Occurrence Of Parasitoids Research Articles

Occurrence of Megaselia scalaris Loew (Diptera: Phoridae) in Mischocyttarus cassununga Von Ihering (Hymenoptera: Vespidae: Polistinae) nests

Social wasp nests create an environment rich in resources, such as food and shelter, which consequently attract predators, parasites, and parasitoids. Parasitoids attacks can be one of the main causes of mortality among social wasps in the early stages of development. Therefore, the aim of this work is to report the occurrence of parasitoids in Mischocyttarus cassununga Von Ihering (Hymenoptera: Vespidae: Polistinae) nests, in an area of Cerrado, at the Federal Institute of Education, Science and Technology of Minas Gerais (IFMG) - Campus Bambuí, Brazil. There was an emergence of four parasitoids from two nests of M. cassununga, identified as Megaselia scalaris (Loew) (Diptera: Phoridae), the first record of this parasitoid in M. cassununga in a Cerrado area.

Parasitoids of dipterans and hemipterans collected in to cultivate on maize in Brazil

This paper has the objective of relating the occurrence of parasitoids to cultivate on maize in Itumbiara, Goiás during the crop 2001. Four groups of parasitoids were collected: two Brasema sp. (Hyemnoptera: Eupelmidae), two of Conura sp. (Hymenoptera: Chalcididae), eleven Gryon gallardoi (Bréthes, 1913) (Hymenoptera: Scelionidae) and nine of Pteromalidae sp. (Hymenoptera: Pteromalidae). The most important obtained parasitoids were found in Leptoglossus zonatus (Dallas, 1852) (Hemiptera: Coreidae) with Brasema sp. and G. gallardoi, prevailing the parasitism of 26,8% and 4,8%, respectively. Hymenoptera is one of the largest orders of insects. The lesser known Hymenoptera are parasitoids that develop in immature stages of other arthropods. They are considered important in the biological control of insect pests.

Influence of rice crop stage on the distribution of hymenopteran parasitoids of insect pests

A total of 43 insect parasitoid species belonging to fourteen families (Aphelinidae, Braconidae, Ceraphronidae, Diapriidae, Encyrtidae, Eulophidae, Eurytomidae, Ichneumonidae, Megaspilidae, Mymaridae, Platygasteridae, Proctotrupidae, Pteromalidae, Trichogrammatidae) has been documented in the rice ecosystem using yellow pan trap. The observations were made at four important stages of rice crop like early tillering, active tillering, booting and panicle development. The parasitoids were also compared with the occurrence of sixteen insect pests that were recorded simultaneously in each stage of the crop. The result revealed that, there is a significant difference in the occurrence of parasitoids according to the stage of the crop and insect host availability. This understanding help in the introduction of specific parasitoids at respective stages for effective biocontrol.

Parasitismo natural em ovos crisopídeos

Os predadores, em geral, apresentam hábitos generalistas e por isso podem ser usados em programas de controle biológico, em diferentes agroecossistemas. A sobrevivência dos predadores é afetada por diversos fatores, como, por exemplo, a presença de parasitóides. Este trabalho foi conduzido com os objetivos de identificar os parasitóides de crisopídeos, especialmente os parasitóides de ovos, e determinar o nível de parasitismo natural. As amostragens foram feitas na Embrapa Hortaliças, em campos de milho-doce, de setembro/1997 a fevereiro/1998. Os ovos de crisopídeos foram coletados semanalmente, sendo individualizados em cápsulas de gelatina até a emergência da larva e/ou do parasitóide. Foram coletados 800 ovos de crisopídeos, sendo que em 71% dos ovos, as larvas sobreviveram; 9% dos ovos foram considerados inviáveis e 20% foram parasitados por seis espécies de microhimenópteros. Destes, 57% foram parasitados por Telenomus sp. (Scelionidae), 32% por Trichogramma pretiosum (Trichogrammatidae), 6% por Oencyrtus chrysopae Crawford (Encyrtidae) e 5% por Aprostocetus sp. (Eulophidae).

Survey for natural enemies of the invasive alien chrysomelid, Diabrotica virgifera virgifera, in Central Europe

The western corn rootworm, Diabrotica virgifera virgifera LeConte(Coleoptera: Chrysomelidae), is the mostdestructive pest of maize (Zea mays L.)in North America, and began to successfullyinvade Central Europe in the early 1990's. Thispaper reports a three-year field surveyconducted in Hungary, Yugoslavia, and Croatia,which are currently the focal points ofinvasion, with the aim to determine theoccurrence of indigenous natural enemies ofD. v. virgifera in Europe. A total of9,900 eggs, 550 larvae, 70 pupae and 33,000adults were examined for the occurrence ofparasitoids, nematodes, and fungal pathogens. It can be concluded from the survey resultsthat effective indigenous natural enemies arenot attacking any of the life stages of D.v. virgifera in Europe. The exception is theoccurrence of the fungi Beauveriabassiana (Bals.) Vuill. (Mitosporic fungi;formerly Deuteromyces) and Metarhiziumanisopliae (Metsch.) Sorok (Mitosporic fungi)attacking adults of D. v. virgifera at anextremely low level (< 1%). However no otherentomopathogenic fungal pathogens,entomopathogenic nematodes, or parasitoids werefound on eggs, larvae, pupae or adults. Whileseveral natural enemies in North and CentralAmerica are known to attack D. v.virgifera, it is apparent that indigenousnatural enemies in Europe have not adapted tothe high population density of the alieninvasive species D. v. virgifera. Classical biological control may provide anopportunity to reconstruct the natural enemycomplex of an invading alien pest, and itsapplication to manage D. v. virgiferapopulations in Europe should be considered.

Microhimenópteros parasitóides de dípteros muscóides coletados em diferentes substratos em área de mata em Itumbiara, Goiás

This paper reports the occurrence of parasitoids in pupae of flies (Diptera) collected from several different substrata in Itumbiara, Goias, Brazil. The pupae were isolated by flotation. They were individually placed into gelatin capsules and kept until the emergency of adult flies or their parasitoids. From March 2001 through April 2002, a total of 684 parasitoids and 830 pupae of flies were collected from humans feces, chicken viscera, fish, and bovine kidney. Brachymeria podagrica were identified in a high number of samples. The prevalence of parasitism was of 82.4%.

Application rate trials with a nuclear polyhedrosis virus to control Spodoptera frugiperda (Smith) on maize

Different concentrations of nuclear polyhedrosis virus were applied as aqueous suspensions using a tractor mounted or a backpack-manual sprayer to control Spodoptera frugiperda (Smith) larvae on maize (Zea mays L.). Larval mortality varied with the application equipment. For the tractor-mounted sprayer application of at least 2.5 x 10(12) P.I.B./ha was necessary to attain a control comparable to that obtained with the backpack-manual sprayer application (70.2%). For this application method it can be used the dose of 2.5 x 10(11) PI.B./ ha, butNPV persistence was very short. A greaterNPV persistence was obtained with doses over 1.25 x 10(12) P.I.B./ha (93.4% mortality). The occurrence of parasitoids in the experimental area increased larval mortality rate (16.4%), independent of the application method. Among the parasitoids, the most prevalent was Campoletis flavicincta (Ashmead) (53.0%), followed by Chelonus insularis (Cresson) (31.3%), and Eiphosoma spp. (15.6%).