Ortho Orthene Fire Ant Killer (Works for Roaches Too!)

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Ortho Orthene Fire Ant Killer is a popular fire ant killer that works great against roaches.

Here’s a detailed breakdown on what this product is, as well as how to use it on both ants and roaches.

What is Ortho Orthene Fire Ant Killer?

Ortho Orthene is a powerful insecticide that can potentially kill a whole host of unwanted insect pests, including roaches. Ortho has marketed this product for use against fire ants, but it retains its ability to kill other creepy crawlies as well.

It comes in a 12-ounce container of granules and works best when used as part of the Ortho 2-Step System.

Ortho Orthene Fire Ant Killer
  • Starts to kill in hours
  • No watering-in required
  • Reduced odor formula

Active Ingredients

Unlike most pesticides which have a tiny percentage of active ingredients, Orthene contain a whopping 50 percent acephate.

Acephate can be described as a wide range of organophosphate types, but what’s important is that it works.

The chemical is a contact insecticide primarily designed to fight aphids and other pests on vegetable plants such as tomato or carrots.

It’s moderately persistent, meaning acephate continues to function as a systemic insecticide for up to 15 days. Acephate has a highly soluble white powder form, taking on a white appearance. In other products, it can also be colorless.

Did You Know?
The name "Orthene" is registered to Ortho. However, due to Ortho's fame as a pesticide company, the name Orthene is actually considered a valid synonym for acephate. It's a lot like how we use "Q-Tip" and "Lego" to often describe a range of products when they're actually specific brands.

How Does Ortho Orthene Work Against Fire Ants?

Ortho Orthene for roaches

This product is meant to be used as a mound treatment when dealing with fire ants and works in two ways.

When sprinkled on a mound, it will affect any ants that walk on it. These ants may also track it into the nest, affecting other ants.

If ingested, the acephate is converted into methamidophos, an even stronger insecticide. In this form, it can be passed between ants as they share food from their communal stomachs.

For both chemicals, the nervous system is affected, causing nerves and muscles to become overactive. In a short amount of time (usually around an hour), the effects become lethal.

How Long Does It Take Orthene to Work?

As mentioned, it only takes about 60 minutes to kill an exposed ant.

Depending the mound size, an entire colony can be wiped out in as little as 3 to 7 days.

What Else Does Orthene Get Rid Of?

As mentioned, acephate was originally designed to kill plant pests.

Some of these include:

  • Ants
  • Aphids
  • Bagworms
  • Mealybugs
  • Roaches
  • Spider Mites
  • Thrips

However, while this product will work on other bugs, it’s formulated to be used exclusively for fire ants.

Is Orthene Toxic?

While generally considered safe, Acephate can have toxic effects if inhaled or ingested.

Symptoms in humans may include:

  • Abdominal cramps
  • Confusion
  • Diarrhea
  • Dizziness
  • Increased heart rate
  • Nausea
  • Shaking
  • Sweating

Thankfully, most of the acephate will pass through your body quickly and without undergoing chemical changes.

However, the effects will be worse in children and those with a compromized immune system.

Is Orthene Safe for Pets?

Again, the effects can vary and will depend on your pet, but the effects are certainly more severe.

Symptoms in dogs may include:

  • Diarrhea
  • Difficulty breathing and/or walking
  • Shaking
  • Vomiting

Cats and small dogs will have a more severe reaction than larger dogs or livestock. Acephate can be fatal to birds.

When to use Orthene for Fire Ants

This product works best if applied when the ants are most active. You should also apply it as soon as you discover a new mound.

Its effectiveness will decrease in prolonged heat or dry conditions.

Also, try not to apply during a heavy dew or right before rain is expected, as this will wash the powder away.

Finally, make sure you don’t apply it if bees are actively gathering nearby and are at risk of exposure.

Application Instructions

Perhaps the single biggest complaint you’ll find in Ortho Orthene Fire Ant Killer reviews is the lack of clear application instructions.

This is important, because there are some big differences from how you would apply similar products.

Here are more complete instructions based on the 2002 EPA product label proposal sheet:

  1. ONLY use this product around lawns and ornamental plants (including flowers, shrubs, and trees)!
  2. DO NOT use on or near blooming plants where bees are active or near water!
  3. DO NOT shake the container before applying.
  4. Open the container and sprinkle 1 tablespoon of the powder directly onto the ant mound.
  5. Avoid disturbing the mound and do not water-in.
  6. Repeat if ants return.

You can optionally follow up with Ortho Fire Ant Killer Broadcast Granules as part of a 2-step fire ant method that ensures these pests won’t return for up to 6 months.

Ortho Fire Ant Killer Broadcast Granules, 6 Month Protection, Treats up to 5,000...
  • Ortho Fire Ant Killer Broadcast Granules target and kill fly-in queens to...
  • FAST ACTING: This outdoor fire ant killer will kill fire ant mounds in 15...
  • PROTECT THE GROUND: Treat the entire lawn area to protect your lawn from fire...

Can You Use Ortho Orthene For Roaches?

Yes, you can use Ortho Orthene Fire Ant Killer on roaches with excellent results!

In fact, a huge percentage of people who purchase this product use it specifically for roach control.

Using Ortho in this manner may count as a Federal usage violation, as roaches are not listed on the label. The following sections should be considered as being provided for informational purposes only.

Can You Use Orthene for Roaches in the House?

Well, yes and no.

When Acephate was originally registered with the EPA in 1973, it was cleared for use in homes, commercial and industrial buildings, on golf courses, and many other places.

However, as time went on, its use indoors became more restricted.

Today, it’s not recommended to use acephate products indoors due to the potential health risks. Orthene’s product details only designate it for use on ant mounds.

How to Use Ortho Orthene for Roaches

Let’s be clear here: Since Ortho Orthene is meant for fire ants, we can’t tell you exactly how to use orthene for roaches.

In most cases, orthene roach killer products come as granules.

Consumers seem to get around this problem by using a mix of sugar and ortho powder for roaches.

This homemade bait is then placed in small trays where kids and pets can’t reach it.

The roaches will consume this bait and die not long after.

Known Issues When Using Orthene Powder for Roaches Indoors

Who’s making kimchi behind the stove?

If you’re using Ortho’s orthene ant killer for roaches, there will be a number of potential problems not present if using the product as directed.

For example, there’s a much higher chance of coming into contact with the powder.

If the powder gets into your eyes or nose, it can lead to irritation or worse problems.

There’s also a higher risk of contaminating food.

But perhaps the worst issue is that Ortho Orthene smells bad – really bad.

Some have described it as smelling like rotting cabbage, while others say it smells like warm or spoiled milk.

Either way, be sure the room is well-ventilated so you’re not breathing in the fumes.