Does Pressure Washing Kill Spotted Lanternfly Egg Masses

What we tested was the use of stream spray cleaners for egg masses on equipment. These have been used for years in NY for cleaning equipment due to the possibility of Golden Nematode being on equipment used in potato fields. We had this request to test from NY, who had a concern about stored snow plows.

What we found was the loss of heat from the end of the wand to the surface would not be high enough to kill SLF eggs, and definitely lacking in time of exposure to higher temps, and that was based on hot water bath exposures of egg masses.

We did have information for a Pest Risk Analysis by EPPO where power washing was referenced for removal of egg masses in China.¹ We were able to get the report where this method, along with others, was used to manage or lower populations in a city area in China.²

We did include this method in our methods, with the caveat of not using this method on trees or plant material.

So we really did not actually test the power washing method and just referenced the report from China. Again, we only recommended this method for use on objects or surfaces. I am not aware of any group beside homeowners possibly using this method though.

1. Chen B. (1996) Test on high pressure water spray gun smashing egg masses of Lycorma delicatula. Beijing Garden, 3: 37–38 (in Chinese) — cited in the EPPO Pest Risk Analysis above; this original publication could not be located and isn’t available to link.
2. Zheng YQ (2015) An analysis on causes of outbreak of Lycorma delicatula in Yinchuan City and countermeasures for its prevention and control. Ningxia Journal of Agricultural and Forestry Science & Technology, 56(8): 53–54 (in Chinese) — also cited in the EPPO Pest Risk Analysis; this is the Yinchuan City report. Published via CNKI; no public link available.