Comparison of two populations of the pantropical predator Amblyseius largoensis (Acari: Phytoseiidae) for biological control of Raoiella indica (Acari: Tenuipalpidae)

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.     

Survival and behavioural response to acaricides of the coconut mite predator Neoseiulus baraki

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.     

Geographic distribution and host plants of Raoiella indica and associated mite species in northern Venezuela

The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive pest in the New World, where it is currently considered a serious threat to coconut and banana crops. It was first reported from northern Venezuela in 2007. To determine its current distribution in this country, surveys were carried out from October 2008 to April 2010 on coconut (Cocos nucifera L.), banana (Musa spp.), ornamental plants and weeds in northern Venezuela. Higher population levels of RPM were registered on commercial coconut farms in Falcón and Sucre states but also on other plant species naturally growing along the coastal line in Anzoategui, Aragua, Carabobo, Monagas and Nueva Esparta states. Out of 34 botanical species evaluated, all RPM stages were observed only on eight arecaceous, one musaceous and one streliziaceous species, indicating that the pest developed and reproduced only on these plants. Mite specimens found on weeds were considered spurious events, as immature stages of the pest were never found on these. Amblyseius largoensis (Muma) (Acari: Phytoseiidae) was the most frequent predatory mite associated with RPM in all sampling sites. The results indicate that RPM has spread to extensive areas of northern Venezuela since its initial detection in Güiria, Sucre state. Considering the report of this pest mite in northern Brazil in the late 2009, additional samplings in southern Venezuela should be carried out, to evaluate the possible presence of RPM also in that region.     

Development and reproduction of <Emphasis Type="Italic">Amblyseius largoensis</Emphasis> (Acari: Phytoseiidae) feeding on pollen, <Emphasis Type="Italic">Raoiella indica</Emphasis> (Acari: Tenuipalpidae), and other microarthropods inhabiting coconuts in Florida,USA

The red palm mite, Raoiella indica (Acari: Tenuipalpidae), is an important pest of palms (Arecaceae) and other species within the Zingiberaceae, Musaceae and Strelitziaceae families. Raoiella indica was discovered in the USA (Palm Beach and Broward counties, Florida) late in 2007, and it subsequently spread to other Florida counties. The predatory mite Amblyseius largoensis (Acari: Phytoseiidae) has been found associated with R. indica in Florida. In order to verify whether A. largoensis can develop and reproduce when feeding exclusively on R. indica, the biology of this predator was evaluated on various food sources, including R. indica. Five diets [R. indica, Tetranychus gloveri¸ Aonidiella orientalis, Nipaecocus nipae, oak (Quercus virginiana) pollen] and a no-food control were tested to determine the predators’ development, survivorship, oviposition rate, sex ratio and longevity at 26.5 ± 1°C, 70 ± 5% RH and a 12:12 L:D photophase. Amblyseius largoensis was able to complete its life cycle and reproduce when fed exclusively on R. indica. The development of immature stages of A. largoensis was faster and fecundity and survivorship were higher when fed on R. indica or T. gloveri compared to the other food sources. The intrinsic rate of natural increase of A. largoensis was significantly higher when fed on R. indica than on other diets. These results suggest that, despite earlier assessments, A. largoensis can play a role in controlling R. indica.     

Variability in response of four populations of Amblyseius largoensis (Acari: Phytoseiidae) to Raoiella indica (Acari: Tenuipalpidae) and Tetranychus gloveri (Acari: Tetranychidae) eggs and larvae

Raoiella indica (Acari: Tenuipalpidae) is a phytophagous mite that recently invaded the Neotropical region. A predatory mite Amblyseius largoensis (Acari: Phytoseiidae) has been found associated with R. indica in Florida. This study evaluated A. largoensis by determining its likelihood of consuming eggs and larvae of R. indica and Tetranychus gloveri (Acari: Tetranychidae) under no-choice and choice conditions. To detect variations in the response of A. largoensis to R. indica, four populations of predators were examined: (1) predators reared exclusively on R. indica in the laboratory for 2 years, (2) predators reared on T. gloveri in the laboratory for 2 months but reared on R. indica for 2 years previously, (3) predators collected from a field infested with R. indica, and (4) predators collected from a field that had never been infested with R. indica. Results of this study suggest that A. largoensis is likely to accept and consume high numbers of R. indica eggs regardless of their previous feeding experience. In contrast, all populations consumed relatively fewer R. indica larvae than the other prey tested. Predators previously exposed to R. indica were more likely to consume R. indica larvae. By contrast, predators not previously exposed to R. indica showed the lowest likelihood of choosing to feed on this prey item. Plasticity in the response of A. largoensis to R. indica larvae could be associated to selection, learning, or a combination of both. The possible implications of the observed differences in terms of biological control of R. indica are discussed.     

