often reported in association with different organisms including nematodes. The significance of this interaction and whether nematodes can influence their life‐history traits is unclear. We collected Rhynchophorus ferrugineus red palm weevils at different developmental stages and locations in Tunisia, observed and dissected them in search for nematodes and other interacting organisms, established laboratory colonies and identified the nematodes associated with them, and conducted nematode–insect interaction assays to determine the capacity of the nematodes to influence their life‐history traits. We observed Beauveria bassiana fungi in larvae, nymph, and adults; Centrouropoda and Uroobovella acari associated with the adults, and Teratorhabditis synpapillata nematodes associated with larvae and adults. Nematode–insect interaction bioassays revealed that T. synpapillata nematodes reduce the lifespan of the insect larvae in a population‐dependent manner, but do not influence the lifespan of adults. Our study uncovers an important factor that may determine population dynamics of this important palm pests and provides evidence to conclude that these organisms establish a parasitic relationship, rather than a phoretic relationship.

Pathogenicity of Beauveria bassiana Vuill in compost media for Oryctes rhinoceros L. oil palm pest control

The Oryctes rhinoceros pest is an important pest of palm oil plant. Pest problems occur because Oil Palm Empty Fruit Bunches (OPEFB) is added for soil fertility to create a breeding site for larvae O. rhinoceros. Generally, OPEFB will receive the plants more quickly when composted, and pest control is carried out in the compost. Biological control is more recommended because it is environmentally friendly, Therefore compost is added with biological control agent O. rhinoceros namely B. bassiana. This study is aimed to obtain the best conidia density of Beauveria bassiana in compost in controlling larvae O. rhinoceros. The research was carried out at the Plant Pest Laboratory and Experimental Garden, Faculty of Agriculture, Riau of University. The study was carried out from February to November 2020. The experiment on the conidia density of B. bassiana fungi in compost media against larvae O. rhinoceros, using a Completely Randomized Design (CRD), with 6 treatments 4 replications obtained 24 experimental units, while the treatments were 0 g.l-1, 15 g.l-1, 30 g.l-1, 45 g.l-1, 60 g.l-1 and 75 g.l-1. The results of the research revealed that OPEFB compost + sawdust containing the fungus B. bassiana 75 g.l-1 (83,2 x108 kon/ml) had the best ability to control larvae O. rhinoceros with a total larvae mortality of 87% which caused early death of 54 hours after application, LT50 of 213 hours after application, and LC50 of 3,3% or the equivalent of 33 g.l-1 at 14 days after application.

Genome-Wide Identification of the Gustatory Receptor Gene Family of the Invasive Pest, Red Palm Weevil, Rhynchophorus ferrugineus (Olivier, 1790)

Simple SummaryThe red palm weevil (Rhynchophorus ferrugineus) is an invasive pest that causes severe economic loss in palm plant cultivation (e.g., oil palm, date, and coconut) in many regions of the world. The development of efficient approaches to controlling this pest is urgently needed. Previous research focused on the molecular basis of its olfaction, leading to the identification of this species’ aggregation pheromone receptor, which can help develop biosensors and bait traps. To gain more understanding of the chemoreception in this species, we used a bioinformatic approach to identify all the gustatory receptor genes from its genome and transcriptome data. There are 50 gustatory receptor genes encoding 65 functional receptors, including CO2, sugar, and bitter receptors. Our results will help elucidate how this beetle discriminates and evaluates food and egg-laying sites and communicates via gustation.The red palm weevil (Rhynchophorus ferrugineus) is a highly destructive pest of oil palm, date, and coconut in many parts of Asia, Europe, and Africa. The Food and Agriculture Organization of the United Nations has called for international collaboration to develop a multidisciplinary strategy to control this invasive pest. Previous research focused on the molecular basis of chemoreception in this species, particularly olfaction, to develop biosensors for early detection and more effective bait traps for mass trapping. However, the molecular basis of gustation, which plays an essential role in discriminating food and egg-laying sites and chemical communication in this species, is limited because its complete gustatory receptor gene family still has not been characterized. We manually annotated the gene family from the recently available genome and transcriptome data and reported 50 gustatory receptor genes encoding 65 gustatory receptors, including 7 carbon dioxide, 9 sugar, and 49 bitter receptors. This study provides a platform for future functional analysis and comparative chemosensory study. A better understanding of gustation will improve our understanding of this species’ complex chemoreception, which is an important step toward developing more effective control methods.

