Blue bottles, thunder flies, and house flies: Information and how to get rid of them

Flies are a nuisance, and as summer approaches and you’re more likely to have the windows open, it’s good to be prepared for this pest. This article hopes to both give you a bit more information on the various types of flies (so that you can prevent an infestation), as well as some top tips on how to get rid of them if they’re a common sight in your house. It’s not often maggot or fly infestations get so bad that pest professionals such as ourselves have to intervene, but we have seen some extreme cases in the past, and if you are unsure as to whether you can take care of your pest problem, do get in touch.

The different types of flies

There are many different types of flies: in fact, there are around 120,000 different species. We definitely don’t have space in this article to discuss them all, but we’ll do our best to focus on the three of the most common kinds! We’re going to look at blue bottles, thunder flies, and house flies.

Blue bottle flies

Blue bottle flies are one of the most common types of fly in the UK. They’re a real nuisance if they get into your house because not only are they loud, but they can also lay larvae that in turn produce more blue bottles!

Where do blue bottle flies come from?

Blue bottles flies are found all over the world, so, unfortunately, it doesn’t really matter where you live. They’ll mostly be found outside, but will sometimes fly into your house through open doors and windows.

What do blue bottle flies eat?

Blue bottle flies will feed on pretty much anything organic. So any food left out, say fruit, for example, will attract them. The problem usually worsens if there’s any decaying food that’s easily accessible, as this is particularly attractive to flies.

Thunder flies

Thunder flies, sometimes referred to as thrips, are another incredibly common pest. They’re typically small, slender, and dark coloured, and feed predominantly on plant sap.

House flies

Similar to blue bottles, house flies can be found all over the world. They’re slightly smaller than blue bottles, and duller in appearance. Again, they feed on pretty much any food that might be left out, and are particularly common around bins where decaying food can be found.

How do flies reproduce?

The lifecycle of flies is a complex one consisting of four stages: egg, larva, pupa and adult fly. Initially, the female fly lays eggs fly eggs in virtually any warm and moist material that will offer food for the larvae. The environment must remain wet and above 12 degrees to hatch. The female fly can lay around 500 eggs over three or four days, laying in batches of 75 to 150 eggs, and in warm weather, these eggs can hatch in 12 to 24 hours.

These eggs then develop into the second stage of the lifecycle: larvae, also recognised as maggots. The maggot’s outer layer then hardens as it develops through the lifecycle and as the fly transforms into a pupa, as seen below. From this, the adult fly emerges, using a large expanding sac on its head called a ptilinum to break its way out. Adult flies optimally live for 15-25 days but can live for up to two months, although without food they can only survive for 2-3 days. Adult flies require nutrition before they will copulate. Once they have eaten, copulation will be completed in as little as two minutes or as long as 15 minutes. Female flies also need food, specifically protein, to produce eggs, and with the right nutrients, oviposition will begin 4-20 days after copulation.

understanding lifecycle of a fly maggot larvae into pupae to prevent fly infestation

Understanding biology to prevent flies

Understanding that flies need warmth, moisture and food to copulate, develop and hatch means that you can prevent them at every stage of their lifecycle. In summer, of course, flies are more prevalent because of the temperature,  so ensure that all waste food put in bins outside is tightly seated – double-bagging all rubbish is a good way to make sure fly eggs cannot be laid in the warm, decomposing food.

If you have a dog or other pet that leaves faeces outside where flies can lay eggs on them, try to tidy this away as much as possible as manure offers particularly good nutrition and moisture for flies. Keep bins and other surfaces clean and dry wherever possible (flies need moisture to hatch) and avoid letting food rot in the open, such as ripe fruit falling from trees in your garden.

Do maggots become flies?

The larvae (or maggots) which you might find in bins or on rotten food, will then develop into pupae. It’s after this stage that the adult fly emerges from the pupae. The fly which emerges from the pupae is fully grown and developed.

How long does it take for fly larvae to hatch?

At optimal temperatures (35 to 38°C) fly larvae can hatch as quickly as one week or as long as a fortnight, but at lesser temperatures (12 to 17°C) can take up to two or three months.

Dealing with flies in the house

There are a number of different ways of getting rid of flies in your home if they’ve become a real problem. First off, you could buy a fly trap. These can be either chemical traps which attract flies with different scents, or UV light traps.

Secondly, you can use an insecticide to spray the areas on which flies might be resting, or use an insecticide aerosol spray in order to deal with flies immediately.

But really, as in many cases, prevention is better than cure. It’s best to make sure that all food and materials on which flies could lay their eggs are kept well away in cupboards or your fridge. Doing this can mean you won’t have to bother with any of the more expensive methods of fly removal at all!

We hope you found this information useful – let us know via our Twitter or Facebook what you’d like to learn more about, or what you found most interesting!

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