Aceria Guerreronis Research Articles

Primer registro de Aceria guerreronis Keifer, 1965 (Acari: Eriophyidae) en Panamá

Aceria guerreronis or coconut mite, has been documented for the first time in the Republic of Panama. The species was detected in the Cinta Costanera in Panama City, where Cocos nucifera fruits exhibited the characteristic symptoms of the pest. This report provides a brief morphological description of the species, supplemented with scanning electron microscopy images. It is expected that this communication will serve as a valuable tool for timely sampling, assessment of the phytosanitary risk posed by this species, and, if necessary, the implementation of phytosanitary measures to manage it.

Problems and Issues of Tropical Coconut Cultivation

A complicated web of issues threatens the productivity and long-term viability of tropical coconut agriculture. The health and vitality of coconut palms are seriously threatened by illnesses including Rhincosporium Palm Leaf Spot, Lethal Yellowing Disease, and infestations by coconut mites. The fragility of coconut crops is exacerbated by the increasing effects of climate change, which show up as rising temperatures and unpredictable rainfall patterns. In coastal areas, where coconut farming is common, soil erosion and saline intrusion provide additional challenges that reduce the resilience of coconut trees. The use of monoculture techniques, which are common in coconut farming, depletes the nutrients in the soil and increases vulnerability to pests and illnesses. Inadequate management of water and nutrients in agricultural operations makes these problems worse and may even hinder the growth of coconuts. Coconut cultivation is made less profitable by urbanisation and market complexities including price swings and limited market access. Adoption of sustainable practices is hampered by limited access to contemporary farming technologies, financial constraints, and unstable land tenure, which further impedes long-term investments. To strengthen the resilience and sustainability of tropical coconut cultivation in the face of various adversities, a comprehensive strategy that includes strong research initiatives, widespread technology dissemination, supportive policies, and community engagement is essential in navigating this complex landscape. Keywords: Tropical coconut cultivation, challenges, diseases, pests, climate change, soil erosion, salinity intrusion, monoculture, nutrient management, water management, urbanization, market fluctuations, technology access, financial constraints, land tenure, resilience, sustainability.

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.

Population dynamics of Aceria guerreronis and its natural enemies in coconut tree with and without application of pesticides

The coconut mite Aceria guerreronis Keifer is considered one of the most important pests of the coconut tree (Cocos nucifera L.), causing fruit malformation due to the appearance of cracks on the surface of the perianth below the bracts. This damage compromises fruit growth, reducing the production of solid and liquid albumen. The continuous use of chemical pesticides increases pest control costs, as in addition to being a practice highly harmful to the environment, it can also cause selection of resistant populations, as well as eliminate beneficial species. Therefore, the objective was to evaluate the population dynamics of A. guerreronis and its natural enemies, through the quantification of the most frequent and abundant predator species in two commercial areas of coconut plantation of the cultivar PB-121 (cross between Malaysian Yellow Dwarf x West African Giant). The study was conducted in Area 1 (with pesticide application), and Area 2 (without pesticide application - control) monthly from August 2018 to July 2019. Leaflets were collected (basal, median and apical part) from leaf 14 and fruits (bunches 4, 5, 6 and 7–4 to 6 months after inflorescence fertilization). In both areas, 933.580 mites were collected, 426,245 in Area 1 and 507.335 in Area 2, with emphasis on A. guerreronis (931.706 specimens – estimated value). Eriophid mites represented almost 100% of the specimens sampled, with high population density in periods with less precipitation. Among the predators, specimens belonging to the Phytoseiidae family were predominant, highlighting the species Amblydromalus zannouii Famah Sourassou, Amblyseius aerialis (Muma) and Amblyseius tamatavensis Blommers, present both in leaflets and in fruits, with the exception of A. zannouii, which was found only in leaflets.

Control effects and sublethal effects of four pesticides on Atheloca bondari (Lepidoptera: Pyralidae) caterpillars

