Pollen feeding habits of Chrysoperla carnea s.l. adults in the olive grove agroecosystem

Chrysoperla carnea s.l. (Stephens) larvae are important natural enemies in agroecosystems. However, adults feed on honeydew excreted by hemipterans, and pollen and nectar from flowering plants. Pollen is essential for egg production, but to our knowledge, the pollen diet of C. carnea in perennial crops has never been addressed. In this work, the objective was to study the diversity and potential selection of pollen types consumed by C. carnea in the olive grove agroecosystem. For this study, C. carnea adults were captured from April to December of 2012 and 2013, and simultaneously, inventories of the plant diversity were obtained in olive orchards and adjacent scrubland and herbaceous patches. The pollen types contained in C. carnea guts were identified by microscopy and compared with the pollen types in the environment using Jacobs`s second selection index. The results indicated that (i) C. carnea females and males captured in the olive tree canopy visited scrub and herbaceous vegetation patches; (ii) they fed on different anemophilous and entomophilous pollen types from tree and scrub (Olea europaea, Fabaceae, Pinaceae, Cistaceae or Ericaceae) and herbaceous (Asteraceae, Apicaceae, Brassicaceae, Poaceae, Rumex type or Plantago type) strata; and (iii) adults fed not only on flowers but also on pollen settled on vegetation surfaces. Here, we demonstrated that C. carnea could benefit not only from the diversity of entomophilous pollen during the plant flowering periods but also from other pollens that could remain in the environment in different periods. This has important implications for the management of the floral diversity adjacent to the crop.The authors are grateful to the Portuguese Foundation of Science and Technology for financial support through the project EXCL/AGRPRO/ 0591/2012 “Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions.” M.V. thanks FCT, PostDoc grant (SFRH/BPD/ 119487/2016).info:eu-repo/semantics/publishedVersio

Pollen feeding habits of Chrysoperla carnea s.l. adults in the olive grove agroecosystem.

Chrysoperla carnea s.l. (Stephens) larvae are important natural enemies in agroecosystems. However, adults feed on honeydew excreted by hemipterans, and pollen and nectar from flowering plants. Pollen is essential for egg production, but to our knowledge, the pollen diet of C. carnea in perennial crops has never been addressed. In this work, the objective was to study the diversity and potential selection of pollen types consumed by C. carnea in the olive grove agroecosystem. For this study, C. carnea adults were captured from April to December of 2012 and 2013, and simultaneously, inventories of the plant diversity were obtained in olive orchards and adjacent scrubland and herbaceous patches. The pollen types contained in C. carnea guts were identified by microscopy and compared with the pollen types in the environment using Jacobs`s second selection index. The results indicated that (i) C. carnea females and males captured in the olive tree canopy visited scrub and herbaceous vegetation patches; (ii) they fed on different anemophilous and entomophilous pollen types from tree and scrub (Olea europaea, Fabaceae, Pinaceae, Cistaceae or Ericaceae) and herbaceous (Asteraceae, Apicaceae, Brassicaceae, Poaceae, Rumex type or Plantago type) strata; and (iii) adults fed not only on flowers but also on pollen settled on vegetation surfaces. Here, we demonstrated that C. carnea could benefit not only from the diversity of entomophilous pollen during the plant flowering periods but also from other pollens that could remain in the environment in different periods. This has important implications for the management of the floral diversity adjacent to the crop

PHYSIOLOGICAL AND SANITARY QUALITIES OF MAIZE LANDRACE SEEDS STORED UNDER TWO CONDITIONS

The preservation of seed quality during the storage period depends not only on the conditions during production and harvesting but also on the storage and maintenance of appropriate storage product conditions. Thus, the aim of this study was to evaluate the physiological and sanitary qualities of maize landrace seeds stored under two conditions. The maize seed batch varieties Oito carreiras, Cabo roxo and Lombo baio were used. Tests included germination, first count, cold test, accelerated aging and sanity. Based on the results it was concluded that the physiological quality of these seed varieties decreased with the storage period. The major fungi identified in the maize seeds during storage were from the genera Aspergillus, Fusarium and Penicillium, which caused deterioration and reduction of the physiological quality. Storage using a paper bag at a temperature of 10 °C did not prevent the deterioration of maize seeds but was more effective at preserving the quality of the seed compared with a plastic bag at room temperature

Plantas espontâneas em floração como recurso alimentar para adultos de Chrysoperla carnea s.l. no agroecossistema olival

As larvas de Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) são consumidores generalistas de pragas nos agroecossistemas, nomeadamente no olival. Os adultos alimentam-se de meladas de hemípteros, pólen e néctar de plantas desempenhando a flora adventícia do olival um papel relevante em proteção biológica de conservação. Considerando que o pólen pode ser um recurso florístico essencial para a reprodução e fecundidade no predador e que o conhecimento acerca da dieta polínica de C. carnea é escasso, o presente trabalho teve por objetivo estudar a potencial seleção de tipos polínicos consumidos por C. carnea s.l. no agroecossistema olival. De abril a dezembro de 2012 e 2013, em olivais com coberto vegetal na região de Mirandela foram capturados adultos de C. carnea s.l. na copa da oliveira. Em laboratório, procedeu-se à remoção do conteúdo estomacal dos insetos para identificação, ao microscópio ótico, dos diferentes tipos polínicos. Paralelamente realizaram-se inventários das plantas em floração nos olivais e parcelas adjacentes de vegetação herbácea e arbustiva para comparação dos tipos polínicos consumidos e presentes no agroecossistema. Os resultados indicaram que os indivíduos de C. carnea s.l. consumiram pólen de diferentes plantas anemófilas e entomófilas pertencentes aos extratos arbóreo e arbustivo (Fabaceae, Pinaceae, Cistaceae ou Ericaceae) e ao extrato herbáceo (Asteraceae, Apicaceae, Brassicaceae, Poaceae, tipo Rumex o tipo Plantago). Por outro lado, verificou-se ainda que os adultos de C. carnea se alimentaram não só do pólen das flores mas também do outro pólen que provavelmente se encontra depositado sobre a superfície da vegetação, o que poderá representar um reservatório alimentar para períodos de escassez. Os resultados obtidos evidenciam a importância da flora espontânea nos agroecossistemas e podem contribuir para a gestão destas espécies no olival com vista ao fomento da comunidade de inimigos naturais de pragas da cultura.info:eu-repo/semantics/publishedVersio