Charles Martins de Oliveira

Economic impact of exotic insect pests in Brazilian agriculture

Agriculture represents one of the major strengths of the economic sector in Brazil. The need to avoid economic losses because of insect pest populations is one of the greatest challenges faced by this sector. Insect pests have caused annual losses of US

Growth and Nutrition of Mollicute-Infected Maize

12.0 billion to the Brazilian economy, of which approximately US

First record of Phyllophaga sp. aff. capillata (Coleoptera: Melolonthidae) as a soybean pest in the Brazilian "Cerrado".

1.6 billion are because of exotic pest species. Furthermore, exotic insect species often show greater potential to cause harm than native species. In Brazil, since the late nineteenth century, 24 species of insect pests have been introduced into the country, and they have caused significant economic losses. Many of these species, including Bemisia tabaci, Hypothenemus hampei, Ceratitis capitata, Oryzophagus oryzae and Anthonomus grandis, are major crop pests, and they were accidentally introduced during trading of agricultural products. In this review, we present an overview of Brazilian agriculture, a brief history of the introduction of insect pests in the country and the Brazilian legislation on agricultural defence, and we estimate the economic losses caused to the Brazilian economy by the main insect pest species that have been introduced into Brazil over the last 112 years.

Influence of Latitude and Elevation on Polymorphism Among Populations of the Corn Leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), in Brazil

Maize bushy stunt phytoplasma (MBSP) and corn stunt spiroplasma (CSS) diseases are widespread in Brazil. The leafhopper Dalbulus maidis is the insect vector for these pathogenic mollicutes. The effects of these diseases on the development of maize plants and the possible interaction of soil water availability on these effects were evaluated in two experiments carried out on potted plants. Experiment 1 was carried out in a 2 × 4 factorial, where factor 1 corresponded to healthy and mollicute-infected plants and factor 2 to the maintenance of 40, 60, 80, and 100% of the total soil water availability. Leafhoppers collected from a field with high incidence of these diseases were used to inoculate plants with mollicutes. There were three treatments in experiment 2: healthy plants, plants infected with phytoplasma, and plants infected with spiroplasma. MBSP was predominant in experiment 1. The infected plants grew less and lowered nutrient uptake, in distinct proportions, indicating a differential effect of mollicutes on nutrient uptake independent of available soil water. Soil water availability did not significantly affect plant growth and nutrient uptake or mollicute infection. The results indicated that plants infected by mollicutes contained less protein than healthy plants. Experiment 2 showed a reduction in growth of plants infected with mollicutes and less nutrient uptake by spiroplasma-infected plants. The results showed a detrimental effect of the spiroplasma on Mg uptake. Both experiments showed more water retention by infected plants than by healthy ones. These experiments clearly demonstrated that reduced plant growth and nutrient uptake are major effects on plants infected with MBSP and CSS.

Characterization of sweet cassava accessions based on molecular, quantitative and qualitative data

Insects known in Brazil as “coros” are beetle larvae (Coleoptera) of the family Melolonthidae ( sensu Endrodi 1966; Moron 1997, 2001a; Moron et al. 1997). Many of these species feed on roots of a wide range of cultivated plants and are considered pests worldwide (Moron 1997). The genus Phyllophaga Harris stands out as one of the most important due to the damage many cause to agricultural systems (Saylor 1942). They could be considered one of the most serious pests in Mexico and Central America (Moron et al. 1996). Damage caused by Phyllophaga in the Americas have been recorded in several crops, including corn ( Zea mays L.), potato ( Solanum tuberosum L.), sugar cane ( Saccharum officinarum L.), peanut ( Arachis hypogea L.), bean ( Phaseolus vulgaris L.), pepper ( Capsicum annum L.), coffee ( Coffea arabica L.), pastures, vegetables, ornamental plants (Pardo-Locarno et al. 2005; Moron 1997; King 1984), soybean ( Glycine max (L.) Merrill) (Oliveira et al. 2004; Salvadori & Oliveira 2001), and wheat ( Triticum aestivum (L.) Thell) (Salvadori & Silva 2004; Salvadori & Oliveira 2001). About 369 species of Phyllophaga are known in Mexico (Moron 2003). Although many related studies have been conducted in Mexico and Central America, information on their bioecology, lifecycle, host preference, and reproductive behavior are still rare for most species (Moron 1986; King 1984). In South America, the knowledge of Phyllophaga is also critical, and extensive taxonomic reviews are required (Moron 2004). In 1985, serious damage attributed to “coros” in Brazil started being recorded in soybean fields in

Aegopsis bolboceridus (Coleoptera: Melolonthidae): An Important Pest on Vegetables and Corn in Central Brazil

Abstract Morphological variations in insects have been shown to be influenced by latitude and elevation. Here we show that these two parameters markedly influence the appearance of the corn leafhopper Dalbulus maidis (DeLong and Wolcott). Leafhopper samples were collected in maize from 27 localities in 10 Brazilian states, with latitudes from 5 to 28° S and elevations from 16 to 1,628 m. D. maidis was the only Dalbulus species found in the samples. Up to 10 males and 10 females of D. maidis from each collection site were evaluated for size, pigmentation, and body weight. Females were always bigger and heavier than the males in the same locality. For both sexes, there was a positive and significant correlation between the morphological variables measured and the latitude and elevation from where specimens were collected. Individuals from higher latitudes (southern region) were bigger, darker, and heavier than those from lower latitudes (northeastern region). There was also a tendency for an increase in body weight, head capsule width, and wing length at higher elevations.

