---
product_id: 63075595
title: "Cluster Fly Killer Spray 2 x 1Ltr - Formula 'C+' Advanced Cluster Fly Spray (UK Government HSE approved and tested – professional strength for amateur use)"
brand: "pest expert"
price: "Bs.1674"
currency: BOB
in_stock: true
reviews_count: 8
category: "Pest Expert"
url: https://www.desertcart.bo/products/63075595-cluster-fly-killer-spray-2-x-1ltr-formula-c-advanced
store_origin: BO
region: Bolivia
---

# Fast-acting knockdown Water-based & low-odour 12-week residual protection Cluster Fly Killer Spray 2 x 1Ltr - Formula 'C+' Advanced Cluster Fly Spray (UK Government HSE approved and tested – professional strength for amateur use)

**Brand:** pest expert
**Price:** Bs.1674
**Availability:** ✅ In Stock

## Summary

> 🦟 Zap cluster flies fast, stay fly-free longer!

## Quick Answers

- **What is this?** Cluster Fly Killer Spray 2 x 1Ltr - Formula 'C+' Advanced Cluster Fly Spray (UK Government HSE approved and tested – professional strength for amateur use) by pest expert
- **How much does it cost?** Bs.1674 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.bo](https://www.desertcart.bo/products/63075595-cluster-fly-killer-spray-2-x-1ltr-formula-c-advanced)

## Best For

- pest expert enthusiasts

## Why This Product

- Trusted pest expert brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Long-Lasting Defense:** Up to 12 weeks of continuous cluster fly protection with residual effect
- • **Safe & Clean Application:** Water-based, non-staining formula with low odour for indoor use around family
- • **Triple-Action Powerhouse:** Three potent actives including insect growth regulator for total lifecycle disruption
- • **Rapid Results, Real Relief:** Kills cluster flies on contact, stopping infestations fast and preventing rebounds
- • **Maximum Coverage Efficiency:** 2L pack covers 100m², delivering cost-effective, professional-grade pest control

## Overview

Pest Expert Cluster Fly Killer Spray Formula 'C+' is a UK Government HSE approved, professional-strength, water-based spray combining three active ingredients—including an insect growth regulator and natural pyrethrum—to deliver fast, effective cluster fly eradication and up to 12 weeks of residual protection. Its low-odour, non-staining formula covers 100m² per 2L pack, making it ideal for homes and businesses seeking a powerful, safe, and long-lasting solution to cluster fly infestations.

## Description

Pest Expert Formula 'C+' Cluster Fly Spray is a fast-acting cluster fly killer with a long-lasting residual that helps maintain cluster fly control. Our latest innovative formulation incorporates two additional active ingredients. The first is pyriproxyfen, a ground-breaking insect growth regulator that halts the progression of the lifecycle development from juvenile to adult, resulting in the inability for the fly to reproduce. The second is the addition of chrysanthemum cinerariaefolium extract, a natural pyrethrum, which when combined with cypermethrin (0.1%) has a synergistic effect, helping to deliver an even faster knockdown and longer-lasting residual for ongoing control of all lifecycle stages. Pest Expert Formula 'C+' is the most powerful cluster fly killer spray available to the amateur market, offering both fast-acting and long-lasting cluster fly control to help you eradicate a cluster fly infestation in your home, loft or roof space. Formula 'C+' Cluster Fly Spray should be applied to any alighting surfaces including window frames and roof timbers. Formula 'C+' is water-based and low-odour, making it perfectly suitable for use in homes with children and/or pets, provided they are kept out of the area being treated until all surfaces are dry (2-3 hours).

Review: This works - and keeps on working! - We moved into an old house, three years ago, in a rural setting, that turned out to be infested (and I mean properly badly infested - hundreds of the little blighters every day) with cluster flies in the loft. They come into the eaves through the (old and gappy) roof tiles, then come into the loft room from the eaves, they also find their way into the inside of the frames of the velux windows. I sprayed this onto the glass of the velux windows, and also opened the velux windows and sprayed all round the inside of the frames. It doesn't deter the flies from coming in, but it certainly kills them (very quickly) once they have landed on an area that has been sprayed. I got a second hand vacuum cleaner specifically to keep in the loft to hoover them all up. I re-apply the spray every couple of months, which seems to keep the killing power going. This year, we have noticed that there have been far fewer flies than the previous years, so I think we are gradually winning. (Cluster flies leave scent markings where they get in to let other cluster flies know it's a good place, so, as long as we can keep decreasing the numbers, I'm hopeful that the end of the infestation will eventually come!!) There are also carpet moths in the loft room (it's a boarded, carpeted room, but not to the standard of a room you could properly use, it's really just a storage area with carpet) and this spray seems to work on them too - I've sprayed loads on the carpet at the doorway in the hope that the carpet moths won't spread to the carpets in the rooms that we do use - the joys of living in an old house......!! One note, it's strong stuff, so I always wear gloves and a mask when I use it, I still sometimes can smell it - even with an FFP3 mask on, which I don't like as I reckon that if I can smell it, that means it's going into my lungs - so please use carefully!
Review: Finally a product that produced lasting results! - I have been fighting flies in my house for the past 10 days due to humidity in the subfloor of my kitchen and using Raid was not enough - it would kill them sure but they kept laying eggs so the next day I would have >20 more flies. This product after I sprayed it on the areas where the flies would hang they all immediately died within 1 hour. Around ~40 flies where dead near my window. I 100% recommend this product it was the best solution. It also left no smell in the applied area. I can also confirm that the affected area stays "affected" even in the following day as I have not sprayed again but any flies that approach it die.

