AGROBIONT SPIDERS IN SOYBEAN CROPS IN ARGENTINA

ALMADA, MELINA; SOSA, MARÍA ANA

Durban

Congreso; WORLD SOYBEAN RESEARCH CONFERENCE IX; 2013

WORLD SOYBEAN RESEARCH

Soybean (Glycine max Merrill) is one of the most important crops in Argentina. In the last decade, a few changes have occurred within the technological systems available to produce soybean including the incorporation of transgenic cultivars tolerant to glyphosate (1996) and zero tillage cropping systems. Associated with these transformations, current changes were also observed, e.g., colonization habit and abundance of defoliation pests, the bug complex and predators as well as the emergence of new pests. Accordingly, actions were initiated to reduce the level of damage, optimizing final yields and minimizing environmental degradation. Pest monitoring and studies of beneficial arthropod communities have shown a high abundance of spiders in these agroecosystems which play an important role as pest predators. This high dominance of spiders in the agroecosystem has been named the “Agrobiont” species. These agrobiontic species have not been studied in Argentina in soybean crops. We propose to describe the main families and species of spiders in this crop. An extensive literature review was done to search for studies involving spiders on soybean in Argentina and it was found that some work was carried out in Buenos Aires, Entre Ríos and Santa Fe. Also, during summer and autumn (January and April 2010), two main samplings were carried out in five soybean A8000 (RR) plots at the Agricultural Experimental Station of INTA Reconquista (29°11’ S-59°52’ W), Santa Fe, Argentina. The sampling design method involved two linear transects in each of the plots, where 10 pitfalls traps were placed separated by about 10m from each other, to capture ground spiders; and likewise, was aspirated through the G-Vac (Garden-vacuum) to capture spiders in the herbaceous layer. 2885 spiders, representing 21 families and 138 species/morfospecies were collected The percentages of the dominant species from herbaceous samples were: 31,32%Glycine max Merrill) is one of the most important crops in Argentina. In the last decade, a few changes have occurred within the technological systems available to produce soybean including the incorporation of transgenic cultivars tolerant to glyphosate (1996) and zero tillage cropping systems. Associated with these transformations, current changes were also observed, e.g., colonization habit and abundance of defoliation pests, the bug complex and predators as well as the emergence of new pests. Accordingly, actions were initiated to reduce the level of damage, optimizing final yields and minimizing environmental degradation. Pest monitoring and studies of beneficial arthropod communities have shown a high abundance of spiders in these agroecosystems which play an important role as pest predators. This high dominance of spiders in the agroecosystem has been named the “Agrobiont” species. These agrobiontic species have not been studied in Argentina in soybean crops. We propose to describe the main families and species of spiders in this crop. An extensive literature review was done to search for studies involving spiders on soybean in Argentina and it was found that some work was carried out in Buenos Aires, Entre Ríos and Santa Fe. Also, during summer and autumn (January and April 2010), two main samplings were carried out in five soybean A8000 (RR) plots at the Agricultural Experimental Station of INTA Reconquista (29°11’ S-59°52’ W), Santa Fe, Argentina. The sampling design method involved two linear transects in each of the plots, where 10 pitfalls traps were placed separated by about 10m from each other, to capture ground spiders; and likewise, was aspirated through the G-Vac (Garden-vacuum) to capture spiders in the herbaceous layer. 2885 spiders, representing 21 families and 138 species/morfospecies were collected The percentages of the dominant species from herbaceous samples were: 31,32% Paracleocnemis sp. (Philodromidae), 16,50% Ocrepeira sp. (Araneidae) and 11,48% Oxyopes salticus (Oxyopidae). However, the ground species were 81,58% Allocosa sp. (Lycosidae), 3,58% Goeldis sp. (Titanoecidae) and 3,51% Jollas sp. (Salticidae). Comparing these results with those from other provinces showed six families (Araneidae, Lycosidae, Oxyopidae, Philodromidae, Theridiidae and Thomisidae) in common, excluding only Titanoecidae previously found. These differences were probably due to the sampling methods used as well as to environmental conditions that may vary depending on the locations. The current data will be useful for future research work to develop and improve management strategies for biological pest control.sp. (Philodromidae), 16,50% Ocrepeira sp. (Araneidae) and 11,48% Oxyopes salticus (Oxyopidae). However, the ground species were 81,58% Allocosa sp. (Lycosidae), 3,58% Goeldis sp. (Titanoecidae) and 3,51% Jollas sp. (Salticidae). Comparing these results with those from other provinces showed six families (Araneidae, Lycosidae, Oxyopidae, Philodromidae, Theridiidae and Thomisidae) in common, excluding only Titanoecidae previously found. These differences were probably due to the sampling methods used as well as to environmental conditions that may vary depending on the locations. The current data will be useful for future research work to develop and improve management strategies for biological pest control.(Oxyopidae). However, the ground species were 81,58% Allocosa sp. (Lycosidae), 3,58% Goeldis sp. (Titanoecidae) and 3,51% Jollas sp. (Salticidae). Comparing these results with those from other provinces showed six families (Araneidae, Lycosidae, Oxyopidae, Philodromidae, Theridiidae and Thomisidae) in common, excluding only Titanoecidae previously found. These differences were probably due to the sampling methods used as well as to environmental conditions that may vary depending on the locations. The current data will be useful for future research work to develop and improve management strategies for biological pest control.Goeldis sp. (Titanoecidae) and 3,51% Jollas sp. (Salticidae). Comparing these results with those from other provinces showed six families (Araneidae, Lycosidae, Oxyopidae, Philodromidae, Theridiidae and Thomisidae) in common, excluding only Titanoecidae previously found. These differences were probably due to the sampling methods used as well as to environmental conditions that may vary depending on the locations. The current data will be useful for future research work to develop and improve management strategies for biological pest control.