• The concentration of abamectin used to control A. guerreronis caused 100% mortality of A. bondari caterpillars; • The residues of abamectin, azadirachtin, and fenpyroximate affected the behaviour of A. bondari caterpillars; • Acaricide residues did not interfere with infestation of coconut fruits by A. bondari caterpillars. Atheloca bondari Heinrich is an opportunistic lepidopteran that uses necrosis caused by the mite Aceria guerreronis Keifer, the most important pest of the coconut palm, to access the meristematic region of coconuts. Because of this moth-mite positive association, pesticides used to control A. guerreronis (abamectin, azadirachtin, fenpyroximate, and pyridaben) may impact A. bondari caterpillar behavior and/or survival. Thus, we used three methodologies (toothpick, triangle, and mesocarp fragment) to evaluate mortality caused by abamectin, the most commonly used pesticide to control A. guerreronis . The toothpick method proved to be suitable for toxicity tests of A. bondari caterpillars. Subsequently, the mortality caused by these four pesticides was evaluated, and abamectin caused 100% mortality in A. bondari caterpillars. Abamectin showed higher toxicity than the other pesticides to A. bondari caterpillars, with LC 50 and LC 95 values of 1.35 and 3.64 mg/L, respectively. The preference test showed that A. bondari caterpillars infested pesticide-treated fruits in the same proportion as untreated fruits. In the behavioral test, A. bondari caterpillars showed lower locomotor speed when exposed to surfaces with abamectin, azadirachtin, and fenpyroximate residues. Our study presented that pesticides used to control A. guerreronis affect the behavior and survival of A. bondari caterpillars. We discuss how spraying these pesticides can indirectly control the population of A. bondari , reducing the impact of this moth on coconut production, and modifying the importance of this species as a pest of coconut palm.

On a collection of (Insects, Acari) some insects and mites from medicinal plants of Ramakrishna mission, Narendrapur (India: West Bengal, Dist south 24 Paraganas)

A total 37 species of mites (under 22 genera, 9 family and 2 orders) and 17 species of insects (under 14 genera,11 family and 3 orders) has been recorded from 99 medicinal plants grown in three medicinal plant gardens of Ramakrishna Mission Ashrama, Narendrapur, collected during November 2021 - July 2022. Out of 37 species of mites, 23 species belonged to phytophagous group and 13 species predatory groups respectively. Among the phytophagous and predatory mites, Brevipalpus phoenicis, Petrobia harti, Steneotarsonemus spinki and Aceria guerreronis were found to be serious pests causing damage to their respective host plants, while Gynaneseius eharai, Amblyseius largoensis and Euseius finlandicus were found to be promising predatory mites feeding mostly upon Tetranychidae and Eriophyidae pest mites. In case of insects, 16 species was recorded as phytophagous and only 1 species (Scolothrips sexmaculatus) was predatory in nature. Among the phytophagous insects 3 species. Aphis nerii, Aspidiotus destructor, Kola vesta found to occur abundantly on the medicinal plants, causing serious damage symptoms to their respective host plants. The present study also recorded 25 mite species and 10 insect species shows new host records.

Geometric Morphometric Analysis and Molecular Identification of Coconut Mite, Aceria guerreronis Keifer (Acari: Eriophyidae) Collected from Thailand.

One of the most impactful pests in several coconut production regions across the world is the coconut mite, Aceria guerreronis Keifer. Scholars can obtain some necessary biogeographic information about coconut mites from studies that explore the geographic patterns of morphological variations and molecular properties among coconut mite populations from various locales. To investigate the geographical origin, ancestral host associations, and colonization history of the mite in Thailand, we obtained DNA sequence data from two mitochondrial (16s and COI) and one nuclear region (ITS) from coconut mite samples originating from 25 populations; additionally, we analyzed the morphological variations in the prodorsal shield and the coxigenital and ventral regions of the mite idiosoma. From the results of experiments using both identification methods, we identified the mite as the coconut mite, A. guerreronis (Acari: Eriophyidae). According to the phylogenetic analysis results of the 25 mite samples, we classified the mites as being closely related to mites found by the authors of a previous report in India. We are the first to report the results of a geometric morphometric analysis and molecular identification of A. guerreronis in Thailand, and our findings support the idea that the mites' origin and invasion history are not well documented, which makes it difficult to apply quarantine procedures and search for biological pest control agents.

Incorporation of essential oil from Vitex gardneriana (Lamiaceae) in microemulsions systems based on mineral and cottonseed oils increased its bioactivity against a coconut pest mite

