Diversity of Braconidae (Insecta, Hymenoptera) of the Parque Natural Municipal de Porto Velho, Rondonia, Brazil

Braconidae is a highly diversified family of Hymenoptera and usually known by their role in biological control both in agricultural and natural ecosystems. Despite of that, little is known about its diversity in the Amazon region. The present work inventoried the braconid fauna of an Open Ombrophylous Forest with Palm Trees of the Parque Natural Municipal de Porto Velho, RO. Insects were collect from June/2008 to May/2009 using six Malaise traps in different parts of the reserve. A total of 377 wasps were captured, 17 subfamilies and 56 genera identified. Braconinae, Microgastrinae, Doryctinae and Rogadinae subfamilies were very abundant, and also the genera Aleiodes, Bracon, Capitonius, Compsobracon, Heterospilus, Hymenochaonia, Opius, Pedinotus, Rogas and Stantonia. The calculated Shannon diversity index was 2.15 and 3.3 for subfamily and genera, respectively, which were, generally, higher than the values found for other regions in Brazil. Generally, parasitoids were more abundant during the rainy season. The present work contributes with new genera records and faunistic data of Braconidae in Rondonia State, western Amazon.

Phenology of Spalangia endius Walker (Hymenoptera, Pteromalidae) in pupae of Musca domestica Linnaeus (Diptera, Muscidae) under laboratory conditions

This work describes the phenology of Spalangia endius Walker in pupae of Musca domestica Linnaeus under laboratory conditions. In order to understand the developmental cycle of Spalangia endius under laboratory conditions, 360 Musca domestica pupae aged from 24 to 48 hours were exposed to 15 S. endius pairs for a period of 24 hours at 26 ± 2ºC. These pupae were kept in a BOD incubator at the same temperature, with a relative humidity of <70%, and 12 hours photophase. Fifteen hymenopteran specimens were dissected daily to evaluate their stage and development time. The phenology concluded that S. endius had a development cycle of 19 days with an incubation period of 24 hours. The development of the larvae of S. endius occurred in the subsequent eight days, during which a series of morphological alterations were observed. The pre-pupal stage occurred on the tenth day, where the movement ceased and elimination of the meconium started. The pupal stage occurred from the 11th to the 19th day, with emergence of males first, followed by female emergence approximately 24 hours later. These results allowed the evaluation of aspects of the detailed bionomics of the development of S. endius in order to record and program production of this parasitoid, thus optimizing its utilization as a biological control agent.

Egg parasitoids of Edessa meditabunda (Fabricius) (Pentatomidae) in lettuce crop

Egg parasitoids of Edessa meditabunda (Fabricius) (Pentatomidae) in lettuce crop. This study evaluated the occurrence of parasitoids in eggs of the stink bug, Edessa meditabunda (Fabricius, 1794) (Heteroptera, Pentatomidae) found on lettuce crop in Mato Grosso State, Brazil. Samples were collected in the vegetable garden "Cheiro Verde", in the municipality of Tangará da Serra, in curly lettuce. A bed of lettuce was selected randomly, where the eggs of E. meditabunda were collected. Five-hundred and seventy eight eggs of E. meditabunda were collected, 86.3% of them parasitized by Telenomus podisi Ashmead, 1893 (Hymenoptera, Platygastridae), Trissolcus urichi Crawford, 1913 (Hymenoptera, Platygastridae) and Neorileya albipes Girault, 1913 (Hymenoptera, Eurytomidae), representing respectively 57.0%, 38.2% and 4.8% of the emerged individuals. This is the first record of these three species parasitizing eggs of E. meditabunda in lettuce.

