Opisina Arenosella Research Articles

Predicting the geographical potential distribution of species Opisina arenosella Walker in China under different climate scenarios based on the MaxEnt model.

As global warming increases with the frequency of extreme weather, the distribution of species is inevitably affected. Among them, highly damaging invasive species are of particular concern. Being able to effectively predict the geographic distribution of invasive species and future distribution trends is a key entry point for their control. Opisina arenosella Walker is an invasive species, and its ability to live on the backs of foliage and generate canals to hide adds to the difficulty of control. In this paper, the current and future distributions of O. arenosella under three typical emission scenarios in 2050 and 2090 are projected based on the MaxEnt model combining 19 bioclimatic variables. Filter through the variables to find the four key environment variables: BIO 1, BIO 6, BIO 11 and BIO 4. The results show that O. arenosella is distributed only in the eight provinces of Tibet, Yunnan, Fujian, Guangxi, Taiwan, Guangdong, Hong Kong and Hainan in the southeastern region. Its high suitability area is concentrated in Taiwan and Hainan. In the long run, highly suitable areas will continue to increase in size, while moderately suitable areas and poorly suitable areas will decrease to varying degrees. This paper aims to provide theoretical references for the control of O. arenosella.

Isolation and selection of active Bacillus strains that have the ability to control black-headed insect (Opisina arenosella Walker) causing damage to coconut trees in Ben Tre province

Isolation and selection of active Bacillus strains that have the ability to control black-headed insect (Opisina arenosella Walker) causing damage to coconut trees in Ben Tre province

Potential distribution of three invasive agricultural pests in China under climate change

Invasive pests reduce biodiversity and ecosystem service functions, thereby leading to economic and also agricultural losses. Banana skipper (Erionota torus Evans), red palm weevil (Rhynchophorus ferrugineus), and coconut caterpillar (Opisina arenosella Walker) are invasive insect pests in the palm-growing regions and they have had serious consequences for the planting of bananas (Musa nana), palms (Trachycarpus fortune) and coconut (Cocos nucifera). Based on screened occurrence data, the present research utilized Maximum Entropy model (Maxent) to simulate the distribution dynamics of these three invasive insects in China, under current and future climate (2050s, 2070s, 2090s) in two shared socio-economic pathways (SSPs: 126 and 585) of the newly released coupled model intercomparison project phase6 (CMIP6). The results show that: (1) Under current and future climate conditions, all model groups exhibited an AUC value exceeding 0.92, which shows that the model prediction results are very good;(2) The suitable habitat area of E. torus Evans remains relatively stable with some expansion in the SSP126 of 2090s and some contraction in the SSP585 of 2090s. The suitable habitat area of R. ferrugineus showed an overall contraction, with substantial contraction in the SSP585 of 2090s.The suitable habitat area of O. arenosella has an overall expansion, with the most pronounced expansion in the SSP585 of 2070s; (3) The current centroid of suitable habitats for R. ferrugineus and E. torus Evans is located in Guangxi Province and wholely shift toward the south direction under future climate. The centroid of suitable habitats for O. arenosella is currently located in the northeastern maritime area of Hainan Province and will shift toward the north direction under future climate; (4) Temperature, precipitation and Human disturbance factors (Population density and Human influence index) were crucial variables for describing the distribution of the three species. For E. torus Evans in particular, percentage contributions of Population density was up to 31.4, which is only 0.1 different from ranked first Bio19 (Precipitation of the coldest quarter). The dynamics of habitats of these three species and the correlating driver factors proposed in this work provide essential insights into future spatial management of the three invasive insects in China. Our work is necessary and timely in identifying newly areas at high risk of expansion of the three invasive insects in the future, then suggesting strategic control measures to prevent their spread, and finally providing scientific evidence for the early prevention and rapid response to the three invasive insects.

