ABSTRACT
The mite Tetranychus mexicanus (McGregor) is considered a pest of a variety of plant species in the Americas. Although this mite apparently causes economic damage to Annonaceae, little is known about its biology. Here we studied the biology of T. mexicanus on soursop (Annona muricata), sweetsop (Annona squamosa) and araticum (Annona coriaceae). The first two species are the most important economical Annonaceae species in northeast Brazil; araticum is commonly found in the region, but not commercially explored. The mites were collected in the field from leaves of A. muricata and maintained in the laboratory for six months on detached leaves of A. muricata, A. squamosa and A. coriaceae, respectively, before observations started. Tetranychus mexicanus developed more slowly on A. squamosa than on the two other hosts, but oviposition was considerably lower on A. coriaceae. As indicated by the calculated life table parameters, biotic potential was higher on A. muricata than on the other hosts. Despite the observed differences in the T. mexicanus biology on the different evaluated hosts, development and reproduction were satisfactory in all of the hosts used.
Subject(s)
Animals , Annonaceae/parasitology , Tetranychidae/physiologyABSTRACT
Este trabalho teve como objetivo avaliar a acarofauna em grãos de feijão, milho e ração em supermercados e feiras livres da cidade do Recife, PE. Em cada estabelecimento foi coletada uma amostra de 500 g de cada grão e ração, em intervalos bimensais, no período de agosto/2002 a junho/2003. Cada amostra foi dividida em duas sub-amostras de 250 g. Uma delas foi submetida à extração de ácaros logo após a coleta e a outra foi incubada a 26°C e umidade relativa de 78 por cento por 30 dias. Ao final desse período a segunda sub-amostra foi processada da mesma forma que a primeira. Os ácaros foram montados em lâminas para microscopia em meio de Hoyer e identificados pelo menos até o nível de gênero. Foram coletados 11.956 ácaros pertencentes às famílias Acaridae, Ebertiidae, Glycyphagidae, Cheyletidae, Stigmaeidae, Pyemotidae, Tarsonemidae, Tydeidae, Cunaxidae, Ameroseiidae, Ascidae e Phytoseiidae. Dentre os ácaros primários, a espécie Suidasia medanensis Oudemans foi a predominante no levantamento (3.035 indivíduos), seguida de Caloglyphus hughesi (Samsinak) (436 indivíduos). Metapronematus sp. foi predominante (3.417 indivíduos), dentre os ácaros secundários, seguido de Tarsonemus granarius Lindquist (3.003). O número de ácaros coletados nas amostras incubadas foi sempre superior em relação às amostras não incubadas, assim como nas amostras de feira livre em relação às de supermercado.
The mite fauna was assessed in bean, maize and pet food in supermarkets and markets in Recife, PE, Brazil. A 500 g sample of each grain and food was collected in each establishment at two weekly intervals, from August 2002 to June 2003. The sample was divided into two 250 g sub-samples. One of them was submitted to spider mite evaluation shortly after collection and the other was incubated at 26°C and 78 percent humidity for 30 days. At the end of this period the second sub-sample was processed in the same way as the first. The spider mites were mounted on slides for microscopy in Hoyer medium and identified at least at genus level. Eleven thousand nine hundred and fifty-six spider mites were collected belonging to the Acaridae, Ebertiidae, Glycyphagidae, Cheyletidae, Stigmaeidae, Pyemotidae, Tarsonemidae, Tydeidae, Cunaxidae, Ameroseiidae, Ascidae e Phytoseiidae families. Among the primary spider mites the Suidasia medanensis Oudemans species was predominant in the survey (3,035 individuals) followed by Caloglyphus hughesi (Samsinak) (436 individuals). Metapronematus sp. was predominant (3,417 individuals) among the secondary spider mites followed by Tarsonemus granarius Lindquist (3,003). The number of mites collected in the incubated samples was always greater compared to the non-incubated samples in both the market and supermarket samples.