Development of a control alternative for the citrus fruit borer, Ecdytolopha aurantiana (Lepidoptera, Tortricidae): from basic research to the grower

All research steps, developed from 1995 to 2000, to synthesize the sex pheromone of Ecdytolopha aurantiana (Lima, 1927) are described, in order to monitoring this pest that causes losses in the order of 50 million dollars per year to citriculture in the State of São Paulo. The basic researches conducted are described, including the development of an artificial diet for the insect, the study of its temperature and humidity requirements, behavioral studies, and synthesis of the male-attracting substance up to the formulation and distribution of the pheromone to the grower, by means of its commercialization. It is a case of success, at a cost of 50 thousand dollars, involving inter- and multidisciplinary researches, which can be adopted to other insect pests in the country.

Plant compounds insecticide activity against Coleoptera pests of stored products

The objective of this work was to screen plants with insecticide activity, in order to isolate, identify and assess the bioactivity of insecticide compounds present in these plants, against Coleoptera pests of stored products: Oryzaephilus surinamensis L. (Silvanidae), Rhyzopertha dominica F. (Bostrichidae) and Sitophilus zeamais Mots. (Curculionidae). The plant species used were: basil (Ocimum selloi Benth.), rue (Ruta graveolens L.), lion's ear (Leonotis nepetifolia (L.) R.Br.), jimson weed (Datura stramonium L.), baleeira herb (Cordia verbenacea L.), mint (Mentha piperita L.), wild balsam apple (Mormodica charantia L.), and billy goat weed or mentrasto (Ageratum conyzoides L.). The insecticide activity of hexane and ethanol extracts from those plants on R. dominica was evaluated. Among them, only hexane extract of A. conyzoides showed insecticide activity; the hexane extract of this species was successively fractionated by silica gel column chromatography, for isolation and purification of the active compounds. Compounds 5,6,7,8,3',4',5'-heptamethoxyflavone; 5,6,7,8,3'-pentamethoxy-4',5'-methilenedioxyflavone and coumarin were identified. However, only coumarin showed insecticide activity against three insect pests (LD50 from 2.72 to 39.71 mg g-1 a.i.). The increasing order of insects susceptibility to coumarin was R. dominica, S. zeamais and O. surinamensis.

Molecular and morphological characterization of heterorhabditid entomopathogenic nematodes from the tropical rainforest in Brazil

Despite massive losses of primary forest, the Amazonian rainforest remains an extremely rich source of biodiversity. In recent years, entomopathogenic nematodes (EPNs) have been isolated from soil in various parts of the world and used successfully as biological control agents against numerous insect pests. Therefore, a sampling in the rainforest of Monte Negro, Rondônia, Brazil was conducted with the aim of discovering new strains and/or species of EPNs for future development as biological control agents. From 156 soil samples taken at nine collecting sites, 19 isolates were obtained, all of them belonging to the genus Heterorhabditis. Four strains were subjected to detailed morphological and molecular evaluation. Based on morphometrics and internal transcribed spacer (ITS) sequence data, the strains LPP1, LPP2 and LPP4 were identified as Heterorhabditis indica, whereas LPP7 was considered Heterorhabditis baujardi. Comparative analysis of the ITS1 sequence of H. indica and H. baujardi isolates showed a polymorphic site for the restriction enzyme Tth 111 that could be used to distinguish the two species. Consequently, strains LPP1, LPP2, LPP3, LPP4, and LPP9 were identified as H. indica, whereas LPP5, LPP7, LPP8 and LPP10 were identified as H. baujardi.

Análise da riqueza da fauna de Braconidae (Hymenoptera, Ichneumonoidea) em remanescentes naturais da Área de Proteção Ambiental (APA) de Descalvado, SP

Analysis of the Braconidae (Hymenoptera: Ichneumonoidea) fauna richness in natural remnants of the Área de Proteção Ambiental (APA) of Descalvado, SP. A survey of the Braconidae fauna on fragmentary natural environments at northeast São Paulo State was conducted using Malaise traps installed in five sites of Área de Proteção Ambiental of Descalvado. A total of 2,262 specimens, representing 22 subfamilies and 94 genera, was sampled throughout a period of sixteen months (from May, 1999 to August, 2000). Biological data were obtained from current literature and behavior patterns of host utilization for the studied fauna, mainly Braconidae which have been successful in control of agricultural insect pests. Statistical analyses indicated that the asymptote of the genera richness has been approached using this sampling method. This is the most complete survey yet available from natural fragmentary areas of the Descalvado Braconidae fauna. Patterns of distribution and richness of the Braconidae genera were established. Cluster Analysis was adopted taking as attribute the number of Braconidae genera.

