Some Helpful Hints and Tips to get your Flies through the Cold

Introduction

Fruit Flies (Drosophila sp.) are one of the most popular feeder insects for those animals that require smaller prey items, such as poison dart frogs. Unfortunately, these typically easy to culture insects often encounter difficulties with colder weather. This blog entry will address the most common issues, and what to do about them.

Shipping

The reduced temperatures winter brings makes shipping live animals even more difficult than it already is, and shipping fruit flies are no exception. At Josh’s Frogs, we ship using styrofoam lined boxes and with heat packs when the temperature drops, but even so, the interior temperature of a package can vary widely in transit, depending on how it is handled by the carrier, and the length of it’s travels.

During winter, Josh’s Frogs ships using styrofoam lined boxes with heat packs.

In a styrofoam lined box, a fruit fly culture will maintain interior temperatures approximately 10 degrees above that of it’s surroundings. Adding a heat pack will raise the temperatures another 10 degrees. Even at 20 degrees above ambient temperature, the cultures will experience a wide range of temperatures in transit, due to the change in the daytime highs and overnight lows the part of the country the package passes through experiences. This constant temperature shift certainly does not have a positive effect on the fruit fly cultures – at best, it has a neutral effect, and often negatively impacts the culture. It’s very easy for cold weather to slow down or stop the natural progression of a fruit fly culture during shipping. Often, it delays peak production by several days – that is why producing cultures sometimes take a few days to catch up after shipping in winter. If the fruit fly culture is exposed to very cold temperatures, flies, pupae, and/or larvae may perish. Once situated in a proper environment the culture will rebound, but sometimes chilly weather may cause the culture to fail, and/or allow grain mites to exponentially reproduce in the culture, leading to it’s demise.

Temperature

Average house temperature during the winter is substantially less across the United States. Lower temperatures will not necessarily result in less fruit flies produced per culture, but can greatly increase the length of time it takes a culture to produce flies. Accompanying the delay in fly production is an increased threat of grain mites – these pests are capable of reproducing in a much wider range of conditions than fruit flies are. Grain mites are present in all fruit fly cultures, and in most situations are not harmful, but if given the proper conditions, they are capable of overrunning a fruit fly culture, and eventually crashing it. Typically, if the temperature is increased to a level more favorable for fruit flies, they will resume production, and the mites themselves will be out competed.

There are several ways to insure that fruit flies receive the required temperatures during the winter (ideally as close to 78F as possible). The easiest method is to keep the fruit flies near a heat source, such as a water heater or lights used to light the animal enclosures. When trying this, remember that heat rises, and often cultures located nearer the ceiling of a room will be several degrees warmer than ones located near the floor. Alternatively, creating an incubator of sorts for the cultures can keep them warm. Anything from reptile egg incubators to a plastic container with a heat source, such as a basking bulb or heat pad, can be effective.

Humidity

The cold winter weather generally leads to the furnace running most of the time. This not only increases the household temperature, but also substantially decreases the relative humidity. Ideally, fruit fly cultures are maintained at 60-80% humidity, and lower humidity can result in the culture media drying out, allowing a ‘skin’ to form over the surface of the media (just like pudding can form a ‘skin’ if left in the fridge). This ‘skin’ will suffocate the larvae, or cause them to climb up the sides of the culture in search of oxygen. Spraying the culture with a bit of water will correct this issue.

Under ideal humidity, fruit fly pupae should be concentrated around the mid level of a culture.

By looking at the placement of pupae on the side of a culture, you can infer if the culture is receiving the proper humidity or not. Under ideal conditions, the pupae will be spread evenly throughout the sides of the culture, with most of them located at mid level. If most of the pupae are located at the top of the culture, the humidity is too high. If the pupae seem concentrated lower in the culture, towards the media, the humidity is too low. Keeping cultures in plastic storage drawers, such as those made by Sterilite, is a quick and easy way to insure that proper humidity is maintained.

Conclusion

Winter poses many challenges to the proper production of fruit flies. Using the hints and tips outlined in this blog post, most problems can be solved quickly, and plenty of fruit flies can be produced for your herps.

Providing Quality Fruit Flies Since 2004

Introduction

Since 2004, Josh’s Frogs has produced our own fruit fly media and cultures. Demand for both products continue to grow, and we thought we’d share what goes in to providing thousands of high quality fruit fly cultures to the pet trade.

Media

Let’s start by discussing Josh’s Frogs Fruit Fly Media. We are the only company to offer specific medias for the two most popular species of fruit flies – Drosophila melanogaster and D. hydei. Both will do well on either media, but will truly thrive on their specific media. Josh’s Frogs Fruit Fly media is enriched with vitamins, minerals, and other ingredients to insure the best nutrition possible. Methyl paraben, a food grade ingredient, is used to prevent mold growth. Our media is easy to use, inexpensive, and is known for it’s ability to produce thousands of flies. Demand continues to grow – in 2011, we sold over 11 tons of Josh’s Frogs Fruit Fly media, all produced right here in Owosso, Michigan. By buying ingredients in quantities larger than the average consumer (we buy potato flake by the ton), we’re able to provide a top quality product cheaper than you’d be able to if you made it yourself!

We made and sold over 12 tons of fruit fly media last year!

Making the Fruit Fly Cultures

Every week, staff at Josh’s Frogs makes over 1000 fruit fly cultures. This may seem a daunting process, but it can easily be broken down into several basic steps.

