Serologies use in the identification of insects predators prey.

This study aimed to produce antiserum for the main pests found in maize, Spodoptera frugiperda, Helicoverpa zea and armigera, Rhopalosiphum maidis, and uses it to determine their predators. Pest samples were macerated in 0.85% saline solution. The macerated were centrifuged and the supernatants were used as immunizing antigens to obtain the antiserum. For this purpose, a rabbit was immunized with 3.0 ml of the immunizing antigen on the lymph node region. Homologous serological tests were performed by double diffusion in agar. The homologous serological reactions were positive after seven days of antigen inoculation. The technique has sensitivity to detect predation of the pests studied. The tests were positive for a prey in the digestive tract of the predator to 96 hours of ingestion. Regarding the number of prey ingested there was no difference in the lines. It is concluded that after a single injection of antigen in rabbit lymph node region, it was possible to get an antiserum specific for pests of corn. Field tests showed that there was a certain food preference of Doru luteipes by S. frugiperda, Chrysoperla externa by aphid.

Parasite communities of the predatory fish, Acestrorhynchus falcatus and Acestrorhynchus falcirostris, living in sympatry in Brazilian Amazon.

This study investigated the parasite communities of wild Acestrorhynchus falcatus and Acestrorhynchus falcirostris populations living in sympatry in Brazilian Amazon. In these two hosts, a total of 12 parasite species e 1-9 parasite species were found per fish, and 10 of these species are metazoans. Eight species of parasites were common to both host species and four of them exhibited differences in abundance and/or prevalence. Parasite communities of the hosts were taxonomically similar (83%) and composed of both ectoparasites and endoparasites, and characterized by high prevalence and high abundance of endoparasites and an aggregated dispersion pattern. For A. falcirostris, the dominant parasite was Ichthyophthirius multifiliis, and for A. falcatus, it was Piscinoodinium pillulare. Shannon diversity and Berger-Parker dominance were similar for both hosts, while the parasites species richness and evenness showed differences influenced by the ectoparasites species. These two populations of hosts that inhabited the same geographical area had different sizes, but were exposed to the same infective stages, and acquired qualitatively and quantitatively similar endoparasites community, thus indicating that the amounts and types of prey congeneric that they were eating were similar. Therefore, the overlap in the same occurrence area play an important role in the parasite communities to these phylogenetically related hosts.