Feromônios associados aos coleópteros-praga de produtos armazenados

One strategy to overcome risks of insecticide-based control in agriculture is to use semiochemicals. In the case of pheromones, these specific compounds can be applied in traps to detect and monitor the occurrence, abundance and distribution of insect pests. Reliable detection helps to time insecticide sprays, to decide the quantity of insecticide that will be used and the place where it will be applied. This manuscript aims to give an overview of the pheromones associated to coleopteran pests in stored products, and their utilization in integrated pest management.

Feromônios de insetos: tecnologia e desafios para uma agricultura competitiva no Brasil

Pheromones are chemical compounds used by species to communicate intra and inter specifically. As strategy of integrated pest management (IPM), the use of these compounds allows the monitoring of target insects that results in more reliable interventions and consequently avoiding unnecessary use of pesticides. In certain crops these compounds are used as a control measure, not only monitoring. The Brazilian agriculture has a portfolio of 49 major crops that are attacked by 447 species of insects. Of this total, 103 species have already been the subject of study in the research with pheromones. Currently, in the Brazilian market, 28 pheromone products are indicated for the control of 19 insect pests. However, these products are not used regularly in major crops of the country. This stems from the lack of implementation of IPM of these crops. While the research focused on the main species of agribusiness pests, marked of pheromones products is serving to more marginal crops like apples and peaches at the expense of major crops like soybean and corn.

Life cycle of Misumenops pallida (Araneae, Thomisidae)

Postembryonic development of Misumenops pallida (Keyserling) (Araneae, Thomisidae), one of the most abundant predator species in soybean fields in Buenos Aires Province (Argentina) was studied. The life cycle was observed in the laboratory from egg sacs collected in the field, and from egg sacs spined in the laboratory by gravid females collected in the field. Results indicated that instar length and feeding rate increased throughout the life cycle being higher in females than in males. Greater mortality was observed to third and fourth instars decreasing thereafter. These results may contribute to deternmine the efficiency of this species as a natural enemy of insect pests of soybean.

Avaliação da infestação de insetos-praga associados à batata (Solanum tuberosum L.) sob efeito de nutrientes nitrogenados e potássicos e teores acumulados de aminoácidos livres nas cultivares Achat e Monalisa

Evaluation of insect-pest infestation associated to potato (Solanum tuberosum L.) under effect of nitrogen and potassium fertilizers and the accumulated amount of free aminoacids in Achat and Monalisa cultivars. The objective of this work was to evaluate the occurence of insect-pests on potato plants influenced by dosages of nitrogen and potassium accumulated in plant organs. A total of 169 plants of the Achat and Monalisa cultivars were evaluated to determine the presence-absence of Diabrotica speciosa Germar, 1824 and Agrotis ipsilon Hüfnagel, 1767. The experiment was carried out and executed at the Universidade Federal Fluminense, and the delineation was complete randomized block design, with four replication and nine treatments, using three fertilization level (0; 75 and 150 Kg/ha) with N-urea + KCl. The aminoacid levels were adjusted by the Leucine standard-curve (µg/l), using the Ninhydrin method, at 570 nm. The results showed that the tubercles of Monalisa accumulated high free aminoacid levels with 7,95% in the treatment N1K2 and 7,75% in the N2K1.These treatments, induced the infestation by D. speciosa larvae in 27,03%, when the aminoacid level was 2,01 ± 0,58% (X ± EP), with probability of 0,0196

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

Survey of ear flies (Diptera, Ulidiidae) in maize (Zea mays L.) and a new record of Euxesta mazorca Steyskalin Brazil. Species of Euxesta (Diptera, Ulidiidae), known as silk flies or ear flies, are becoming increasingly important as maize insect pests in South America, although very little is known about them in Brazil. The larvae of some species of this genus initially damage female reproductive tissues, and then the developing kernels on the ear. As a result of feeding, fermentation and associated odors cause complete loss of the grain because it is no longer fit for human or livestock consumption. The main objective of this work was to evaluate the incidence of Euxesta spp. in Brazilian maize fields and to determine the most prevalent species using two different hydrolyzed protein foods attractants, BioAnastrepha® (hydrolyzed maize protein) and Torula, placed inside McPhail traps. The two species identified were E. eluta Loew and E. mazorca Steyskal, the latter being a new record from Brazil. Between the two species, E. eluta was the more abundant in maize fields. Both attractants were efficient in capturing the two species. However, BioAnastrepha® captured significantly more insects than Torula.

