Featured Research

from universities, journals, and other organizations

'Grubby' Research Promises Environmental, Economic Benefits

Date:
March 22, 2005
Source:
Texas A&M University
Summary:
Jeff Tomberlin's research could lend a whole new meaning to the phrase "grub for a living." Tomberlin, a Texas A&M entomologist, is looking into the possibility that black soldier fly larvae – "grubs" to the uninitiated – could be used to turn livestock manure into high-protein feed.

Dr. Jeff Tomberlin, entomologist with the Texas Agricultural Experiment Station, holds about a half pound of soldier fly larvae. Tomberlin is investigating the use of the soldier fly to turn livestock manure into a source of protein and energy for poultry, while reducing numbers of the common housefly. (Texas Cooperative Extension photo by Robert Burns)

STEPHENVILLE – Jeff Tomberlin's research could lend a whole new meaning to the phrase "grub for a living."

Related Articles


Tomberlin, a Texas A&M entomologist, is looking into the possibility that black soldier fly larvae – "grubs" to the uninitiated – could be used to turn livestock manure into high-protein feed.

The concept itself has been proven practical for reducing poultry litter: The flies lay their eggs in the animal manure without much encouragement. The eggs hatch into larvae that eat the manure as if it's caviar, growing into fat little creatures that are 40 percent or more protein. The chickens do what chickens do naturally, eat the worm-like larvae with relish, said Tomberlin, who has a joint appointment with Texas Cooperative Extension and the Texas Agricultural Experiment Station.

"No special harvest equipment is needed," said Tomberlin, who is based at the Texas A&M University System Agricultural Research and Extension Center at Stephenville.

Tomberlin expects to find the same manure-reduction techniques that work with poultry can be adapted to Central Texas dairy farms and other livestock operations, including feedyards. Whether the larvae can be recycled as livestock feed is another question, but he has plans to investigate this as well with feeding trials.

Tomberlin does know that when large numbers of soldier fly eggs are introduced to a manure pile, the resulting larvae can reduce dry weight of the manure by 30 percent to 50 percent in two weeks. Preliminary work with calf hutches shows this to be true. (Calf hutches are small, individual, roofed pens for young calves.)

"We also showed the residual manure nitrogen and phosphorus was reduced by half. Reducing phosphorus levels are particularly important, as excess phosphorus can be a primary pollutant," he said. "We're just learning to use what Mother Nature has already provided to reduce pollution."

The soldier fly occurs naturally in Texas, but unlike other fly species, it does not invade houses or become a pest to domestic animals. "The adults are short-lived and prefer to live in a wild environment," he said.

Even better, Tomberlin said, introducing black solder flies to manure can actually reduce the numbers of house flies because the two species compete for larval habitat. Female house flies will not lay eggs where soldier fly larvae are abundant.

In his preliminary study, Tomberlin compared four treatments to calf hutch manure at a cooperating Comanche dairy. Sixteen calves were used in the study. Catch trays, 3 x 4 feet in size, were placed under each calf. After allowing manure to accumulate for two weeks, he inoculated four of the manure buildups with 2,000 immature black soldier fly larvae.

"That's about a 1/4 pint of larvae," Tomberlin said.

He repeated treatment four times over the course of the study, which lasted three months, from late June to late August, the time during which conditions are most favorable for flies to breed and lay eggs.

Eight of the other trays were sprayed with a commonly used fly control pyrethroid pesticide. Four were treated at the pyrethroid's lowest labeled rate; four at the highest labeled rate.

A fourth of the catch-trays were left untreated.

Throughout the three months, Tomberlin and Bob Whitney, Extension agricultural and natural resources agent in Comanche County, weighed the accumulated manure and took samples to estimate house fly larval populations. Tomberlin also measured moisture levels of the accumulated manure so he could determine if any manure reduction was due to its drying out or from actual loss of solids.

Soldier fly larvae did reduce manure. The untreated – either without soldier fly larvae or pyrethroids – averaged 60 pounds of accumulated manure. Those inoculated with soldier fly larvae averaged 43 pounds.

The average weight of the piles treated with the high- and low-levels of pyretheroid was heavier, 65 and 57 pounds respectively. This is because naturally occurring house fly larvae also reduce manure, though not to the degree as do black soldier fly larvae, Tomberlin said. And house fly larvae – were their counts reduced in the manure piles inoculated with soldier fly larvae?

Averaged, the counts show a reduction of numbers, but from a scientific standpoint, there was such a wide range of variation between the various treatments, that he could only honestly label the results as "inconclusive," Tomberlin said.

"The weekly counts were just all over the place, probably because of measuring problems," he said.

Because he was more interested in manure reduction over time, Tomberlin couldn't screen the entire contents of any given tray for house fly larvae. Instead, he resorted to taking small samples and extrapolating estimates for the entire pile.

One interesting note: The house fly larvae counts were actually higher in the piles treated with the pyrethroid insecticide. Tomberlin believes this is not due to a measurement error, but that "some of these insecticides for fly control aren't very effective."

"They also kill biological beneficials that feed on house fly larvae," he said."for instance, parasitic wasps, mites and predatory beetles." Tomberlin believes these measurement problems could be eliminated with an expanded study.

"This was first-year preliminary data. A larger study would (show) what's actually occurring in nature."

He also thinks inoculating piles with larger numbers of soldier fly larvae would show better results. The larvae are easy to rear in trays, he noted.

Tomberlin also said the use of black soldier fly larvae should be well adapted for small- and medium-size livestock producers. His work in Central Texas has to date been only with dairies, but the biological controls show promise to work in other confined livestock operations, such as poultry and swine.

"I'd be eager to collaborate with any swine or poultry producers," Tomberlin said.


Story Source:

The above story is based on materials provided by Texas A&M University. Note: Materials may be edited for content and length.


Cite This Page:

Texas A&M University. "'Grubby' Research Promises Environmental, Economic Benefits." ScienceDaily. ScienceDaily, 22 March 2005. <www.sciencedaily.com/releases/2005/03/050309135653.htm>.
Texas A&M University. (2005, March 22). 'Grubby' Research Promises Environmental, Economic Benefits. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2005/03/050309135653.htm
Texas A&M University. "'Grubby' Research Promises Environmental, Economic Benefits." ScienceDaily. www.sciencedaily.com/releases/2005/03/050309135653.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Christmas Kissing Good for Health

Christmas Kissing Good for Health

Reuters - Innovations Video Online (Dec. 22, 2014) Scientists in Amsterdam say couples transfer tens of millions of microbes when they kiss, encouraging healthy exposure to bacteria. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
New Fish Species Discovered, Setting Record for World's Deepest

New Fish Species Discovered, Setting Record for World's Deepest

Buzz60 (Dec. 22, 2014) A new species of fish is discovered living five miles beneath the ocean surface, making it the deepest living fish on earth. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins