No abstract

The coffee leaf miner (CLM) Leucoptera coffeella has a wide distribution and causes significant losses in coffee plantations (Coffea spp.) in Brazil. Its occurrence can be mitigated in intercropped systems, with the rubber tree (Hevea brasiliensis ) adapting well to the consortium, while also providing extra income to the producer. We aimed to determine whether the afforestation influences the microclimate and affects the leaf miner incidence and its predation by wasp in coffee plants intercropped with rubber trees. The study was undertaken in state of Paraná, Brazil, using coffee plants intercropped with rubber trees planted in double rows (alleys) spaced at 13, 16 and 22 m between alleys, and compared to sole cropping coffee plots. From January 2008 to November 2010, the presence of CLM's lesions including those with signs of wasp predation was monitored in coffee plants intercropped with rubber trees and in the non-consorted coffee. A higher CLM's incidence was verified in monoculture coffee plots, while coffee plants located under and two meters away from rubber trees had the lowest incidences. CLM's incidence in intercropping system got higher as it increased distance from the trees. The number of lesions with signs of predation by wasps was positively correlated with the number CLM's lesions, indicating a density-dependent predator-prey relationship. The coffee plants intercropped with alley rubber trees reduce the CLM's occurrence and can be a management's tactic for this economically important pest.

The effects of alternative treatments on the oviposition and viability of Leucoptera coffeella eggs and larvae were evaluated. Under controlled conditions, coffee sprouts cv. IAPAR-59, eight months old, were sprayed with brown propolis extract (1%), pyroligneous extract with pepper and garlic (PEPG) (2%), silicate clay (2%), kaolin (5%), lime sulfur (2%), neem oil (1%) and kaolin + neem oil (5% + 1%), distilled water and no treatment. In a first no-choice bioassay, coffee sprouts were sprayed before oviposition and kept in cages, where adult insects within three days after emergence were released. Adults remained in the cages for 24 hours. Eggs were then counted. 10 eggs per sprout were preserved to verify larval mortality. The number of eggs when treated with propolis extract, neem oil, kaolin + neem oil and PEPG decreased in the evaluations. Treatments with neem oil caused greater larval hindrance. Eggs laid on leaves were also sprayed with the treatments. Egg viability was reduced by treatments containing neem oil and lime sulfur. Neem oil treatments resulted in slim adult emergence; intermediate viability with lime sulfur and slight hindrance with silicate clay. Finally, treatments were also sprayed on leaves, hosting first or third instar larvae. Neem treatment caused high mortality for 1st and 3 rd instar larvae, however, this effect was reduced when mixed with kaolin. Nonetheless, these negative effects disappeared when considering the adult survival ratio. Results indicated that propolis extract, PEPG and neem oil treatments are suitable for reducing egg deposition, neem oil considerably diminished larvae survival and adult emergence.

The green-belly stinkbug (Dichelops melacanthus) stands out due to its damage potential towards corn and wheat crops. The population distribution and size greatly influence the potential damage. The insect’s reproductive capacity depends on different temperature conditions during various crop seasons and its lifecycle. The study aimed to evaluate the influence of different constant temperatures on the D. melacanthus biology. The study was performed twice, once in the year of 2017, and again in 2019. The biological features were observed in temperature-controlled climate chambers with the following temperatures: 11, 16, 21, 26, 31 and 36 °C, each with a fluctuation of ±1 °C, using a RH of 65±15% and photophase of 14 h. The evaluations were conducted from eggs to adults in terms of: nymphal hatch period, each instar duration, female fecundity and egg viability. There were no eggs hatching at 11 ºC and it also reached 100% mortality during the second instar at 16 °C. The eggs-to-adult duration for the temperatures 21, 26, 31 and 36 °C in the trial of 2017 was 58.4, 30.1, 18.2 and 16.3 days, respectively. In the same temperatures, but during the 2019 trial, the eggs to adult duration was 58.1; 29.7; 21.3 and 19.1 days, respectively. The reproductive capacity in the temperatures of 21 and 36 °C impaired the female fecundity and egg viability. The temperatures 26 and 31 °C favored the development of D. melacanthus.

