D3204: Management of crapemyrtle aphid (Hemiptera: Aphididae) on crapemyrtle (Myrtales: Lythraceae) in greenhouses

Crapemyrtle aphid (Sarucallis kahawaluokalani) (CMA) is a pest of crapemyrtle (Lagerstroemia spp. L.) that has been introduced to the United States. CMA honeydew secretion promotes further pests and diseases, adding to the destruction caused by infestations. Controlling CMA infestations has been an area of interest as many insecticides are not recommended due to the attractiveness of crapemyrtle blooms to many pollinators. In greenhouse production, there is greater risk of infestations and less concern about pollinators. We wanted to assess the efficacy of various suggested integrated pest management methods that include biocontrol and pollinator-friendly chemical options with standard insecticides such as Aria and Kontos. We set up four chamber plots in a greenhouse with 4 cultivars of crapemyrtle in each chamber. Twenty nymphs were placed on each plant in the chamber and allowed to infest for one week. At the end of one week, we applied separate IPM strategies to each of the chambers to assess their effectiveness over a 3-month period. We also calculated the cost we spent on each chamber, running correlation models between effectiveness and cost of each IPM strategy. While standard chemical insecticide rotations had the greatest effect on lowering CMA populations, effectiveness of IPM strategy interacted with the cultivar of crapemyrtle. Our findings suggest that greenhouse management strategies for CMA on crapemyrtles is dependent on the cultivar in production. We also recommend that growers integrate other forms of control into the IPM that may be more sustainable and cost effective.