Maria de Lourdes Corrêa Figueiredo

Damage of Spodoptera frugiperda (Smith) in different maize genotypes cultivated in soil under three levels of aluminium saturation

This study was conducted to assess the damage caused by artificial infestation by the fall armyworm Spodoptera frugiperda (J. E. Smith) larvae in Al-tolerant and Al-susceptible maize cultivars at different levels of Al saturation (low, medium and high) in an acid soil. The experiments were conducted in the field, in Sete Lagoas, MG, Brazil, during four consecutive years in plots corrected with lime, according to the soil analysis to provide three levels of aluminum saturation: toxic (m > 50%), intermediate (m < 20%), and without aluminum (m < 5%). Three maize cultivars were used, BR 201 tolerant (hybrid with yellow endosperm), BR 400 (yellow sweet maize) and BR 451 (High Quality Protein Maize, white endosperm) sensitive to toxic levels of Al saturation, respectively. The treated plots were artificially infested with young larvae. The non-infested plots were maintained free from natural infestation of the fall armyworm using granular insecticide applied directly to the whorl. Yield reductions due to fall a...

Relação entre a lagarta-do-cartucho e seus agentes de controle biológico natural na produção de milho

This work had the objective of quantifying the losses in the maize hybrid BRS 3123 due to the attack of fall armyworm (Spodoptera frugiperda), in the absence or presence of its natural enemies. Fifteen days after the plant emergency, an artificial infestation (one egg mass per square meter) was accomplished. The larvae fed on the plant, without the interference of its natural enemies, by using an appropriated protection cage (initial protection for two days after infestation, until a maximum protection period of 16 days). The damage caused by the pest, determined through a visual scale from 0 (plants without damage) to 5 (dead plants), was on average, 4.01, 1.39, 1.09 and 0.93 for the pest protection period of 16, 6, 4 and 2 days, respectively. In the absence of the biological control agents, the attack of the pest caused losses of 47.27% in the dry matter production and losses of 54.49% in grain yield. The results evidenced the importance of natural enemies in the suppression of fall armyworm in maize crop.

CONTROLE INTEGRADO DE SPODOPTERA FRUGIPERDA (SMITH & ABBOTT) UTILIZANDO-SE O PARASITÓIDE TELENOMUS REMUS NIXON

Este estudo foi conduzido em 1996 e 1997 para avaliar a eficiencia da liberacao de Telenomus remus Nixon (cerca de 200.000 adultos/ha), sozinho ou integrado ao virus de poliedrose nuclear de Spodoptera frugiperda (VPNSf) ou a um inseticida quimico seletivo, para o controle de Spodoptera frugiperda (Smith & Abbott). Os experimentos foram conduzidos em delineamento experimental de blocos ao acaso, com seis tratamentos e quatro repeticoes. Foram avaliados os danos provocados pela praga as folhas (escala de 0 a 5) e o rendimento de espigas. De maneira geral, os danos provocados pela praga foram significativamente superiores nas parcelas testemunhas (nota media de 2,94). Nao houve diferenca significativa entre os demais tratamentos (media 1,04). De maneira semelhante, houve diferenca significativa no rendimento de espiga entre testemunha (7.165 kg/ha) e demais tratamentos (9.084 kg/ha). Nao houve efeito dos tratamentos no comprimento da espiga e no dano as espigas.

Isolation, Identification, Synthesis, and Field Evaluation of the Sex Pheromone of the Brazilian Population of Spodoptera frugiperda

Several studies have shown intraspecific geographical variation in the composition of sex pheromones. Pheromone lures from North America and Europe were not effective against the fall armyworm Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) in Brazil, so we examined the composition of the sex pheromone produced by females from Brazilian populations. Virgin female gland extracts contained (Z)-7-dodecenyl acetate (Z7-12:Ac), (E)-7-dodecenyl acetate (E7-12:Ac), dodecyl acetate, (Z)-9-dodecenyl acetate, (Z)-9-tetradecenyl acetate (Z9-14:Ac), (Z)-10-tetradecenyl acetate, tetradecyl acetate/(Z)-11-tetradecenyl acetate (Z11-16:Ac), and (Z)-11-hexadecenyl acetate. The relative proportions of each acetate were 0.8:1.2:0.6:traces:82.8:0.3:1.5:12.9, respectively. This is the first time that E7-12:Ac has been reported from the pheromone gland of S. frugiperda. Only three compounds, Z9-14:Ac, Z7-12:Ac, and E7-12:Ac, elicited antennal responses, and there were no differences in catch between traps baited with either Z7-12:Ac + Z9-14:Ac or Z7-12:Ac + Z9-14:Ac + Z11-16:Ac blends. However, the Z7-12:Ac + Z9-14:Ac + E7-12:Ac blend was significantly better than Z7-12:Ac + Z9-14:Ac, indicating that E7-12:Ac is an active component in the sex pheromone of the Brazilian populations of S. frugiperda.

Efeito da idade de lagartas de Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) no desempenho do parasitóide Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) e consumo foliar por lagartas parasitadas e não-parasitadas

The potential of parasitism of Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) on Spodoptera frugiperda (Smith) larvae of different ages and foliar consumption of parasitized and non-parasitized larvae were evaluated. When 3-d old larvae were offered to the parasitoid the number of pararasitized larvae was 232/female, similar to what was obtained with 2-d old larvae (182 larvae/female); with 4-5-d old larvae, parasitism was 80.7 and 71.0/female, respectively. Healthy larvae consumed 209.3 cm2 of leaf, while parasitized larvae consumed 14.5 cm2 (6.9% of consumption by healthy larvae).

Application rate trials with a nuclear polyhedrosis virus to control Spodoptera frugiperda (Smith) on maize

Diferentes concentracoes de virus da poliedrose nuclear (VPN) foram aplicadas em suspensao aquosa, usando-se pulverizador (acoplado a um trator ou costal-manual), para o controle de larvas de Spodoptera frugiperda (Smith), em milho (Zea mays L.). A mortalidade das larvas variou com o equipamento de aplicacao. Na aplicacao via trator, foi necessaria uma dose de pelo menos 2,5 x 1012 corpos de inclusoes poliedricas (CIP)/ha para se ter eficiencia comparavel a que se obteve com o pulverizador costal-manual (70,2%). Para este tipo de pulverizador pode-se usar 2,5 x 1011 CIP/ha, porem o efeito residual foi muito curto. Maior persistencia foi obtida com doses acima de 1,25 x 1012 CIP/ ha (93,4% de mortalidade). A ocorrencia de parasitoides na area experimental propiciou um aumento medio na taxa de mortalidade larval (16,4%), independente da metodologia de aplicacao. Entre os parasitoides, a maior ocorrencia foi de Campoletis flavicincta (Ashmead) (53,0%), seguido por Chelonus insularis (Cresson) (31,3%), e Eiphosoma spp. (15,6%).

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.

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.