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.

Morphological and chemical characteristics of onion plants ( Allium cepa L.) associated with resistance to onion thrips

Mealybugs (Hemiptera: Pseudococcidae) are important pests of the grapevine Vitis spp. and are responsible for direct and indirect damage to production. The main mealybug species present in wine grapevine (Vitis vinifera L.) in Southern Brazil were identified and their incidence evaluated. Bunch-samples (n=50) from 131 vineyards located in the Serra Gaúcha Region (RS) of Brazil were analyzed at harvest, and the occurrence of mealybugs in the roots was evaluated at the time of eradication of plants for replanting. Mealybugs were reared in laboratory until adulthood for species determination. The species Dysmicoccus brevipes (Cockerell, 1983), Dysmicoccus sp., Planococcus citri (Risso, 1813), Pl. minor (Maskell, 1897), Pseudococcus viburni (Signoret, 1875) and Pseudococcus sp. were identified in bunches. Dysmicoccus sp., D. umbambae Granara de Willink, 2009, Pl. citri and Pseudococcus sp. were found in the roots. Pl. citri (31.4%) and Dysmicoccus sp. (22.7%) were the most common species found in wine grape bunches in the Serra Gaúcha Region

The obscure mealybug Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) is one of the most important damaging mealybugs in vineyards worldwide and in South American temperate fruit production. The life history of P. viburni on 3 fruit species was studied under laboratory conditions. Leaves of apple Malus domestica (Borkh.), persimmon Diospyros kaki L., and grapevine Vitis labrusca L., were used as host plants. Mealybugs were able to develop, survive, and reproduce on all 3 hosts; however, persimmon and grape leaves were most suitable for P. viburni development and reproduction. The cumulative development time (nymph to adulthood) ranged from about 35 d on persimmon and grape leaves to 40.87 ± 0.53 d on apple leaves for females, and from 30.68 ± 0.44 d on persimmon to about 34 d on apple and grape leaves for males. The obscure mealybug exhibited biparental oviparous reproduction, and the fecundity significantly decreased on apple leaves from a mean of 88 eggs per female on persimmon and g... Resumen La cochinilla oscura, Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae,) es una de las cochinillas más perjudiciales en los viñedos de todo el mundo y en la producción sudamericana de frutas templadas. Se estudio la historia de vida de P. viburni sobre 3 especies de frutos bajo condiciones de laboratorio. Se usaron hojas de manzana Malus domestica (Borkh.), caqui Diospyros kaki L. y vid Vitis labrusca L., como plantas hospederas. Las cochinillas podrian desarrollarse, sobrevivir y reproducirse sobre los 3 hospederos; sin embargo, el caqui y las hojas de uva fueron las más adecuadas para el desarrollo y la reproducción de P. viburni. El tiempo de desarrollo acumulado (ninfa a la edad adulta) varió entre aproximadamente 35 dias en hojas de caqui y de uva a 40,87 ± 0,53 dias sobre hojas de manzana para las hembras y de 30,68 ± 0,44 d en hojas de caqui a aproximadamente 34 dias en hojas de manzana y de uva para los machos. La cochinilla oscura exhibió la reproducción biparental ovipara y la ...

Mealybugs are insects belonging to the family Pseudococcidae. This family includes many plant-pest species with similar morphologies, which may lead to errors in mealybug identification and delimitation. In the present study, we employed molecular-species-delimitation approaches based on distance (ASAP) and coalescence (GMYC and mPTP) methods to identify mealybugs collected from coffee and other plant hosts in the states of Espírito Santo, Bahia, Minas Gerais, and Pernambuco, Brazil. We obtained 171 new COI sequences, and 565 from the BOLD Systems database, representing 26 candidate species of Pseudococcidae. The MOTUs estimated were not congruent across different methods (ASAP-25; GMYC-30; mPTP-22). Misidentifications were revealed in the sequences from the BOLD Systems database involving Phenacoccus solani × Ph. solenopsis, Ph. tucumanus × Ph. baccharidis, and Planacoccus citri × Pl. minor species. Ten mealybug species were collected from coffee plants in Espírito Santo. Due to the incorrect labeling of the species sequences, the COI barcode library of the dataset from the database needs to be carefully analyzed to avoid the misidentification of species. The systematics and taxonomy of mealybugs may be improved by integrative taxonomy which may facilitate the integrated pest management of these pests.