Residual bioassay to assess the toxicity of Acaricides against Aceria guerreronis (Acari: Eriophyidae) under laboratory conditions

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.     

Acaricide toxicity and synergism of fenpyroximate to the coconut mite predator Neoseiulus baraki

The non-target effects of acaricides, used against Aceria guerreronis (Acari: Eriophyidae) the coconut mite, on its natural enemies are not known. Therefore we assessed the susceptibility of A. guerreronis and its predator Neoseiulus baraki (Acari: Phytoseiidae) to selected acaricides, their impact on N. baraki rate of increase, and the synergism of fenpyroximate towards this predator. Toxicity bioassays and synergism of fenpyroximate (with piperonyl butoxide, triphenyl phosphate and diethyl maleate) were performed by spraying the mites under a Potter tower. The instantaneous rate of increase (r _i ) was calculated ten days after spraying the predator. Chlorfenapyr and fenpyroximate were selective (both LC₅₀ and LC₉₀ were higher for N. baraki than for A. guerreronis) and did not affect the predator r _i . Only piperonyl butoxide significantly synergized fenpyroximate suggesting the involvement of cytochrome P450 monooxygenase in the N. baraki tolerance. Fenpyroximate and chlorfenapyr are promising agents for managing A. guerreronis in combination with N. baraki because both are selective and do not affect its predator r _i .     

Acaricides impair prey location in a predatory phytoseiid mite

The use of predatory mites as the sole management tactic in biological control programmes frequently does not fully and reliably prevents damage of phytophagous mites on plants. Therefore, as an alternative, the integration of predatory mites with acaricides can provide more effective control of phytophagous mites than that of the predators only. However, for such integration, acaricides minimal negative impacts on predatory mites are required. In this study, we evaluated the sublethal effects of three acaricides on the foraging behaviour of Neoseiulus baraki (Athias‐Henriot) (Acari: Phytoseiidae) in a coconut production system. The acaricides were assessed for interference with the location of prey habitat using a Y‐tube olfactometer and for interference with the location of the prey colony within the habitat using a video‐tracking system. In addition to the choice of odour source, the time required and the distance walked to make the choice were assessed. The acaricides tested were abamectin, azadirachtin and fenpyroximate. The predatory mite preferred coconuts infested with the coconut mite Aceria guerreronis Keifer (Acari: Eriophyidae) over uninfested coconuts when not exposed to acaricides. However, when exposed to acaricides, the predator did not distinguish between infested and uninfested fruits. When exposed to abamectin, N. baraki spent more time resting and walked greater distances before making the choice of an odour source. Thus, the acaricides impair the ability of the predatory mite N. baraki to locate a prey habitat and to locate a prey within that habitat. The acaricides differentially affected prey foraging by interfering with odour perception.     

Control effects and sublethal effects of four pesticides on Atheloca bondari (Lepidoptera: Pyralidae) 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 LC₅₀ and LC₉₅ 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.     

Bioinsecticide-Predator Interactions: Azadirachtin Behavioral and Reproductive Impairment of the Coconut Mite Predator Neoseiulus baraki

Synthetic pesticide use has been the dominant form of pest control since the 1940s. However, biopesticides are emerging as sustainable pest control alternatives, with prevailing use in organic agricultural production systems. Foremost among botanical biopesticides is the limonoid azadirachtin, whose perceived environmental safety has come under debate and scrutiny in recent years. Coconut production, particularly organic coconut production, is one of the agricultural systems in which azadirachtin is used as a primary method of pest control for the management of the invasive coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae). The management of this mite species also greatly benefits from predation by Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae). Here, we assessed the potential behavioral impacts of azadirachtin on the coconut mite predator, N. baraki. We explored the effects of this biopesticide on overall predator activity, female searching time, and mating behavior and fecundity. Azadirachtin impairs the overall activity of the predator, reducing it to nearly half; however, female searching was not affected. In contrast, mating behavior was compromised by azadirachtin exposure particularly when male predators were exposed to the biopesticide. Consequently, predator fecundity was also compromised by azadirachtin, furthering doubts about its environmental safety and selectivity towards biological control agents.     

