Impact of Zinnia elegans Cultivation on the Control Efficacy and Distribution of Aphidius colemani Viereck (Hymenoptera: Braconidae) against Aphis gossypii Glover (Hemiptera: Aphididae) in Cucumber Greenhouses.

Simple Summary: This study investigated the potential for enhancing the efficacy of the biological control agent, Aphidius colemani, against the cotton aphid, Aphis gossypii, by planting Zinnia elegans flowers alongside cucumbers in greenhouses. Three treatments were examined: (1) the combined use of Z. elegans and A. colemani; (2) A. colemani alone; and (3) a control without either. Our results indicated that the Z. elegans and A. colemani combination maintained a lower A. gossypii population compared to other treatments. While A. colemani alone initially suppressed the A. gossypii population, it soon increased. This study concluded that integrating Z. elegans with the biological control agent could more effectively manage aphid populations in cucumber greenhouses. This study aimed to evaluate the enhancement of A. gossypii control by A. colemani when Z. elegans was planted as a companion crop in cucumber greenhouses. The density and spatial distribution of A. gossypii and parasitized mummies were investigated across three treatment plots: (1) the simultaneous application of A. colemani and cultivation of Z. elegans (parasitoid-zinnia plot); (2) the application of A. colemani alone (parasitoid plot); and (3) a control plot (no application of both). A. gossypii maintained low densities in the parasitoid–zinnia plots, while its densities in the parasitoid plots initially decreased but rapidly increased thereafter. The spatial distribution patterns of A. gossypii and parasitized mummies showed similar trends across treatments. However, the parasitism rate of A. gossypii exhibited random distribution in parasitoid and control plots, while showing uniform distribution in the parasitoid–zinnia treatment. These results supported the idea that cultivating Z. elegans alongside cucumber could enhance the effectiveness of A. colemani as a biocontrol agent against A. gossypii, highlighting the importance of such companion planting in pest management strategies. [ABSTRACT FROM AUTHOR]