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The coconut production system, in which the coconut mite Aceria guerreronis is considered a key pest, provides an interesting model for integration of biological and chemical control. In Brazil, the most promising biological control agent for the coconut mite is the phytoseiid predator Neoseiulus baraki. However, acaricides are widely used to control the coconut mite, although they frequently produce unsatisfactory results. In this study, we evaluated the simultaneous direct effect of dry residue contact and contaminated prey ingestion of the main acaricides used on coconut palms (i.e., abamectin, azadirachtin and fenpyroximate) on life-history traits of N. baraki and their offspring. These acaricides are registered, recommended and widely used against A. guerreronis in Brazil, and they were tested at their label rates. The offspring of the exposed predators was also evaluated by estimating the instantaneous rate of population increase (r i ). Abamectin compromised female performance, whereas fenpyroximate did not affect the exposed females (F0). Nonetheless, fenpyroximate strongly compromised the offspring (F1) net reproductive rate (R0), intrinsic rate of population growth (r i ), and doubling time (DT). In contrast, fenpyroximate did not have such effects on the 2nd generation (F2) of predators with acaricide-exposed grandparents. Azadirachtin did not affect the predators, suggesting that this acaricide can be used in association with biological control by this predatory species. In contrast, the use of abamectin and fenpyroximate is likely to lead to adverse consequences in the biological control of A. guerreronis using N. baraki.

Reducing the losses caused by Aceria guerreronis Keifer has been an arduous task for farmers. However, there are no detailed studies on losses that simultaneously analyse correlated parameters, and very few studies that address the economic viability of chemical control, the main strategy for managing this pest. In this study the objectives were (1) to estimate the crop loss due to coconut mite and (2) to perform a financial analysis of acaricide application to control the pest. For this, the following parameters were evaluated: number and weight of fruits, liquid albumen volume, and market destination of plants with and without monthly abamectin spraying (three harvests). The costs involved in the chemical control of A. guerreronis were also quantified. Higher A. guerreronis incidence on plants resulted in a 60 % decrease in the mean number of fruits harvested per bunch and a 28 % decrease in liquid albumen volume. Mean fruit weight remained unaffected. The market destination of the harvested fruit was also affected by higher A. guerreronis incidence. Untreated plants, with higher A. guerreronis infestation intensity, produced a lower proportion of fruit intended for fresh market and higher proportions of non-marketable fruit and fruit intended for industrial processing. Despite the costs involved in controlling A. guerreronis, the difference between the profit from the treated site and the untreated site was 18,123.50 Brazilian Real; this value represents 69.1 % higher profit at the treated site.

The predatory mite Neoseiulus paspalivorus (De Leon) is often found in association with the coconut mite, Aceria guerreronis Keifer. The identification of natural enemies is essential for the definition of biological control strategies. Therefore, the present study aimed to confirm whether the mite populations from different Northeastern Brazilian states identified as N. paspalivorus belong to the same species. This determination was accomplished through the study of morphometric variability in 33 anatomical characters and of molecular variability in two DNA fragments: Internal Transcribed Spacer (ITS) rDNA and cytochrome c oxidase subunit I (COI) mtDNA. This study also determined whether there is reproductive isolation between the two most morphologically distinct populations (Rio Grande do Norte and Paraíba). Intraspecific morphometric variability was observed among the five populations of N. paspalivorus. Despite this variability, the crosses and backcrosses of the most morphologically distinct populations did not show reproductive incompatibility. The molecular analysis indicated the absence of genetic differences among the N. paspalivorus populations for the ITS fragment. Three haplotypes were identified for the COI fragment, and the genetic distance ranged from 0 to 0.2 %. Despite the morphometric differences, the results of the molecular and biological analysis corroborate the previous identification of N. paspalivorus for all of the studied populations. The present study contributes to the systematics of Phytoseiidae predatory mites and to the biological control of A. guerreronis by the accurate identification and characterization of one of its main natural enemies along extensive areas in Brazil.