Coconut (Cocos nucifera L.) is an important cash crop for Asia, Africa and tropical America. The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae) is a major coconut pest, inflicting heavy damage to fruits, thereby reducing yields and farmers profitability. Previous research has demonstrated that high contents of sesquiterpenes compounds present in the essential oil of Vitex gardneriana Schauer (Lamiaceae) (EOVG) showed high potential to control A. guerreronis. Systems stabilized by surfactants, such as microemulsions (MEs), are promising to carry essential oils due to their solubilization and protection properties, generally allow for greater spreadability, wettability and have thermodynamic stability and lower viscosity. Here, we compared the acaricidal activity of MEs containing EOVG a based cottonseed oil (CO) and mineral oil (MO) as different oily phases. MEs formulations were obtained through the pseudoternary phase diagram using a 1:1 mixture of polysorbate 80: propylene glycol as surfactant and co-surfactant, respectively, and CO and MO as oily phases and water as aqueous phase. The MEs were characterized by polarized light microscopy, dynamic light scattering as well as by rheological behavior. Results based on concentration-mortality bioassays, showed that the toxicity of ME-CO containing EOVG was higher (LC50 = 195 ppm) in comparison with ME-CO without EOVG (LC50 = 669 ppm). Similarly, adding EOVG to ME-MO increased the toxicity further (LC50 = 120 ppm). Moreover, the LC50 of ME with and without EOVG for A. guerreronis was higher than the LC50 determined for the EOVG alone (LC50 = 888 ppm). The MEs containing EOVG in their LC80 and mainly LC50, repelled the mite. Overall, our results indicate that the MEs hold potential for controlling A. guerreronis, especially when EOVG was added with both oil phases.

Mite damage provides refuges and affects preference and performance of a subsequent herbivorous moth

AbstractDamage by herbivores often modifies plant structure and physiology, which may change the behaviour and performance of future herbivores. Here, we studied such interactions among the major coconut pest, the mite Aceria guerreronis (Acari: Eriophyidae), and two minor pests, the mite Steneotarsonemus concavuscutum (Acari: Tarsonemidae) and the moth Atheloca bondari (Lepidoptera: Pyralidae). All these species develop in the meristematic zone of coconuts, which is difficult to access because of the small opening between the epicarp and perianth. Both mites cause necrosis on the epicarp of the nuts, which may facilitate access to the meristematic zone by caterpillars of the moth. However, the caterpillars co‐occur predominantly with A. guerreronis and not with S. concavuscutum. We show that caterpillars did not colonize nuts without mites and colonized nuts with A. guerreronis most frequently, in agreement with the openings caused by this mite and caterpillar size. When the opening between epicarp and perianth was artificially increased, caterpillars also colonized nuts without mites and nuts with S. concavuscutum. When offered a choice, caterpillars preferred nuts with easy access to the meristematic region, regardless of the presence of mites. Caterpillars performed better on the A. guerreronis‐infested nuts than on other nuts, but moth females did not preferentially oviposit in coconut bunches infested with mites. Hence, caterpillars, not adults, select suitable feeding sites within a bunch of coconuts, and A. guerreronis facilitates the infestation of coconuts by A. bondari. We discuss how damage by mites affects the relevance of A. bondari as a coconut pest.

Model‐based prediction of the potential geographical distribution of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae) based on MaxEnt

Abstract The coconut mite Aceria guerreronis Keifer (Acari: Eriophyidae), is a destructive mite pest of coconut, causing significant economic losses. However, an effective pest management strategy requires a clear understanding of the geographical areas at risk of the target pest. Therefore, we predicted the potential global distribution A. guerreronis using a machine learning algorithm based on maximum entropy. The potential future distribution for A. guerreronis covered the 2040 and 2060 periods under two climate change emission scenarios (SSP1‐2.6 and SSP5‐8.5) in the context of the sixth assessment report (AR6) of the Intergovernmental Panel on Climate Change. The MaxEnt model predicts the habitat suitability for A. guerreronis outside its present distribution, with suitable habitats in Oceania, Asia, Africa, and the Americas. The habitat suitability for the pest will decrease from 2040 to 2060. The areas with the highest risk of A. guerreronis are those with an annual average temperature of around 25°C, mean annual precipitation of about 1459 mm, mean precipitation seasonality close to 64%, an average variation of daytime temperature of about 8.6°C, and mean seasonality of temperature of about 149.7°C. Our findings provide information for quarantine measures and policymaking, especially where A. guerreronis is presently still absent.

