Aphidius colemani (Viereck) was reported in Brazil before the Biological Control Program of Wheat Aphids (BCPWA) when Mediterranean genotypes were introduced from France and Israel. This species was re-described as a complex called A. colemani group composed of three species. Consequently, uncertainty remains about which parasitoid of the group is occurring in southern Brazil. This study has two main objectives: (i) re-examine the species status of A. colemani group collected during the introduction of parasitoids and from a 10-year (2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018) monitoring program in wheat fields in northern Rio Grande do Sul (RS), Brazil; (ii) describe the variation in the population density of parasitoids and its association with meteorological factors during this period. We examined 116 specimens from the Embrapa Wheat entomological collection, and those collected in Moericke traps in Coxilha, RS. All the parasitoids of the A. colemani group from the BCPWA period were identified as Aphidius platensis (Brèthes). In traps, 6541 cereal aphid parasitoids were collected, of which 61.9% (n = 4047) were from A. colemani group and all those were identified as A. platensis. Temperature was the factor that effected population density with the highest number of parasitoids recorded in the winter months. Sex ratio changed between years varying from 0.50 to 0.97. The parasitoid A. platensis was the only species in the A. colemani group sampled during 10 years of monitoring.

In different parts of the world, aphid populations and their natural enemies are influenced by landscapes and climate. In the Neotropical region, few long-term studies have been conducted, maintaining a gap for comprehension of the effect of meteorological variables on aphid population patterns and their parasitoids in field conditions. This study describes the general patterns of oscillation in cereal winged aphids and their parasitoids, selecting meteorological variables and evaluating their effects on these insects. Aphids exhibit two annual peaks, one in summer–fall transition and the other in winter-spring transition. For parasitoids, the highest annual peak takes place during winter and a second peak occurs in winter–spring transition. Temperature was the principal meteorological regulator of population fluctuation in winged aphids and parasitoids during the year. The favorable temperature range is not the same for aphids and parasitoids. For aphids, temperature increase resulted in population growth, with maximum positive effect at 25°C. Temperature also positively influenced parasitoid populations, but the growth was asymptotic around 20°C. Although rainfall showed no regulatory function on aphid seasonality, it influenced the final number of insects over the year. The response of aphids and parasitoids to temperature has implications for trophic compatibility and regulation of their populations. Such functions should be taken into account in predictive models.

Phaenoglyphis villosa (Hartig, 1841) (Hymenoptera: Figitidae: Charipinae) is a secondary endoparasitoid of Aphidiinae (Hymenoptera: Braconidae), a subfamily which are important primary parasitoids of aphids (Hemiptera: Aphididae). It is here registered for the first time in Brazil, collected from primary parasitoids in field-exposed aphids. Phaenoglyphis villosa was recorded during wheat crop season (winter and spring), emerging from Rhopalosiphum padi (Linnaeus, 1758) mummies (n = 35♀). It was also recorded from Sitobion avenae (Fabricius, 1775) mummies, in wheat crop season (late winter) (n = 13♀) and black oat crop season (late autumn) (n = 1♀). We suggest three possible primary braconid parasitoids as hosts to this hyperparasitoid: Aphidius platensis Brèthes, 1913, Aphidius rhopalosiphi de Stefani-Perez, 1902, and Aphidius uzbekistanicus Luzhetzki, 1960.

A tri-trophic network of domesticated grasses (host), various aphids (vector) and barley yellow dwarf virus (pathogen) species has been spread by humans from Eurasia to the rest of the world. Understanding how climate, natural and agricultural landscapes challenge pathogens, vectors, and their natural enemies and shape their dynamics is the key to managing this pathosystem. This chapter provides an overview of this complex system and its evolution. The chapter includes a case study of biological control of aphids causing wheat BYDV in Brazil. The current challenge is to create tools that integrate knowledge of this complex pathosystem and facilitate monitoring and decision making for rational management to reduce the burden of disease.

