Population dynamics of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) and its hymenopteran, parasitoids in Northwestern Argentina

MURÚA, M. G.; MOLINA OCHOA, J.; COVIELLA C.

FLORIDA ENTOMOLOGIST

Año: 2006 vol. 89 p. 175 - 182

0015-4040

In order to know the population dynamics of the fall armyworm, Spodoptera frugiperda (Smith), and its parasitoids in Northwestern Argentina, FAW larvae samplings were conducted weekly at two different agrological regions of Northwestern Argentina (Tafí Viejo: Tafí Viejo Department and Vipos: Trancas Department) over four years. The relationship between FAW population and the parasitoid population fluctuations and climatologic factors, percent of infested plants, parasitoid relative importance index, frequency, abundance of the parasitoids and percent of parasitism were estimated. FAW attacked cornfields when the plants achieved V1, and V2 stages. Temperature and rainfall were the climatologic factors that significantly affected the pest density, and the temperature affected the parasitoid abundance as well. The FAW parasitoids collected were: Campoletis grioti (Blanchard) (Hym.: Ichneumonidae), Chelonus insularis (Cresson) (Hym.: Braconidae), Ophion sp (Hym.: Ichneumonidae) and Archytas spp. (possibly marmoratus and/or incertus) (Dip.: Tachinidae). The average parasitism percentage was 39.39% and 15% in T. Viejo and Vipos, respectively. The parasitoid abundance in both regions was similar, but the diversity was not alike, a possible refuge role of the native surrounding vegetation in Vipos is speculated. This is the first report of population dynamics of the fall armyworm, and its parasitoids in Northwestern Argentina.