Amblyseius largoensis (Muma) (Acari: Phytoseiidae) and Euseius alatus De Leon (Acari: Phytoseiidae) are predatory mites that are mostly found on leaves and on the exposed fruit surface of coconut plants. Their morphology hampers the access to the microhabitat occupied by Aceria guerreronis Keifer (Acari: Eriophyidae), the most important pest of coconut fruits throughout the world. However, it was suggested that they can prey on A. guerreronis under natural conditions when this pest leaves its refuge to disperse. Since the trophic interactions between A. largoensis or E. alatus and A. guerreronis are unknown, we compare the frequencies of occurrence of A. largoensis and E. alatus under the bracts of coconut fruits and on coconut leaflets. In addition, because phytoseiids feed by liquid ingestion, we used molecular analysis to confirm the potential role of A. largoensis or E. alatus as predators of A. guerreronis and to assess how fast the A. guerreronis DNA fragment is degradated in the A. largoensis digestive tract. Our study demonstrated that E. alatus was only present on coconut leaflets whereas A. largoensis was found mostly on leaflets and, to a much lesser extent, under the bracts of coconuts. Species-specific ITS primers designed for A. guerreronis were shown to have a high degree of specificity for A. guerreronis DNA and did not produce any PCR product from DNA templates of the other insects and mites associated with the coconut agroecosystem. Based on molecular analysis, we confirmed that the predatory mites, A. largoensis and E. alatus, had preyed on the coconut mite in the field. Overall the predatory mites collected in the field exhibited low levels of predation (26.7% of A. largoensis and 8.9% of E. alatus tested positive for A. guerreronis DNA). The fragment of A. guerreronis DNA remained intact for a very short time (no more than 6 h after feeding) in the digestive tract of A. largoensis.

Acaricides may interfere with a myriad of interactions among arthropods, particularly predator-prey interactions. The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), and its phytoseiid predator, Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae), provide an opportunity to explore such interference because the former is a key coconut pest species that requires both predation and acaricide application for its management. The objective of the present study was to assess the effect of the acaricides abamectin, azadirachtin and fenpyroximate on the functional response of N. baraki to A. guerreronis densities. The following prey densities were tested: 5, 10, 20, 40 and 80 preys. The type of functional response and prey handling time (Th) were not altered by the acaricides. However, the attack rate (a') was modified by abamectin and fenpyroximate, and the consumption peak was reduced by abamectin. All of the acaricides allowed for the maintenance of the predator in the field, but exposure to abamectin and fenpyroximate compromised prey consumption.

For the coconut mite, Aceria guerreronis Keifer, its host plant, the coconut palm, is not merely a source of food, but more generally a habitat to live in for several generations. For these minute organisms, finding a new plant is difficult and risky, especially because their main mode of dispersal is passive drifting with the wind and because they are highly specialized on their host plant. Consequently, the probability of landing on a suitable host is very low, let alone to land in their specific microhabitat within the host. How coconut mites manage to find their microhabitat within a host plant is still underexplored. We tested the hypothesis that they use volatile chemical information emanating from the plant to find a specific site within their host plants and/or use non-volatile plant chemicals to stay at a profitable site on the plant. This was investigated in a Y-tube olfactometer (i.e. under conditions of a directed wind flow) and on cross-shaped arenas (i.e. under conditions of turbulent air) that either allowed contact with odour sources or not. The mites had to choose between odours from specific parts (leaflet, spikelet or fruit) of a non-infested coconut plant and clean air as the alternative. In the olfactometer experiments, no mites were found to reach the upwind end of the Y-tube: <5 % of the mites were able to pass the bifurcation of the "Y". On the cross-shaped arenas, however, a large number of coconut mites was found only when the arm of the arena contained discs of fruit epidermis and contact with these discs was allowed. The results suggest that coconut mites on palm trees are not attracted to specific sites on the plant by volatile plant chemicals, but that they arrested once they contact the substrate of specific sites. Possibly, they perceive non-volatile chemicals, but these remain to be identified.