Effect of gossypol on survival and reproduction of the zoophytophagous stinkbug Podisus nigrispinus (Dallas)

Effect of gossypol on survival and reproduction of the zoophytophagous stinkbug Podisus nigrispinus (Dallas). Gossypol is a sesquiterpene aldehyde found in cotton plants conferring resistance against herbivory. Although the effect of this sesquiterpenoid on insect pests of cotton is known, the interaction of this compound with zoophytophagous predators such as Podisus nigrispinus (Dallas) (Hemiptera, Pentatomidae) has not been studied so far. Thus, the objective of this study was to evaluate the effect of the purified gossypol on nymphs and adults of P. nigrispinus. Nymphs and adults of this predator were fed on Tenebrio molitor pupae and supplemented with solutions of gossypol at concentrations of 0.00, 0.05, 0.10, and 0.20% (w/v) during the nymphal and adult stages or, only during the adult stage of P. nigrispinus. The nymphal stage of the predator was, on average, two days longer when suplemmented with gossypol. Emerged adults had lower fecundity and egg hatching, especially at the highest gossypol concentration (0.20%) ingested during the nymphal and adult stages. However, this predator was not affected when it ingested the compound only during the adult stage. P. nigrispinus can have delayed nymphal development and lower reproductive performance when ingesting the gossypol during the nymphal and adult stages, but only at higher concentrations of gossypol than that produced by cotton plants.

Hypatropis inermis (Hemiptera, Pentatomidae): first record on rice crops

This study reports for the first time the occurrence of Hypatropis inermis on upland rice crops (variety Cambará), in Novo Progresso, state of Pará, Brazil (7°07'45.71"S 55°23'21.13"W). The inventory of insect pests was conducted between November 2010 and March 2011 with entomological sweep nets and visual search on stems of rice plants. This record indicates that rice crops may represent important feeding and mating sites for this species.

Thevetia peruviana (Family: Apocynaceae) in the control of slug and snail pests

An aqueous extract prepared from Kernels of the fruit of Thevetia peruviana (Pers.) Schumann (Family : Apocynaceae) was found under experimental conditions, to be toxic ti the slug Laevicaulis alte (Férussac) and the snail Achatina fulica Bowdich, the important agrihorticultural pests of Indo-Pacific countries. Concentrations as low as 1% (w/v) killed all the slugs exposed in less than 981.00 (± SD 22.76) min, and 2% of the extract killed 100% of the slugs L. alte and 50%, 50% and 30% of the snail A. fulica in between 92.34 (± SD 6.63) - 321.33 (± SD 4.14) and 271.20 (± SD 17.54) - 298.26 (± SD 16.69) min respectively. The most effective concentration of the extract was 20%; it killed 100% of exposed slugs and snails within a short time (40-50 and 90-1440 min respectively) when the extract was exposed on the soil in experimental trays or when it was applied to potato slices offered as food to the gastropods.

Transmission blocking vaccines to control insect-borne diseases: a review

Insect-borne diseases are responsible for severe mortality and morbidity worldwide. As control of insect vector populations relies primarily on the use of insecticides, the emergence of insecticide resistance as well to unintended consequences of insecticide use pose significant challenges to their continued application. Novel approaches to reduce pathogen transmission by disease vectors are been attempted, including transmission-blocking vaccines (TBVs) thought to be a feasible strategy to reduce pathogen burden in endemic areas. TBVs aim at preventing the transmission of pathogens from infected to uninfected vertebrate host by targeting molecule(s) expressed on the surface of pathogens during their developmental phase within the insect vector or by targeting molecules expressed by the vectors. For pathogen-based molecules, the majority of the TBV candidates selected as well as most of the data available regarding the effectiveness of this approach come from studies using malaria parasites. However, TBV candidates also have been identified from midgut tissues of mosquitoes and sand flies. In spite of the successes achieved in the potential application of TBVs against insect-borne diseases, many significant barriers remain. In this review, many of the TBV strategies against insect-borne pathogens and their respective ramification with regards to the immune response of the vertebrate host are discussed.