Reproductive compatibility and genetic and morphometric variability among populations of the predatory mite,Amblyseius largoensis (Acari: Phytoseiidae), from Indian Ocean Islands and the Americas

The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive phytophagous mite that was recently introduced into The Americas. The predatory mite Amblyseius largoensis Muma (Acari: Phytoseiidae) has been the only natural enemy consistently found in association with RPM. This study aimed to determine if A. largoensis populations from the Indian Ocean Islands (La Réunion and Mauritius) and the Americas (Brazil, Trinidad and Tobago and the USA) consist a taxonomic unit or a group of cryptic species. First, the morphological variability among the A. largoensis populations from these areas was evaluated through morphometric analyses of 36 morphological traits. Then, their genetic variability and phylogenetic relationships were assessed based on two target DNA fragments: the nuclear Internal Transcribed Spacer and the mithochondrial 12S rRNA. Finally, reproductive compatibility of the populations from La Réunion and Roraima, Brazil was evaluated. Morphometric differences between the A. largoensis specimens from La Réunion Island and the Americas were observed, most of them on the length of the setae. Molecular analysis indicated that the A. largoensis populations from the Indian Ocean Islands and the Americas belong to the same taxonomic entity, although to two well defined genetic groups. Crossings involving the A. largoensis populations from La Réunion Island and Roraima, Brazil revealed complete reproductive compatibility between these populations. Information on the morphometric and genetic variability among studied A. largoensis populations can be further exploited in future studies to follow colonization of Indian Ocean Islands populations in the Americas, in the case of field releases.     

Can the red palm mite threaten the Amazon vegetation?

The red palm mite Raoiella indica Hirst (Tenuipalpidae) was first reported in the New World in 2004, dispersing quickly and widely while adopting new plant species as hosts. Since then, it has caused severe damage in this region, especially to coconut (Cocos nucifera L.). It was first found in Brazil in 2009, in the northern Amazonian state of Roraima. In the present study, native and introduced plants were sampled between March 2010 and February 2011 in sites of the 15 Roraima municipalities, to estimate its distribution and the associated mite fauna. In addition, monthly samples were taken from a coconut plantation in Mucajaí throughout the same period, for an initial appraisal of the levels R. indica could reach. It was found in 10 municipalities, on 19 plant species of four families. Six species are reported for the first time as hosts. Among the associated predators, 89.1% were Phytoseiidae, most commonly Amblyseius largoensis (Muma), Iphiseiodes zuluagai Denmark & Muma and Euseius concordis (Chant). The highest densities of R. indica, 1.5 and 0.35 mites/cm² of leaflet (approx total of 331 and 77 mites/leaflet), were reached respectively in March 2010 and February 2011. The highest density of phytoseiids on coconut (0.009 mites/cm² or about 2 mites/leaflet) was reached in November 2010. The average densities of R. indica recorded for Roraima were comparable to those reported for countries in which the mite is reportedly economically damaging. The dispersal of R. indica through the Amazon forest may result in damage to cultivated and native palms, and plants of other families, if the projected increase in both the frequency and the severity of drought events occurs. Parts of the Amazon have undergone periods of low rainfall, a condition that appears to favour the biology of this mite. Its eventual arrival to northeastern Brazil may result in heavy economic and ecological losses.     

Chemical control of the red palm mite, Raoiella indica (Acari: Tenuipalpidae) in banana and coconut

The red palm mite (RPM), Raoiella indica Hirst, is a predominant pest of coconuts, date palms and other palm species, as well as a major pest of bananas (Musa spp.) in different parts of the world. Recently, RPM dispersed throughout the Caribbean islands and has reached both the North and South American continents. The RPM introductions have caused severe damage to palm species, and bananas and plantains in the Caribbean region. The work presented herein is the result of several acaricide trials conducted in Puerto Rico and Florida on palms and bananas in order to provide chemical control alternatives to minimize the impact of this pest. Spiromesifen, dicofol and acequinocyl were effective in reducing the population of R. indica in coconut in Puerto Rico. Spray treatments with etoxanole, abamectin, pyridaben, milbemectin and sulfur showed mite control in Florida. In addition, the acaricides acequinocyl and spiromesifen were able to reduce the population of R. indica in banana trials.     

