Transference of Citizen Science Program Impacts: A Theory Grounded in Public Participation in Scientific Research

Citizen science is known for increasing the geographic, spatial, and temporal scale from which scientists can gather data. It is championed for its potential to provide experiential learning opportunities to the public. Documentation of educational outcomes and benefits for citizen scientists continues to grow. This study proposes an added benefit of these collaborations: the transference of program impacts to individuals outside of the program. The experiences of fifteen citizen scientists in entomology citizen science programs were analyzed using a constructivist grounded theory methodology. We propose the substantive-level theory of transference to describe the social process by which the educational and attitudinal impacts intended by program leaders for the program participants are filtered by citizen scientists and transferred to others. This process involves individual and external phases, each with associated actions. Transference occurred in participants who had maintained a long-term interest in nature, joined a citizen science program, shared science knowledge and experiences, acquired an expert role to others, and influenced change in others. Transference has implications for how citizen scientists are perceived by professional communities, understanding of the broader impacts and contributions of citizen science to wicked problems, program evaluation, and the design of these programs as informal science education opportunities

Dose–Response Relationships of Clothianidin, Imidacloprid, and Thiamethoxam to \u3ci\u3eBlissus occiduus\u3c/i\u3e (Hemiptera: Blissidae)

The western chinch bug, Blissus occiduus Barber (Hemiptera: Blissidae), has emerged as a serious pest of buffalograss, Buchloë dactyloides (Nuttall) Engelmann. In general, neonicotinoid insecticides effectively control a variety of turfgrass insects, particularly phloem-feeding pests. However, because of well documented inconsistencies in control, these compounds are generally not recommended for chinch bugs. This study was designed to document the contact and systemic toxicity of three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) to B. occiduus. In contact bioassays, thiamethoxam was ~20-fold less toxic than clothianidin or imidacloprid to B. occiduus nymphs and three-fold more toxic to adults. In adult systemic bioassays, thiamethoxam was up to five-fold more toxic than clothianidin or imidacloprid. Interestingly, thiamethoxam was significantly more toxic to adults than to nymphs in both contact and systemic bioassays. This was not observed with clothianidin or imidacloprid. Bifenthrin, used for comparative purposes, exhibited 1,844-fold and 122-fold increase in toxicity to nymphs and adults, respectively. These results provide the first documentation of the relative toxicity of these neonicotinoid insecticides to B. occiduus

Feeding behavior of \u3ci\u3eAphis glycines\u3c/i\u3e (Hemiptera: Aphididae) on soybeans exhibiting antibiosis, antixenosis, and tolerance resistance

Aphis glycines Matsumura (Hemiptera: Aphididae) is a serious pest of soybean in North America. Plant resistance is a valuable tool for the management of this pest, and a better understanding of the interactions between aphid and soybeans expressing varying levels and different categories of resistance can assist in the development of aphid resistant or tolerant genotypes. The electrical penetration graph (EPG) technique was used to evaluate the feeding behavior of A. glycines (biotype 1) on 4 soybean genotypes: (1) ‘Dowling’ (contains Rag1 gene and exhibits antibiosis); (2) PI 200538 (contains Rag2 gene and exhibits antixenosis); (3) KS4202 (exhibits tolerance); and (4) ‘SD76RR’ (susceptible to aphid). Aphids spent shorter periods in the sieve element phase on ‘Dowling’ and exhibited a greater number of pathway phases, non-probing events, and a longer time in nonprobing events in PI 200538 and ‘Dowling.’ For ‘SD76RR’ and KS4202, aphids demonstrated more sustained phloem ingestion, spent shorter time in non-probing events, and exhibited fewer pathway phases and potential drops. These results indicate that resistance factors are present in the phloem of ‘Dowling.’ For PI 200538, it is suggested that antixenotic factors are involved in resistance to A. glycines. Because KS4202 is tolerant to biotype 1 of A. glycines, the suitability of this genotype was expected already. This study provides important data that contribute to the understanding of how soybean aphids (biotype 1) feed on soybean genotypes with various aphid resistant genes and categories. In addition to assisting in the distinction between resistance categories, these results are useful in soybean breeding programs focusing on developing genotypes with greater resistance to insects. Aphis glycines Matsumura (Hemiptera: Aphididae) é uma das principais pragas da cultura da soja na América do Norte. Dentre as técnicas de manejo da praga, a resistência de plantas a insetos se destaca como uma ferramenta valiosa. Assim, uma melhor compreensão sobre as interações entre o afídeo e plantas de soja que expressam variáveis níveis e diferentes categorias de resistência, pode auxiliar no desenvolvimento de genótipos resistentes ao inseto. A técnica de EPG foi utilizada para avaliar o comportamento alimentar de A. glycines (biótipo 1) em 4 genótipos de soja: (1) ‘Dowling’ (contém gene Rag1 e expressa antibiose); (2) PI 200538 (contém gene Rag2 e expressa antixenose); (3) KS4202 (expressa tolerância); e (4) ‘SD76RR’ (suscetível ao afídeo). Os afídeos demonstraram curtos períodos de alimentação na fase de seiva em ‘Dowling’ e exibiram uma grande quantidade de fases de caminhamento estiletar, número de períodos de não-prova e longos período de não-prova em PI 200538 e ‘Dowling.’ Para ‘SD76RR’ e KS4202, os afídeos mostraram um maior período de alimentação em vasos do floema, apresentaram curtos períodos de não-prova e exibiram poucas fases de caminhamento estiletar, além de menor número de quedas de potencial. Os resultados indicam que fatores de resistência estão presentes nos vasos floemáticos de ‘Dowling.’ Para PI200538, sugere-se que fatores antixenóticos estão envolvidos na resistência a A. glycines. Uma vez que KS4202 expressa tolerância ao biótipo 1 de A. glycines, a adequabilidade deste genótipo como fonte de alimento para o inseto já era esperada. Este estudo fornece importantes dados que contribuem para um melhor entendimento de como o pulgão-da-soja (biótipo 1) se alimentam de plantas de soja portadoras de diferentes genes e categorias de resistência. Além de auxiliar na distinção entre as categorias de resistência, esses resultados podem ser úteis em programas de melhoramento de soja, com intuito de selecionar genótipos mais resistentes a insetos

