Acaricide resistance management of leprosis mite (Brevipalpus phoenicis) in Brazilian citrus

Abstract

IntroductionThe Brazilian citrus industry is responsible for more than 30% of world citrus production.1 In order to compete in a global market, new production technologies are constantly reviewed and adopted by citrus producers. At the moment, among major problems that a †ect citrus production in Brazil, the phytophagous mite Brevipalpus phoenicis (Geijskes) is one of the most serious pests because it transmits citrus leprosis virus.2h4 Symptoms of the leprosis disease appear on fruits, leaves and stems and can lead to premature leaf and fruit drop, or even the death of the plant. For its control, great progress in the area of integrated pest management (IPM) has been achieved by Brazilian scientists. Studies on the bioecology of leprosis mite,5h7 sampling procedures,8 cultural practices,6,9 pesticide selectivity,10,11 and biological control11h13 have all contributed to improve leprosis mite management in citrus groves. However, we still rely on the use of chemicals for e †ective control of this pest.Approximately US$80 million are spent per year on acaricides in Brazilian citrus groves, which represents 21% of the citrus production cost.14 Acaricide use has increased due to the occurrence of another important acarine pest, the citrus rust mite, Phyllocoptruta oleivora (Ashmead). Both B. phoenicis and P. oleivora occur throughout the year on citrus trees. However, the critical period of mite infestation di †ers for each species. P. oleivora is a major problem during the summer and fall seasons when the temperature and relative humidity are very high. On the other hand, population densities of B. phoenicis start increasing when the relative humidity is lower, i.e. during the winter and spring seasons under Brazilian conditions.6 Hence acaricides are used throughout the citrus growing season with an average of two to four applications per year.Failure to control B. phoenicis with conventional acaricides has been reported frequently by citrus growers and advisors. Interestingly, control problems with this pest have also been detected for some new molecules that are coming to the market. Because of constant selection pressure with acaricides, the evolution of resistance in B. phoenicis could be one of the major factors a †ecting the efficacy of some products. Despite intensive use of acaricides on citrus in Brazil, there is a lack of research on the detection and monitoring of pest resistance to pesticides. This summary reports work to implement acaricide resistance management for B. phoenicis in Brazilian citrus. Factors a †ecting the evolution of resistance in Brevipalpus phoenicisFactors that may promote the development of resistance in B. phoenicis include its mode of reproduction, predominantly by thelytoky, and the karyotype of only two heterologous chromosomes.15 From an evolutionary perspective, thelytoky is often thought to be an evolutionary "dead endÏ because it increases homozygosity and mutational load, and limits or inhibits genetic recombination. However, the holokinetic chromosome structure and invert...

Towards new botanical pesticides: the toxic effect of Eremanthus goyazensis (Asteraceae) leaves essential oil against Brevipalpus phoenicis (Acari: Tenuipalpidae)

“…7 There are reports that there is a northward movement of the virus, which could endanger citrus crop fields of North America. 8 Currently B. phoenicis suffers a selective pressure caused by the most commonly used acaricides on citrus crop protection such as dicofol, 9,10 hexythiazox, 11 and propargite. 12 In addition to this pressure, B. phoenicis shows parthenogenetic development leading to a quick promotion of the appearance of an evolved and chemical-resistant type of mite.…”

Adaptation in the Asexual False Spider Mite Brevipalpus phoenicis: Evidence for Frozen Niche Variation

“…It has a worldwide distribution in the tropics and subtropics (Kennedy 1995;Childers et al 2003), it is extremely polyphagous, being reported from 486 plant species from 114 different plant families (Childers et al 2003), and it rapidly develops pesticide resistance (Omoto 1998;Campos and Omoto 2002).…”

Mecanismos de dispersão de Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) em pomares de citros

“…O controle de B. phoenicis tem sido realizado principalmente mediante o uso de produtos químicos (Omoto 1998). Devido à alta pressão de seleção, casos de desenvolvimento da resistência de B. phoenicis já foram detectados para os principais acaricidas utilizados na citricultura, tais como dicofol (Omoto et al 2000), hexitiazox (Campos & Omoto 2002) e propargite (Franco 2002).…”