Rafael Braga da Silva

Using sex pheromone traps in the decision-making process for pesticide application against fall armyworm (Spodoptera frugiperda [Smith] [Lepidoptera: Noctuidae]) larvae in maize

The fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), is a major pest of maize and frequently demands control measures. The timing of insecticide application is a key factor in determining its efficiency, so an experiment was designed to investigate this. Application of insecticide was based on three criteria: (i) the number of trap-caught moths in a Delta-type trap with a commercial sex pheromone lure placed in the center of the target area, soon after plant emergence; (ii) the percentage of plants exhibiting pinhole-type damage (10% or 20%) and (iii) the percentage of plants exhibiting shot hole-type damage (10% or 20%) compared to a check plot without any control measures. We found that the number of trap-caught moths was, compared to the other methods, the best means of deciding on insecticide application in maize to control the fall armyworm. Using pheromone traps, we obtained the best performance of the insecticide Spinosad, causing >90% larval mortality. Without insecticide application, maize yield reduction due to fall armyworm larva damage was 39%.

New record of Tetrastichus howardi (Olliff) as a parasitoid of Diatraea saccharalis (Fabr.) on maize

Diatraea saccharalis (Fabr.) (Lepidoptera: Pyralidae) spends the largest part of its life cycle inside the stalk of the host plant,which provides protection against the action of conventional control methods. Biological control has been considered a viable alternative to control this pest in sugarcane (Saccharum officinarum L.) and corn (Zea mays L.), two pest preferential hosts. This paper reports the occurrence in Brazil of Tetrastichus howardi (Olliff) (Hymenoptera; Chalcidoidea: Eulophidae) parasitizing pupae of D. saccharalis obtained from corn plants. It also includes preliminary biological data about the insect. A single female of T. howardi is able to produce up to 66 offspring using a single pupa of the host D. Saccharalis and apparently does not distinguish between the host pupae of different ages. The life cycle of the parasitoid was around 25.5 days. The presence of the parasitoid in Brazil opens a new perspective on suppression of the sugarcane borer, considering the promising results already obtained in Asian countries. The insect is well adapted to laboratory conditions, can be produced in large scale and may became an additional option for the integrated pest management in those crops where D. saccharalis is a key pest such as the sugarcane, corn and sorghum (Sorghum bicolor (L.) Moench).

Survey of ear flies (Diptera, Ulidiidae) in maize (Zea mays L.) and a new record of Euxesta mazorca Steyskal in Brazil

Levantamento de mosca-da-espiga (Diptera: Ulidiidae) em milho (Zea mays L.) e primeiro relato de ocorrencia de Euxesta mazorca Steyskal no Brasil. Especies de Euxesta (Diptera, Ulidiidae), conhecidas como moscas do cabelo ou moscas da espiga estao aumentando em importância nas culturas de milho em diferentes paises, embora muito pouco se conheca sobre elas no Brasil. As larvas das especies representativas de Ulidiidae inicialmente danificam a parte reprodutiva feminina da planta e depois os graos em desenvolvimento. Como resultado da alimentacao das larvas ocorre fermentacao e odor forte tornando a espiga inapropriada para o consumo humano ou animal. O principal objetivo deste trabalho foi avaliar a incidencia de especies de Euxesta em areas de producao de milho e identificar as especies predominantes usando dois atraentes alimentares diferentes a base de proteinas hidrolisaveis, BioAnastrepha® (proteina hidrolisavel de milho) e Torula, colocados no interior de armadilha McPhail. As duas especies identificadas foram E. eluta Loew and E. mazorca Steyskal, registrada pela primeira vez no Brasil. Entre as especies, E. eluta foi predominante no milho. Ambos os atraentes foram eficientes na captura das duas especies. No entanto, as armadilhas com BioAnastrepha® capturaram significativamente mais insetos do que aquelas com Torula.

Organismos de solo associados à supressora de plantas daninhas Crotalaria juncea (fabaceae) e sua importância como refúgio para inimigos naturais

Organismos de solo desempenham um importante papel em cultivos orgânicos de Crotalaria juncea (Fabaceae) e estao associados com a conservacao natural do ambiente. O presente estudo teve como objetivo investigar a populacao de organismos de solo no cultivo orgânico de C. juncea, bem como sua importância como um refugio para inimigos naturais. Dalbulus maidis (Hemiptera: Cicadellidae), Diabrotica sp. (Coleoptera: Chrysomelidae), Doru luteipes (Dermaptera: Forficulidae), Gryllus assimilis (Orthoptera: Gryllidae), Lagria villosa (Coleoptera: Lagriidae), Melanotus sp. (Coleoptera: Elateridae), Meloidogyne incognita (Tylenchida: Heteroderidae), Nephila clavipes (Araneae: Nephilidae), Orius insidiosus (Hemiptera: Anthocoridae), Pheidole sp. (Hymenoptera: Myrmicidae), Phyllophaga sp. (Coleoptera: Scarabeidae), Procornitermes sp. (Isoptera: Termitidae), Solenopsis sp. (Hymenoptera: Formicidae) e Utetheisa ornatrix (Lepidoptera: Arctiidae) foram identificados em C. juncea. Os organismos que foram encontrados durante um periodo de tres meses em 144 trincheiras em C. juncea foram as especies de pragas (84,47%) e inimigos naturais (15,53%). Inimigos naturais tiveram uma media de 11,89 individuos por 1,08 m3 de solo cultivado com C. juncea. A abundância de organismos na fase de vagem (5,49%) de C. juncea foi menor do que nas fases vegetativa (83,50%) e floracao (11,01%). Plantas de C. juncea podem ser usadas como parte de um sistema de cultivo para o Manejo Integrado de Pragas.

Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål) (Hemiptera, Pentatomidae)?

Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stal) (Hemi- ptera, Pentatomidae)? The stink bug Supputius cincticeps (Stal) (Hemiptera, Pentatomidae) is a predator found in several Brazilian regions, which possesses desirable attributes as a natural control agent and in biological control programs. The aim of this study was to test if the attack behavior and predation success of S. cincticeps were affected by prey species. Larvae of Tenebrio molitor (L.) (Coleoptera, Tenebrionidae), Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae), and Thyrinteina arnobia (Stoll) (Lepidoptera, Geometridae) were offered to S. cincticeps in laboratory bioassays where predatory attack and prey defensive beha- viors were observed for 2-hour periods. The attack behavior of S. cincticeps changed with the prey species offered. More than 25% of T. molitor and S. frugiperda larvae were immediately attacked, but T. arnobia was not immediately attacked by S. cincticeps. Successful attack (i.e., successful insertion of the predator stylets into the prey) depends on the region of the body attacked, with a greater proportion of successful attacks in the anterior than in the median or posterior regions. Larvae of T. arnobia and S. frugiperda displayed a sequence of abrupt head and body movements in response to S. cincticeps attack. Attempts of predation were more successful on T. molitor and S. frugiperda than on T. arnobia. Information about the differential attack behavior of S. cincticeps on different prey species is important for designing successful biological control programs using this hemipteran predator.

Potential of Tyrophagus putrescentiae (Schrank) (Astigmata: Acaridae) for the Biological Control of Lasioderma serricorne (F.) (Coleoptera: Anobiidae)

This work investigated the potential of Tyrophagus putrescentiae (Schrank) (Astigmata: Acaridae) to control Lasioderma serricorne (F.) (Coleoptera: Anobiidae) in the laboratory. L. serricorne is the most destructive insect pest ever found on stored tobacco. The experimental delineation had 33 arenas being each experimental unit with 11 arenas of experiments with eggs, larva of L. serricorne with the density of T. putrescentiae maintained constant, where from 11 of these arenas, eight were for the analysis of predation and three to evaluate the natural mortality of the insect. The highest predation rate was found during the larval stage with, approximately, 54, 68 and 78% mortality of L. serricorne from the fourth until the sixty day of predation. These results indicated that it was possible to use the predatory mite T. putrescentiae in pest management programs of L. serricorne in the storage units of tobacco.

Development and Reproduction of Olla v-nigrum (Coleoptera: Coccinellidae) Fed Anagasta kuehniella (Lepidoptera: Pyralidae) Eggs Supplemented with an Artificial Diet

ABSTRACT Olla v-nigrum Mulsant (Coleoptera: Coccinellidae) preys on eggs and larvae of Coleoptera and Lepidoptera and on aphids in arboreal plants. Alternative prey supplemented with artificial diets may be used to mass rearing Coccinellidae predators for biological control programs. This study assessed the development and reproduction of O. v-nigrum fed Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) eggs supplemented with an artificial diet. Adults of O. vnigrum were collected from Caesalpinia peltophoroides Benth. (Fabales: Fabaceae) and taken to the laboratory. Three male + female couples were fed on A. kuehniella eggs and an artificial diet (100 g of yeast, 40 g of honey, 0.5 g of ascorbic acid and 60 mL of water). Eight male + female couples obtained from this initial generation were subjected to the same procedure in order to assess the effects on subsequent generations. The mean number of eggs per egg mass was 11.7 ± 0.7 with a viability of 54.8 ± 2.9% and an incubation period of 3.1 ± 0.02 days. The durations of instars I, II, III and IV and the durations of the larval, pre-pupal, pupa and larva to adult stages were 2.4 ± 0.3, 1.8 ± 0.2, 2.0 ± 0.3, 5.8 ± 0.1, 12.1 ± 0.3, 1.0 ±0.01, 4.0 ±0.2 and 17.1 ± 0.5 days, respectively. The viabilities of the larval, pre-pupal and pupal stages of this predator were 46.3 ± 4.5%, 90.0 ± 5.0% and 100%, respectively. The diet and other methods employed in this study were adequate for laboratory rearing of O. v-nigrum but, because of the low viabilities of the eggs and immature stages observed with these methods, further improvements will be necessary for successful mass rearing of this valuable predator.