Bearded Dragon Hatchlings Grow Faster When Fed BSFL As Staple Diet

Black soldier fly larvae (BSFL) has long been admired among the reptile community for their superior nutrition benefits, however, there was no study demonstrated how could the dietary intake of BSFL benefit the reptile. Our study first shown that bearded dragon hatchlings grew faster on a BSFL staple diet than those on supplemented dubia staple diet; at the end of the 8th week, the BSFL group dragons weighted 35.29% more than the others. In addition, the molting time for the dragons on BSFL diet averaging 2 days earlier than the dragons on supplemented dubia diet.

The study demonstrated that our BSFL could provide sufficient protein and calcium for faster growth of bearded dragons, without any additional supplement.

Black soldier fly larvae (BSFL) have recently been accepted as the best staple feeder insect for many reptiles, because of their naturally high calcium content. However, studies indicate that the nutritional value of BSFL is greatly influenced by rearing practices and diet, and there are no data to demonstrate how or why BSFL are the best feeder insects. Currently, dubia roaches have been catching a lot of attention for the higher nutritional values than crickets, superworms and mealworms, and are the most popular feeder insects used among reptile breeders in the US. We designed a feeding trail to compare our BSFL to dubia roaches, in order to provide this information to reptile breeders and hobbyists.
​
We were grateful to have the Dragon Den (Josh/Glenn) to perform this experiment. This controlled study included 6 bearded dragon (hypo trans/double het hypo trans, reds) hatchlings from the same clutch of eggs. Three of them were provided dubia roaches with calcium and vitamin D3 supplement (AKA dusted dubia roaches), and the other three were provided unsupplemented Symton feeding grade BSFL. The insect mass was provided equal amount, however, there could be bias due to palatability. The calcium content indeed is not equal, nor for the Ca:P ratio, because this is a major point we tried to hit--to compare the most common practice with feeding BSFL. In one study done by Saint Louis Zoo, they found that the Ca content in supplemented cricket is much higher than in the BSFL, causing an imbalance of Ca:P (5.3:1), versus in the BSFL is 2.5:1. The off-chart Ca content could block the P absorption, and this is why the dragons in our study can absorb better nutrient from the BSFL, resulting in greater weight gain per insect mass, and molt two days faster. Along with the insects, the dragons were provided adequate vegetables to make the diet balanced, such as kale, collards, mustard, butternut squash, and zucchini. Also, floor heat lights and ZOOMED 10.0 UVB lamps were installed in the enclosures. Temperature was kept between 80-85F. A weight measurement of each dragon was taken every week, until all dragons in both treatments successfully molted twice. The study lasted 8 weeks, and all dragons showed healthy signs of development throughout the study.

The results show that dragons fed on unsupplemented Symton feeding grade black soldier gain weight faster than those fed on dusted dubia roaches. The individual variation is small as in the end of the 8th week, the standard deviations of weights were only 0.58g in the dubia group and 1.53g in the BSFL group, when the difference of mean was 4.00g. Statistically (ONE-Way ANOVA, p=0.0132) their weights were different between groups, and the effect should be accounted to the feeder insects, not genetic variations of the dragons. Although we only used 3 replicates in this study, which is the minimal number for experiment replicate in scientific manner, because this study had only one variable, it generates enough statistic power to make an inference. At the end of the 8th week, dragons fed our BSFL weighed 35.29% more than those fed on ​dusted dubia roaches. For this particular study, because there were extremely small variations between individuals, we are 95% confident about the result, statistically.

The study demonstrated that our BSFL could provide sufficient protein and calcium for faster growth of bearded dragons, without any additional supplement. However, it should be noted that these data only apply to our feeding grade black soldier fly larvae, that were reared on a proprietary diet formula and rearing conditions, and result does not apply to compost grade product.