A mudança dos métodos de ensino presencial para o ensino remoto desde o início da pandemia de Covid-19 exigiu, no campo da educação, a adaptação repentina da comunidade acadêmica à garantia da continuidade do Ensino Superior. A entomologia é a ciência que estuda os insetos, sendo um componente majoritariamente prático. Logo, as disciplinas que englobam esta ciência, normalmente, exigem a montagem e entrega de uma coleção de insetos pelos alunos, e os conteúdos curriculares contemplam aulas práticas de laboratório em que se analisam espécimes com auxílio de microscópios, lupas e chaves dicotômicas. Diante do cenário imposto pela pandemia, as aulas práticas de laboratório ficaram impossibilitadas de serem ministradas por parte dos professores de entomologia, que tiveram que se adaptar para garantir atividades pedagógicas à promoção da aprendizagem durante o ensino remoto emergencial (ERE). Desta forma, este estudo objetivou analisar a prática docente dos professores de entomologia durante a pandemia de Covid-19 no estado do Rio Grande do Sul (RS), Brasil. Para a realização deste estudo, foi aplicado um formulário do Google, transformado em uma base de dados anonimizada, considerando a prática docente de março de 2020 até maio-julho de 2022. Foi questionada a formação docente antes da pandemia; descrita a relação entre Instituição de Ensino Superior (IES) e o docente; o suporte e a capacitação durante o ERE; a cátedra docente, e as adaptações mandatórias que afetaram os professores de entomologia. Os resultados obtidos com a pesquisa mostraram que os professores enfrentaram dificuldades e obstáculos específicos, devido à própria formação e a habitual necessidade das aulas práticas de entomologia em laboratório, com isso, os docentes tiveram que passar pelo processo de aprendizagem frente às diferentes infraestruturas tecnológicas. Os professores conseguiram atingir os objetivos didáticos/pedagógicos propostos, fazendo com que os seus alunos continuassem as suas graduações em meio a pandemia. Por conseguinte, estudo revelou a falta da disponibilidade de instrumentos de trabalho (computadores, câmeras e estúdios) e de apoio financeiro das IESs para trabalho em “home office” dos docentes. Até o momento ainda não existem tecnologias que viabilizem as aulas práticas de laboratório por meio remoto. Por fim, ficou evidente que as aulas teóricas remotas têm a sua qualidade regulada pela participação e interesse dos alunos, em síntese essa situação serviu para que as IESs desenvolvam protocolos para problemas complexos futuros.

No abstract

1. In the 1970s, cereal aphids populations (specially Metopolophium dirhodum) were out of balance in the subtropical region of South America and a successful biological control program with the introduction of parasitoids restored equilibrium. After that, changes in crop systems may have affected aphid-parasitoid communities.2. The objective of this work was to evaluate the current assemblage of cereal aphid parasitoids, describing their oscillations, parasitism level, and trophic relationships in food webs in a cereal succession system (wheat-corn-oat) currently adopted in this region.3. Over a year, the associated parasitoid/hyperparasitoid species were inventoried by field-exposed Rhopalosiphum padi, Schizaphis graminum, M. dirhodum, and Sitobion avenae (recruitment method) and by Moericke traps. 4. Six species of primary parasitoids were sampled in both aphids and traps with the same abundance sequence: A. platensis, A. rhopalosiphi, L. testaceipes, D. rapae, A. uzbekistanicus, and A. ervi.5. Parasitism and complexity of food webs were higher during the wheat season (winter-spring), decreasing in corn (summer) and increasing again in oat (autumn).6. In the current assemblage of cereal aphid parasitoids in the subtropical region of South America, three species of parasitoids that were already present before the biological control program and three that were introduced oscillate in abundance throughout the year, resulting in an alternation of the complexity of the food webs and in the levels of parasitism in the crop seasons. A. platensis and A. rhopalosiphi are the most abundant species and A. rhopalosiphi remains fundamental in the control of M. dirhodum and S. avenae.