Morphological characteristics of Bracon hebetor (Hymenoptera: Braconidae), a larval parasitoid of coconut Black Headed Caterpillar Opisina arenosella Walker (Lepidoptera: Xyloryctidae)

The Bracon hebetor is an essential natural enemy in suppressing the coconut black-headed caterpillar (BHC) Opisina arenosella, which was common in coconut field in Ben Tre province. Under laboratory conditions, with six-instar larvae of BHC as a host, the adult body of B. hebetor was yellow-brown and the male’s antennae were longer than those of the female, with oblong and rectangular shapes consisting of 17 - 20 segments, while the female’s antennae were square-shaped with 11 - 14 segments. The abdomen of B. hebetor was pale yellow, with its last segment being dark brown. Females of B. hebetor were larger than males. The average body length of female and male was 3.2 ± 0.17 mm and 3.0 ± 0.18 mm, respectively. The average body length of 2-day-old pupae was 3.0 ± 0.20 mm and that of 3-day-old ones was 3.5 ± 0.21 mm. The average egg length was 0.7 ± 0.07 mm. The findings of this study helped provide information on the identification of B. hebetor larval parasitic wasps on the BHC host, aiding in the search for natural enemies of BHC in coconut fields. Additionally, the research also facilitated the exploration of the biological and ecological aspects of this natural adversary in Vietnam.

Pest and Disease Challenges, Control Strategies as Well as Policy Support for The IPM Program on Coconut

Coconut played an important role in humans as an estate commodity. Many efforts have been made to increase coconut production through intensification, extensification, and diversification but those efforts have not given maximum results yet, likewise, assembling superior coconut varieties also have been carried out, to produce superior coconut varieties such as Tall coconut, Dwarf coconut, Hybrid coconut, but this is also not been able to increase coconut production optimally. On the other hand, several factors can cause the decline in coconut production, such as severe damage caused by major pests and diseases. The list of highlighted major pests in this article was as follows, Rhynchophorus spp., Cyrtotrachelus sp., Oryctes rhinoceros, Amblypelta sp., and Opisina arenosella. Three species of it were categorized as new emerging pests in Indonesia: Cyrtotrachelus sp., Amblypelta sp., and O. arenosella. Cyrtotrachelus sp. has been reported to cause damage, and mortality of coconut plants reached 10.63%, as well as Amblypelta sp., as reported in North Sulawesi Province, while the O. arenosella has been reported to caused severe damage to coconut plantations in West Java. For diseases, are Bud Rot Disease and Nut Fall Disease caused by Phytophthora palmivora. In 2022, Nias Yellow Dwarf coconuts in Tiniawangko Village, South Minahasa, North Sulawesi, infected with Bud Rot disease by 31.53%, causing coconut plants to die, and Nut Fall Disease causing a decrease in production by 25.00%. In addition, it was found that coconut plants died due to infection with an Unknown Disease. Integrated Pest Management (IPM) is an effective approach to control all pests and diseass, where possible. This is a combination of methods (pesticides, physical controls such as site hygiene, and biological controls) to minimize the use of pesticides and the cost of control. The IPM program can run well if there is policy support from the government.

Developmental Biology of Trichospilus pupivorus Ferrière (Hymenoptera: Eulophidae), a Pupal Parasitoid of the Coconut Black-headed Caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae)

Background: The coconut black-headed caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae) has been a serious defoliator of coconut plants in many coconut producing countries including Vietnam. Trichospilus pupivorus Ferrière (Hymenoptera: Eulophidae) is pupal endo-parasitoid of O. arenosella with high percent parasitism and abundance in the coconut fields and appears to be a good biological control agent against the coconut black-headed caterpillar in Vietnam. The objective of this study was to investigate the developmental biology of T. pupivorus on O. arenosella. Methods: The experiment was carried out at the Faculty of Agronomy, Nong Lam University, Viet Nam during 2020 and 2021. The developmental biology of T. pupivorus on O. arenosella was studied in the laboratory at a constant temperature of 28°C and a photoperiod of 12L: 8D. Result: Total developmental time from egg to adult emergence was 14.0 days. The females laid a mean of 124.2 eggs during an average lifespan of 9.4 days. The number of progenies emergence from a single pupa of O. arenosella was 103.8. The offspring sex ratio was female-biased (8.0%). The results would contribute to the knowledge of the biology of this parasitoid to optimize a mass rearing system for a biological control program against O. arenosella.

Ecology, invasion history and biodiversity-driven management of the coconut black-headed caterpillar Opisina arenosella in Asia.

