ABSTRACT
O desenvolvimento pós-embrionário, a produtividade da pupa, a taxa de parasitismo e a razão sexual de Nasonia vitripennis (Walker) criadas em pupas de Cochliomyia macellaria (Fabricius) foram estudadas. Diferentes densidades do parasitóide foram utilizadas (proporções 1:1, 2:1, 3:1, 4:1 e 5:1) com exposição de 72 horas. Fêmeas nulíparas originárias da colônia estoque foram individualizadas em tubos de ensaio cobertos com algodão hidrofóbico, contendo uma pupa hospedeira. Cada tratamento foi constituído de 10 repetições. Após a exposição, as vespas foram descartadas e as pupas hospedeiras foram individualizadas em tubos de ensaio até a emergência dos adultos de C. macellaria ou N. vitripennis. Amostras de pupas hospedeiras não expostas ao parasitismo e recebendo o mesmo tratamento experimental foram utilizadas como controle. O período pós-embrionário foi significativamente mais curto na proporção 2:1 (13,73 dias) e mais longo na relação 5:1. Os picos de emergência ocorreram no 14º dia após a exposição do parasitóide ao hospedeiro para todas as relações, com exceção da relação 4:1(13º dia). A produtividade de N. vitripennis não variou significativamente entre as diferentes proporções. Conforme o número de parasitóides aumentou foi observado uma maior duração do período do desenvolvimento pós-embrionário e um aumento na proporção de machos na prole. A taxa de parasitismo apresentou queda quando o hospedeiro foi exposto a cinco parasitóides.
The post-embryonic development, the productivity of the pupae, the rate of parasitism and the sexual ratio of Nasonia vitripennis (Walker) reared in pupae of Cochliomyia macellaria (Fabricius) were studied. Different densities of the parasitoid were used (proportions 1:1, 2:1, 3:1, 4:1, and 5:1) with exposition of 72 hours. Nulliparous females originating from the stock colony were individualized in test tubes covered with hydrophobic cotton and containing the host pupae. Each treatment was constituted by 10 repetitions. After the exposition, the wasps were discarded and the host pupae were individualized in test tubes until the emergency of the adults of C. macellaria or N. vitripennis. Samples of host pupae not exposed to parasitism and receiving the same experimental treatment were used as control. The post-embryonic period was significantly shorter in the proportion of 2:1 (13,73 days) and longer in the relation of 5:1. The peaks of emergence occurred in the 14th day after the exposition of the parasitoid to the host in all relations, except for the relation of 4:1(13rd day). The productivity of N. vitripennis does not vary significantly among the different proportions. As the number of parasitoids grows, its post-embryonic development gets slower and the sexual ratio of males grows up. The rate of parasitism showed a decrease when the host was exposed to five parasitoids.
Subject(s)
Reproductive Behavior/classification , Pest Control, Biological/methods , Diptera , Host-Parasite Interactions , Parasites/classification , Wasps/classification , Wasps/parasitologyABSTRACT
Only one insect (the scale insect Eriococcus sp.) is known, in which photoreceptive lamellae appear to have replaced the usual arthropod rhabdom microvilli. We are now reporting the presence of photoreceptive membranes, which also appear to resemble lamellae rather than microvilli, but they are in the ocellus of the tiny wasp Centrodora sp., which parasitizes scale insect eggs. The apparently optically homogenous lens of the Centrodora ocellus measures approximately 10 µm in diameter and, thus, operates at the limits of diffraction. We calculated that the lens is capable of focusing a parallel bundle of rays on the retina of the ocellus.
Subject(s)
Male , Animals , Wasps/anatomy & histology , Gene Transfer, Horizontal , Hemiptera/genetics , Cell Membrane/ultrastructure , Eye/ultrastructure , Photoreceptor Cells , Wasps/parasitology , Hemiptera/physiology , Host-Parasite Interactions , Retina/ultrastructureABSTRACT
The presence of a polydnavirus in the ovary of the microhymennoptera Apanteles galleriae was detected. This wasp parasites the larvae of the wax moth Galleria mellonella. To study the possible viral effects on the total protein of G. mellonella, hemolymph extracts of the ovary calyxes of parasitized A. galleriae were injected into 6th and 7th instar cells of G. mellonella larvae. Protein profiles on polyacrilamide gel electrophoresis containing sodium dodecyl sulfate (SDS-PAGE) of host cell extracts showed a suppression of several protein bands when infection occurred in the 6th instar. However, in the 7th instar, parasitism caused an amplification in the synthesis of most proteins with some changes in the electrophoretic profile.