Evaluating categories of resistance in soybean genotypes from the United States and Brazil to \u3ci\u3eAphis glycines\u3c/i\u3e (Hemiptera: Aphididae)

Aphis glycines Matsumura (Hemiptera: Aphididae), the soybean aphid, has become an important pest of soybeans, leading to significant yield losses in the United States. Host plant resistance is a viable alternative for managing A. glycines. The objectives of this study were to identify and categorize sources of resistance in soybean to A. glycines on genotypes from the United States and Brazil. An antixenosis assay was initially conducted with 8 genotypes to evaluate attractiveness to A. glycines. The selected soybean genotypes were further evaluated in a colonization assay to investigate the resistance of the genotypes at V1 (fully developed leaves at unifoliate node, 1st trifoliate leaf unrolled) and V3 (fully developed leaf at 2nd trifoliate node, 3rd trifoliate leaf unrolled) stages. An antibiosis assay was also conducted, in which multiple biological parameters of A. glycines were recorded. In the antixenosis assay, PI 200538, IAC 24, and IAC 17 genotypes were least attractive to adults of A. glycines, indicating moderate levels of antixenosis. The colonization assay showed that genotypes infested at the V3 stage had greater resistance when compared with the respective plants infested at the V1 stage. In addition, high levels of antibiosis to A. glycines were found in UX 2569-159, PI 200538, and PI 243540 genotypes. The identification of soybeans with resistance to A. glycines is of importance for the integrated pest management of this insect pest in the United States. Moreover, this research represents the first report on potential sources of resistance to A. glycines in soybeans from Brazil. O pulgão-da-soja, Aphis glycines Matsumura (Hemiptera: Aphididae), tornou-se uma importante praga da soja, levando a significativas perdas de produção nos Estados Unidos da América (EUA). A resistência de plantas é considerada uma alternativa viável para o manejo de A. glycines. Os objetivos deste estudo foram identificar e categorizar fontes de resistência em soja a A. glycines, avaliando genótipos dessa leguminosa do Brasil e EUA. Um ensaio de antixenose foi conduzido inicialmente com oito genótipos de soja a fim de avaliar a atratividade de A. glycines. Os genótipos selecionados foram posteriormente avaliados em um ensaio de colonização, visando verificar sua resistência nos estádios V1 (folhas do primeiro nó totalmente desenvolvidas; primeiro trifólio aberto) e V3 (folhas do segundo trifólio totalmente desenvolvidas; folhas do terceiro trifólio abertas). Um ensaio de antibiose também foi realizado, avaliando-se diversos parâmetros biológicos de A. glycines. No ensaio de antixenose, os genótipos PI 200538, IAC 24 e IAC 17 foram menos atrativos a adultos de A. glycines, indicando níveis moderados de antixenose. O ensaio de colonização mostrou que genótipos de soja infestados no estádio V3 apresentam maior resistência em comparação com plantas infestadas no estádio V1. Em adição, este estudo constatou altos níveis de antibiose para A. glycines nos genótipos UX 2569-159, PI 200538 e PI 243540. A identificação de genótipos de soja com resistência a A. glycines é importante para os programas de manejo integrado de pragas (MIP) nos EUA. Em adição, esta pesquisa apresenta o primeiro registro de genótipos de soja brasileiros como potenciais fontes de resistência ao pulgão-da-soja