Patogenity Of Beauveria bassiana On Compost Media For Palm Oil Pest Control Oryctes rhinoceros L

Oryctes rhinoceros is an important pest of oil palm. This study aimed to obtain the best ability of several compost organic materials containing B. bassiana for controlling O. rhinoceros larvae, to obtain the ability of B. bassiana in compost to control various instars of O. rhinoceros larvae, and to obtain the best concentration of Beauveria bassiana in compost in controlling O larvae. rhinoceros. Three stages of the research experiment were: 1) testing of several compost organic materials containing B. bassiana at 75 gl-1 concentration, using a completely randomized design (CRD), Experiment 2 were: test the ability of B. bassiana with 75 gl-1 concentration of compost at various instars of O. rhinoceros larvae. Experiment 3 were: concentration test of B. bassiana fungi in compost media against O. rhinoceros larvae, with 6 treatments 4 replications obtained 24 experimental units, while the treatments were 0 gl-1, 15 gl-1, 30 gl-1, 45 gl-1, 60 gl-1, and 75 gl-1. Compost organic material contains the fungus B. bassiana which has the best ability to control O. rhinoceros, namely OPEFB + sawdust because caused total mortality to reach 90% with conidia number 115.2 x108, initial death 67.2 hours after application, lethal time 50 206, 4 hours after application. B. bassiana fungi in OPEFB + sawdust compost can control O. rhinoceros 3 instar larvae with total mortality of up to 92.5% and control 1, 2, and 3 instars larvae of O. rhinoceros have no effect on the initial time of death and lethal time 50 on each instar. The initial time of death used was 54-75 hours and the lethal time 50 was 198-252 hours. OPEFB compost + sawdust containing the fungus B. bassiana 75 gl-1 had the best ability to control O. rhinoceros larvae with a total larvae mortality of 87% which caused early death 54 hours after application, 50 lethal times of 213 hours, and LC50 of 3.3% or the equivalent of 33 gl-1.

Minimum Effective Dose of Chlorantraniliprole and Chromafenozide to Control Oil Palm Bunch Moth Tirathana mundella Walker

The bunch moth, Tirathaba mundella is one of the leading pests in oil palm estates established on peatland. Severely infested male inflorescences usually would fail reaching anthesis. Reduction in the number of inflorescences at anthesis stage would suggest less food source and breeding ground for oil palm pollinating weevils, Elaeidobius kamerunicus, thus, affecting the fruiting percentage of oil palm and its yield. Despite to be less detrimental to the environment, biopesticide usages in the field is losing favour due to its slower rate of kill compared with conventional chemical pesticides, shorter persistence in the environment and susceptibility to unfavourable environmental conditions. The use of high host specificity chemical pesticides, such as chlorantraniliprole and chromafenozide are gaining popularity in pest management regimes. In this study, the optimum dose for chlorantraniliprole and chromafenozide in controlling T. mundella was assessed to provide valuable information for sustainable oil palm pest management. Several dosages of pesticide were evaluated for their effectiveness against T. mundella in a 7-year-old oil palm estate for six months. Based on the results obtained, application of 30 g or 40 g active ingredient (a.i.) per ha chlorantraniliprole were recommended to provide the longest protection period. To make plan for an effective pest management that could reduce material and labour cost per ha as well as the risks in developing pesticide resistance among pest, 30 g a.i per ha of chlorantraniliprole is recommended to be rotated with 25 g a.i. per ha chromafenozide for a total of four rounds in a year.

Trapping, identification and rearing of edible palm weevils in Kenya and Uganda

Palm weevils, Rhynchophorus spp. (Coleoptera: Curculionidae) double as devastating invasive pests of palms, and delicacies in many communities. This study evaluated ethyl acetate and 3-methyl-octan-4-ol for trapping palm weevils from coconut, oil and raffia palms in Kenya and Uganda; taking into account the distance of traps on oil palm from a forest or raffia palm. Eggs from the weevils from different locations were incubated and their larvae reared on sugarcane under laboratory conditions. All the 285 weevils collected were identified by morphological and molecular techniques as Rhynchophorus phoenicis, and the catch was female-biased. 3-methyl-octan-4-ol attracted more weevils than ethyl acetate. More weevils were caught at ~100 m away from the forest than within 15 m outside the forest; and on raffia palm than oil palm irrespective of distance apart. Eggs took ~4 d to develop and 95-100% of pupae developed into adults, irrespective of the collection site. Larval and pupal developmental periods for weevils from Uganda were longer than those of Kenya, resulting in egg-adult development of ~6 months and ~4 months, respectively. The sex ratio of laboratory produced males and females was similar. These results can guide in designing an integrated R. phoenicis management system with a dual benefit of protecting palms from weevil attack and utilising the weevils to improve human nutrition.