Functional and numerical responses of the predatory mite Amblyseius aerialis (Acari: Phytoseiidae) to Aceria guerreronis (Acari: Eriophyidae)

The coconut mite, Aceria guerreronis Keifer, is one of the main pests of the coconut tree (Cocos nucifera L.) worldwide. Its control is mainly based on the use of acaricides. However, due to the habitat of this pest mite, which is protected by fruit bracts that act as a physical barrier, chemical control is often inefficient. Thus, natural enemies have been studied as an alternative to acaricides. We evaluated the functional and numerical responses of Amblyseius aerialis (Muma) to increasing densities of A. guerreronis (40, 80, 160, 240 and 360) and additionally the oviposition rates of the phytoseiid A. aerialis over 11 days on different food sources: coconut pollen, A. guerreronis and a mix of pollen and A. guerreronis. Our results showed that Amblyseius aerialis showed a type III functional response, where prey consumption increasing as the density of A. guerreronis increased, with a maximum consumption of up to 175 prey per predator. All the prey densities allowed female oviposition. The number of eggs laid by A. aerialis increased with increasing prey density and stabilized between 240 and 360 A. guerreronis individuals, with an average oviposition of 1.7 eggs/female. Furthermore, our results showed that all the food sources (coconut pollen, A. guerreronis and a mix of pollen and A. guerreronis) supported oviposition. The mean oviposition was approximately 1.5 eggs/female on all the food sources. Our study suggests that A. aerialis can be effective in the biological control of A. guerreronis. However, further studies are needed to investigate whether A. aerialis can explore the habitat of A. guerreronis and if that prey can support the development of immature stages and the reproduction of A. aerialis.

Incidence of Rhinoceros Beetle (Oryctes rhinoceros) and Eriophyid Mite (Aceria guerreronis) on a Coconut Plantation In Pollachi Area

A survey was carried out to identify the major insect pests in the coconut farm of the Pollachi area. There were two major pests viz., rhinoceros beetle, Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae), eriophyid mite, Aceria guerreronis Keifer (Acari: Eriophyidae) were predominant during the period of observation. Natural enemies viz., Chelisochus mori, and Campsomeriella collaris were identified, and the level of population was meagre. The incidence of rhinoceros beetle ranged from 36.26 to 41.97 % of which the highest incidence was recorded in B and E block, respectively. The incidence of eriophyid mite ranged from 4.52 to 16.45 %, against a minimum of 4.52 % noticed in D block. The incidence of rhinoceros beetle was maximum (43.50%) during April, followed by March month as compared to the lowest in January (34.7%). Similarly, the incidence of eriophyid mite was maximum (12.92%) during April followed by March (9.78%) as against the lowest incidence during January (7.40%). The peak occurrence of eriophyid mite was recorded during March and April might be due to the influence of either temperature or relative humidity.

Bioactivity of the essential oil from sweet orange leaves against the coconut mite Aceria guerreronis (Acari: Eriophyidae) and selectivity to a generalist predator

Several species of predatory mites, naturally occurring in coconut plantations, play an important role in regulating populations of phytophagous mites that are key pests of this crop. Plant essential oils (EOs) are bioactive mixtures of compounds that hold potential for controlling phytophagous arthropods with minimal impacts on non-target organisms and the environment. This study aimed to characterize the chemical composition and assess the bioactivity of the EO extracted from the leaves of the ‘Pera’ sweet orange grafted on ‘Rangpur lime’ to a key pest of coconut plantations worldwide, namely the coconut mite Aceria guerreronis (Acari: Eriophyidae), and its compatibility with the naturally-occurring generalist predatory mite Typhlodromus ornatus (Acari: Phytoseiidae). Briefly, sabinene was the major component, followed by δ-3-carene and (E)-β-ocimene. The EO was toxic to A. guerreronis (LC50 = 4.28 mg/mL; LC80 = 10.39 mg/mL) but not to T. ornatus. The LC80 of the EO did not repel A. guerreronis and was toxic to the pest mite only in the first hours (<9 h). Moreover, this concentration did not affect the growth rate of the predator, which was positive over the 10 days of exposure to the oil. Therefore, the EO of ‘Pera’ sweet orange holds potential for the management of coconut mite and is compatible with the generalist predatory mite T. ornatus.

Toxicity and repellency of the essential oil from Lippia gracilis to the coconut mite Aceria guerreronis (Acari: Eriophyidae)

ABSTRACT The essential oil (EO) from different genotypes of Lippia gracilis Schauer (Verbenaceae) present two distinctive chemotypes containing either thymol or its isomer carvacrol as major compounds, both of which have proven bioactivity against several agricultural pests. Recently, we have shown that L. gracilis accession LGRA 106 and its major compound thymol are toxic and repellent against the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), a key pest of coconut plantations in Asia, Africa and America. Since intraspecific variation affects the chemical composition of EO and hence, its bioactivity, here we assessed the acaricidal and repellent effects of L. gracilis accession LGRA109 to A. guerreronis. Leaves of this accession contain carvacrol (49.35%) as major compound. The LC50 of the EO and of carvacrol estimated for A. guerreronis were 28.01 and 6.84 mg/mL, respectively. Carvacrol, at its LC50, as well as the EO and carvacrol at their LC99, repelled the mite. Our results indicated that carvacrol and the EO of L. gracilis accession LGRA109 were bioactive against A. guerreronis; however, the EO was less effective than its major compound.