For more than three decades the coconut mite Aceria guerreronis Keifer is one of the most important pests of coconut palms and has recently spread to many coconut production areas worldwide. Colonization of coconut palms is thought to arise from mites dispersing aerially after take-off from other plants within the same plantation or other plantations. The underlying dispersal behaviour of the mite at take-off, in the airborne state and after landing is largely unknown and this is essential to understand how they spread from tree to tree. In this article we studied whether take-off to aerial dispersal of coconut mites is preceded by characteristic behaviour, whether there is a correlation between the body position preceding aerial dispersal and the direction of the wind, and whether the substrate (outer surface of coconut bracts or epidermis) and the wind speed matter to the decision to take-off. We found that take-off can sometimes be preceded by a raised body stance, but more frequently take-off occurs while the mite is walking or resting on its substrate. Coconut mites that become airborne assumed a body stance that had no relation to the wind direction. Take-off was suppressed on a substrate providing food to coconut mites, but occurred significantly more frequently on the outer surface of coconut bracts than on the surface of the fruit. For both substrates, take-off frequency increased with wind speed. We conclude that coconut mites have at least some degree of control over take-off for aerial dispersal and that there is as yet no reason to infer that a raised body stance is necessary to become airborne.

Ambulatory movement of plant-feeding mites sets limits to the distances they can cover to reach a new food source. In absence of food-related cues these limits are determined by survival, walking activity, walking path tortuosity and walking speed, whereas in presence of food the limits are also determined by the ability to orient and direct the path towards the food source location. For eriophyoid mites such limits are even more severe because they are among the smallest mites on earth, because they have only two pairs of legs and because they are very sensitive to desiccation. In this article we test how coconut mites (Aceria guerreronis Keifer) are constrained in their effective displacement by their ability to survive in absence of food (meristematic tissue under the coconut perianth) and by their ability to walk and orient in absence or presence of food-related cues. We found that the mean survival time decreased with increasing temperature and decreasing humidity. Under climatic conditions representative for the Tropics (27 °C and 75 % relative humidity) coconut mites survived on average for 11 h and covered 0.4 m, representing the effective linear displacement away from the origin. Within a period of 5 h, coconut mites collected from old fruits outside the perianth moved further away from the origin than mites collected under the perianth of young fruits. However, in the presence of food-related cues coconut mites traveled over 30 % larger distances than in absence of these cues. These results show that ambulatory movement of eriophyoid mites may well bring them to other coconuts within the same bunch and perhaps also to other bunches on the same coconut palm, but it is unlikely to help them move from palm to palm, given that palms usually do not touch each other.

The coconut mite, Aceria guerreronis Keifer, is a major pest of coconut palm in the world. The control of this pest species is done through acaricide applications at short time intervals. However, the predators of this pest may also be affected by acaricides. Among the predators of A. guerreronis, Neoseiulus baraki (Athias-Henriot) has potential for biological control. The objective of this study was to assess the effect of acaricides on the survival and behavior of N. baraki. The survivorship of N. baraki was recorded in surface-impregnated arenas. Choice and no-choice behavioral bioassays were carried out using a video tracking system to assess the walking behavior of the predator under acaricide exposure. Although all acaricides negatively affected the survival of N. baraki, chlorfenapyr and azadirachtin caused lower effect than the other acaricides. No significant differences in walking behavior were observed under exposure to fenpyroximate, chlorfenapyr and chlorpyrifos on fully-contaminated arenas. Azadirachtin and chlorpyrifos caused repellence. Irritability was observed for all acaricides, except for abamectin. Chlorfenapyr was the most suitable product for managing the coconut mite because of its low effect on survival and behavior of N. baraki.

