Resistance of dwarf Cocos nucifera L. (Arecaceae) cultivars to Raoiella indica Hirst (Acari: Tenuipalpidae).

The red palm mite Raoiella indica Hirst, 1924 (Acari: Tenuipalpidae) is an important pest of the coconut palm Cocos nucifera L. (Arecaceae) and has caused problems in coconut production worldwide. Research has been carried out aiming at controlling the mite through chemical, biological, alternative, and host plant resistance methods. Identifying coconut palm cultivars resistant to R. indica is important to reduce the problems caused to plantations. Therefore, the objective of this work was to evaluate the performance of R. indica in six dwarf coconut palm cultivars, to identify sources of resistance. The cultivars of the sub-varieties green, red, and yellow evaluated were Brazilian Green Dwarf-Jiqui (BGDJ), Brazilian Red Dwarf-Gramame (BRDG), Cameroon Red Dwarf (CRD), Malayan Red Dwarf (MRD), Brazilian Yellow Dwarf-Gramame (BYDG), and Malayan Yellow Dwarf (MYD). Confinement and free choice tests of R. indica on the cultivars were performed, in which biological parameters and preference were evaluated. Mite performance was different in the cultivars evaluated. In the confinement bioassay, R. indica had the worst performance in the cultivar BGDJ, the best performance in CRD, MRD, and BRDG, and intermediate performance in BYDG and MYD. In the free choice test, the cultivars MRD and MYD were preferred in relation to BGDJ, and CRD was less preferred in relation to BGDJ. Therefore, we considered that the cultivar BGDJ is the most resistant to R. indica, by antibiosis and antixenosis; CRD has resistance by antixenosis; and MRD, BRDG, BYDG, and MYD are susceptible.

Occurrence of Raoiella indica Hirst (Acari, Tenuipalpidae) in the Southeast region of the state of Pará, Brazil.

The red palm mite Raoiella indica Hirst attacks coconut, banana and açai trees. In 2007, the mite was recorded for the first time in South America. In the State of Pará, R. indica was recorded in the municipalities of the northwest, a region that is closer to the State of Amazonas, called 'Low Amazons'. Between October and November 2019, it was observed, by chance, that coconut and banana plants infested by R. indica, in residential backyards in municipalities from Marabá and Parauapebas, Southest of Pará, Brazilian Amazon. Three species from the Araceae family, two from Arecaceae, one Heliconiaceae and one Zingiberaceae, in addition to the banana Musaceae and açaí plantations, were examined. All stages of development of R. indica were found on coconut, banana trees and imperial palms, and few individuals were found on areca palm and red ginger leaves. This is the first record of the occurrence of the pest mite in the Southeast Pará sub-region.

Climate-based seasonal dynamics of the invasive red palm mite Raoiella indica.

BACKGROUND: Raoiella indica Hirst (Acari: Tenuipalpidae) is the most critical coconut and banana pest recently introduced in Brazil. Once the mite pests are introduced, it is essential to understand their dynamics in important crops under open-field climatic conditions to implement strategies for their management and determine the periods when species populations may increase in the field. Modelling tools have been used to determine the potential distribution of species and implications for the management of invasive species. Thus, our aim in this study was to determine the seasonal variation in R. indica and the influence of the monthly climate using CLIMEX modelling. We adjusted the CLIMEX model for R. indica based on distribution data, additional biological characteristics, and fluctuations in the R. indica population in a commercial coconut plantation. RESULTS: The model for the current climate shows a good match between the ecoclimatic index and the global distribution of R. indica. The model results demonstrate that most states of Brazil and several regions worldwide include areas with highly suitable climatic conditions for R. indica. We observed variations in the density of R. indica in commercial coconut crops, with the highest incidence occurring during the first months of the year. CONCLUSION: Our results showed different alterations in seasonal suitability for R. indica that may provide information for the implementation of methods for time management, such as strategies for sampling and control during periods with a high degree of suitability for R. indica. © 2020 Society of Chemical Industry.

Potential of native palm species in Northeast Brazil as hosts for the invasive mite Raoiella indica (Acari: Tenuipalpidae).

