Ocorrência de Planococcus minor Maskell (Hemiptera: Pseudococcidae) em algodoeiro no Nordeste do Brasil

Abstract

-The mealybug Planococcus minorMaskell is a significant pest of more than 250 cultivated plants belonging to at least 80 families. Among the host plants several Malvaceae species are attacked, including the genera Gossypium. In 2005 and 2006 the mealybug P. minor was observed infesting cotton fields in the arid area of northeast region of Brazil. The occurrence was registered in high densities and in several farms resulting in mortality of plants in some cases. This species is not cited as a cotton pest in any region of Brazil where cotton grows, although it is enlisted in the Global Pest and Disease Database. Hence, there is a lack of studies what makes this pest of great deal to control.KEY WORDS: Mealybug, Gossypium, sesame, alternative host RESUMO -A cochonilha Planococcus minor (Maskell) é uma praga importante de mais de 250 culturas pertencentes a cerca de 80 famílias. Entre as plantas hospedeiras, várias espécies de Malvaceae são atacadas, incluindo o gênero Gossypium. Durante as safras de 2005 e 2006 constatou-se o ataque de P. minor em lavouras de algodão localizadas no semi-árido nordestino do Brasil. A constatação foi feita em diferentes localidades, onde altas densidades populacionais da cochonilha chegaram a ocasionar mortalidade de plantas. Esse inseto não é citado como praga do algodoeiro em nenhuma região onde se cultiva o algodoeiro no Brasil, apesar de constar na lista de Pragas e Doenças Globais. Conseqüentemente, não existem estudos sobre essa cochonilha como praga do algodoeiro o que torna o seu manejo difícil no momento.

Occurrence of new species of mealybug on cotton fields in the states of Bahia and Paraíba, Brazil

“…In the field, P. solenopsis can be identified by displaying the oval body about five millimeters in length, color ranging from dark green to almost black, red legs, covered by a thin layer of white wax, mealy, with 18 pairs of waxy filaments short and medium-sized around the body and anal filaments with about one quarter the length of the body and two dark stripes on both sides of the border in the middle of the body, which form a pair of dark longitudinal lines on the back (Tanwar et al, 2011) (Figure 1). These morphological characteristics differ considerably from species Planococcus minor Maskel (Hemiptera: Pseudococcidae) described by Bastos et al (2007) attacking different locations of cotton crop. Specimens of the genus Planococcus differs from Phenacoccus to present all dorsal setae flagellate, even if minutely short (Williams and Willink, 1992) and is devoid of a pair of horizontal dark stripes at the tip of the end of the body.…”

“…In Brazil, there is no information on the occurrence of P. Solenopsis attacking cotton (Gossypium hirsutum L.), although high infestations of scale insects have been verified in cotton crop located in the Paraíba State (Patos, São João do Rio do Peixe, Campina Grande, Itaporanga and Choró), Ceará State (Barbalha and Missão Velha) (Bastos et al, 2007) and Bahia State (Middle and South regions of São Francisco River and Guanambí).…”

Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell) (Hemiptera, Pseudococcidae) on cotton

“…Similarly, widespread infestation was observed for the species P. solenopsis (Aheer et al 2009), Planococcus minor (Maskell, 1897) (Hemiptera, Pseudococcidae) (Bastos et al 2007), and M. hirsutum (Muralidharan & Badaya 2000) on cotton plants. In the time interval of 25 days, an irregular distribution of mealybugs was observed within the plant, and the highest density was found on the leaves.…”

“…In Brazil, all these three mealybug species have been recorded in cotton and in other plants (Bastos et al 2007;SilvaTorres et al 2013;Culik et al 2013). Recently, infestations of striped mealybug were found in cotton plants in the semiarid region of Pernambuco.…”

“…The mealybugs (Hemiptera, Pseudococcidae) are outstanding for causing loss of yield of cotton crops in several countries (Fuchs et al 1991;Muralidharan & Badaya 2000;Dhawan et al 2007;Hodgson et al 2008;Wang et al 2009), including Brazil (Bastos et al 2007). Mealybugs feed by sucking the plant sap and causing leaf senescence and premature leaf fall, as well as reduced growth and even plant death (Culik & Gullan 2005).…”