Feeding behavior of \u3ci\u3eAphis glycines\u3c/i\u3e (Hemiptera: Aphididae) on soybeans exhibiting antibiosis, antixenosis, and tolerance resistance

Aphis glycines Matsumura (Hemiptera: Aphididae) is a serious pest of soybean in North America. Plant resistance is a valuable tool for the management of this pest, and a better understanding of the interactions between aphid and soybeans expressing varying levels and different categories of resistance can assist in the development of aphid resistant or tolerant genotypes. The electrical penetration graph (EPG) technique was used to evaluate the feeding behavior of A. glycines (biotype 1) on 4 soybean genotypes: (1) ‘Dowling’ (contains Rag1 gene and exhibits antibiosis); (2) PI 200538 (contains Rag2 gene and exhibits antixenosis); (3) KS4202 (exhibits tolerance); and (4) ‘SD76RR’ (susceptible to aphid). Aphids spent shorter periods in the sieve element phase on ‘Dowling’ and exhibited a greater number of pathway phases, non-probing events, and a longer time in nonprobing events in PI 200538 and ‘Dowling.’ For ‘SD76RR’ and KS4202, aphids demonstrated more sustained phloem ingestion, spent shorter time in non-probing events, and exhibited fewer pathway phases and potential drops. These results indicate that resistance factors are present in the phloem of ‘Dowling.’ For PI 200538, it is suggested that antixenotic factors are involved in resistance to A. glycines. Because KS4202 is tolerant to biotype 1 of A. glycines, the suitability of this genotype was expected already. This study provides important data that contribute to the understanding of how soybean aphids (biotype 1) feed on soybean genotypes with various aphid resistant genes and categories. In addition to assisting in the distinction between resistance categories, these results are useful in soybean breeding programs focusing on developing genotypes with greater resistance to insects. Aphis glycines Matsumura (Hemiptera: Aphididae) é uma das principais pragas da cultura da soja na América do Norte. Dentre as técnicas de manejo da praga, a resistência de plantas a insetos se destaca como uma ferramenta valiosa. Assim, uma melhor compreensão sobre as interações entre o afídeo e plantas de soja que expressam variáveis níveis e diferentes categorias de resistência, pode auxiliar no desenvolvimento de genótipos resistentes ao inseto. A técnica de EPG foi utilizada para avaliar o comportamento alimentar de A. glycines (biótipo 1) em 4 genótipos de soja: (1) ‘Dowling’ (contém gene Rag1 e expressa antibiose); (2) PI 200538 (contém gene Rag2 e expressa antixenose); (3) KS4202 (expressa tolerância); e (4) ‘SD76RR’ (suscetível ao afídeo). Os afídeos demonstraram curtos períodos de alimentação na fase de seiva em ‘Dowling’ e exibiram uma grande quantidade de fases de caminhamento estiletar, número de períodos de não-prova e longos período de não-prova em PI 200538 e ‘Dowling.’ Para ‘SD76RR’ e KS4202, os afídeos mostraram um maior período de alimentação em vasos do floema, apresentaram curtos períodos de não-prova e exibiram poucas fases de caminhamento estiletar, além de menor número de quedas de potencial. Os resultados indicam que fatores de resistência estão presentes nos vasos floemáticos de ‘Dowling.’ Para PI200538, sugere-se que fatores antixenóticos estão envolvidos na resistência a A. glycines. Uma vez que KS4202 expressa tolerância ao biótipo 1 de A. glycines, a adequabilidade deste genótipo como fonte de alimento para o inseto já era esperada. Este estudo fornece importantes dados que contribuem para um melhor entendimento de como o pulgão-da-soja (biótipo 1) se alimentam de plantas de soja portadoras de diferentes genes e categorias de resistência. Além de auxiliar na distinção entre as categorias de resistência, esses resultados podem ser úteis em programas de melhoramento de soja, com intuito de selecionar genótipos mais resistentes a insetos