The coconut black-headed caterpillar (BHC), Opisina arenosella Walker (Lepidoptera: Xyloryctidae) is an important herbivore of palm trees that originates in South Asia. Over the past decades, O. arenosella has spread to several countries in Eastern and Southeast Asia. BHC larval feeding can cause severe defoliation and occasional plant death, resulting in direct production losses (e.g., for coconut) while degrading the aesthetic value of urban and rural landscapes. In this review paper, we systematically cover taxonomy, bio-ecology, invasion history and current management of O. arenosella throughout Asia. Given that O. arenosella is routinely controlled with insecticides, we equally explore options for more sustainable management through agroecological and biodiversity-based tactics e.g., cultural control or biological control. Also, recent advances in chemical ecology have unlocked lucrative opportunities for volatile-mediated monitoring, mating disruption and mass-trapping. Substantial progress has been made in augmentation biological control, with scheduled releases of laboratory-reared parasitoids lowering BHC infestation pressure up to 95%. Equally, resident ants provide 75-98% mortality of BHC egg masses within the palm canopy. Biological control has been effectively paired with sanitary measures and good agronomy (i.e., proper fertilization, irrigation), and promoted through participatory farmer training programs. Our comprehensive listing of non-chemical preventative and curative tactics offer bright prospects for a more environmentally-sound, biodiversity-driven mitigation of a palm pest of regional allure.

Developmental biology of the coconut black-headed caterpillar, Opisina arenosella (Walker) (Lepidoptera: Xyloryctidae)

The coconut black-headed caterpillar, Opisina arenosella (Walker) (Lepidoptera: Xyloryctidae) has been one of the most serious defoliators of coconut plants in Vietnam. This study was carried out at the Entomology Laboratory, Faculty of Agronomy, Nong Lam University, Vietnam during 2020-21 to determine some biological characteristics of O. arenosella at a constant temperature of 28oC and a photoperiod of 12L : 12D. It was concluded from this study that the total developmental time from egg to adult emergence of O. arenosella was 57.7 days for female and 52.6 days for male. The eggs hatched in 6.1 days after oviposition. The duration of the larval period was 41.2 days. The pupal development lasted for an average of 3.6 days. The females produced a mean of 278.8 eggs during an average lifespan of 4.9 days. The longevity of the female (4.9 days) was shorter than that of the male (10.7 days). The knowledge of the basic biological characteristics of this caterpillar is of fundamental importance for facilitating improved timing of application of control measures and mass-rearing techniques for O. arenosella to supply insect hosts to mass-rearing of its parasitoids.

Biology of Brachymeria kamijoi Habu (Hymenoptera: Chalcididae), a pupal parasitoid of the coconut black-headed caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae)

The coconut black-headed caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae) has been one of the most serious defoliators of coconut plants in Vietnam. Brachymeria kamijoi Habu (Hymenoptera: Chalcididae) is a pupal parasitoid of O. arenosella with high percent parasitism and abundance in the coconut fields and appears to be a good biological control agent against the coconut black-headed caterpillar in Vietnam. This study was carried out at Entomology Laboratory, Faculty of Agronomy, Nong Lam University, Vietnam during 2020 – 2021 to determine some biological characteristics of B. kamijoi on O. arenosella at a constant temperature of 28 oC and a photoperiod of 12L: 8D. Total developmental time from egg to adult emergence was 13.8 days. The females laid a mean of 98.1 eggs during an average lifespan of 30.7 days. Fecundity peaked at a large range of age 7 -29 days. The results would contribute to the knowledge of the biology of B. kamijoi to optimize a mass-rearing system for a biological control programme against O. arenosella.

