The vine mealybug (VMB), Planococcus ficus, is a major grapevine pest worldwide, whose chemical control is often unsatisfactory due to its cryptic behavior, insecticide resistance and high fecundity rate. Recently, increasing restrictions have been applied to insecticides used for managing VMB. This review discusses sustainable VMB management strategies in organic viticulture. Pheromone-mediated mating disruption has been proved to be effective in both organic wine and table-grape vineyards. Biocontrol projects carried out through the release of parasitoids and/or predators have often provided inconclusive results, ranging from effective reduction of mealybug infestation to a marginal impact of parasitoids on VMB density. The latter outcome is likely due to constraints affecting the parasitoid activity, such as the disrupting activity of mealybug-tending ants and broad-spectrum insecticides, or untimely release of parasitoids. Ant suppression should be associated with the release of beneficial organisms, as mealybug-tending ants can severely affect the parasitoid activity. Cultural and physical control and the employment of entomopathogens and natural products mitigate the buildup of VMB populations, but they are not widely applied. VMB control in organic viticulture requires the integration of different strategies, as application of single control tools as a stand-alone treatment may not be effective, especially for high pest infestation. Future research to determine the density action threshold below which sustainable methods are effective and calibrate efforts in relation with pest infestation is needed. A multi-disciplinary approach is required to define the most appropriate sustainable control protocols in different environmental conditions and promote a further spread of organic viticulture.

Mealybugs (Hemiptera: Pseudococcidae) are pests constraining the international trade of Brazilian table grapes. They damage grapes by transmitting viruses and toxins, causing defoliation, chlorosis, and vigor losses and favoring the development of sooty mold. Difficulties in mealybug identification remain an obstacle to the adequate management of these pests. In this study, our primary aim was to identify the principal mealybug species infesting the major table grape-producing regions in Brazil, by morphological and molecular characterization. Our secondary aim was to develop a rapid identification kit based on species-specific Polymerase Chain Reactions, to facilitate the routine identification of the most common pest species. We surveyed 40 sites infested with mealybugs and identified 17 species: Dysmicoccus brevipes (Cockerell), Dysmicoccus sylvarum Williams and Granara de Willink, Dysmicoccus texensis (Tinsley), Ferrisia cristinae Kaydan and Gullan, Ferrisia meridionalis Williams, Ferrisia terani Williams and Granara de Willink, Phenacoccus baccharidis Williams, Phenacoccus parvus Morrison, Phenacoccus solenopsis Tinsley, Planococcus citri (Risso), Pseudococcus viburni (Signoret), Pseudococcus cryptus Hempel, four taxa closely related each of to Pseudococcus viburni, Pseudococcus sociabilis Hambleton, Pseudococcus maritimus (Ehrhorn) and Pseudococcus meridionalis Prado, and one specimen from the genus Pseudococcus Westwood. The PCR method developed effectively identified five mealybug species of economic interest on grape in Brazil: D. brevipes, Pl. citri, Ps. viburni, Ph. solenopsis and Planococcus ficus (Signoret). Nevertheless, it is not possible to assure that this procedure is reliable for taxa that have not been sampled already and might be very closely related to the target species.

Thrips tabaci Lindeman is the main pest of onion crops, and chemical control is the main method adopted by farmers. Alternative control methods should be prioritised to reduce the amount of insecticides used. Resistant cultivars are one efficient way to control thrips in the field. Our aim was to assess the influence of morphological and chemical characteristics of seven onion cultivars and their resistance to T. tabaci. The number of thrips and the morphological and chemical characteristics of the plants were assessed. Among the evaluated cultivars, Alfa São Francisco RT, BR 29 and Sirius showed resistance to T. tabaci, as indicated by the lower number of thrips observed during the cycle (64, 87, and 74 thrips, respectively). Morphological and chemical characteristics were associated with onion's resistance to T. tabaci. For the cultivar Alfa São Francisco RT, a wider central angle (16.4°), a thinner cuticle, a larger amount of epicuticular waxes, and stomata on the surface of leaves accounted for resistance. For the cultivars BR 29 and Sirius, the resistance was likely due to the presence of resistance-conferring substances or high amounts of some component in the chemical composition of plants.Características morfológicas e químicas de plantas de cebola (Allium cepa L.) associadas à resistência ao tripes da cebola RESUMO. Thrips tabaci Lindeman é a principal praga da cultura da cebola e o controle químico é o principal método adotado pelos agricultores. Métodos alternativos de controle devem ser priorizados, visando diminuir a quantidade de inseticidas utilizada. Cultivares resistentes representam um método eficiente de controle de tripes no campo. Nosso objetivo foi verificar a influencia de características morfológicas e químicas de sete cultivares de cebola conferindo resistência a T. tabaci. O número de tripes, características morfológicas e químicas das plantas foram avaliadas. Dentre as cultivares avaliadas, Alfa São Francisco RT, BR 29 e Sirius mostraram-se resistentes a T. tabaci, uma vez que apresentaram um baixo número de tripes observados durante o ciclo (64, 87 e 74 tripes respectivamente). Características morfológicas e químicas estão associadas à resistência de plantas de cebola a T. tabaci. Para a cultivar Alfa São Francisco RT, um maior ângulo central (16,4˚), uma menor espessura de cutícula, e uma maior concentração de ceras epicuticulares e estômatos na superfície das folhas conferem resistência. Para as cultivares BR 29 e Sirius, a resistência provavelmente esta relacionada à presença de substâncias ou de quantidades elevadas de algum componente na composição química das plantas.Palavras-chave: Thrips tabaci, Thysanoptera, Thripidae, cebola, resistência de plantas a insetos.

The Serra Gaúcha region is the most important temperate fruit-producing area in southern Brazil. Despite mealybugs (Hemiptera: Pseudococcidae) infesting several host plants in the region, there is a lack of information about the composition of species damaging different crops. A survey of mealybug species associated with commercial fruit crops (apple, persimmon, strawberry and grapes) was performed in Serra Gaúcha between 2013 and 2015, using both morphology and DNA analyses for species identification. The most abundant species were Pseudococcus viburni (Signoret), found on all four host plant species, and Dysmicoccus brevipes (Cockerell), infesting persimmon, vines and weeds. The highest diversity of mealybug species was found on persimmon trees, hosting 20 different taxa, of which Anisococcus granarae Pacheco da Silva & Kaydan, D. brevipes, Pseudococcus sociabilis Hambleton and Ps. viburni were the most abundant. A total of nine species were recorded in vineyards. Planococcus ficus (Signoret) and Pseudococcus longispinus (Targioni Tozzetti) were observed causing damage to grapes for the first time. A single species, Ps. viburni, was found associated with apples, while both Ps. viburni and Ferrisia meridionalis Williams were found on strawberry. Four of the mealybug species found represent new records for Brazil.