PARASITOIDS OF THE FAMILY CHALCIDIDAE COLLECTED IN PASTURES AND FORESTS USING YELLOW TRAPS, IN ITUMBIARA, GOIÁS, BRAZIL

The objective of this study was to appraise the occurrence of parasitoids of the family Chalcididae in Itumbiara County, State of Goiás, central Brazil. Insect samples were collected in pastures and native forest areas using pan traps, from January to December 1998. The traps consisted of circular yellow plastic containers (30 cm in diameter and 12 cm in height) containing a mixture of 2 L of water, 2 ml of detergent, and 2 ml of formaldehyde. Samplings were performed weekly by placing 10 traps at soil level (5 traps in the pasture and 5 in the woods). During 1998, 121 specimens of Chalcididae were collected. Haltichella sp.4 was the most abundant species collected (15.7%).

Chalcididae may be ectoparasitoids or endoparasitoids.Most appear to be idiobionts; some are koinobionts.Many chalcidids are strictly primary parasitoids, but others are facultative or obligatory hyperparasitoids.Most chalcidids are solitary parasitoids but a few are gregarious (Hanson & Gauld, 1995).About 200 species of Brachymeria exist worldwide, with 42 described from the Neotropics.
They develop as parasitoids in the pupae of a wide range of Lepidoptera, Coleoptera, and Diptera hosts (Boucek, 1963).Conura is primarily a New World genus with probably over 1000 species in the Neotropics which are parasitoids of pupae of Lepidoptera, Diptera, Coleoptera, and Hymenoptera (Hanson & Gauld, 1995).Melanosmicra is retricted to the Neotropics where there are about 30 species (biology unknown) (Hanson & Gauld, 1995).The genus Dirhinus consists of about 15 species in the Neotropics region which are parasitoids in puparia of various Diptera (Calliphoridae, Muscidae, Sarcophagidae, and Tephritidae).The genus Haltichella is represented in the Neotropics by five species; there are currently about 20 species of this genus parasitizing Lepidoptera pupae (Hanson & Gauld, 1995).
The objective was to identify species of Chalcididae (Hymenoptera: Chalcidoidea) collected in the savanna forests and pastures in Itumbiara County, State of Goiás, central Brazil, using yellow pan traps.
The experiment was carried out at the Agronomy College Farm, located near the Paranaíba River shore, 5 km from the center of the city of Itumbiara (18º25'S; 49º13'W).The farm has approximately 12 hectares.The 1.5 hectare sampling area is constituted of ciliary forest along the Paranaíba River, gradating to mesophytic semideciduous forest and savanna.
Areas close by have been the site of selective deforestation and forest burning, while the sampling area itself was circled by sugar cane croppings and pastures.The samplings were conducted weekly using 10 traps randomly placed at the soil level, totaling five traps in the pasture and five traps in the woods for each sampling.These traps consisted of circular yellow plastic containers approximately 30 cm in diameter and 12 cm in height, containing a mixture of 2 L of water, 2 ml detergent, and 2 ml formaldehyde.
Dr. Marcelo Teixeira Tavares, from the Universidade Federal do Espírito Santo, Vitória, State of Espírito Santo, identified the Chalcididae species.The proof material is deposited in the Biodiversity Laboratory of the Centro Universitário de Araraquara.
Of 520 samplings performed in January-December 1998, 121 specimens of Chalcididae from five different genera and 25 different species were collected.Of these individuals 73.6% were collected in the pastures and 26.4% in the forests (Table 1).The higher number of specimens collected in the pastures was probably due to an increase in attraction promoted by the traps in this area.In the woods, the tree canopes may have reduced incidence of sunlight, thus reducing the reflection of the yellow color of the containers, found by Noyes (1989) to be very useful tools in collecting parasitoids.Marchiori et al. (1998) reported that forest areas are important as sites of origin for parasitoids that are natural enemies of other insects.
The Chalcididae fauna in the pastures and forest were similar.Collection site proximity may explain the similarity of species obtained in these areas.
Among the Chalcididae specimens collected, the species most frequently found was Haltichella sp.4 (15.7%), followed by Conura sp.1 (13.2%) (Table 1).These data are important since they add to what is known about parasitoids in Brazil.