ORLANDO, Fla. -

The defense began day 21 of the Casey Anthony murder trial with a forensic entomologist.

Dr. Tim Huntington was the first defense witness called to the stand Friday morning. Huntington is a certified forensic entomologist and a professor at Concordia University in Nebraska.

Huntington said he was called by Anthony?s defense team on Dec. 11, 2008, the day Caylee Anthony's remains were found. He said he arrived in Orlando on Dec. 13.

Huntington said the entomological evidence indicates that Caylee Anthony's body was moved to the wooded area where her remains were found after decomposition began. He said, if she had fully decomposed in the spot where her remains were found, there would have been a stain from decompositional fluids.

Huntington also said evidence in the trunk of Anthony's car indicate a body did not decompose in the car. The defense claims the smell from the trunk was from a bag of trash. Prosecutors say it came from the girl's body.

The defense's expert witness also testified about what he'd expect to see in the trunk of a car with a decomposing body, based on research about what happened to decomposing pigs inside car trunks.

In that research, which took place in September 2010 in Nebraska, Huntington put dead pigs in the trunks of cars and observed them as they decomposed. He referenced finding blow flies, or the first type of flies drawn to decomposing material, soon after death. He also noted the presence of a pronounced stain of decomposition fluid on the carpeting of the trunk.

He said he would expect to see the same things in a trunk with a decomposing human body.

"If we assume that a body was in the (Anthony) trunk, you expect to find many flies," Huntington said. "... I would expect to find hundreds, thousands of those dead insects as I did in the experiment."

Huntington described the decomposition fluid he observed in the pig experiment as distinct.

"It is a sticky, greasy, disgusting material," he said. "Once it soaks in there, I'm not sure a professional cleaner could get it out."

Huntington reviewed reports made by prosecution bug expert Neal Haskell but never examined the trunk himself. Also, the pig research was conducted during September in Nebraska and not in Florida's hot summer months, when Caylee Anthony was reported missing.

Anthony?s defense claimed during opening statements that meter reader Roy Kronk somehow obtained Caylee?s body and held onto it for months before placing it in the woods to obtain reward money when he reported finding it.

Huntington said he received much of the same entomological evidence that state expert Dr. Neal Haskell studied in the case.

On Saturday, Haskell testified that a decomposing body had been in Anthony?s trunk for a few days before being removed.

Haskell said that entomological evidence showed that Caylee?s body had been in the woods off Suburban Drive around six months before her remains were found in December 2008.

Haskell said entomological evidence found on a paper towel found in the garbage in the trunk of Anthony's car was used to clean up decompositional fluid, but on Friday, Huntington suggested the flies in the bag were attracted to a container of "tobacco spit."

He also noted food in the bag that could have attracted flies.

Huntington said the most important fly involved in decomposition is the Blow fly.

?Blow flies specifically key in on dead animals, these are the blue and green flies you see buzzing around road kill,? Huntington said.

Huntington said they show up very soon after death -- within minutes or hours.

Huntington said the Blow fly evidence indicates Caylee's body was moved after her death.

Huntington is a former student of Haskell's, but that fact was not told to jurors.

The defense began presenting evidence on Thursday with several crime scene investigators and FBI forensics experts. Lead defense attorney Jose Baez attempted to poke holes in theories presented by the state.

Anthony, 25, is charged with first degree murder Caylee's death. If convicted, she could face the death penalty.