Japanese beetle infestation

(Question)

My vines etc. etc. have been decimated! We hung those WW2 looking bomb things and hand picked off the little devils and drown them in soapy water. To the tune of about 20lbs!
We have an order in for nematodes to treat the soil around as many place we can think of. My ques. is
1) Do we repeat the use of nematodes in the spring and if so what month?
We also were told to throw a huge bucket of soapy water to wash the grubs to the surface so the birds will eat them. 2)Do we combine the soapy water treatment with the nemotodes or will we just waste the use of the nemotodes.
Thank you for your time in reading this.

(Answer)

This is a common question posted at this time of year. The Ontario Ministry of Agriculture and Food has a website at the bottom of which there is a lists of plants that are most susceptible to damage by this insect.   To control Japanese beetles you can either control the adult or the larvae. the best method (although still time consuming but strangely satisfying) is to go out in the early morning or in the late evening when they are not as likely to fly around and simply knock them into a small bucket/jar of water (add a few drops of soap) where they drown. You will need to begin this process at the end of June or the beginning of July and continue until sometime in early August. After that, the next method of control is to go after the larva. Nematodes are best applied in August and are watered into the affected area. They attack the larva of Japanese beetle, June bugs and European chafer all of which racoons and skunks like to dig up the lawn in search of. When applying nematodes it is important to keep them refrigerated until you are ready to apply them. Ideally they should be applied on an overcast morning or evening. If the lawn is dry it should be irrigated first with about ½ to 1 inch of water. You should prepare and use the entire pack and water (while agitating) them into the soil. You might need to irrigate the lawn again to “wash” the nematodes into the soil. You can also reference our other responses to this problem at Roses and Grey Grubs in the Lawn