Hymenopteran parasitoids are important biological control agents in agroecosystems, and their diversity can be increased with habitat heterogeneity. Thus, the purpose of the study is to evaluate the influence of distance of rice-growing areas from natural fragment, type of crop management (organic and conventional) and crop stages (vegetative and reproductive stages) on parasitoids family diversity. The work took place in two irrigated rice crops, one with organic management (O.M.) and another one with conventional management (C.M.), in the municipality of Nova Santa Rita, RS, Brazil, during the 2013/2014 and 2014/2015 seasons. The parasitoids were collected with Malaise trap arranged at different distances in relation to the native vegetation surrounding the rice crop in both places. Specimens were collected twice a month from seeding until the rice harvest. Average abundance between management, distances and rice development were compared. The most abundant families were Platygastridae, Mymaridae, Encyrtidae, Eulophidae and Trichogrammatidae. Parasitoid average abundance was significantly higher on OM only in the second season. There was a negative correlation between distance from native vegetation and parasitoid abundance in C.M. areas. There were differences in the composition of the parasitoid assembly between the phenological stages of rice.

Soybean production is usually performed on large scales, requiring simple but efficient pest management to be successful. Soybean fields are inhabited by several species of arthropods, demanding constant development of management practices to prevent pest outbreaks. More recently, stink bugs have become the most important pest group of soybeans in the Neotropics, responsible for up to 60% of the applied insecticides in Brazil. Natural enemies represent an important mortality factor that can keep the damage caused by stink bugs below the economic threshold levels without additional control actions. Thus, Conservation Biological Control (CBC) strategies can be adopted to preserve or even promote the increase in such natural enemies in the fields, or alternatively, massive releases of biocontrol agents in Augmentative Biological Control (ABC) programs could be adopted. Simple practices such as reducing insecticide use (with the adoption of economic thresholds), prioritizing harmless insecticides or biopesticides, and planting resistant soybean cultivars have been adopted in Brazil with positive results. The challenges to increasing the adoption of more complex stink bug management in commodity crops such as soybean may be overcome using the more recent economic incentives in the global agenda of decarbonized agriculture. The potential and challenges of conservation and augmentative biological control are further discussed in this review.

Simplified environments characterize agroecosystems, reducing the diversity of associated plants, which are not cultivated for economic purposes, causing unbalances that can promote the emergence of cultivated plants pests, as well as the reduction of their natural enemies. Management systems that increase diversity in agroecosystems can extend the action of natural enemies of pests. Studies to understand the diversity of insects associated with rice cultivation and determine their ecological guilds can provide information about the composition and structure of such ecosystems, which can be applied to integrated pest management. Therefore, the study aimed to describe and compare groups of insects in irrigated rice fields, with organic management using two different systems of levees vegetation management, and relate them to the phenological states of rice cultivation (seedling, vegetative, and reproductive). Samples were taken in a plantation located in Águas Claras district of Viamão, RS. The total area of 18 ha was divided into two. A subarea called not cut (NC), where wild vegetation of levees was maintained, and the subarea named cut (C), where monthly cuts were made to levees vegetation, from the beginning of soil preparation until the harvest. From October 2012 to March 2013 were held weekly collections in quadrats randomly located in both the rice fields and the levees. A total of 800 insects were collected, 429 in the C subarea and 371 in the NC. There were identified 97 morphospecies in the C and 108 in NC, being 54 shared between the subareas. The captured insects were grouped into guilds: saprophages (C = 38.2%; NC = 27.5%), phytophagous (C = 28.5%; NC = 33.2%), entomophagous (grouping parasitoids and predators) (C = 29.4%; NC = 35%) and finally other insects (C = 4 %; NC = 4.3%). The peak abundance of phytophagous and entomophagous was registered in the vegetative stage of rice. At the same stage the UPGMA analysis showed that similarity in species composition was greater than 90% in the groups obtained in the paddy fields of C and NC subareas. The vegetation of levees can positively influence the presence of entomophagous in the field. Although the abundance did not change clearly, the greatest diversity in the NC areas of all the groups, may contribute to the maintenance of ecological services expanding the system resilience.

Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) was introduced in 1994, in Northeastern Brazil, to evaluate its use in biological control programs of fruit flies. However, the effects of this specie on parasitism rates on the population of native parasitoids and fruit flies in Southern Brazil conditions are unknown. The objective of this study was to evaluate the impact of releases of D. longicaudata on the parasitism rates on loquats, peach trees, strawberry guava trees, and persimmons in an experimental area in the city of Eldorado do Sul, Rio Grande do Sul, in southern Brazil. In the first year of the study, fruits were collected and stored in the laboratory to obtain pupae. The flies or parasitoids that emerged were counted and identified. In the second year, adults of D. longicaudata were reared in the laboratory on Anastrepha fraterculus (Wied.) and larvae were released in the field (1.700 insects/ha) at each harvest time and the parasitism was evaluated in the same manner as in the first year. In the third year, the procedure was the same as the first year, without any releases. A significant increase in the rates of parasitism was recorded in the second year except in the persimmon, in which no parasitoid was recovered in any year. In the second year the number of emerged fruit flies was also lower. In the third year, no D. longicaudata were recorded and parasitism rates of parasitism were statistically similar to those found in the first year. The native parasitoids collected were Aganaspis pelleranoi (Brèthes), Doryctobracon areolatus (Szépligeti), Doryctobracon brasiliensis (Szépligeti) and Utetes anastrephae (Viereck). These species were found in at least one kind of fruit even in the years after the introduction of the exotic parasitoid, indicating that it was not harmful to these species. We conclude that D. longicaudata can help to reduce the population of fruit flies in Eldorado do Sul region, in Rio Grande do Sul.

O parasitoide de ovos Telenomus podisi Ashmead, 1893 é um importante agente de controle natural de percevejos e seu sucesso de parasitismo está associado à habilidade para a localização do hospedeiro, sendo a aprendizagem e a memória um dos fatores que podem influenciar esta interação. O trabalho avaliou a capacidade de aprendizagem e tempo de retenção da memória de T. podisi ao extrato de capim-limão [Cymbopogon citratus (DC.) Stapf. (Poales, Poaceae)], em diferentes estágios do desenvolvimento da fase imatura. Ovos de Euschistus heros (Fabricius, 1798) (Hemiptera, Pentatomidae) parasitados por T. podisi foram individualizados em tubos de vidro contendo papel filtro com extrato de capim-limão ou solvente acetona (controle) e mantidos em diferentes estágios do desenvolvimento jovem dos parasitoides. Após a emergência, fêmeas de T. podisi foram testadas em olfatômetro tipo "Y" aos odores de ambos tratamentos. Fêmeas inexperientes foram submetidas aos mesmos odores das experientes. Para avaliar a memória, fêmeas oriundas de ovos que permaneceram em contato com o extrato de capim-limão por todo o desenvolvimento do estágio imaturo, foram testadas, após 24, 48, 72 e 96 horas de idade ao odor de capim-limão e acetona. Fêmeas que permaneceram em contato com o capim-limão por toda a fase jovem, direcionaram-se preferencialmente para este extrato, diferente das inexperientes ou das expostas à acetona, as quais preferiram o solvente. A presença do capim-limão, durante todo o estágio do desenvolvimento imaturo, alterou a orientação quimiotáxica de T. podisi, desencadeando aprendizagem nestes organismos, a qual se manteve por até 72 horas.