[rmk9785e]

We had our SFH in Northern California vacated a couple of months ago and it was roach infested with German and American roaches. We initially used pesticide smoke cans and they did kill many but not all. Then we purchased Advion gel bait tubes and applied it at all places it could be consumed by them but it didn't help much as it dries out quickly. Next I've sprayed Boric Acid all around the baseboards, cabinets, under the stove/oven and refrigerator.

I still see a few around.
What should I do next to rid of roaches while the house is empty before the next tenant moves in?

 

[Nik333]

Was the house cleaned well?


Is there something outside that is attracting them?

 

[rmk9785e]

Was the house cleaned well?
Is there something outside that is attracting them?

Yes, the whole house was cleaned and carpets were professionally cleaned as well. There has been no food in the house for 2 months and the only source of water is the drains or toilets. There's nothing visible outside the house that could attract them.

 

[ChuckTin]

Good luck!
First I'd look at the drains and water lines. Roaches, I was told, are water bugs. Then I'd close and seal all doors and windows and bomb the place. Here I Fly I can still find some places that sell pesticides that work. Best to _throughly_ air the place out afterwards.

 

[DoomsDave]

We had our SFH in Northern California vacated a couple of months ago and it was roach infested with German and American roaches. We initially used pesticide smoke cans and they did kill many but not all. Then we purchased Advion gel bait tubes and applied it at all places it could be consumed by them but it didn't help much as it dries out quickly. Next I've sprayed Boric Acid all around the baseboards, cabinets, under the stove/oven and refrigerator.

I still see a few around.
What should I do next to rid of roaches while the house is empty before the next tenant moves in?

Those roaches make bunny rabbits seem downright celibate by comparison. Females lay egg cases that hatch into legions and legions of babies that grow into like numbers of adults, which lay more egg cases, and . . ..

All the materials you've already tried will work and appear to have worked, but I suggest one more thing in addition:

"Growth regulator" or growth inhibitor. It's a hormone that, sprayed in the areas the roaches run, prevents baby roaches ("nymphs") from maturing to adulthood by stopping them from shedding their skin, and stopping the reproductive cycle. The really great thing also is: it only hurts the bugs, not you or your pets, and it works on fleas, too. There's no odor, it won't stain things. Just spray it, as much as possible, where it won't get washed off by water.

The only downside is that it takes a bit of time. But, it works. The one for "german" roaches will work on "American" roaches, too. Murder 'em all.

If you feel really desperate, you can tent the house and fumigate it with methyl bromide or like chemical. That kills EVERYTHING. Including roach egg cases. But it's costly, and MB might have been banned.

I'll bet that if you do a good job with the inhibitor, the roaches will stop appearing. That said, if you want to try and plug drains, etc., can't hurt.

https://www.amazon.com/s?k=german+roach+growth+regulator&crid=1ALFY89JIS4RO&sprefix=german+roach+gro%2Caps%2C190&ref=nb_sb_ss_organic-pltr-v2_1_16

Let us know what you do and how it goes.

GOOD LUCK!

 

[PestGuy]

90% of a german roach job is inspection. They could be anywhere.

 

[DoomsDave]

We had our SFH in Northern California vacated a couple of months ago and it was roach infested with German and American roaches. We initially used pesticide smoke cans and they did kill many but not all. Then we purchased Advion gel bait tubes and applied it at all places it could be consumed by them but it didn't help much as it dries out quickly. Next I've sprayed Boric Acid all around the baseboards, cabinets, under the stove/oven and refrigerator.

I still see a few around.
What should I do next to rid of roaches while the house is empty before the next tenant moves in?

So, advise of progress or otherwise?

This is all a public service. :vs_cool:

 

[user_12345a]

You can't use contact killer bug sprays and the gel at the same time.

They can sense the spray and it repels them.

The repellent sprays never get rid of the infestation.

Also, roaches develop tolerance for baited products very quick - the chemicals the manufacturers have to change every few months or years and the roaches are always one step ahead.

 

[ultrazonex]

Pest Control Companies are usually effective, but sometimes only after 2-3 consecutive treatments.

Therefore, I only sign contracts with pest control companies that offer a “guarantee” that they will eliminate the pests – which means they will continue to come back for follow-up treatments until the pesky invaders are gone.

 

[DoomsDave]

You don’t need to hire a company unless of course someone ELSE is paying the bill.

I did it they are still gone and it was worth the trouble.

 

[Calson]

I have used dry bait as a control but it is also important to seal any openings around your indoor plumbing using spray foam. Sink valves and drain openings in walls are seldom sealed. This will also help with air intrusion so a win-win.

I had a problem with critters getting in through my floor vents and removed the grates and applied caulk between the sheet metal ducting and the wood subflooring and this fixed the problem.

 

[dj3]

I use BORIC ACID powder. Cheap and effective.

 

[rmk9785e]

So, advise of progress or otherwise?

This is all a public service. :vs_cool:

Thank you all for your advice and ideas. I learned much from your shared knowledge. I finally contracted with a reputable local pest control business. They are taking care of it in coordination with the tenant.
It seems the former tenants were not keen at cleanliness. There were a lot of food crumbs in all nooks and crannies. Next time I'll try the Growth Inhibitor/regulator.

 

[DoomsDave]

Thank you all for your advice and ideas. I learned much from your shared knowledge. I finally contracted with a reputable local pest control business. They are taking care of it in coordination with the tenant.
It seems the former tenants were not keen at cleanliness. There were a lot of food crumbs in all nooks and crannies. Next time I'll try the Growth Inhibitor/regulator.

Always nice to hear back! And to hear of success.

But . . . if failure, that teaches, too.

If you're really concerned about roaches going forward, maybe treat with growth inhibitor as often as you can, whether you need it or not? It gets rid of fleas, too.