Occurrence and seasonal prevalence of the coconut mite, Aceria guerreronis (Eriophyidae), and associated arthropods in Oman

The coconut palm is an important crop in the sub arid coastal plain of Dhofar, Oman, for the high demand for its nut water and its use as ornamental plant. Damage of coconut fruits by the eriophyid mite Aceria guerreronis Keifer was first reported in that region in the late 1980s, but background information about the ecology of the pest in Oman was missing. Four surveys were conducted in different seasons from 2008 to 2009, to assess the distribution and prevalence of the coconut mite and its damage as well as the presence of natural enemies. Infestation by the coconut mite was conspicuous on most (99.7 %) palm trees, with 82.5 % damaged fruits. The average (±SE) density of coconut mites per fruit was 750 ± 56; this level of infestation led to the incidence of over 25 % of surface damage on more than half of the fruits. The mite appeared more abundant at the end of the cold season through the summer. No significant differences were observed between infestation levels on local varieties, hybrids and on dwarf varieties. Neoseiulus paspalivorus (De Leon), Cydnoseius negevi (Swirski & Amitai) and Amblyseius largoensis (Muma) were the predatory mites found under the bracts of over 30 % of the coconut fruits and on 68 % of the coconut trees. Considering all sampling dates and all varieties together, average (± SE) phytoseiid density was 1.4 ± 1.19 per fruit. Other mites found in the same habitat as A. guerreronis included the tarsonemids Steneotarsonemus furcatus De Leon and Nasutitarsonemus omani Lofego & Moraes. The pathogenic fungus Hirsutella thompsonii Fisher was rarely found infecting the coconut mite in Dhofar. Other fungal pathogens, namely Cordyceps sp. and Simplicillium sp., were more prevalent.     

Toxicity of some insecticides and acaricides to the predatory bugDicyphus tamaninii (Het.: Miridae)

Several pesticides were tested in the laboratory for their side-effects upon the mirid bugDicyphus tamaninii, a polyphagous predator used for IPM programmes in some vegetable crops. Residual toxicity to 3rd -4th instar nymphs on tomato leaflets was checked 24, 48 hours and seven days after treatment. The acaricides bromopropylate, dicofol+tetradifon and fenpyroximate were harmless to the nymphs. The insect growth regulators azadirachtin, buprofezin, lufenuron and pyriproxyfen were also harmless to nymphs and teflubenzuron was slightly harmful seven days after treatment. Among the conventional insecticides tested, only pirimicarb and tau-fluvalinate were harmless toD. tamaninii nymphs     

Molecular and morphological characterization of the predatory mite <Emphasis Type="Italic">Amblyseius largoensis</Emphasis> (Acari: Phytoseiidae): surprising similarity between an Asian and American populations

The accurate characterization of biological control agents is a key step in control programs. Recently, Amblyseius largoensis from Thailand were introduced in Brazil to evaluate their efficiency for the control of the red palm mite, Raoiella indica. The aim of this study was to confirm their identification and to characterize the population from Thailand, comparing it to populations of the Americas and Indian Ocean islands. In addition, a population of A. largoensis from New Caledonia, Oceania, of which DNA sequences were available, was included in phylogenetic analyses. Morphometric data obtained for the population of A. largoensis from Thailand were compared to those of populations from Reunion Island and the Americas through univariate and multivariate analyses. Two DNA fragments were amplified and sequenced: the nuclear ribosomal region ITSS and the mitochondrial 12S rRNA. Haplotypes (12S rRNA) and genotypes (ITSS) were identified and phylogenetic analyses using both fragments were conducted separately and combined using maximum likelihood and the Bayesian information criterion. The integrative approach reveals morphometric and molecular variabilities among populations of A. largoensis and shows that the population identified as A. largoensis collected in Thailand, as well as that from New Caledonia, are conspecific to the populations of the Americas and Indian Ocean islands. Populations from the Americas and Asia are more related to each other than with that from the Indian Ocean islands. Hypotheses to explain this clustering are proposed. Data on the molecular intraspecific variability of this predatory mite from remote areas will be helpful for the development of molecular diagnosis.     