Influence of temperature on the development and reproduction of Habrobracon hebetor (Say), as parasitoid of Opisina arenosella Walker

Opisina arenosella Walker is a coconut leaf-eating caterpillar that invaded the Hainan Province of China in 2013. Habrobracon hebetor Say is an ectoparasitoid used as a control agent of various lepidopteran pests. Laboratory experiments were conducted to determine the effects of constant temperatures (16, 20, 24, 28, and 32 °C) on the parasitism, development, survival, and reproduction of H. hebetor on O. arenosella. The results showed that developmental duration and adult longevity shortened with the increase in temperature. The preadult survival rates were higher at 20 to 32 °C (55 to 72%) than at other temperatures. The parasitism rate and the fecundity increased with the increase in temperature, and reached the highest value at 28 °C (82.03% and 325.17 eggs), then decreased at 32 °C (76.96% and 152.57 eggs). The developmental threshold (T0 ) and effective accumulated temperature (k) for completing a generation of H. hebetor were 13.71 °C and 143.28 degree days, respectively. At 28 °C, net reproductive rate (R0 ) and intrinsic rate of increase (r) were 65.03 and 0.229 d−1, respectively. These results can provide a reference for mass rearing and field release of H. hebetor on O. arenosella.

Outbreak of defoliator Coconympha iriarcha Meyrick on coconut

A sporadic outbreak of the rare lepidopteran insect pest Coconympha iriarcha Meyrick (Gelechiidae: Lepidoptera) was recorded on the coconut palm (Cocos nucifera L.) (Arecales: Arecaceae). The larvae of these can be differentiated from the larvae of Opisina arenosella, the black headed caterpillar, by its size and colour. The former is with yellowish cream body with a pale brown head and is small (< 4 mm); latter is with a greenish body with red dorsal lines and a black head, and >11 mm long. In this study, reoccurrence of C. iriarcha is documented and it is redescribed with illustrations and damage symptoms.

Effect of Adult Nutrition at Different Concentrations on Reproduction and Longevity of <i>Bracon brevicornis</i>, Larval Parasitoid of Coconut Black-Headed Caterpillar

Coconut black-headed caterpillar (<i>Opisina arenosella</i>) or BHC is one of the main coconut palm defoliators in many Asian countries, including Malaysia, where it was discovered in 2017. Since then, an effort has been made to manage the pest by the use of larval parasitoids, started with a study on the effects of sucrose diet on reproduction, longevity and parasitism of a naturally occurring parasitoid known as <i>Bracon brevicornis</i> (Hymenoptera: Braconidae). The aim of this study was to determine the optimal sucrose concentration for improving its rearing technique. Two experiments were conducted, i.e., a) reproductive performance study; and b) longevity study. In each study, different sucrose concentrations were tested on mated females in five (5) replications. Feeding on 20% sucrose concentration resulted in significantly (P<0.05) highest fecundity (82.4 ± 0.9), hatchability (100%), pupation, fertility (82.7%) and longest reproductive period (12.8 ± 0.3 days) of <i>B. brevicornis</i> among treatments. Meanwhile, 40% sucrose was able to prolong its adults’ lifespan (20.6 days). Adults fed on 20% sucrose had the highest parasitism (33.4±0.6 host larvae), despite the fact that 30% sucrose had no statistically significant difference. Thus, this study suggested that 20% sucrose could be suitable to increase fertility and parasitism by <i>B. brevicornis</i>. However, additional research on its effect on behaviours is necessary to acquire a better knowledge of its efficiency in the field.

Discrete generation cycles in Coconut black headed caterpillar, Opisina arenosella Walker (Lepidoptera: Oecophoridae)

Field study was carried out to determine generation cycles and to comprehend the different developmental stages and their density at a particular time interval to assess the population structure of coconut black headed caterpillar, Opisina arenosella Walker (Lepidoptera: Oecophoridae) in Mandya district, Karnataka, India. The sampled population of O. arenosella showed discrete generation. The different stages of O. arenosella viz ., larvae, pupae and adults were not observed on any single sampling date. Therefore, the definite periodicity in the appearance of O. arenosella suggested to discreet generation cycles.