Compatibility of degummed soybean and babassu oils with the generalist predatory mite Typhlodromus (Anthoseius) ornatus (Acari: Phytoseiidae) preying on Aceria guerreronis (Acari: Eriophyidae)

ABSTRACT Typhlodromus (Anthoseius) ornatus Denmark & Muma (Acari: Phytoseiidae) is one of the predatory mites associated with the coconut mite Aceria guerreronis (Acari: Eriophyidae), considered a severe pest of coconut plantations worldwide. In addition to predatory mites, vegetable oils such as degummed soybean and babassu oils have shown high efficiency in controlling A. guerreronis. Here, we evaluated the effects of degummed soybean and babassu oils on the functional response and oviposition of T. (A.) ornatus preying on A. guerreronis. Exposure to the tested oils did not alter either the functional response or the attack rate of T. (A.) ornatus. The variation in prey consumption with the exposure to vegetable oils did not differ from the control, although degummed soybean oil led to higher consumption compared to babassu oil. In addition, prey handling time and peak consumption were negatively affected by the exposure to babassu oil. The number of eggs laid by the female of T. (A.) ornatus at intermediate prey density decreased under exposure to degummed soybean oil. Overall, our results indicate that the tested oils are generally compatible with T. (A.) ornatus as they do not alter predatory responses but oviposition rate is affected by degummed soybean oil.

Geographical and seasonal distribution of the coconut mite, Aceria guerreonis (Acari: Eriophyidae), in Puerto Rico and Florida, USA

The coconut mite, Aceria guerreronis Keifer, was collected for the first time in Puerto Rico in 1977. It was reported for the first time in Florida in 1984, although it may have been present in the state since the 1950s. On the basis of damage symptoms observed during 1986-87, the coconut mite was distributed in almost all plantings of coconut in Puerto Rico. The percentage of trees with symptoms was highest on the west coast, where planting density is highest. During the same period, the percentage of coconut palms infested with coconut mites varied from 66 to 98% at different sites on the Florida Keys. On the Florida mainland, the percentage of trees with coconut mite damage was usually less than 7%. At several sites on the Florida mainland revisited in 1988, coconut mites had spread locally. At Playa Tres Hermanos in Añasco, Puerto Rico, and Bahía Honda Key, Florida, where monthly sampling was conducted, coconut mite population fluctuations did not appear to be strongly associated with dry and wet periods or mean daily temperatures. A list of mite species associated with the coconut mite was reported. It included four species reported for the first time in Puerto Rico. In Puerto Rico, Bdella distincta preyed on both coconut mite and Steneotarsonemus furcatus. In Florida, Amblyseius largoensis, Neoseiulos mumai, and N. paspalivorus were observed preying on coconut mites. However, these predators apparently do not significantly affect coconut mite populations. Tarsonemus sp. inflicted damage on the coconut similar to that caused by the coconut mite. Coconut mites beneath tepals of coconuts exposed to —1.5° C for 5.5 hours were not affected adversely by this treatment. Some eggs remained viable after exposure to —3° C up to 5 hours. Coconut mites survived at 5° C for 10 days. Thus, coconut mites are capable of surviving most winters on the Florida mainland.

Biomonitoring the &amp;lt;i&amp;gt;Vitex gardneriana&amp;lt;/i&amp;gt; Shauer (Lamiaceae) Toxic Effects to Shed Light on Bioactive Compounds against a Major Coconut Pest Mite

The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), is a major pest of coconut plantations (Cocos nucifera L.) worldwide. Here, we conducted a bioguided phytochemical approach using toxicity and repellency bioassays of nonpolar extract and its fractions of Vitex gardneriana Schauer (Lamiaceae) leaves to this pest. Nonpolar crude extract was fractionated by column chromatography using solvents with increased polarity and binary mixtures, resulting in five semipurified groups. The biomonitoring bioassay provided active fractions and led to the isolation and characterization of the bioactive compound squalene, a biosynthetic precursor of 20-hydroxyecdysone, which plays an important role in plant defense against arthropods. The LC50 of the crude extract of V. gardneriana for A. guerreronis was estimated to be 0.185 mg·mL-1 and LC80 = 4.123 mg·mL-1. Also, the extract was highly repellent to this pest for up to 24 h. The fractions of V. gardneriana, and also squalene, caused mortality to A. guerreronis. The potential of V. gardneriana fractions/squalene as biopesticides for controlling A. guerreronis in coconut plantations is discussed herein.

