Lighting for Black Soldier Fly Breeding
Note: Definitions of the various units of measurement used below are shown at the bottom of the page (link). Formal Research I've found very little research on-line about lighting used for rearing BSF indoors. A 2002 study (by Tomberlin et al.) tried 430-watt Pro Ultralight light and 40-watt Sylvania Gro Lux systems but mating was not observed and infertile eggs were oviposited.
A 2010 paper on the Journal of Insect Science website (www.insectscience.org) details successful indoor breeding in China using a 500-watt quartz-iodine lamp. It notes that mating peaked "at a light intensity of approximately 110 µmol m²sı".The study concluded that "... wavelengths from 450 to 700 nm were influencing mating behavior". That matches light from a Compact Fluorescent Light (CFL) according to this FDA (link):
"Since CFLs are designed to provide general illumination, the majority of the light emitted by CFLs is localized to the visible region of the spectrum (approximately 400-700 nm in wavelength). In addition, typical CFLs emit a small amount of UVB (280-315 nm), UVA (315-400 nm) and infrared (> 700 nm) radiation."
Citizen Science It's interesting that a lot of the existing on-line information about rearing BSF indoors comes from herptile (reptiles and amphibians) and permaculture (feed for chickens, fish, etc.) forums. A good example of this is the 'Breeding of the black soldier fly (Hermetia illucens)' topic (link) at the Terrarienbilder.com forum (in German). This information, along with information in the Black Soldier Fly Forums (link) in late 2011, document that mating can be achieved in a fairly small space (storage tote size) using bright artificial lighting rated at 3500 lumens and above. There are further discussions about sunlight and lighting on forums (link and link). Using this information I successfully bred BSF indoors using Compact Fluorescent Lights rated at a total of 4100 lumens (two 1600 lumen 23 watt and one 900 lumen 14 watt) in 2012 (link). The lights were in reflectors immediately over top of a small bin and were on three hours daily on average. Direct sunlight measures between 32,000 and 130,000 lux while full daylight (not direct sun) is between 10,000 and 25,000 lux (link). My bin is about 1/4 square metre and the lights are rated at 4100 lumens which works out to about 17,000 lux or well below the values given for sunlight but within those for daylight. It would also seem logical that bulbs that produce a temperature similar to daylight would work best. Wikipedia (link) lists daylight as between 5000K and 6000K. However I checked the CFLs I used in 2012 and the 14watt 900 lumen bulb is indicated to produce a color temperature of 2700K. I couldn't find a color temperature for the 23watt 1600 lumen bulbs but both types are labelled as 'soft white' so they are probably the same. So it looks like color temperature might not be as important as intensity. One concern with fluorescent lights is "cathode decay" which results in a loss of intensity over time (link).
Lighting Used In Successful Indoor BSF Breeding Systems Below is a short summary of the systems I've found to date. Note that some of the lights used may not be available everywhere.
Units Of Measurement Lumens (link) are a measure of the "amount" of visible light emitted as compared to the more familiar Watts which are actually a measure of the power consumed.
Lux (link) - One lux is equal to one lumen per square metre:
"A flux of 1,000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance of 1,000 lux. However, the same 1,000 lumens, spread out over ten square metres, produces a dimmer illuminance of only 100 lux."
Color temperature (link) - daylight is shown as between 5000K and 6000K.
"Color temperature is conventionally stated in the unit of absolute temperature, the kelvin, having the unit symbol K."
Nanometre (link) - (symbol nm) is a unit of length equal to one billionth of a metre.
"The nanometre is commonly used to specify the wavelength of electromagnetic radiation near the visible part of the spectrum: visible light, in particular, ranges from 400 to 700 nm."
Photosynthetic Photon Flux Density (PPFD) - Full Sunlight in Summer @ Noon = 2000 PPFD (link).
Expressed as µmol m²sı (micromoles of photons per meter squared per second)Mole - the basic SI unit of amount of substance; the amount that contains as many elementary entities as there are atoms in 0.012 kilogram of carbon-12. The entity must be specified and may be an atom, a molecule, an ion, a radical, an electron, a photon, etc. Symbol mol [from German Mol, short for Molekül molecule]. A micromole equals one millionth (10-6) of a mole.
My BSF Lighting
Lighting for the Bin
Compact Fluorescent Lights rated at a total of 4100 lumens
(two 1600 lumen 23 watt and one 900 lumen 14 watt)
Temperature At Top Of Cone Reflector Maxed Out at 51°C(123°F)
Compact Fluorescent Lights From Below
Links to information about lighting for raising Black Soldier Flies: 'Breeding of the black soldier fly (Hermetia illucens)' topic at the Terrarienbilder.com Forum (in German)
'Small Scale Indoor Breeding' topic at the Black Soldier Fly Blog Forum
'BSF breeding - lighting requirements' Topic at the Black Soldier Fly Farming Forum