The red palm mite, Raoiella indica Hirst (Tenuipalpidae), has mainly been registered on palm species (Arecaceae), and its expansion in Brazil has the potential to cause significant negative impact on cultivated as well as native palms. Here, we evaluate the potential of native palms from Northeast Brazil to act as hosts of R. indica. Specifically, we used in situ free-choice and confinement tests, in which sections of palm leaves/leaflets of various species were experimentally infested with R. indica. We tested the following species: Acrocomia aculeata, Acrocomia intumescens, Allagoptera caudescens, Attalea funifera, Attalea oleifera, Bactris acanthocarpa var. acanthocarpa, Bactris ferruginea, Bactris glassmanii, Bactris hirta var. spruceana, Bactris pickelii, Copernicia prunifera, Desmoncus orthacanthos, Desmoncus polyacanthos, Syagrus coronata and Syagrus schizophylla. All of these were compared with the mite's preferred host, the coconut palm, Cocos nucifera. In the free-choice test, both male and female R. indica preferred C. nucifera in comparison to each of the native palms. In the confinement test, we observed significant differences in the survivorship between mites on native palms and those on coconut palms after the second day of infestation. By the fifth day, survivorship of mites on the native palms was almost always significantly lower than on C. nucifera (excepting for C. prunifera). We conclude that, among all the native palms evaluated, only the carnauba palm (C. prunifera) is at risk from R. indica. This result is relevant as this palm is an economically important species in the region.

Raoiella of the world (Trombidiformes: Tetranychoidea: Tenuipalpidae).

We describe 16 new species and redescribe six established species in the genus Raoiella-R. argenta sp. nov. Beard, R. australica Womersley, R. bauchani sp. nov. Beard Ochoa, R. calgoa sp. nov. Beard Ochoa, R. crebra sp. nov. Beard Ochoa, R. davisi sp. nov. Beard, R. didcota sp. nov. Beard, R. eugeniae (Mohanasundaram), R. goyderi sp. nov. Ochoa Beard, R. hallingi sp. nov. Beard, R. illyarrie sp. nov. Beard Ochoa, R. indica Hirst, R. karri sp. nov. Ochoa Beard, R. macfarlanei Pritchard Baker, R. marri sp. nov. Beard Ochoa, R. pandanae Mohanasundaram, R. pooleyi sp. nov. Beard Ochoa, R. shimpana Meyer, R. tallerack sp. nov. Beard Ochoa, R. taronga sp. nov. Beard Ochoa, R. todtiana sp. nov. Beard Ochoa, R. wandoo sp. nov. Beard Ochoa. We discuss molecular evidence of species separation, shared character states among groups of species, and patterns in the additions of leg setae throughout ontogeny that occur in the genus. We provide a key to the known species of Raoiella.

First Report of Raoiella indica (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.

Infestation of Raoiella indica Hirst (Trombidiformes: Tenuipalpidae) on Host Plants of High Socio-Economic Importance for Tropical America.

The mite Raoiella indica Hirst was recently introduced into America, where it has shown amazing ability to disseminate and broaden its range of hosts. An experiment was conducted in Cancún, Mexico, to determine infestation levels of this mite on plants recorded as hosts: coconut palm (Cocos nucifera) of cultivars Pacific Tall and Malayan Dwarf, oil palm (Elaeis guineensis) hybrids Deli x Ghana and Deli x Nigeria, Dwarf Giant banana (Musa acuminata, AAA subgroup Cavendish), Horn plantain (M. acuminata x Musa balbisiana, AAB subgroup Plantain), lobster claw (Heliconia bihai), and red ginger (Alpinia purpurata). Nursery plants of these host species or cultivars were artificially infested with R. indica in February 2011. In the four replications of 10 plants, each plant was infested with 200 R. indica specimens, and the numbers of infesting mites were recorded for 6 months. A maximum of 18,000 specimens per plant were observed on coconut Pacific Tall and Malayan Dwarf, followed by lobster claw, with a maximum of 1000 specimens per plant. Infestations were minimal for the remaining plants. Mite numbers on all plants declined naturally during the rainy season. All plant materials sustained overlapping mite generations, indicating that they are true hosts. Complementarily, infestation level was determined in backyard bananas and plantains. Correlations of infestation with plant height, distance from coconuts, and exposure to direct sunlight were estimated. Both bananas and plantains were infested by R. indica even when situated far from infested coconut palms. A Spearman correlation was found between infestation and plant height, although it was significant only for Silk plantain.

First report of Raoiella indica Hirst (Acari: Tenuipalpidae) in South America / Primer reporte de Raoiella indica Hirst (Acari: Tenuipalpidae) en Sur América

The presence of the red palm mite, Raoiella indica Hirst is recorded for the first time in South America. High populations and severe damages caused by this new invasive mite were found on coconut and banana leaves in Sucre (10° 27' 47" N and 64°10' 38" W) and Monagas (9º46'60" N and 63º12'0" W) states in northeastern Venezuela.

Se registra la presencia de Raoiella indica Hirst por primera vez en Sur América. Altas poblaciones y daños severos causados por esta nueva especie invasiva fueron encontrados en hojas de coco y banana en los estados nororientales de Venezuela, Sucre (10° 27' 47" N y 64°10' 38" W) y Monagas (9º46'60" N y 63º12'0" W).