Divergent Switchgrass Cultivars Modify Cereal Aphid Transcriptomes

Schizaphis graminum Rondani (Hemiptera: Aphididae) and Sipha flava Forbes (Hemiptera: Aphididae) are two common pests of bioenergy grasses. Despite the fact that they are both considered generalists, they differ in their ability to colonize Panicum virgatum cultivars. For example, S. flava colonizes both P. virgatum cv. Summer and P. virgatum cv. Kanlow whereas S. graminum can only colonize Summer. To study the molecular responses of these aphids to these two switchgrass cultivars, we generated de novo transcriptome assemblies and compared the expression profiles of aphids feeding on both cultivars to profiles associated with feeding on a highly susceptible sorghum host and a starvation treatment. Transcriptome assemblies yielded 8,428 and 8,866 high-quality unigenes for S. graminum and S. flava, respectively. Overall, S. graminum responded strongly to all three treatments after 12 h with an upregulation of unigenes coding for detoxification enzymes while major transcriptional changes were not observed in S. flava until 24 h. Additionally, while the two aphids responded to the switchgrass feeding treatment by downregulating unigenes linked to growth and development, their responses to Summer and Kanlow diverged significantly. Schizaphis graminum upregulated more unigenes coding for stress-responsive enzymes in the Summer treatment compared to S. flava; however, many of these unigenes were actually downregulated in the Kanlow treatment. In contrast, S. flava appeared capable of overcoming host defenses by upregulating a larger number of unigenes coding for detoxification enzymes in the Kanlow treatment. Overall, these findings are consistent with previous studies on the interactions of these two cereal aphids to divergent switchgrass hosts

Evaluation of Greenbug and Yellow Sugarcane Aphid Feeding Behavior on Resistant and Susceptible Switchgrass Cultivars

Switchgrass (Panicum virgatum L.) is an emerging biofuel crop that serves as host for aphids. To discern the effects of plant age and possible resistance mechanisms, the feeding behavior of greenbugs (Schizaphis graminum Rondani.) and the yellow sugarcane aphid (Sipha flava Forbes.) was monitored on three diverse switchgrasses by the electrical penetration graph (EPG) technique. Callose deposition and genes associated with callose metabolism were also analyzed to discern their association with plant resistance. There was a strong host effect on greenbugs feeding on lowland cultivar Kanlow at the V3 stage of development, as compared to the greenbug-susceptible upland cultivar Summer and plants derived from Kanlow (♂) × Summer (♀) (K×S) crosses. These data confirmed that Kanlow at the V3 stage had antibiosis to greenbugs, which was absent in the Summer and K×S plants. In contrast, similar effects were not observed for yellow sugarcane aphids, excluding significant differences in the time to first probe on Kanlow plants at the V1 stage and reduction in time spent on pathway processes on Kanlow plants at the V3 stage. These data demonstrated that Kanlow plants may have multiple sources of resistance to the two aphids, and possibly some were phloem based. Microscopy of leaf sections stained with aniline blue for callose was suggestive of increased callose deposition in the sieve elements in Kanlow plants relative to Summer and K×S plants. RT-qPCR analysis of several genes associated with callose metabolism in infested plants was equivocal. Overall, these studies suggest the presence of multiple defense mechanisms against aphids in Kanlow plants, relative to Summer and K×S plants

Divergent Switchgrass Cultivars Modify Cereal Aphid Transcriptomes

Schizaphis graminum Rondani (Hemiptera: Aphididae) and Sipha flava Forbes (Hemiptera: Aphididae) are two common pests of bioenergy grasses. Despite the fact that they are both considered generalists, they differ in their ability to colonize Panicum virgatum cultivars. For example, S. flava colonizes both P. virgatum cv. Summer and P. virgatum cv. Kanlow whereas S. graminum can only colonize Summer. To study the molecular responses of these aphids to these two switchgrass cultivars, we generated de novo transcriptome assemblies and compared the expression profiles of aphids feeding on both cultivars to profiles associated with feeding on a highly susceptible sorghum host and a starvation treatment. Transcriptome assemblies yielded 8,428 and 8,866 high-quality unigenes for S. graminum and S. flava, respectively. Overall, S. graminum responded strongly to all three treatments after 12 h with an upregulation of unigenes coding for detoxification enzymes while major transcriptional changes were not observed in S. flava until 24 h. Additionally, while the two aphids responded to the switchgrass feeding treatment by downregulating unigenes linked to growth and development, their responses to Summer and Kanlow diverged significantly. Schizaphis graminum upregulated more unigenes coding for stress-responsive enzymes in the Summer treatment compared to S. flava; however, many of these unigenes were actually downregulated in the Kanlow treatment. In contrast, S. flava appeared capable of overcoming host defenses by upregulating a larger number of unigenes coding for detoxification enzymes in the Kanlow treatment. Overall, these findings are consistent with previous studies on the interactions of these two cereal aphids to divergent switchgrass hosts