EFFICIENCY OF ORIGANUM MAJORANA ESSENTIAL OIL AS INSECTICIDAL AGENT AGAINST RHYNCHOPHORUS FERRUGINEUS THE RED PALM WEEVIL (OLIVIER) (COLEOPTERA: CURCULIONIDAE)

Rhynchophorus ferrugineus is the most dangerous palm pest in Egypt and the Middle East. A lot of efforts have been made since three decades up to date to solve this problem. In this study, the essential oil of Origanum majorana was tested in vitro against larvae, pupa and adult stages of R. ferrugineus. In addition, the chemical composition of the essential oil was elucidated by gas chromatography and mass spectrometry (GC-MS) analysis. Two main toxic components (benzonitrile, 2-hydroxy 23.67%and L-linalool16.32%) were found. A significant mortalities were achieved after exposure to three concentrations (5, 10 and 15%) of O. majorana oil. Each concentration contains five replicates with 5 larva, pupa or adultfor each replicate. The effect reached 50% for 10% concentration at 96 hrs, 48 hrs and 12 hrs for larva, pupa and adult, respectively. In addition, the cuticle of treated larvae was investigated histopathologically, and corrugation and a thinning surface were found. These results suggest that O. majorana essential oil is a promising alternative to chemicalpesticides and can be used as a biopesticide against larvae, pupa and adult of R. ferrugineus.

Phenylalanine ammonia lyase (PAL) activity in genotypes of Opuntia spp. against artificial infestation of Dactylopius opuntiae submitted to biotic and abiotic resistance inducers

Products of biotic and abiotic origin are being investigated for use in pest management, many of these substances can act as resistance inducers, which induces the metabolism of enzymes involved in defense mechanisms. There is a search for efficient and alternative ways of controlling carmine cochineal (Dactylopius opuntiae Cockerell), the main pest of forage palm (Opuntia spp) in Northeast Brazil. The aim of the study was to evaluate the application of biotic and abiotic inducers on the palms to induce resistance through the activity of the antioxidant enzyme phenylalanine ammonia lyase. The experiment was carried out in a greenhouse at the Federal University of Agreste of Pernambuco, using an Completely Randomized Design (CRD), distributed in a factorial scheme (3x8x3) with three Opuntia genotypes, eight treatments: Trichoderma viride URM 6824, Trichoderma viride URM 6823, Aureobasidium pullulans URM 6874, salicylic acid, chitosan, amino butyric acid, distilled water with the insect (positive control), distilled water without the insect (negative control), with three collection periods and four repetitions. The results were subjected to analysis of variance (ANOVA), the means being compared by the Scott-Knott test at the level of 5% probability (p <0.05) and by orthogonal contrasts. The biological inducers T. viride URM 6824 and T. viride URM 6823 as well amino butyric acid influenced the increase in the enzymatic activity of phenylalanine ammonia lyase. This result demonstrates the potential for use in alternative management, and future studies are needed to deepen the applicability in field conditions.

Virulence of Beauveria bassiana Balsamo to red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae)

BackgroundThe red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae), is a cosmopolitan pest of palms. Current management strategies largely depend on insecticides, and use of insect pathogenic fungi is needed in integrated pest management (IPM) programs.ResultsThe effectiveness of Beauveria bassiana was determined against 3rd instar R. ferrugineus larvae by using the following concentrations, i.e., 3 × 108, 2 × 108, 1 × 108, 1 × 107, and 1 × 106 spores/ml. The lowest LC50 value (1.3×107 spores/ml) was recorded at the Khyber Pakhtunkhwa (KPK) population, followed by those populations from Punjab, Sindh, and Baluchistan, which had LC50 values of 1.5×107, 5.3 ×107, and 1.02 ×108 spores/ml, respectively, on the 7th day post-treatment; the highest mortality rates were 90.0, 85.0, 77.5, and 75.0% for the KPK, Punjab, Sindh, and Baluchistan populations, respectively, at the highest tested concentration of B. bassiana.ConclusionThe findings of this study indicate the potential use of B. bassiana in IPM programs for R. ferrugineus that are more ecologically sound than those programs that are heavily reliant on insecticides.

