Diversidade e sazonalidade de coccinelídeos (Coleoptera: Coccinellidae) em pomar no município de Ponta Grossa, Paraná

Resumo. Uma análise sobre a flutuação populacional da entomofauna associada a culturas de interesse econômico pode fornecer subsídios para o manejo integrado de pragas. Dentre os grupos economicamente relevantes podemos citar os coccinelídeos, conhecidos por serem predadores naturais de pragas agrícolas como afídeos. O presente trabalho se faz necessário visto que os Campos Gerais ainda carecem de dados sobre Coccinellidae relacionados a pomares de árvores frutíferas. O estudo foi realizado no pomar do Colégio Agrícola Estadual Augusto Ribas (Ponta Grossa-PR) de julho de 2004 a junho de 2006. As coletas foram feitas usando cada espécie do pomar, sendo elas agrupadas em dois grupos: cítricas e decíduas. Harmonia axyridis (Pallas) foi a espécie mais representativa na amostragem, compreendendo 38,35 % das coletas. as árvores cítricas apresentaram o maior número de insetos totalizando 82,19% da amostragem. É pertinente sugerir que a presença da H. axyridis pode ter afetado a diversidade da comunidade local, sendo ela uma espécie invasora e considerada uma melhor competidora. As árvores cítricas se apresentaram como as mais diversas. Podemos atribuir essa distribuição a maior presença de afídeos nas árvores cítricas, que foram atraídos pelos óleos voláteis secretados por essas plantas. No período final da amostragem houve uma queda populacional, que pode ser atribuída a condições climáticas desfavoráveis, e consequente redução a abundância dos afídeos presa e dos próprios coccinelídeos. Uma maior quantidade de recursos de presa permitiria que mais espécies de joaninhas coexistissem sem competir fortemente. Uma pesquisa futura poderia comparar situação da comunidade, analisando a influência da H. axyridis nas espécies locais.Diversity and seasonality of coccinellids (Coleoptera: Coccinellidae) in an orchard in the city of Ponta Grossa, ParanáAbstract. An analysis of the population fluctuation of entomofauna associated with crops of economic interest can provide subsidies for integrated pest management. Among the economically relevant groups we can mention the Coccinellidae, known to include natural predators of agricultural pests such as aphids. The present work is necessary since Parana's Campos Gerais still lack data on Coccinellidae related to orchards of fruit trees. The study was conducted in the orchard of Augusto Ribas State Agricultural College (Ponta Grossa-PR) from July 2004 to June 2006. Samples were collected from each species of the orchard, grouped into two groups: citrus and deciduous. Harmonia axyridis (Pallas) was the most representative species in the sample, comprising 38.35% of the collections. Citrus trees had the highest number of insects totaling 82.19% of the sample. It is pertinent to suggest that the presence of H. axyridis may have affected the diversity of the local community, being an invasive species and considered a better competitor. The citrus trees presented themselves as the most diverse. We can attribute this contribution to the greater presence of aphids in the citrus trees, which were attracted by the volatile oils secreted by these plants. In the final period of sampling there was a decrease in population size, which can be attributed to unfavorable climatic conditions, and consequent reduction in the abundance of prey aphids and of the coccinellids themselves. A greater amount of prey resources would allow more species of ladybugs to coexist without competing strongly. A future research could compare community situation by analyzing the influence of H. axyridis on local species.

The genus Harmonia (Coleoptera, Coccinellidae) in the Middle East region

The harlequin ladybird, Harmonia axyridis (Pallas, 1773), is native to Asia but has been introduced to many countries, both intentionally and unintentionally. In the Middle East region, H. axyridis was so far only known from Iran and Turkey. This study reports H. axyridis for the first time from a country with a hot desert climate, Saudi Arabia. The single specimen that was found is most likely the result of unintentional release. Successful spreading of H. axyridis in Saudi Arabia will be limited because of high temperatures during summer and scarcity of prey (aphids). New records from Iran and Turkey suggest fast spreading of H. axyridis in these parts of the Middle East. In addition, we also present new records from Iran and Turkey for H. quadripunctata (Pontoppidan, 1763), the other species in the genus that occurs in the Middle East region. A key and illustrations are provided for both species.

Composition and role of hoverfly (Diptera: Syrphidae) communities in an organic apple orchard

The use of hoverfly (Syrphidae) larvae in biological control is gaining more attention where the damage by their prey, aphids is significant, especially in agricultural fields and orchards, where they lower the number of aphids. The present study focuses on one hand on faunistics, on the other hand on testing the different available collecting methods for later research. Collecting in an organic apple orchard near Debrecen yielded 525 specimens of Syrphidae mostly by netting but also with white tray traps. Collected species are differentiated according to their feeding (94.1% aphidophagous). The three species found in greatest numbers are Sphaerophoria scripta (Linnaeus, 1758), Melanostoma mellinum (Linnaeus, 1758) and Episyrphus balteatus (De Geer, 1776). The available information on their biology is reviewed and their potential value of hoverflies in biological control is discussed.

THE INFLUENCE OF APHID PREY CONSUMPTION ON SEARCHING BEHAVIOR, WEIGHT INCREASE, DEVELOPMENTAL TIME, AND MORTALITY OF CHRYSOPA CARNEA (NEUROPTERA: CHRYSOPIDAE) AND HIPPODAMIA CONVERGENS (COLEOPTERA: COCCINELLIDAE) LARVAE

The behavior of larval stages of the green lace wing, Chrysopa carnea Stephens, and of the ladybird beetle Hippodamia convergens G.-M. were studied in the laboratory. With increasing hunger level, only first instar H. convergens larvae spent more time searching in the upper part of alfalfa stems, where both prey aphids, Acyrthosiphon pisum (Harris) and Acyrthosiphon kondoi (Shinji), are found. All larval instars tested except first instar C. carnea visited more stems per unit time with increasing hunger level. The weight gain, the developmental time, and the mortality of all larvae were adversely influenced at low food levels, but differently for each predator size and species. C. carnea larvae had higher rates of fat body utilization and weight gain than coccinellid larvae.