Release strategies of Telenomus podisi for control of Euschistus heros: a computational modeling approach

Abstract

The egg-parasitoid wasp Telenomus podisi has received attention as a biological-control agent for one of the most important soybean pests in Brazil, the stink bug Euschistus heros. As yet, no studies have conclusively established strategies for the release of T. podisi. We developed a computational model employing cellular automata to investigate release strategies for T. podisi in soybean crops, in order to optimize the use of these wasps in managing E. heros. A computational model was developed, using cellular automata in the C programming language and assuming a two-dimensional grid of cells corresponding to a soybean eld. The biological dynamics of E. heros and T. podisi were programmed. The following parameters for release strategy were investigated: release mode, number of releases, number of parasitoids per hectare per release, and spacing between release points or strips. The sensitivities of the release and movement parameters were analyzed. The release strategies capable of maintaining an E. heros population below the Economic Threshold level involved releasing a total of at least 15,000 female parasitoids per hectare, in three or four releases of 5,000 or more. A 25-m spacing between release points or strips was indicated. The theoretical results produced by the computational model are expected to guide future eld studies to improve T. podisi release plans for managing E. heros in soybeans.

Optimizing the Release Pattern of Telenomus podisi for Effective Biological Control of Euschistus heros in Soybean

“…Despite some differences between matrices in this study ( Figure 2 ), our results indicate that T. podisi has a dispersal capacity of about 39.0 m in the Vn–R1 stage and 30.9 m at R5–R6. These findings align with a previous computational model that suggested a 25 m spacing between release points [ 25 ]. Thus, to ensure an effective distribution of T. podisi and maintain a well-protected coverage area, it is advisable to set release points at a maximum distance of 30 m from each other.…”

Release of Adults and Pupae of T<em>elenomus podisi</em> (Hymenoptera: Scelionidae) For the Management of <em>Euschistus heros</em> (Hemiptera: Pentatomidae) In Soybean

“…Given the efficiency of T. podisi parasitism on eggs of pest pentatomids, especially E. heros [13], the difference in the total and male population of brown stink bugs between areas can best be explained by the density of parasitoids released in the field. In general, it is recommended to release at least 15,000 T. podisi females per hectare throughout the season, which can be divided into three or four applications [14]. To reach the recommended dose, four releases of 7500 females per hectare were carried out in this study.…”

The Viromes of Six Ecosystem Service Provider Parasitoid Wasps

“…Its prey is primarily aphids, which are very damaging pests of a wide range of crops of economic importance, including cereal crops [21,22]. Finally, Telenomus podisi (Platygastridae), an egg-parasitoid wasp found in Brazil and in the United States [23], has been shown to be important in controlling its preferential host Euchistus heros, an abundant pest of soybean crops [24,25]. Previous research focused on parasitoid wasps' virome revealed the presence of members of Reoviridae, Iflaviridae [26], Dicistroviridae [27,28], Lispiviridae, Rhabdoviridae [29], and Nyamiviridae [30].…”