Hymenoptera Parasitoid dan Persentase Parasitasi terhadap Berbagai Ulat Pemakan Daun Kelapa Sawit di Kebun Cikasungka PTPN VIII, Cindali, Bogor

Palm oil is one of the plantation commodities in Indonesia and had widespread in Indonesia. One of pests that attack oil palm is insect, and the most damaging pests usually from Lepidoptera. The aim of this study was to determine and counting percent parasitization of the parasitoids that parasitize palm leaf-eating pests in the oil palm plantation of PTPN VIII Cindali, Bogor. The study was conducted in 6 blocks of PTPN VIII Cindali oil palm plantation from September 2014 - June 2015 with observations once a month. Sample was taken by means of each block taken 5 plants in every plots randomly to be observed and palm leaf-eating insects taken to kept until the parasitoid was emerged. The outgoing parasitoids then counted and identificated. The results of the study founds 6 species of palm leaf-eating pests and 5 species of Hymenoptera parasitoids that parasitize these pests. Pests that found were Setora nitens , Amatissa sp., Birthosea bisura , Mahasena corbetti , Metisa plana and Pseudococcus sp. Whereas parasitoids that found were Spinaria spinator , Charops bicolor , Telenomus podisi , Aphanogmus sp. and Acerophagus sp.

Climate Change Impacts and Forecasts of Oil Palm Leaf Miner Populations

Agricultural production is very sensitive to climate change, and it suffers from periodic outbreaks of insect pests which cause considerable losses especially in the humid and sub-humid tropics which severely constrain the productivity potential of global agriculture under changing climate conditions. The oil palm leaf miner is a major pest of the oil palm. Mathematical relationships between the leaf miner insect stages and weather factors were developed for pest predictions and forecasting. Decadal variation in air temperature was characterized by wide differences between 1961 – 1970 and 2001 – 2010. The assessment of the sensitivity of leaf miner to variability in weather and climate conditions is important in view of evidence that show expansion of pest ranges as a result of climate variability impacts. The study has established an upward increase in temperature, attributed to climate change, with a concomitant increase in leaf miner abundance between 1980 and 2010. Larvae showed an increasing trend for the observed period. When this observation was correlated with the weather (temperature, rainfall, and relative humidity) during these periods, it could be inferred that there was proliferation as a result of weather changes. This was different from the decreasing trend observed during the 1976 – 1980 period. Pupae showed a decreasing trend for the observed period. Adults showed an increasing trend for the observed period. It could be inferred that adults were proliferating due to temperature increases and rainfall decreases. An incremental increase in temperature could help explain fluctuations in insect pest populations within and between years. Thus climatic conditions greatly influenced seasonal leaf miner populations. The climate forecast up to 2050 indicates an upward trend in temperature and a downward trend in rainfall and relative humidity. This followed the climate trend between 1961 and 2010. This study contributes to the understanding of the insect pest-weather relationship in broad agricultural and food security terms. A major advantage is the potential for limiting the spread of outbreaks through timely control of early pest infestations.

Insecticidal activity of supernatant and crude extract of Bacillus thuringiensis-based bio-insecticide towards oil palm pests Oryctes rhinoceros (Coleoptera: ‘/Scarabaeidae)

Oryctes rhinoceros is an important pest in oil palm plants. Larvae and imago are stadia which attack plants. Control by using synthetic chemical insecticides often create a negative impact on non-target insects and the environment. B. thuringiensis can be used as an alternative. The aim of the study was to study the insecticidal activity of B. thuringiensis isolates from South Sumatra on the larvae of Oryctes. The study was conducted at Entomological Laboratory, Department of Plant Protection, Faculty of Agriculture, Sriwijaya University, from March to May 2019. The study was designed by a factorial complete randomized design with two factors in the form of Bt isolates (four isolates) and the presence of spores (crude extract and supernatant) with each repeated 3 times. The treatments were B. thuringiensis isolates propagated in Biourin media and applicated in the form of crude and supernatant. B. thuringiensis propagated in NB media was used as control. Tested insects were 1st instar larvae of Oryctes. The results showed application of crude solution of B. thuringiensis resulted in higher mortality compared to supernatant treatment. It was assumed in crude solution there was a mixtured of spores and proteins compared with the solution of the supernatant which only contains spores. KJ3P1 isolate was able to cause the highest mortality in crude treatment.

Histopathological studies of red palm weevil Rhynchophorus ferrugineus, (Olivier) larvae and adults to evaluate certain nano pesticides.