Raoiella indica Hirst (Acari: Tenuipalpidae) is considered a pest of coconut palm in Asia and the Middle East. This mite was recently introduced in the Americas, where it spread to several countries and expanded its range of hosts, causing heavy losses to coconut and banana production. The phytoseiid mite Amblyseius largoensis (Muma) is one of the predators most often encountered in coconut palms. Because the current prospects for the control of R. indica in the New World indicate the use of acaricides and the management of their natural enemies, the objective of this study was to evaluate the toxicity of selected acaricides to R. indica and the selectivity (i.e., toxicity to the predator relative to toxicity to the prey) for A. largoensis. Assays were performed by the immersion of banana leaf discs in acaricide solutions, followed by the placing of adult females of the pest or predator on the discs. Mortality of the mites was evaluated after 24 h, and the data obtained were subjected to probit analysis. Abamectin, fenpyroximate, milbemectin and spirodiclofen were the products most toxic to R. indica adults, whereas fenpyroximate and spirodiclofen were the most selective for A. largoensis.

The red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae), was recently introduced in the Americas. It spread quickly throughout coconut palm growing areas, expanding considerably its host range. The invasion of this species has caused high economic impact in several countries. In Brazil, extensive areas are expected to be affected. For logistical reasons and other concerns, chemical control does not seem desirable for the control of this pest in most Latin American countries. Biological control of R. indica by introducing exotic natural enemies seems to be an important control measure to be considered. Surveys in many countries have shown that Amblyseius largoensis (Muma) (Acari: Phytoseiidae) is a very common predator on coconut palms. This study compared the biology of a population of A. largoensis found for a long time in association with R. indica in La Reunion Island (Indian Ocean) with a population from Roraima State (northern Brazil), where R. indica was first found about two and a half years ago. No significant differences were observed between populations in relation to the duration of different immature stages or total survivorship. However, the oviposition period, prey consumption and net reproductive rate were significantly higher for the La Reunion population, warranting further investigation to determine whether that population should be released in Roraima to control the pest.

The coconut mite (CM), Aceria guerreronis Keifer, has spread to most coconut production areas worldwide and it has been considered one of the most notorious and important pests of coconut fruits in many countries. Although CM has been reported to damage coconuts for over 40 years in the Americas and Africa it continues to cause considerable losses in countries of these continents, and in the last 15 years it has also reached countries from southeast Asia-India and Sri Lanka. Several other countries of southeast Asia are also major coconut producers and the impact by the mite in currently affected areas suggests that the dispersion of CM to these major producers could lead to very heavy losses. Great advances about our knowledge on CM and its control have been achieved, especially in the last decade, after its introduction into Asia. However, much remains to be known to allow the design of efficient strategies to it. This paper brings together information on CM invasive history, distribution, hosts, morphology, biology, dispersal, colonization process, population dynamics, symptoms and injury, estimated losses, sampling techniques, control strategies and new perspectives for its control.

Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of the coconut (Cocos nucifera L.), and the use of pesticides is the current method to control it. However, no standard toxicological tests exist to select and assess the efficiency of molecules against the coconut mite. The aim of this study was to develop a methodology that allows for the evaluation of the relative toxicity of acaricides to A. guerreronis through rapid laboratory procedures. We confined A. guerreronis on arenas made out of coconut leaflets and tested two application methods: immersing the leaf fragments in acaricides and spraying acaricides on the leaf fragments under a Potter spray tower. In the latter application method, we sprayed leaf fragments both populated with and devoid of mites. We evaluated the comparative toxicity of two populations (Itamaracá and Petrolina, Pernambuco, Brazil) by spraying on leaflets without mites and submitted the mortality data to probit analysis after 24 h of exposure. No difference was observed in the LC50, regardless of whether the leaflets were immersed or sprayed with acaricide (abamectin, chlorfenapyr or fenpyroximate). The toxicity of chlorfenapyr and fenpyroximate did not differ, irrespective of whether it was applied directly to the leaflet or to the mite; however, the toxicity of abamectin was higher when applied directly to the mite. Chlorpyrifos and abamectin toxicities were lower for the Petrolina population than for the Itamaracá population. Immersing and spraying coconut leaflets can be used to assess the mortality of A. guerreronis under laboratory conditions.