Distinct genetic structure in populations of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) shown by genetic markers ISSR and COI gene

Distinct genetic structure in populations of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) shown by genetic markers ISSR and COI gene. Green lacewings are generalist predators, and the species Chrysoperla externa presents a great potential for use in biological control of agricultural pests due to its high predation and reproduction capacities, as well as its easy mass rearing in the laboratory. The adaptive success of a species is related to genetic variability, so that population genetic studies are extremely important in order to maximize success of the biological control. Thus, the present study used nuclear (Inter Simple Sequence Repeat - ISSR) and mitochondrial (Cytochrome Oxidase I - COI) molecular markers to estimate the genetic variability of 12 populations in the São Paulo State, Brazil, as well as the genetic relationships between populations. High levels of genetic diversity were observed for both markers, and the highest values of genetic diversity appear associated with municipalities that have the greatest areas of native vegetation. There was high haplotype sharing, and there was no correlation between the markers and the geographic distribution of the populations. The AMOVA indicated absence of genetic structure for the COI gene, suggesting that the sampled areas formed a single population unit. However, the great genetic differentiation among populations showed by ISSR demonstrates that these have been under differentiation after their expansion or may also reflect distinct dispersal behavior between males and females.

Thermal hygrometric requirements for the rearing and release of Tamarixia radiata (Waterston) (Hymenoptera, Eulophidae)

Thermal hygrometric requirements for the rearing and release of Tamarixia radiata (Waterston) (Hymenoptera, Eulophidae). Tamarixia radiata is the main agent for the biological control of Diaphorina citri in Brazil with a parasitism rate ranging from 20 to 80%. This study investigated the influence of temperature on the development, fecundity and longevity of adults of T. radiata and the effect of relative humidity (RH) on their parasitism capacity and survival rate in the pre-imaginal period. The effect of temperature was assessed in the range between 15 and 35 ± 1ºC, 70 ± 10% RH, and a 14-h photophase. The RH effect was evaluated in the range from 30 to 90 ± 10%, temperature at 25 ± 1ºC, and photophase of 14-h. At 25ºC, circa 166.7 nymphs were parasitized, the highest parasitism capacity observed compared to other treatments. The longest longevity of females was observed at 25ºC, although the rate did not differ in the 20-30ºC temperature range. The threshold temperature (TT) was 7.2ºC, and 188.7 degrees-day were required for the development (egg-to-adult period). The parasitism rate and longevity were higher at 50 and 70% of RH. This shows that temperature and RH may affect the parasitism capacity of T. radiata on nymphs of D. citri, which can explain the great parasitism variation for D. citri observed in citrus groves in São Paulo State, Brazil.

Isolation of Bacillus thuringiensis from the state of Amazonas, in Brazil, and screening against Aedes aegypti (Diptera, Culicidae)

We investigated the use of Bacillus thuringiensis isolated in the state of Amazonas, in Brazil, for the biological control of the dengue vector Aedes aegypti. From 25 soil samples collected in nine municipalities, 484 bacterial colonies were obtained, 57 (11.78%) of which were identified as B. thuringiensis. Six isolates, IBt-03, IBt-06, IBt-07, IBt-28, IBt-30, and BtAM-27 showed insecticidal activity, and only BtAM-27 presents the five genes investigated cry4Aa, cry4Ba, cry10Aa, cry11Aa, and cry11Ba. The IBt-07 and IBt- 28, with lower LC50 values, showed equal toxicity compared to the standards. The isolates of B. thuringiensisfrom Amazonas constitute potential new means of biological control for A. aegypti, because of their larvicidal activity and the possibility that they may also contain new combinations of toxins.

Efficiency of the induced mating technique for Toxorhynchites theobaldi (Diptera, Culicidae)

Toxorhynchites mosquitoes play important ecological roles in aquatic microenvironments, and are frequently investigated as potential biological control agents of mosquito disease vectors. Establishment of Toxorhynchites laboratory colonies can be challenging because for some species, mating and insemination either do not occur or require a prohibitive amount of laboratory space for success. Consequently, artificial insemination techniques have been developed to assist with mass rearing of these species. Herein we describe an adapted protocol for colony establishment of T. theobaldi, a species with broad distribution in the Neotropics. The success of the technique and its implications are discussed.