Rhynchophorus ferrugineus (RPW) (Olivier) (Coleoptera: Curculionidae) is one of the most destructive pest of palm according to dozens of literature, a lot of effort have been made since three decades up to date to solve this problem, one of newest solution raised is using nano pesticides. Imidacloprid and Chloropyrophos and their nano form were tested against 10 days-old larvae and newly emerged adults of the red palm weevil. The pesticides had toxicological and pathological effects on Rh. ferrugineus larvae and adults. The toxicity effect of nano chloropyrophos was more than others. The damage included vaculation of cytoplasm, analyzes and destroyed nuclei of the epithelial cells. The larvae were more sensitive in the total damages in comparison with adults. This investigation is the first record to the histopathological effects of nano pesticides.

Quantification of the Life Time Flight Capabilities of the South American Palm Weevil, Rhynchophorus palmarum (L.) (Coleoptera: Curculionidae).

Simple SummaryThe South American palm weevil, Rhynchophorus palmarum, is an invasive pest that has killed thousands of ornamental palms in San Diego County in California, USA. Emerging management plans for this pest need to consider the flight capabilities of this insect, which are not well understood. To address this shortcoming, flight mills, a type of computerized insect “merry-go round” that measures how far weevils can fly in the laboratory, were used to quantify the flight distances of 101 weevils that were flown repeatedly over the course of their lifetimes. The results indicate that weevils are strong flyers capable of flying numerous times before dying of natural causes. Over their lifetimes, weevils, on average, covered distances that cumulatively totaled >220 km. One female weevil flew an impressive cumulative distance of approximately 806 km over the course of nine consecutive flights before dying.The life time flight capabilities of an invasive palm pest, Rhynchophorus palmarum, were assessed using flight mill assays under controlled conditions in the laboratory. A total of 101 weevils were used for experiments and subjected to repeat flight assays. A total of 17 flight trials were run, of which the first 14 provided useful data prior to weevil death. Male and female weevils exhibited a strong capacity for repeat long distance flights. Flight metrics of interest were not affected by weevil sex or mating status. Cumulative lifetime flight distances for male and female R. palmarum averaged ~268 km and ~220 km, respectively. A maximum lifetime cumulative flight distance of ~758 km and ~806 km was recorded for one male of unknown mating status and one unmated female weevil, respectively. Dispersal data for individual flights (i.e., trials 1 through 9, 10–14 combined) and all flight trial data (i.e., flights 1–14 combined) exhibited platykurtic distributions. The results presented here may have important implications for modeling the spread of this invasive pest and for the development of monitoring and management plans.

The complete mitochondrial genome sequence of Oryctes rhinoceros (Coleoptera: Scarabaeidae) based on long-read nanopore sequencing.

BackgroundThe coconut rhinoceros beetle (CRB, Oryctes rhinoceros) is a severe and invasive pest of coconut and other palms throughout Asia and the Pacific. The biocontrol agent, Oryctes rhinoceros nudivirus (OrNV), has successfully suppressed O. rhinoceros populations for decades but new CRB invasions started appearing after 2007. A single-SNP variant within the mitochondrial cox1 gene is used to distinguish the recently-invading CRB-G lineage from other haplotypes, but the lack of mitogenome sequence for this species hinders further development of a molecular toolset for biosecurity and management programmes against CRB. Here we report the complete circular sequence and annotation for CRB mitogenome, generated to support such efforts.MethodsSequencing data were generated using long-read Nanopore technology from genomic DNA isolated from a CRB-G female. The mitogenome was assembled with Flye v.2.5, using the short-read Illumina sequences to remove homopolymers with Pilon, and annotated with MITOS. Independently-generated transcriptome data were used to assess the O. rhinoceros mitogenome annotation and transcription. The aligned sequences of 13 protein-coding genes (PCGs) (with degenerate third codon position) from O. rhinoceros, 13 other Scarabaeidae taxa and two outgroup taxa were used for the phylogenetic reconstruction with the Maximum likelihood (ML) approach in IQ-TREE and Bayesian (BI) approach in MrBayes.ResultsThe complete circular mitogenome of O. rhinoceros is 20,898 bp in length, with a gene content canonical for insects (13 PCGs, two rRNA genes, and 22 tRNA genes), as well as one structural variation (rearrangement of trnQ and trnI) and a long control region (6,204 bp). Transcription was detected across all 37 genes, and interestingly, within three domains in the control region. ML and BI phylogenies had the same topology, correctly grouping O. rhinoceros with one other Dynastinae taxon, and recovering the previously reported relationship among lineages in the Scarabaeidae. In silico PCR-RFLP analysis recovered the correct fragment set that is diagnostic for the CRB-G haplogroup. These results validate the high-quality of the O. rhinoceros mitogenome sequence and annotation.