The dispersal of plant-feeding mites can occur involuntarily, through transportation of infested plant parts, or voluntarily, by walking to new plant parts or to suitable spots where biotic (phoresis) or abiotic (wind, agricultural tools, etc.) factors carry them over long distances. Elucidating the dispersal mechanisms of the coconut mite, Aceria guerreronis Keifer, is important for understanding the process of colonization of new fruits of a same or different plants, essential for the improvement of control strategies of this serious coconut pest. Thus, the objective of this work was to investigate the voluntary dispersal mechanisms of this mite. The hypothesis that the coconut mite disperses by walking, phoresis or wind were tested. The coconut mite was shown to be able to walk short distances between fruits of the same bunch or between bunches of the same plant. Phoresis on insects of the orders Hymenoptera (Apidae), Coleoptera (Curculionidae) and Lepidoptera (Phycitidae) was evaluated in the laboratory and in the field. Although in the laboratory mites were shown to be able to climb onto honeybees, field investigations failed to show these insects as important carriers of the pest, corroborating findings of previous works; however, both laboratory and field investigations suggested the curculionid Parisoschoenus obesulus Casey to be able to transport the coconut mite between plants. Similarly, laboratory and field investigations suggested wind to be important in the dispersal of the coconut mite between plants.

Several predatory mites have been found in association with the coconut mite, Aceria guerreronis Keifer, in northeast Brazil. However, the latter still causes damage to coconut in that region. The objectives of this work were to compare the frequencies of occurrence of Neoseiulus (Phytoseiidae) and Proctolaelaps (Melicharidae) species on standing and aborted coconuts in coastal Pernambuco State, northeast Brazil and to analyze their possible limitations as control agents of the coconut mite, based on evaluations of the restrictions they may have to access the microhabitat inhabited by the pest and their functional and reproductive responses to increasing densities of the latter. Neoseiulus baraki (Athias-Henriot) was found mostly on standing coconuts whereas Proctolaelaps bickleyi (Bram) was found mostly on aborted coconuts. Measurements of the entrance to the microhabitat occupied by the coconut mite, between the bracts and the subjacent fruit surface, showed that this different pattern of predator prevalence could be related to predator sizes, although other environmental factors could not be disregarded. Progressively higher predation rate of N. baraki was observed up to an experimental density that corresponded to 1,200 coconut mites per fruit, which is close to the average number determined in northeast Brazil, reducing slightly afterwards. Predation rate of P. bickleyi reduced consistently but slightly with increasing prey densities, but in absolute values, rates were always much higher than determined for N. baraki. The excessively high killing capacity of P. bickleyi, probably related to its high feeding requirement, may be detrimental in terms of stability. In fact, such high requirement for food suggests that P. bickleyi might not have a strong relation with the coconut mite and that the latter may not be its main food source under natural conditions. It is concluded that body sizes of both predators and the exceedingly high feeding requirement of P. bickleyi may limit their performance as control agents of the coconut mite.

The phytophagous mite Aceria guerreronis Keifer is an important pest of coconut worldwide. A promising method of control for this pest is the use of predatory mites. Neoseiulus baraki (Athias-Henriot) and Proctolaelaps bickleyi Bram are predatory mites found in association with A. guerreronis in the field. To understand how these predators respond to olfactory cues from A. guerreronis and its host plant, the foraging behavior of the predatory mites was investigated in a Y-tube olfactometer and on T-shaped arenas. The predators were subjected to choose in an olfactometer: (1) isolated parts (leaflet, spikelet or fruit) of infested coconut plant or clean air stream; (2) isolated parts of non-infested or infested coconut plant; and (3) two different plant parts previously shown to be attractive. Using T-shaped arenas the predators were offered all possible binary combinations of discs of coconut fruit epidermis infested with A. guerreronis, non-infested discs or coconut pollen. The results showed that both predators were preferred (the volatile cues from) the infested plant parts over clean air. When subjected to odours from different infested or non-infested plant parts, predators preferred the infested parts. Among the infested plant parts, the spikelets induced the greatest attraction to predators. On the arenas, both predators preferred discs of coconut fruits infested with A. guerreronis over every other alternative. The results show that both predators are able to locate A. guerreronis by olfactory stimuli. Foraging strategies and implications for biological control are discussed.

Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of coconut in many countries in the Americas, Africa and parts of Asia. Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) is one of the predatory mites most commonly found in association with A. guerreronis in parts of northeast Brazil. The objective of this work was to study the distribution of A. guerreronis and N. baraki among and within coconut bunches. The hypothesis was tested that A. guerreronis and N. baraki are homogenously distributed over the fruits in a bunch, independent of the fruits' age and position. Five collections of bunches, each corresponding to leaves 12-16 from apex (about 2-6 month-old), were conducted in each of three fields in northeastern Brazil, from February to October, 2007. A total of 1,986 fruits were examined. The number of mites, the percentage of fruits hosting them and the level of damage caused by A. guerreronis were evaluated. The highest density of A. guerreronis was observed on fruits of bunch 4 whereas the highest density of N. baraki was observed on bunch 5. Considering all fruits together, no significant differences were observed between densities of either A. guerreronis or N. baraki among the basal, median and apical thirds of the bunches. In younger bunches, fruits of the apical region tend to have lower densities of both mites than fruits of the basal region. This pattern, in association with a similar pattern for the percentage of fruits hosting N. baraki, suggests that the predator initially reaches the basal bunch region, from where it moves to the apical region. The results of the present study suggest that the pest population reduction in bunches older than bunch 4 could be due to (1) an effect of the predator, (2) reduction of the proportion of undamaged tissues amenable to attack, and/or (3) less favorable characteristics of the fruits to attack by A. guerreronis, as indicated by their increasing lignin content as they get older.

The presence of the red palm mite, Raoiella indica Hirst, is reported for the first time in Brazil. This invasive mite was found in July 2009 infesting coconut palms and bananas in urban areas of Boa Vista, State of Roraima, in northern Brazil. Comments on the possible pathways of R. indica into the country, present and potential impact of its introduction and mitigating measures to prevent or to delay the mite spread in Brazil are presented.

Aceria guerreronis Keifer (Acari: Eriophyidae) is a major pest of coconut fruits (Cocos nucifera L.) in many countries of the Americas, Africa, and parts of Asia. Considerable attention has been given to studies of biological control agents of A. guerreronis. Proctolaelaps bulbosus Moraes, Reis and Gondim Jr. is a predator recently discovered in association with A. guerreronis. Nothing is known about its biology. The aim of this study was to determine suitable food sources for P. bulbosus, among items commonly found on coconut fruits, including A. guerreronis. Food sources evaluated included the mites A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank), the fungus Rhizopus aff. stolonifer (Ehrenb.) Vuill and coconut pollen; the mite Tetranychus urticae Koch was also included in the assessments, for being a commonly used prey for mass production and laboratory rearing of predatory mites. Proctolaelaps bulbosus was able to develop up to adulthood when fed A. guerreronis, R. aff. stolonifer and T. putrescentiae. It had the highest population growth rates when feeding on the former (R (o) = 17.5; r (m) = 0.392). These results indicate that A. guerreronis is the most suitable food for P. bulbosus among the possible food sources found on coconut fruits and that P. bulbosus can survive in the absence of eriophyid using R. aff. stolonifer as a food source.

Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) has been reported from the Americas, Africa and Asia, often in association with Aceria guerreronis Keifer (Acari: Eriophyidae), one of the most important pests of coconut (Cocos nucifera L.) in different parts of the world. That phytoseiid has been considered one of the most common predators associated with A. guerreronis in Brazil. The objective of this study was to evaluate the feeding preference and the effect of food items commonly present on coconut fruits and several temperature regimes on the life history of a Brazilian population of N. baraki. Completion of immature development was possible when N. baraki was fed A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank). Fecundity was highest on T. putrescentiae (39.4 eggs), followed by A. guerreronis (24.8 eggs). In choice tests, irrespective of the food on which N. baraki was reared, a larger number of adults of this predator chose leaf discs containing A. guerreronis than discs containing other food items, demonstrating a preference of the former for the latter as food. Egg to adult thermal developmental time was calculated as 84.2 degree-days, above a threshold of 15.8 degrees C. This lower developmental threshold is higher than previously published for phytoseiid species from higher latitudes. Neoseiulus baraki was shown to have higher biotic potential at 30 degrees C (r (m) 0.29). The results suggest N. baraki to be a promising biological control agent of A. guerreronis, well adapted to survive and develop in areas with relatively high temperatures, where that pest prevails.

Mites of the genus Euseius are generally considered specialist as pollen feeders. Euseius alatus DeLeon is one of the six species of phytoseiid mites most commonly found on coconut plants in northeast Brazil associated with Aceria guerreronis Keifer. Although the morphology of E. alatus does not favor the exploitation of the meristematic area of the fruit inhabited by A. guerreronis, the predator may have some role in the control of this eriophyid during the dispersion process. The objective of this work was to evaluate the development and reproduction of E. alatus on the following diets: A. guerreronis, Ricinus communis pollen (Euphorbiaceae), and Tetranychus urticae Koch (Tetranychidae) + R. communis pollen + honey solution 10%. Euseius alatus developed slightly faster and had slightly higher oviposition rate when feeding on the diet composed of T. urticae + pollen + honey. However, life table parameters were very similar on all diets, suggesting that E. alatus may contribute in reducing the population of A. guerreronis in the field.

The eriophyid mite Aceria guerreronis occurs in most coconut growing regions of the world and causes enormous damage to coconut fruits. The concealed environment of the fruit perianth under which the mite resides renders its control extremely difficult. Recent studies suggest that biological control could mitigate the problems caused by this pest. Neoseiulus paspalivorus and Proctolaelaps bickleyi are two of the most frequently found predatory mites associated with A. guerreronis on coconut fruits. Regarding biological control, the former has an advantage in invading the tight areas under the coconut fruit perianth while the latter is more voracious on the pest mites and has a higher reproductive capacity. Based on the idea of the combined use/release of both predators on coconut fruits, we studied their compatibility in spatial niche use and intraguild predation (IGP). Spatial niche use on coconut fruits was examined on artificial arenas mimicking the area under the coconut fruit perianth and the open fruit surface. Both N. paspalivorus and P. bickleyi preferentially resided and oviposited inside the tight artificial chamber. Oviposition rate of P. bickleyi and residence time of N. paspalivorus inside the chamber were reduced in the presence of a conspecific female. Residence of N. paspalivorus inside the chamber was also influenced by the presence of P. bickleyi. Both N. paspalivorus and P. bickleyi preyed upon each other with relatively moderate IGP rates of adult females on larvae but neither species yielded nutritional benefits from IGP in terms of adult survival and oviposition. We discuss the relevance of our findings for a hypothetic combined use of both predators in biological control of A. guerreronis.