The broad mite (BM) Polyphagotarsonemus latus is a pest of great prominence for several crops, including the common bean (Phaseolus vulgaris). The objective of this study was to select resistant genotypes and to determine chemicals associated with resistance. In the first experiment, BM incidence was assessed for 36 genotypes in a greenhouse study. A group of 10 genotypes was selected according to the development of BM populations. Mite populations and phytometric and biochemical variables were then determined to study eventual differential genotypic responses to mite infestation. Lower numbers of mite mobile forms (larvae + adults) were found on Verdão, Negrão and Carioca Original genotypes. The magnitude of differences reached 5.4 times more BM in the IAC Alvorada than the Verdão genotype. Plant yields were reduced for the genotypes TAA Bola Cheia, IPR Sabiá, IPR Uirapuru, IAC Alvorada and Carioca Original when plants were infested with BM. The yields for LP 13833, BRS Esteio, Negrão 11, Verdão and MD 1133 were similar between infested and non-infested genotypes, indicating tolerance. Verdão and Negrão 11, besides the tolerance, exhibited low offspring development, indicating antibiosis and/or antixenosis. Higher phenolic compound levels were found in the Verdão genotype. Increased contents of catalase and peroxidase were detected for Negrão 11 genotype when infested with BM. This work allowed the detection of common bean genotypes that express resistance and tolerance to BM. These genotypes can be used in places with a history of BM infestation, or used in breeding programs to incorporate these characteristics in other genotypes.

Cercospora coffeicola is one of the primary diseases that affect coffee plants. Studies indicate that shaded coffee plants reduce the incidence of this disease and that the management of trees and coffee plants arrangement influence in the dissemination of cercospora. The objective of this study was to evaluate the incidence and severity of C. coffeicola at different distances from double rows of rubber trees (Hevea brasiliensis muell. arg.) at two different sunlight exposures (north and south). This study was conducted in Londrina, Parana, between 2008 and 2010, with adult plants of the IAPAR 59 cultivar (Coffea arabica L.) grown at a spacing of 2.5 m x 1.0 m. The distances between the double rows of rubber trees were 13, 16 and 22 m, compared to plants grown under full sun. The disease incidence was assessed monthly by using a non-destructive method. This analysis was conducted on coffee leaves from the third and fourth pairs of two plagiotropic branches, on eight plants per plot, with five replications. These data were used to calculate the area under the curve for the incidence of the brown eye spot. The highest disease incidence occurred in the coffee plants grown under full sun, whereas lowest disease occurred on plants located at up to two meters away from double rows of rubber trees. The incidence of Cercospora leaf spot increased with the distance from the double rows of rubber trees. The results demonstrate that the mapping of cercospora incidence in shaded coffee plants is essential to determinate the best spacing and plants arrangement. (Coffea arabica L). As distâncias entre seringueira em filas duplas foram de 13, 16 e 22 m, comparadas com plantio a pleno sol. A avaliação da incidência da doença foi realizada por método não destrutivo, por meio da contagem de folhas doentes nas folhas do terceiro e quarto pares de dois ramos plagiotrópicos dos cafeeiros. Com base nesses dados calculou-se a área abaixo da curva de progresso da incidência da cercosporiose. A maior incidência da doença ocorreu nos cafeeiros cultivados a pleno sol. Os cafeeiros cultivados até dois metros distantes das seringueiras em filas duplas apresentaram menor incidência da doença. A incidência de cercosporiose do cafeeiro aumentou com o incremento da distância das plantas em relação às seringueiras em filas duplas. Os resultados demonstram que o mapeamento da incidência da cercospora em cafeeiros arborizados é fundamental para a determinação dos melhores espaçamentos e disposição das plantas.

The objective of this study was to evaluate the infestation of Vatiga illudens in cassava varieties and to correlate its infestation with the physical and morphological parameters of resistance. The experiments were conducted in the 2014/2015 and 2016/2017 seasons, out in a randomized complete block design with nine treatments and five replicates. Nymphs and adults of V. illudens were evaluated on the abaxial surface of 16 leaves of the middle third of the plant. The density of trichomes was quantified with the use of electron micrographs, and the roughness of the epicuticular wax was assigned to the leaves of the shoot and the apical third. The color components L*, a*, b*, were measured with a portable digital colorimeter. The cultivars IAC 90 and Santa Helena demonstrated the smallest infestations in the 2014/2015 season and maintained low infestation in the 2016/2017 season. The varieties Baianinha, IAC 576-70 and Catarina-Branca, maintained high infestations in the both seasons. The density of trichomes of the middle third of the plants correlated negatively to the V. illudens infestation for the two seasons. The higher density on trichomes, negatively affects the infestation of V. illudens in cassava varieties, characterizing as a specific resistance factor to this species.

We present the first report on Euphoria lurida (Fabricius) (Coleoptera: Scarabaeidae) infestation on safflower (Carthamus tinctorius L.), a crop of industrial and medicinal importance. Between September and October 2013-2015 in Paraná State, we observed E. lurida adults feeding on safflower plants from the inception of flower head formation onwards, over an area of approximately 400 m. Losses in the productivity of infested plants were estimated between 15 and 50%. The damage was characterized by perforations in the upper portion and at the base of the developing flower heads or open flowers, resulting in withering and abortion of the reproductive structures.