## Features

- ✅ THE STRONGEST CLUSTER FLY SPRAY ON THE MARKET – Our latest innovative formulation contains three powerful active ingredients making it unparalleled in its ability to eradicate cluster fly infestations from the home or business.
- ✅ NEWLY DEVELOPED FORMULATION – Now containing three powerful active ingredients, including an Insect Growth Regulator, Formula C+ kills cluster flies on contact and halts the progression of the cluster fly lifecycle development, resulting in no new numbers.
- ✅ FAST ACTING AND LONG LASTING – The three potent active ingredients work in a synergistic way helping to deliver an even faster and more widespread knockdown of cluster fly and leaves an insecticidal residue that continues to protect for up to 12 weeks.
- ✅ NON-STAINING AND LOW-ODOUR – Formula C+ is a ready-to-use, water-based spray so can be applied directly to any surface and furniture without causing any damage or nasty lingering smells.
- ✅ INCREASED COVERAGE – 2 x Formula C+ now covers 100 square meters in a single application making it the most cost-effective cluster fly spray on the market.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B012D9M39Q |
| Best Sellers Rank | 13,185 in Garden ( See Top 100 in Garden ) 145 in Fly Control |
| Customer Reviews | 4.4 4.4 out of 5 stars (369) |
| Date First Available | 24 Jun. 2015 |
| Manufacturer | Pest Expert |

## Product Details

- **Brand:** Pest Expert
- **Item form:** Spray
- **Liquid volume:** 1000 Millilitres
- **Specification met:** USDA
- **Target species:** Insect,Flies

## Images

![Cluster Fly Killer Spray 2 x 1Ltr - Formula 'C+' Advanced Cluster Fly Spray (UK Government HSE approved and tested – professional strength for amateur use) - Image 1](https://m.media-amazon.com/images/I/71lQiFZ1g6L.jpg)

## Questions & Answers

**Q: Would this be ok to use if you have dogs?**
A: Hi, yes providing the dogs are kept out of the room you're treating until the spray has fully dried (roughly 1 hour).

**Q: Can you use on house plant soil?**
A: I wouldn’t - you have to wear a mask to spray it and then leave the room for a couple hours
So that can’t be good for soil

**Q: Can it be used indoor?**
A: I normally use it around the window frames outside just on the edge so bordering the inside frame but please follow instructions and wear the mask (although we are all wearing them these days ) it leaves a bit of a fly killer smell but it soon goes and it’s worked for me !! 
I never saw a cluster fly at all last year probably get two or three applications out of it depending on how many Windows and doors you have but it’s good stuff !! 
Happy spraying 😹

**Q: Can this be used for regular house flies?**
A: I wouldn’t be spraying freely around house. It is strong and should be left for hour before reentering room. I have only used it around window frames where cluster flies gather.

## Customer Reviews

### ⭐⭐⭐⭐⭐ This works - and keeps on working!
*by N***6 on 11 September 2022*

We moved into an old house, three years ago, in a rural setting, that turned out to be infested (and I mean properly badly infested - hundreds of the little blighters every day) with cluster flies in the loft. They come into the eaves through the (old and gappy) roof tiles, then come into the loft room from the eaves, they also find their way into the inside of the frames of the velux windows. I sprayed this onto the glass of the velux windows, and also opened the velux windows and sprayed all round the inside of the frames. It doesn't deter the flies from coming in, but it certainly kills them (very quickly) once they have landed on an area that has been sprayed. I got a second hand vacuum cleaner specifically to keep in the loft to hoover them all up. I re-apply the spray every couple of months, which seems to keep the killing power going. This year, we have noticed that there have been far fewer flies than the previous years, so I think we are gradually winning. (Cluster flies leave scent markings where they get in to let other cluster flies know it's a good place, so, as long as we can keep decreasing the numbers, I'm hopeful that the end of the infestation will eventually come!!) There are also carpet moths in the loft room (it's a boarded, carpeted room, but not to the standard of a room you could properly use, it's really just a storage area with carpet) and this spray seems to work on them too - I've sprayed loads on the carpet at the doorway in the hope that the carpet moths won't spread to the carpets in the rooms that we do use - the joys of living in an old house......!! One note, it's strong stuff, so I always wear gloves and a mask when I use it, I still sometimes can smell it - even with an FFP3 mask on, which I don't like as I reckon that if I can smell it, that means it's going into my lungs - so please use carefully!

### ⭐⭐⭐⭐⭐ Finally a product that produced lasting results!
*by D***R on 20 June 2025*

I have been fighting flies in my house for the past 10 days due to humidity in the subfloor of my kitchen and using Raid was not enough - it would kill them sure but they kept laying eggs so the next day I would have >20 more flies. This product after I sprayed it on the areas where the flies would hang they all immediately died within 1 hour. Around ~40 flies where dead near my window. I 100% recommend this product it was the best solution. It also left no smell in the applied area. I can also confirm that the affected area stays "affected" even in the following day as I have not sprayed again but any flies that approach it die.

### ⭐⭐⭐⭐ Helped in the hard to get areas
*by S***Z on 21 February 2022*

Flies with in barn in dec/ jan

## Frequently Bought Together

- Pest Expert Cluster Fly Killer Spray 2 x 1Ltr - Formula 'C+' Advanced Cluster Fly Spray (UK Government HSE approved and tested – professional strength for amateur use)
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- Pest Expert Formula ‘P+’ Cluster Fly Killer Fogger Treatment 4 x 150ml – Maximum Strength Fly Bombs for Fast-Acting Effective Control, Professional Strength for Approved Amateur Use

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*Product available on Desertcart Bolivia*
*Store origin: BO*
*Last updated: 2026-01-24*