Field biology of the beetle Aegopsis bolboceridus in Brazil, with a list of host plants.

The purpose of this study was to estimate the genetic divergence in sweet cassava accessions by molecular markers and quantitative and qualitative characters, as well as determine the correlation between these estimates. Sixteen sweet cassava accessions of the Regional Cassava Germplasm Bank of the Cerrado were evaluated under field conditions, for 13 quantitative and 33 qualitative characters. In the laboratory, the accessions were evaluated with RAPD markers. Subsequently, matrixes of genetic dissimilarity/distance among the accessions were estimated based on molecular markers and quantitative and qualitative characters. Besides, the significance of the correlation between the matrixes was estimated. The RAPD, qualitative and quantitative data indicated the existence of high divergence among the accessions. The divergences estimated by molecular markers and by quantitative traits were weakly associated with each other and moderately with the divergence estimated by qualitative characters.

Survival strategies of Dalbulus maidis during maize off-season in Brazil

Beetles belonging to the family Melolonthidae (sensu Endr?di 1966; Mor?n 1997, 2001, 2004b; Mor?n et al. 1997) are primary consumers or de composers. The adults feed on leaves, stems, roots, exudates, flowers, fruits and tubercles of an giosperms, as well as on leaves and roots of gym nosperms. Some adults are predators of other in sect species. Usually the larvae develop in the soil, consuming roots or humus, as well as rotting tree trunks. Larvae of a few species are associated with ants and termites, feeding on detritus or on imma tures ofthose insects. Some larvae occur in rodent

Scarabaeoidea (Insecta: Coleoptera) no Cerrado brasileiro: estado atual do conhecimento

Abstract The white grub, Aegopsis bolboceridus (Thomson) (Coleoptera: Melolonthidae), is an important vegetable and corn pest in central Brazil. The objective of this study was to examine the biology of A. bolboceridus in the field and to update the list of its host plants. The study was conducted in an area with vegetable crops and corn located in the Federal District of Brazil. Samplings were taken to observe the biological stages of A. bolboceridus, preferred oviposition sites, and the adult swarming period. A. bolboceridus exhibited a univoltine cycle that lasted approximately 12 months from egg to active adults. Its eggs were found from October to November. The larval stage lasted approximately eight months, occurring between October and May. Pre-pupae were observed between April and June, and pupae were found between May and July. Inactive adults were observed in July and August, and the swarming period was between September and October. The females preferred to oviposit in sites with taller plants. Four new plant species were identified as hosts for this pest, and two new locations were recorded for its occurrence. This study is the first to describe the biology of a representative of the tribe Agaocephalini in Brazil.

Bio-Ecology of Poekilloptera phalaenoides (Hemiptera: Flatidae) Under the Influence of Climatic Factors in the Brazilian Cerrado

Despite the importance of Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae) as a vector of maize‐stunting pathogens, it is not understood how this leafhopper survives the maize off‐season in regions where overwintering hosts do not occur. We investigated migration and the use of alternate hosts as possible survival mechanisms for D. maidis during maize off‐season in Brazil. Dalbulus maidis populations were monitored with yellow sticky cards for 16–29 months in Anastácio (Mato Grosso do Sul State), in two farms with perennial pastures (Pasture1 and Pasture2), where maize had not been planted for >5 years, in a subsistence farm >20 km distant, where maize was annually planted (spring) (Maize1), and in Piracicaba (São Paulo State), where maize was grown year round (Maize2). RAPD‐PCR analysis of leafhoppers sampled on maize in two plots (Maize1 and Pasture1) at 15–20 and 110–120 days after germination was performed. Dalbulus maidis was trapped in the maize plots of all areas, but not in weedy or woody vegetation adjacent to the plots. Higher numbers were trapped throughout the year in Piracicaba, where maize was continuously grown under irrigation, and in the subsistence farm of Anastácio, where volunteer maize plants were available for long periods in the maize off‐season. In Anastácio farms, some population peaks were recorded in the absence of maize from midwinter to early spring, especially after soil plowing. RAPD‐PCR analysis showed that D. maidis populations sampled were genetically similar. Our data suggest that D. maidis uses a mixed strategy to survive the over‐season period in Brazil, in which part of the population overwinters locally on volunteer maize plants or nearby irrigated maize crops, whereas the other individuals migrate to colonize new maize crops in distant areas or regions. We hypothesize that immigrant D. maidis uses the contrast between plowed and vegetated soil as a visual cue for locating new maize crops.