Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.
Earlier this year, the first global thematic assessment from the Intergovernmental Sci-ence-Policy Platform on Biodiversity and Ecosystem Services (IPBES) evaluated the state of knowledge about pollinators and pollination (1,2). It confirmed evidence of large-scale wild pollinator declines in North West Europe and North America, and iden-tified data shortfalls and an urgent need for monitoring elsewhere in the world. With high level political commitments to support pollinators in the US (3), the UK (4) and France (5), encouragement from the Convention on Biological Diversity’s (CBD) scientific advice body (6), and the issue on the agenda for next month’s Conference of the Parties of the CBD, we see a chance for global-scale policy change. We extend beyond the IPBES report, which we helped to write, and suggest 10 policies that governments should seriously consider, to protect pollinators and secure pollination services. Our suggestions are not the only available responses, but those we consider most likely to succeed, due to synergy with international policy objectives and strategies, or formulation of international policy creating opportunity for change. We make these suggestions as independent scientists, not on behalf of IPBES
Resumo -Nas últimas décadas, o declínio de populações de abelhas silvestres e o colapso de colônias de Apis mellifera têm preocupado pesquisadores e apicultores. O objetivo deste artigo de revisão foi compilar alguns dos estudos mais relevantes relacionados às possíveis causas desses problemas -como nutrição, manejo, patógenos, parasitas e efeitos de agrotóxicos -, além de apresentar um breve histórico da síndrome "colony collapse disorder" (CCD) nos Estados Unidos e na Europa. Abordaram-se com mais detalhes os estudos desenvolvidos no Brasil, principalmente sobre agrotóxicos utilizados na agricultura e patógenos e parasitas que acometem as colônias de A. mellifera africanizada. Casos de enfraquecimento, declínio e colapso têm sido registrados, principalmente nos estados de São Paulo e Santa Catarina, que somam grandes perdas. Resultados das ocorrências analisadas indicaram que as mortalidades em massa registradas no Brasil não estavam associadas a patógenos ou a parasitas. Somente dois casos com características semelhantes às descritas para CCD foram registrados, porém sem causas definidas. Para que se conheçam as causas de enfraquecimentos e perdas de colônias de abelhas, é urgente a implementação de programas oficiais de levantamento sistemático da sanidade apícola, associados a pesquisas com foco nas avaliações dos possíveis impactos da fragmentação de habitats e das práticas agrícolas sobre as comunidades de abelhas.Termos para indexação: Apis mellifera, abelha africanizada, distúrbio do colapso das colônias, nutrição de abelhas, patologia apícola, polinização. Weakness and collapse of bee colonies in Brazil: are there cases of CCD?Abstract -In the last decades, the decline of wild bee populations and the collapse of Apis mellifera colonies have concerned researchers and beekeepers. The objective of this review was to compile some of the most relevant studies related to the possible causes of these problems -such as nutrition, management, pathogens, parasites, and the effects of pesticides -, besides presenting a brief history of the colony collapse disorder syndrome (CCD) in the United States and Europe. The studies developed in Brazil were presented in more detail, mainly those on pesticides used in agriculture and on pathogens and parasites that attack the colonies of Africanized A. mellifera. Cases of weakening, decline, and collapse have been recorded in Brazil, mainly in the states of São Paulo and Santa Catarina, which add up to great losses. Results of the analyzed occurrences indicated that the recorded mass mortalities were not associated with pathogens or parasites. Only two cases with characteristics similar to those described for CCD were recorded, but without defined causes. In order to know the causes of the weakening and collapses of colonies, the implementation of official programs is urgent for the systematic survey of bee health, associated with research focusing on assessments of possible impacts of habitat fragmentation and agricultural practices on bee communities.