Coconut is an important crop in tropical and subtropical regions. Among the mites that infest coconut palms, Aceria guerreronis Keifer is economically the most important. We conducted surveys throughout the coconut growing areas of Brazil. Samples were taken from attached coconuts, leaflets, fallen coconuts and inflorescences of coconut palms in 112 localities aiming to determine the occurrence and the distribution of phytophagous mites, particularly A. guerreronis, and associated natural enemies. Aceria guerreronis was the most abundant phytophagous mite followed by Steneotarsonemus concavuscutum Lofego & Gondim Jr. and Steneotarsonemus furcatus De Leon (Tarsonemidae). Infestation by A. guerreronis was recorded in 87% of the visited localities. About 81% of all predatory mites belonged to the family Phytoseiidae, mainly represented by Neoseiulus paspalivorus De Leon, Neoseiulus baraki Athias-Henriot and Amblyseius largoensis Muma; 12% were Ascidae, mainly Proctolaelaps bickleyi Bram, Proctolaelaps sp nov and Lasioseius subterraneus Chant. Neoseiulus paspalivorus and N. baraki were the most abundant predators on attached coconuts. Ascidae were predominant on fallen coconuts, while A. largoensis was predominant on leaflets; no mites were found on branches of inflorescences. Leaflets harboured higher mite diversity than the attached coconuts. Mite diversity was the highest in the state Pará and on palms surrounded by seasonal forests and Amazonian rain-forests. Neoseiulus paspalivorus, N. baraki and P. bickleyi were identified as the most promising predators of A. guerreronis. Analyses of the influence of climatic factors revealed that dry ambient conditions favour the establishment of A. guerreronis. Neoseiulus paspalivorus and N. baraki have differing climatic requirements; the former being more abundant in warm and dry areas, the latter prevailing in moderately tempered and humid areas. We discuss the significance of our findings for natural and biological control of A. guerreronis.

Aceria guerreronis Keifer is considered one of the main pests of coconuts around the world. Amongst the Phytoseiidae recorded on this crop, Amblyseius largoensis (Muma) has been reported in association with A. guerreronis. In order to verify whether A. largoensis feeds on A. guerreronis, the biology of this predator was evaluated on different food sources, including A. guerreronis. Three types of diet were tested [Tetranychus urticae Koch + castor bean (Ricinus communis L.) pollen + honey at 10%, A. guerreronis + pollen + honey, and only A. guerreronis], determining its development, survivorship, oviposition, sex ratio and longevity at 27 degrees C, 60 +/- 5% RH 12 h photophase. Fertility life tables were constructed. The duration of the immature phase was lower when feeding only on A. guerreronis, while fecundity was higher when feeding on a prey + pollen + honey. There was no difference in relation to survivorship of the immature stages between the three diets. Parameters of fertility life tables were higher when the diet included A. guerreronis or T. urticae + pollen + honey, although the predator was able to complete its life cycle and reproduce when feeding exclusively on A. guerreronis. The results suggest that A. largoensis preys upon A. guerreronis under natural condition and that it might play some role in the control of the latter.

The eriophyoid mite Aceria guerreronis Keifer (Eriophyidae), commonly called the coconut mite, is a key pest of coconut fruits. Surveys conducted on coconut palms in Brazil revealed the predatory mites Neoseiulus paspalivorus DeLeon (Phytoseiidae) and Proctolaelaps bickleyi Bram (Ascidae) as the most commonly associated natural enemies of A. guerreronis on coconut fruits. However, virtually nothing is known about the life history of these two predators. We conducted laboratory experiments at 25 +/- 0.1 degrees C, 70-90% RH and 12:12 h L:D photoperiod to determine the life history characteristics of the two predatory mites when feeding on A. guerreronis and other potential food sources present on coconut fruits such as Steneotarsonemus furcatus DeLeon (Tarsonemidae), coconut pollen and the fungus Rhizopus cf. stolonifer Lind (Mucoraceae). In addition, the two-spotted spider mite Tetranychus urticae Koch (Tetranychidae) was tested for its suitability as prey. Both predators, N. paspalivorus and P. bickleyi, thrived on A. guerreronis as primary food source resulting in shorter developmental time (5.6 and 4.4 days, respectively), higher oviposition rate (1.7 and 7.0 eggs/female/day, respectively) and higher intrinsic rate of increase (0.232 and 0.489 per female/day, respectively) than on any other diet but were unable to develop or lay eggs when fed T. urticae. Coconut pollen and S. furcatus were adequate alternative food sources for N. paspalivorus and Rhizopus for P. bickleyi. We discuss the relevance of our findings for natural and biological control of the coconut mite A. guerreronis.