Claubert Wagner Guimarães de Menezes

Crescimento da mandioca e plantas daninhas em resposta à adubação fosfatada

Growth of cassava and weed in response to phosphate fertilizer Fertilizers may be used to change the competitive relations, favoring the crop species, providing the competing species have different responses to the nutrient application. Thus, the aim of this study was to evaluate the growth of Cassava plant, Bidens pilosa L. and Brachiaria decumbens Stapf, as a function of the amount of P supplied at planting. The experiment was conducted in a greenhouse and the, treatments were arranged in a 3 x 4 factorial, involving the three species studied and four levels of phosphate fertilization (absence of P 2 O 5 , 80 kg ha -1 , 800 kg ha 1 and 4000 kg ha -1 P 2 O 5 , equivalent to 0, 1, 10 and 50 times the phosphorus dose recommended, respectively). A randomized block design was used, with five replications. The application of phosphate fertilizer promoted larger growth of the species evaluated, and cassava had higher growth of the shoot with the increased availability of phosphorus. In general, weeds showed higher responses to lower doses of phosphorus.

Palmistichus elaeisis (Hymenoptera: Eulophidae) as an indicator of toxicity of herbicides registered for corn in Brazil

The diversity of plants in agricultural systems benefits natural enemies. Herbicides are used in weed management in corn (Zea mays L.) to reduce competition and productivity losses, but they can impact natural enemies and contaminate the environment. The objective was to evaluate toxicity of herbicides on pupae parasitoid Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae). The treatments were represented by the host pupae Tenebrio molitor L., 1785 (Coleoptera: Tenebrionidae) and herbicides atrazine, nicosulfuron, paraquat, and tembotrione in commercial doses compared to a control treatment with water. Pupae of T. molitor were immersed in the solution of herbicides and exposed to parasitism by six females of P. elaeisis each. The herbicides atrazine and paraquat were highly toxic and, therefore, not selective to P. elaeisis. Nicosulfuron reduced the sex ratio of P. elaeisis (0.20 ± 0.03), which may affect subsequent generations. Moreover, the herbicide tembotrione was selective to P. elaeisis, showing results comparable to the control. Floristic diversity of weeds can increase food source, habitat, shelter, breeding places and microclimates for insect parasitoids but herbicides formulations can be toxic and these products can affect P. elaeisis or its hosts by direct or indirect contact, showing the importance of selectivity studies for this natural enemy. However, the herbicide tembotrione was selective to P. elaeisis and it can be recommended for programs of sustainable management of weeds in corn crop with this parasitoid.

First Record of Poekilloptera Phalaenoides (Hemiptera: Flatidae) Hosting Mimosa Caesalpiniaefolia (Mimosaceae) in Diamantina, Minas Gerais State, Brazil

Poekilloptera phalaenoides (Hemiptera: Flatidae) was reported on Mimosa caesalpiniaefolia (Fabaceae) in Diamantina, Minas Gerais State, Brazil. Immature and adults of P. phalaenoides were collected for identification on M. caesalpiniaefolia, which represents the first report of this insect on this plant. This preliminary study showed that M. caesalpiniaefolia is a potential host of P. phalaenoides

Morfometria de pupas e adultos de rhinochenus stigma linnaeus 1758 (coleoptera: curculionidae)

Beetles of genus Rhinochenus sp. (Coleoptera: Curculionidae) damage the seeds of species of flora of Brazilian savannah such as jatoba (Hymenea courbaril L.) and copaiba (Copaifera langsdorffii Desf.). Thus, the objective of the present was to evaluate the morphology of pupae and adult R. stigma, as well as behavioral aspects such as emission of sounds, to assist in sexing this species. The insects were obtained from jatoba fruits collected in Sao Goncalo do Rio Preto, Minas Gerais State, Brazil. The morphometric characteristics of both phases did not differ by t test, being not safe for the differentiation of the sexes. For adults of R. stigma, sexing was possible only after death, by dissection of the genitalia.

First record of Aethalion reticulatum (Hemiptera: Aethalionidae) in Vernonia condensata (Asteraceae), a medicinal plant from Brazil

Vernonia condensata Baker, 1875 (Asteraceae) is a medicinal plant from Brazil considered as a host plant of leafhopper pests in agricultural crops. Aethalion reticulatum Linnaeus, 1767 (Hemiptera: Aethalionidae) was observed in V. condensata in Lavras county, Minas Gerais State, Brazil. Immature and adult individuals of A. reticulatum were collected from V. condensata for identification, which represents the first recording of this pest in this plant. The presence of eggs, nymphs and adults of this insect on the plant shows that A. reticulatum has completed its life cycle, indicating that V. condensata is a potential host plant for A. reticulatum.

Manejo del ácaro Aceria litchii (Acari: Eriophyidae) en Litchi chinensis

Litchi chinensis fruits are very popular in the international market. The erinose mite, Aceria litchii (Eriophyidae), a major pest of this crop, feeds on the leaves and on all parts of the plants forming erinea. The purpose of this review is to present the most common control methods and to propose integrated management techniques for L. chinensis production systems. A. litchii infestations were detected in Brazilian orchards in 2008. Chemical pesticides are currently the main control measure for this pest; however, the combination of biological, chemical and cultural methods are more promising in the long term. Controlling and preventing the erinose mite are key factors for reducing its spread and establishment.

Iphimeis dives (Coleoptera: Chrysomelidae): first report on Inga edulis (Fabaceae) in Brazil and data on its biology

Summary Iphimeis dives Germar (Coleoptera: Chrysomelidae) was recorded feeding on young and mature leaves of Inga edulis Mart. (Fabaceae) plants in the urban area of Lavras, Minas Gerais State, Brazil, in Nov 2013 and Nov 2014 at the beginning of the rainy season. Iphimeis dives males and females were brought to the laboratory for species identification, and fecundity characteristics (the proportion of females laying eggs, number of eggs per mass, and the period of time required for an act of oviposition) were determined. Inga edulis is added to the host plant list for I. dives. Each female of this species deposited 69.2 ± 10.6 eggs in a single mass in 2.6 ± 1.1 d (± SE).

Poekilloptera phalaenoides (Hemiptera: Flatidae) on Abarema villosa (Fabales: Fabaceae) in Diamantina, Minas Gerais State, Brazil

Summary Abarema villosa Iganci & M. P. Morim (Fabales: Fabaceae) is a medicinal and ornamental plant in the Cerrado biome of Brazil. Poekilloptera phalaenoides L. (Hemiptera: Flatidae) is a polyphagous pest that imbibes plant sap. This insect was observed on A. villosa plants in Diamantina, Minas Gerais State, Brazil. Poekilloptera phalaenoides uses A. villosa plants as a site for shelter, feeding, and reproduction. This is the first report of A. villosa as a host of P. phalaenoides.