Step 1: Bring water to a boil – we boil filtered water 16 gallons at a time using 4 large coffee urns.

Step 2: Place ½ cup of Josh’s Frogs Fruit Fly Media in a 32oz insect cup.

Step 3: Add 2/3 cup boiling water. We do not mix the water and media – the fruit fly larvae will do that for us!

Step 4: Add excelsior – this provides surface area for the flies to crawl and lay their eggs on. It also keeps the culture intact during shipping.

Step 5: Allow media to cool. We cover the cultures at this point to prevent contamination from flying flies.

Step 6: Add 50-100 fruit flies.

Step 7: Cover culture with a vented insect cup lid.

Caring for Cultures

After the cultures are made, they are incubated in a special ‘bug room’, which is maintained at 78F and a humidity of 70% – optimum conditions for fruit flies. We store the cultures in plastic storage drawers – each drawer holds a dozen cultures, making it easier to transport them around the facility, as well as maintaining the proper humidity in the culture. Paper towels, innoculated with mite spray, are placed in the bottom of each drawer. Between batches, all of the storage drawers are sterilized with bleach.

All of our cultures are incubated at 78F in our bug room.

Every storage drawer is sterilized between each batch of flies.

Conclusion

Josh’s Frogs is the leading producer of 32oz Fruit Fly cultures in the world – we shipped out over 30,000 cultures last year! We strive to provide the pet industry with quality cultures – hopefully, this blog post illustrates the challenges of being the industry leader, and shows how we meet and exceed those challenges.

A Comparison of Drosophila melanogaster and D. hydei

Introduction

Fruit flies (Drosophila sp.) are a common feeder insect when animals that require small prey items are involved, such as dart frogs. Although several different species have made the rounds in the hobby, 2 have consistently been cultured over the years, and remain the most common and easy to work with.

Fruit flies are easy to culture, making them one of the most popular feeder insects for animals requiring small prey items.

Drosophila melanogaster

Drosophila melanogaster (also know as melanogaster, melanos, or mels) are probably the most commonly encountered species of fruit fly in culture, and measure about 1/16^th of an inch long, making them ideal as the staple food for a variety of dart frogs and other animals that prefer smaller prey items. Melanogaster fruit flies have been used to years in genetics experiments around the world, and as such, there are several different genetic mutations of them available. Perhaps the most useful to the average hobbyist is the ‘wingless’ form. These flies lack wings, and as such are unable to fly. Unlike the ‘flightless’ D. melanogaster, the wingless form cannot regain the ability to fly if it gets too warm (the ‘flightless’ deformation is linked to protein folding – if the flies reach a certain temperature, the proteins fold properly and the next generation will be able to fly). The ‘wingless’ trait is recessive – both parents have to carry the trait in order for the offspring to remain wingless. If a ‘wild type’ fly (one with wings) mates with a ‘wingless’ fly, the offspring will be able to fly.

Drosophila melanogaster are a smaller fruit fly, measuring about 1/16” long.

The life cycle of Drosophila melanogaster is very quick. Within 14 days of setting up a new culture, the next generation of flies is emerging. After that 14 day waiting period, new flies emerge every day. This quick generation time means that the culture will produce thousands of flies, fairly consistently, from day 14-28, when the culture is disposed of. Because of this, melanogaster fruit flies are generally preferred by those who are new to culturing fruit flies – melanogaster tend to be more forgiving and easier to culture consistently.

Melanogaster fruit fly cultures will produce thousands of flies over a 28 day period.

Drosophila hydei

Drosophila hydei (also known simply as hydei) are another commonly encountered fruit fly in the hobby. Hydei measure about 1/8”, and are quite a bit larger and ‘meatier’ than D. melanogaster – perfectly suited for dart frogs that prefer larger prey items, or other pets with similar needs. A ‘flightless’ form of hydei is most commonly available – this strain will not revert back to fliers at a higher temperature, unlike ‘flightless’ melanogaster. Like the ‘wingless’ form of melanogaster, this trait is recessive, requiring both parents to carry the trait in order for the offspring to be flightless. Every care should be taken to insure that flying Drosophila hydei do not get into the culture, as the resulting flying insects can quickly become a nuisance.

Drosophila hydei are a larger fruit fly, measuring about 1/8” long.

Compared to that of D. melanogaster, the life cycle of D. hydei is much longer. At average temperatures, it will take 21 days or more until the first new hydei being emerging in a culture. Hydei fruit fly cultures show a particular ‘boom and bust’ cycle – the culture will appear empty, only to suddenly be filled with flies overnight. Most cultures will have 2-3 booms, with 5-7 days between each one. With the large period of time between active booms, hydei cultures are much more likely to dry out than melanogaster, and as such are more prone to crashes and grain mite infestations.

Drosophila hydei fruit fly cultures are more prone to drying out and crashing, due to their ‘boom and bust’ life cycle.

Conclusion

Both species of fruit flies popular in culture are relatively easy to culture. Generally speaking, Drosophila melanogaster – the smaller fruit fly – is easier to culture for novices, and is perfectly suited for most species of dart frogs. Drosophila hydei – the larger fruit fly – will produce more ‘meat’ over the life of the culture, but is more suceptible to crashes.

Next week, we’ll take a look at what goes in to producing all of the fruit fly cultures at Josh’s Frogs.