-The objective of this research was to evaluate the parasitism behavior of Telenomus podisi Ashmead, Trissolcus basalis (Wollaston) e Trissolcus urichi Crawford (Hymenoptera: Scelionidae) on eggs of Nezara viridula L., Euschistus heros F., Piezodorus guildinii Westwood and Acrosternum aseadum Rolston (Heteroptera: Pentatomidae), in no choice and multiple choice experiments. For all parasitoid species, the results demonstrated the existence of a main host species that maximizes the reproductive success. The competitive interactions among the parasitoid species were investigated in experiments of sequential and simultaneous release of different combinations of parasitoid pairs on the hosts N. viridula, E. heros and A. aseadum. Exploitative competition was observed for egg batches at the genus level (Telenomus vs. Trissolcus) and interference competition at the species level (T. basalis vs. T. urichi). Trissolcus urichi was the most aggressive species, interfering with the parasitism of T. basalis. Generally, T. basalis showed an opportunistic behavior trying to parasitise eggs after T. urichi had abandoned the egg batch. The selection of parasitoid species for use in augmentative biological control programs should take into account the diversity of pentatomids present in soybean in addition to the interactions among the different species of parasitoids.Index terms: parasitism, host-parasite relations, biological competition, pest control methods. Termos para indexação: parasitismo, relação parasita-hospedeiro, competição biológica, métodos de combate às pragas. Interações inter-guilda e intra-guilda entre espécies de parasitóides de ovos que atacam o complexo de percevejos da soja
Olfactometer bioassays showed that odors from mature Thyanta perditor males attracted females but not males. Furthermore, odors from females did not attract either sex, indicating that like other phytophagous pentatomid bugs, the males produce a sex pheromone. Attraction appeared to peak in late afternoon to evening. The headspace volatiles collected from male and female T. perditor were analyzed by GC-MS and HPLC. A male-specific compound, methyl (2E,4Z,6Z)-decatrienoate (2E,4Z,6Z-10:COOMe), was identified along with a number of other compounds found in extracts from both sexes. Bioassays carried out with 2E,4Z,6Z-10:COOMe showed it was as attractive to females as the crude extract of male volatiles, suggesting that the male-produced sex pheromone consists of 2E,4Z,6Z-10:COOMe as a single component. Consecutive volatiles collections from males showed that 2E,4Z,6Z-10:COOMe began appearing in extracts from males about 9 d after the final molt, as the males became sexually mature.
The effectiveness of the synthetic sex pheromone of the Neotropical brown stink bug, Euschistus heros, was evaluated both in laboratory and in field assays. Lures loaded with 1 mg of methyl 2,6,10‐trimethyltridecanoate (TMTD) continuously attracted female bugs for more than 30 days to pheromone‐baited traps in field trials. The pheromone‐baited traps were effective in field tests even at low bug population densities, as compared with the usual monitoring technique, shake cloth sampling. Traps around borders or in the centre of soybean fields caught similar numbers of bugs. Trap captures showed a positive relationship with field populations, as monitored with the shake cloth technique, during the reproductive phase of the soybean crop, i.e. from the R1–R5 developmental stage (pod formation to pod fill). The physiological state of the trapped migrating insects was determined. The first insects arriving in the field had fewer eggs in the reproductive tract compared to later arrivals. Some cross‐attraction was also observed, with Piezodorus guildinii and Edessa meditabunda also being caught in pheromone‐baited traps, suggesting that these insects respond to the sex pheromone or to the defensive compounds released by E. heros captured in traps. In brief, the results showed that traps baited with 1 mg of the sex pheromone efficiently caught bugs, that the lures lasted for more than 1 month under field conditions and that placement of traps around the borders of the crop area was as effective as placement inside the crop area. Border‐placed traps were effective at a density of one trap every 200 m.
-The boll weevil causes serious damage to the cotton crop in South America. Several studies have been published on this pest, but its phenology and behavior under the tropical conditions prevailing in Brazil are not well-known. In this study the feeding behavior and main food sources of adult boll weevils throughout the year in Central Brazil was investigated. The digestive tract contents of insects captured in pheromone traps in two cotton fields and two areas of native vegetation (gallery forest and cerrado sensu stricto) were analyzed. The insect was captured all through the year only in the cerrado. It fed on pollen of 19 different plant families, on Pteridophyta and fungi spores and algae cysts. Simpson Index test showed that the cerrado provided greater diversity of pollen sources. In the beginning of the cotton cycle, the plant families used for pollen feeding were varied: in cotton area 1, the weevil fed on Poaceae (50%), Malvaceae and Smilacaceae (25% each); in cotton area 2 the pollen sources were Malvaceae (50%), Asteraceae (25%) and Fabaceae and Clusiaceae (25% each); in the cerrado they were Chenopodiaceae (67%) and Scheuchzeriaceae (33%). No weevils were collected in the gallery forest in this period. After cotton was harvested, the family Smilacaceae was predominant among the food plants exploited in all the study areas. These results help to explain the survivorship of adult boll weevil during cotton fallow season in Central Brazil and they are discussed in the context of behavioral adaptations to the prevailing tropical environmental conditions.
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