Carnaúba (Copernicia prunifera (Miller) H. E. Moore uma nova hospedeira de Raoiella indica Hirst (Acari: Tenuipalpidae)

The red palm mite, Raoiella indica Hirst, 1924 (Tenuipalpidae), has been spreading rapidly and expanding its host range in the Neotropical region. Most of the hosts are palm trees (Arecaceae). In the present work, high population levels of R. indica are reported on “carnauba” [Copernicia prunifera (Miller) H. E. Moore, Arecaceae] in the states of Alagoas and Ceará, northeastern Brazil. This is the first report of R. indica causing damage and injuries on this palm tree native to Brazil in field. Our results allow us to conclude that carnauba is a suitable host for R. indica, with potential risk to its cultivation and exploitation.

First report of damage and population dynamics of Raoiella indica Hirst (Acari: Tenuipalpidae) on Euterpe oleracea (Arecaceae) in the State of Bahia, Brazil

The presence of the red palm mite Raoiella indica Hirst, was recorded on açaí, Euterpe oleracea Mart. (Arecaceae), in Porto Seguro, Bahia State, northeastern Brazil. We evaluated the population dynamics of R. indica from September 2019 to February 2020. The population outbreak and most severe damage caused by R. indica was observed in February, a period of highest temperatures and low relative humidity. This is the first report of damage caused by the red palm mite on E. oleracea in Brazil. Management practices must be implemented to avoid intercropping açaí with other hosts of this mite e.g. coconut, banana and palm trees in order to minimize the occurrence and damage of R. indica on such agrosystems.

Raoiella indica (red palm mite).

R. indica was first described in India in 1924 (Hirst) and has since been reported in several Old World countries. The species became of recent significance in 2004 when it was first reported in the Caribbean (Flechtmann and Étienne, 2004). Since then the mite has successfully spread throughout the islands of the Caribbean and has expanded its range into southern Florida (USDA-APHIS, 2007), South America (northern Venezuela, Vásquez et al., 2008; Brazil, Navia et al., 2010; Colombia, Carrillo et al., 2011) and Mexico (Estrada-Venegas et al., 2010). The mite has been reported on a wide range of palm hosts of the family Arecaceae and apparent new associations with members of the order Zingiberales, including the families Musaceae, Heliconiaceae, Zingiberaceae and Strelitziaceae have been reported. The success of the mite in the invasive range may be attributed to its ability to colonize many different host plant species, its apparent lack of co-evolved natural enemies in its new habitat and its rapid dispersal in its new range.

Acaricidal activity of plant extracts against the red palm mite Raoiella indica (Acari: Tenuipalpidae)

The red palm mite Raoiella indica Hirst has recently invaded the Neotropical region, which demands the implementation of pest management strategies. In this study, toxicity of leaf extracts of Mexican oregano Lippia berlandieri Schauer, neem Azadirachta indica A. Juss, Mexican mint Plectranthus amboinicus (Lour.) Spreng., rue Ruta graveolens L. and Persian lime Citrus x latifolia Tanaka against R. indica was evaluated under laboratory conditions. Raoiella indica females were exposed to each plant extract at concentrations of 0.25, 0.50, 0.75 and 1% (v/v) to assess the cumulative mortality at 24, 48 and 72 h after exposure. Mortality rates of R. indica rose due to increased extract concentration and exposure time. The strongest acaricidal activity was observed with L. berlandieri, A. indica and P. amboinicus, whose 1% concentration and 72 h exposure caused a mean R. indica mortality of 100, 90 and 78%, respectively. These plant extracts hold promise for the chemical management of this pest

Tracking Red Palm Mite Damage in the Western Hemisphere Invasion with Landsat Remote Sensing Data

Red palm mites (Raoiella indica Hirst, Acari: Tenuipalpidae) were first observed in the western hemisphere on the islands and countries surrounding the Caribbean Sea, infesting the coconut palm (Cocos nucifera L.). Detection of invasive pests usually relies upon changes in vegetation properties as result of the pest activity. These changes may be visible in time series of satellite data records, such as Landsat satellites, which have been available with a 16-day repeat cycle at a spatial resolution of 30 m since 1982. Typical red palm mite infestations result in the yellowing of the lower leaves of the palm crown; remote sensing model simulations have indicated that this feature may be better detected using the green normalized difference vegetation index (GNDVI). Using the Google Earth Engine programming environment, a time series of Landsat 5 Thematic Mapper, Landsat 7 Enhanced Thematic Mapper Plus and Landsat 8 Operational Land Imager data was generated for plantations in northern and northeast Brazil, El Salvador, and Trinidad-Tobago. Considering the available studied plantations, there were little or no differences of GNDVI before and after the dates when red palm mites were first revealed at each location. A discussion of possible alternative approaches are discussed related to the limitations of the current satellite platforms.

The establishment of an invasive pest mite, Raoiella indica, affects mite abundance and diversity on coconut plants

The introduction and establishment of an invasive species in a new habitat represents a major threat to biodiversity and ecosystem structure. A recent example of a mite that has become an invasive species is the red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae). After its introduction in the Americas, this species has considerably expanded the number of hosts and has been reported as a key pest of some of these. In the present study we investigated the possibility of mitefauna alteration on coconut leaflets (abundance and diversity) mediated by the introduction and establishment of R. indica. A survey was conducted over a period of 1 year in two areas of coconut cultivation: one infested and one free of R. indica. The results of the present study suggest that the introduction of R. indica modifies the mitefauna existing in coconut leaflets. Differences were detected in the abundance and diversity of mites at the level of the taxonomic categories (family and species) and at the level of the trophic groups (predators, herbivores and mites with undefined feeding mode). Additionally, in plants infested by the invasive species, a similar pattern was observed between the fluctuation of the phytoseiid mites and other tenuipalpid mites. In these plants, the density of the tenuipalpid mites (including R. indica) was also the variable that most contributed to explain the fluctuation of phytoseiid mites. This suggests that the invasive species, R. indica, acts as a keystone species, structuring the mitefauna in coconut plants.