Population of Aceria guerreronis Keifer (Acari: Eriophydae) and damage of the coconut fruit in South Sulawesi, Indonesia

Coconut mite Aceria guerreronis Keifer (Acari: Eriophydae) as important pest in coconut plantation around the world. The population density of A. guerreronis has many impacts to coconut fruit damage. The purpose of research is to study population density of A. guerreronis, the coconut fruit damage and correlation population density in different coconut plantation at South Sulawesi. The information about presence of A. guerreronis is very useful to manage A. guerreronis for the development coconut plantation in South Sulawesi. The research was conducted in coconut plantation near the beach at three regencies of South Sulawesi namely Jeneponto, Wajo and Luwu. The observation of A. guerreronis population was held in laboratory at Plant Pest and Disease Department, Faculty of Agriculture, Universitas Hasanuddin Makassar from July to October 2019. Population of coconut mite A. guerreronis observed with washing twice all of coconut petals. First washing (P1) and second washing (P2) used 30 mL detergent solution. 1 mL of the washing water was collected observed used binocular microscope. The coconut petals after washing process observed under stereo microscope. The results show that the average damage of coconut fruit at Jeneponto was 20.35%, Wajo 14.6% and Luwu 10.6%. Population of adult and eggs of A. guerreronis at Jeneponto (2,566.45 individual and 828.95 eggs), Wajo (1,548 individual and 452.8 eggs) and Luwu (1,078.7 individual and 360.3 eggs). Findings of research show that there was a very strong correlation between population with damage level with R value at Jeneponto (0.919), Wajo (0.954) and Luwu (0.975).

Interference of plant fixed oils on predation and reproduction of Neoseiulus baraki (Acari: Phytoseiidae) feeding on Aceria guerreronis (Acari: Eriophyidae)

The coconut mite, Aceria guerreronis (Acari: Eriophyidae), is a major pest in coconut plantations in America, Africa and Asia. The management of this pest usually relies on scheduled applications of synthetic pesticides. Recent research demonstrated that degummed soybean and cottonseed oils may potentially control the mite. Although these fixed oils have considerable selectivity for predatory mites, little is known about their sublethal effects on these key natural enemies. This study aimed to assess whether degummed soybean and cottonseed oils modify the functional and numerical responses of Neoseiulus baraki (Acari: Phytoseiidae), a predatory mite frequently associated with A. guerreronis. The exposure of N. baraki to the dosage required to kill 99% of the population (LC99) of the plant oils, estimated for A. guerreronis, changed the functional response of the predator from type III to type II. Attack rate and the change in consumption were not influenced by the fixed oils. However, handling time and consumption peak were adversely affected by the exposure of the predator to degummed soybean oil. Additionally, exposure to this oil reduced N. baraki female oviposition. Our results suggest that degummed soybean oil can be more detrimental to the control of A. guerreronis exerted by N. baraki. Although both oils altered the curve of the functional response, the predator could consume high proportions of A. guerreronis, mainly at low prey densities.

Composition and Bioactivity of Essential Oil From the Leaves of Genipa americana Against the Coconut Mite Aceria guerreronis

Genipa americana L. has a diversity of secondary metabolites, including iridoids, phenolic compounds, and alkaloids. Pharmacological and biological properties have also been reported. This study has aimed to evaluate the chemical composition of the essential oil (EO) obtained from the leaves of G. americana and its bioactivity against Aceria guerreronis Keifer (Acari: Eriophyidae), a serious pest of coconut production areas worldwide. EO from the leaves was extracted and analyzed by Gas Chromatography-Mass Spectrometry and flame ionization detection (GC-MS/FID). For the bioassays, the adult coconut mites were subjected to increasing concentrations of EO. The analyses showed a predominance of sesquiterpenes, followed by monoterpenes, aldehydes, and fatty acids. The EO (LC50 = 0.41 mg mL-1; LC90 = 6.43 mg mL-1) showed toxicity and repellent effects against the coconut mite. The tested EO has the potential to develop as a natural product, with acaricidal activities against A. guerreronis, in order to assist in the control of the coconut mite.