Effect of Bacillus sphaericus Neide on Anopheles (Diptera: Culicidae) and associated insect fauna in fish ponds in the Amazon

ABSTRACTWe analyzed the effects of Bacillus sphaericus on Anopheles larvae and on the associated insect fauna in fish farming ponds. Five breeding sites in the peri-urban area of the city of Manaus, AM, Brazil, were studied. Seven samples were collected from each breeding site and B. sphaericus was applied and reapplied after 15 days. The samples were made at 24 h before application, 24 h post-application and 5 and 15 days post-application. We determined abundance, larval reduction and larval density for Anopheles, and abundance, richness, Shannon diversity index and classified according to the functional trophic groups for associated insect fauna. A total of 904 Anopheles larvae were collected and distributed into five species. Density data and larval reduction demonstrated the rapid effect of the biolarvicide 24 h after application. A total of 4874 associated aquatic insects belonging to six orders and 23 families were collected. Regression analysis of diversity and richness indicated that the application of the biolarvicide had no influence on these indices and thus no effect on the associated insect fauna for a period of 30 days. B. sphaericus was found to be highly effective against the larvae of Anopheles, eliminating the larvae in the first days after application, with no effect on the associated insect fauna present in the fish ponds analyzed.

New vineyard cultivation practices create patchy ground vegetation, favouring Woodlarks

Intensive agriculture, in which detrimental farming practices lessen food abundance and/or reduce food accessibility for many animal species, has led to a widespread collapse of farmland biodiversity. Vineyards in central and southern Europe are intensively cultivated; though they may still harbour several rare plant and animal species, they remain little studied. Over the past decades, there has been a considerable reduction in the application of insecticides in wine production, with a progressive shift to biological control (integrated production) and, to a lesser extent, organic production. Spraying of herbicides has also diminished, which has led to more vegetation cover on the ground, although most vineyards remain bare, especially in southern Europe. The effects of these potentially positive environmental trends upon biodiversity remain mostly unknown as regards vertebrates. The Woodlark (Lullula arborea) is an endangered, short-distance migratory bird that forages and breeds on the ground. In southern Switzerland (Valais), it occurs mostly in vineyards. We used radiotracking and mixed effects logistic regression models to assess Woodlark response to modern vineyard farming practices, study factors driving foraging micro-habitat selection, and determine optimal habitat profile to inform management. The presence of ground vegetation cover was the main factor dictating the selection of foraging locations, with an optimum around 55% at the foraging patch scale. These conditions are met in integrated production vineyards, but only when grass is tolerated on part of the ground surface, which is the case on ca. 5% of the total Valais vineyard area. In contrast, conventionally managed vineyards covering a parts per thousand yen95% of the vineyard area are too bare because of systematic application of herbicides all over the ground, whilst the rare organic vineyards usually have a too-dense sward. The optimal mosaic with ca. 50% ground vegetation cover is currently achieved in integrated production vineyards where herbicide is applied every second row. In organic production, ca. 50% ground vegetation cover should be promoted, which requires regular mechanical removal of ground vegetation. These measures are likely to benefit general biodiversity in vineyards.

Discovery and molecular characterization of an ambisense densovirus from South American populations of Solenopsis invicta

In an effort to discover viruses as classical biological control agents, a metatranscriptomics/pyrosequencing approach was used to survey native Solenopsis invicta collected exclusively in Argentina. A new virus was discovered with characteristics consistent with the family Parvoviridae, subfamily Densovirinae. The virus, tentatively named Solenopsis invicta densovirus (SiDNV), represents the first DNA virus discovered in ants (Formicidae) and the first densovirus in a hymenopteran insect. The ambisense genome was 5280 nucleotides in length and the termini possessed asymmetrically positioned inverted terminal repeats, formed hairpin loops, and had transcriptional regulatory elements including CAAT and TATA sites. Phylogenetic analysis revealed that SiDNV belongs to a group that includes two other densoviruses found in insects (Acheta domestica densovirus and Planococcus citri densovirus). SiDNV was prevalent in fire ants from Argentina but completely absent in fire ants found in the USA indicating that this virus has potential for biological control of introduced S. invicta.

Ursinia nana (Anthemideae, Asteraceae), and adventive from South Africa which is becoming naturalized in the Iberian Peninsula. Observations about its reproductive biology and fruit dispersal mechanism.