Characterization and analysis of the transcriptome in Opisina arenosella from different developmental stages using single-molecule real-time transcript sequencing and RNA-seq

Opisina arenosella is one of the main pests harming coconut trees. To date, there have been few studies on the molecular genetics, biochemistry and physiology of O. arenosella at the transcriptional level, and there are no available reference genomes. Here, Illumina RNA sequencing combined with PacBio single-molecule real-time analysis was applied to study the transcriptome of this pest at different developmental stages, providing reference data for transcript expression analysis. Twelve samples of O. arenosella from different stages of development were sequenced using Illumina RNA sequencing, and the pooled RNA samples were sequenced with PacBio technology (Iso-Seq). A full-length transcriptome with 41,938 transcripts was captured, and the N50 and N90 lengths were 3543 bp and 1646 bp, respectively. A total of 36,925 transcripts were annotated in public databases, 6493 of which were long noncoding RNAs, while 2510 represented alternative splicing events. There were significant differences in the gene expression profiles at different developmental stages, with high levels of differential gene expression associated with growth, development, carbohydrate metabolism and immunity. This work provides resources and information for the study of the transcriptome and gene function of O. arenosella and provides a valuable foundation for understanding the changes in gene expression during development.

Contests between beneficial natural enemies: brood‐guarding parasitoids vs. foraging predators

AbstractBeneficial insects, such as natural enemies, are important to agro‐ecosystem functioning and thus agricultural production. Parasitoids and predators can provide sustainable long‐term solutions to pest problems (biological control), reducing the need for expensive and sometimes polluting pesticide applications. When several species of beneficial insects are present, their pest control actions may be additive, synergistic, or disruptive. One form of disruptive interaction between parasitoids and predators is direct interspecific contest for access to individual pests (the resource to be exploited). This study evaluated behavioural interactions between brood‐guarding wasps, Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), which are known to engage in intra‐specific contests, and a predatory bug, Cardiastethus exiguus (Poppius) (Hemiptera: Anthocoridae), which attack the same pest species, Opisina arenosella (Walker) (Lepidoptera: Oecophoridae), a major pest in coconut production systems. Dyadic parasitoid–predator and predator–predator contests were staged to determine the factors that influence the behaviours within, and outcomes of, such interactions. Parasitoids were aggressive towards predators, sometimes killing them, but predators were not aggressive towards parasitoids. Biting and stinging only occurred when there was a host larva present. In the absence of the parasitoid that had oviposited onto a host, predators often consumed the parasitoid’s eggs. Egg consumption sometimes occurred when the parasitoid was present. Intra‐specific competition between pairs of predators was also evaluated: adults were aggressive towards each other, but interactions were not fatal. Biting was more common when there was no prey larva present. When a larva was present, predators were observed feeding simultaneously. We conclude that direct parasitoid–predator interactions are likely to influence pest population dynamics, possibly reducing the overall suppression of O. arenosella by its natural enemies.

Effect of Different Honey Concentrations on Survival, Longevity and Reproduction of Trichospilus pupivorus (Hymenoptera: Eulophidae), a Parasitoid of Coconut Black-Headed Caterpillar, Opisina arenosella (Lepidoptera: Oecophoridae)

Many coconut producing countries in Asia are facing a serious infestation of Opisina arenosella (Lepidoptera: Oecophoridae) or commonly called the coconut black-headed caterpillar. Recently, the pest has been detected in the coconut (Cocos nucifera) planting area in Pahang, Malaysia. Thus, an initiative to manage the pest by using parasitoids has been started with a study on the effects of diet on survival, longevity and reproduction of naturally occurred parasitoid known as Trichospilus pupivorus (Hymenoptera: Eulophidae). The aim of this study was to identify suitable concentrations of honey that can be used in developing its rearing technique. Two independent experiments were conducted, i.e., a) survival and longevity study; and b) reproduction study. In each study, different honey concentrations were tested on ten (eight replications) and one (five replications) female parasitoids respectively. 30% honey concentrations resulted in high survival rate of the adult during early life with relatively prolonged longevity up to 6.0&amp;plusmn;0.19 days and significantly produced the highest number of progenies (105.4&amp;plusmn;0.81). The lowest survival rate was given by 60% honey and significant longevity up to 6.5&amp;plusmn;0.33 days with no progenies. Further studies on other plausible factors affecting the reproduction and fitness of progenies should also be investigated to ensure efficient rearing techniques.