Potential geographical distribution of the red palm mite in South America

Among pests that have recently been introduced into the Americas, the red palm mite, Raoiella indica Hirst (Prostigmata: Tenuipalpidae), is the most invasive. This mite has spread rapidly to several Caribbean countries, United States of America, Mexico, Venezuela, Colombia and Brazil. The potential dispersion of R. indica to other regions of South America could seriously impact the cultivation of coconuts, bananas, exotic and native palms and tropical flowers such as the Heliconiaceae. To facilitate the development of efficacious R. indica management techniques such as the adoption of phytosanitary measures to prevent or delay the dispersion of this pest, the objective of this paper was to estimate the potential geographical distribution of R. indica in South America using a maximum entropy model. The R. indica occurrence data used in this model were obtained from extant literature, online databases and field sampling data. The model predicted potential suitable areas for R. indica in northern Colombia, central and northern Venezuela, Guyana, Suriname, east French Guiana and many parts of Brazil, including Roraima, the eastern Amazonas, northern Pará, Amapá and the coastal zones, from Pará to north of Rio de Janeiro. These results indicate the potential for significant R. indica related economic and social impacts in all of these countries, particularly in Brazil, because the suitable habitat regions overlap with agricultural areas for R. indica host plants such as coconuts and bananas.     

First Report of <Emphasis Type="Italic">Raoiella indica</Emphasis> (Hirst) (Acari: Tenuipalpide) in Southern Brazil

The red palm mite (RPM), Raoiella indica (Hirst) (Acari: Tenuipalpidae), was found for the first time in the Paraná State, in southern Brazil. The first observations occurred in September 2015, on strawberry (Fragaria × ananassa Duch) leaves, which is not considered a typical host plant of RPM. It is probable that its occurrence on this plant was serendipitous. Visual surveys for RPM were carried out on four typical host plants (banana, coconut, foxtail palm, and real palm), in five cities of the Paraná State (Bela Vista do Paraíso, Londrina, Maringá, Marialva, and Sarandi). RPM was found on each of the four typical host plants, in each of the five cities. Our survey extends RPM occurrence to the southern region of Brazil and indicates that the pest could be widespread in the country.     

Comparative toxicity of an acetogenin-based extract and commercial pesticides against citrus red mite

Acetogenins, a class of natural compounds produced by some Annonaceae species, are potent inhibitors of mitochondrial electron transport systems. Although the cellular respiration processes are an important biochemical site for the acaricidal action of compounds, few studies have been performed to assess the bioactivity of acetogenin-based biopesticides on spider mites, mainly against species that occur in orchards. Using residual contact bioassays, this study aimed to evaluate the bioactivity of an ethanolic extract from Annona mucosa seeds (ESAM) (Annonaceae) against the citrus red mite Panonychus citri (McGregor) (Acari: Tetranychidae), an important pest of the Brazilian citriculture. ESAM is a homemade biopesticide which was previously characterized by its high concentration of acetogenins. It caused both high mortality of P. citri females (LC₅₀ = 7,295, 4,662, 3,463, and 2,608 mg l^?1, after 48, 72, 96, and 120 h of exposure, respectively) and significant oviposition deterrence (EC₅₀ = 3.194,80 mg l^?1). However, there was no effect on P. citri female fertility (hatching rate). In addition, the ESAM efficacy (in terms of its LC₉₀) was compared with commercial acaricides/insecticides (at its recommended rate) of both natural [Anosom^® 1 EC (annonin), Derisom^® 2 EC (karanjin), and Azamax^® 1.2 EC (azadirachtin + 3-tigloylazadirachtol)] and synthetic origin [Envidor^® 24 SC (spirodiclofen)]. Based on all of the analyzed variables, the ESAM exhibited levels of activity superior to other botanical commercial acaricides and similar to spirodiclofen. Thus, our results indicate that ESAM may constitute a biorational acaricide for citrus red mite integrated pest management in Brazilian citrus orchards, particularly for local use.     

Effect of coconut palm proximities and Musa spp. germplasm resistance to colonization by Raoiella indica (Acari: Tenuipalpidae)

Although coconut (Cocos nucifera L.) is the predominant host for Raoiella indica Hirst (Acari: Tenuipalpidae), false spider mite infestations do occur on bananas and plantains (Musa spp. Colla). Since its introduction, the banana and plantain industries have been negatively impacted to different degrees by R. indica infestation throughout the Caribbean. Genetic resistance in the host and the proximity of natural sources of mite infestation has been suggested as two of the main factors affecting R. indica densities in Musa spp. plantations. Greenhouse experiments were established to try to determine what effect coconut palm proximities and planting densities had on R. indica populations infesting Musa spp. plants. Trials were carried out using potted Musa spp. and coconut palms plants at two different ratios. In addition, fourteen Musa spp. hybrid accessions were evaluated for their susceptibility/resistance to colonization by R. indica populations. Differences were observed for mite population buildup for both the density and germplasm accession evaluations. These results have potential implications on how this important pest can be managed on essential agricultural commodities such as bananas and plantains.