The presence of Ursinia nana, an Anthemideae of South-African origin which has been introduced into the NE Iberian Peninsula, is reported for the fi rst time in Europe. The data offered cover its precise location, morphology, chromosome number, ecology and a population census, as well as its life cycle, fl oral structure, reproductive biology and fruit dispersal mechanisms. Of special note are the clear predominance of autogamy (geitonogamy) over xenogamy as a reproductive system and the large number of fruits produced with high and immediate germinative capacity. These characteristics permit rapid colonization by the introduced species, which can become invasive. However, fruit predation by the ant Messor barbarus points to a natural mechanism that helps regulate population growth and makes biological control possible. Finally its possibilities of expansion in the colonized area and of naturalization in the NE Iberian Peninsula are assessed.

Fusarium oxysporum strains as biocontrol agents against Fusarium wilt: effects on soil microbial biomass and activity

Before planning the large-scale use of nonpathogenic strains of Fusarium oxysporum as biocontrol agents of Fusarium wilt, their behaviour and potential impact on soil ecosystems should be carefully studied as part of risk assessment. The aim of this work was to evaluate the effects of antagonistic F. oxysporum strains, genetically manipulated (T26/6) or not (233/1), on soil microbial biomass and activity. The effects were evaluated, in North-western Italy, in two soils from different sites at Albenga, one natural and the other previously solarized, and in a third soil obtained from a 10-year-old poplar stand (Popolus sp.), near Carignano. There were no detectable effects on ATP, fluorescein diacetate hydrolysis, and biomass P that could be attributed to the introduction of the antagonists. A transient increase of carbon dioxide evolution and biomass C was observed in response to the added inoculum. Although the results showed only some transient alterations, further studies are required to evaluate effects on specific microorganism populations.

Effect of two dosages of Metarhizium anisopliae var. acridum against Rhammatocerus schistocercoides Rehn

The fungus Metarhizium anisopliae var. acridum, strain CG 423, was tested under field conditions against the gregarious grasshopper Rhammatocerus schistocercoides (Rehn) (Orthoptera: Acrididae). Conidia formulated in a racemic mixture of soybean oil and kerosene were sprayed under field conditions using an ultralow-volume hand-held atomizer Ulva Plus adjusted to deliver 2.9 L/ha. Bands composed of 2nd instar nymphs were treated with either 5.0x10(12) or 1.0x10(13) viable conidia/ha. The number of insects in each band was estimated at day one following spraying and by the end of the field trial (15 to 16 days post-treatment). Reductions in population size reached, in average, 65.8% and 80.4% for bands treated with the higher and lower dosage, respectively. For both dosages, total mortality rates of insects collected at two days post-application, and kept in cages for 14 days under lab conditions, showed no significant differences as compared to that obtained with insects collected immediately after spraying. Healthy insects were fed to native grasses sprayed on the field with 1.0x10(13) viable conidia/ha. Mortality levels of the nymphs fed on grasses collected two and four days post-application were not affected when compared to nymphs fed on grasses collected immediately following application.

Full-genome sequence of the plant growth-promoting bacterium Pseudomonas protegens CHA0.

We report the complete genome sequence of the free-living bacterium Pseudomonas protegens (formerly Pseudomonas fluorescens) CHA0, a model organism used in plant-microbe interactions, biological control of phytopathogens, and bacterial genetics.

Fertility life table of Trichogramma pretiosum and Trichogramma acacioi on eggs of Anagasta kuehniella at different temperatures

Species of the Trichogramma genus are among the most important ones for biological control. The objective of this research was to evaluate parasitism potential of two species of Trichogramma on eggs of Anagasta kuheniella through life fertility table, at temperatures between 15ºC and 35ºC. These species were collected in the State of Espírito Santo parasitising eggs of the avocado defoliator Nipteria panacea. Trichogramma pretiosum and T. acacioi showed adequate reproductive potential between 15ºC and 35ºC which indicates possibilities of using them in biological control programs in avocado plantations.