A novel frond injection method against coconut black headed caterpillar opisina arenosella walker

A field study was conducted in coconut at farmer’s field in Halebudanuru village in Mandya district, Karnataka during 2017-2018. The frond injection, a novel method of insecticide application was evaluated against the black headed caterpillar Opisina arenosella Walker. The insecticides evaluated include: imidacloprid 17.8% SL, acetamiprid 20% SP, clothianidin 50% WG, thiacloprid 21.7% SC, emamectin benzoate 5% SG, spinosad 45% SC, cartap hydrochloride 50% SP and standard check monocrotophos 36% SL. Among these, it was observed that cartap hydrochloride 50%SP and monocrotophos 36% SL gave 100% mortality; all other treatments also gave significant mortality over control. The frond injection method advocated now is an easy, quicker and accurate method, without any secondary infection/ damage to the frond tissues.

Host performance of Trichogramma species on Opisina arenosella, and evaluation of their biological control efficacy

Abstract Five candidate species for biocontrol of Opisina arenosella Walker, a destructive pest of palm trees, were evaluated. To compare host performance, 5 Trichogramma species were allowed to parasitize O. arenosella eggs of different ages and egg densities. The parasitization capacity of two species, T. embryophagum and T. japonicum, were evaluated with respect to adult age. Treatments consisted of field with releases of T. embryophagum or T. japonicum set up in Danzhou, Hainan, and the pest densities was recorded periodically. The results showed that T. embryophagum, T. chilonis, and T. dendrolimi had a strong parasitic ability on 0-day-old O. arenosella eggs. In species comparisons, the parasitism rates of T. embryophagum on 1-day-old and 4-day-old eggs, and T. japonicum on 2-day-old, 3-day-old, and 5-day-old eggs of O. arenosella were significantly higher than those of other Trichogramma species. At densities of 40 and 35 eggs/tube (84.8 cm3), the numbers of eggs parasitized by T. embryophagum and T. japonicum were the highest, at 29.9 and 24.6, respectively. During the first 24-h, the numbers of eggs parasitized by T. embryophagum and T. japonicum were 110.6 and 82.2, accounting for 84.7% and 59.5%, respectively, of the total parasitized eggs. After 2 months releases, the larvae and pupa density of O. arenosella under T. embryophagum and T. japonicun treatment were 0.95 and 0.94 individuals/leaflet, respectively, were significantly lower than untreated control (1.6 individuals/leaflet). These findings encouraged that T. embryophagum and T. japonicun are able to be used for biological control for O. arenosella.

Complete mitochondrial genome of the coconut black-headed caterpillar Opisina arenosella (Lepidoptera: Gelechioidea: Xyloryctidae)

In the present study, we determined the complete mitogenome of Opisina arenosella, the first for the family Xyloryctidae. This mitochondrial genome contains 15,389 bp, with an A + T content of 80.5% and consists of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region (GenBank accession no. MK467611). The genome size, gene arrangement, A + T content, codon usage, and secondary structures of 22 transfer RNA genes of the O. arenosella mitogenome were similar to those of other sequenced Gelechioids. Bayesian analyses performed using the mitogenomes of O. arenosella and other 13 species of Gelechioidea.

Design and selection of an artificial diet for the coconut black-headed caterpillar, Opisina arenosella, based on orthogonal array analysis

Opisina arenosella has been an outbreak pest of coconut trees in southern China since 2013. To develop efficient control methods for this invasive pest, adequate rearing protocols are desirable. In this study, an orthogonal array of artificial diets with 11 factors at 3 levels was deployed for both 2nd–4th and 5th–6th instar larvae of O. arenosella. Biological parameters including survival time of larvae, development time from larva to pupa, pupation rate, emergence rate, and pupal weight were monitored to reveal the most important components in the diet formulas. Biological parameters in O. arenosella were most affected by brewer’s yeast, sucrose, ascorbic acid, and wheat germ. Statistical analysis indicated that different diet combinations supported optimum performance of biological parameters for 2nd–4th and 5th–6th instar larvae. The validity of the optimization predicted by the orthogonal array analysis was confirmed in a follow-up bioassay with similar optimized diets for both 2nd–4th and 5th–6th instar larvae. The optimal artificial diet has great potential for the mass rearing technique, and can provide valuable results for using parasitoids in biological control of O. arenosella.