The testimony, by University of Nebraska forensic entomologist Timothy Huntington, came on the second day defense witnesses have been called in the trial. Anthony is charged with first-degree murder in the death of her 2-year-old daughter, Caylee, in the summer of 2008. The toddler's skeletal remains were discovered in a wooded area not far from her grandparents' home that December.
Anthony has pleaded not guilty and faces a death sentence if convicted. The prosecution contends the child was suffocated by duct tape placed over her nose and mouth. The defense said in its opening statement that she drowned in her grandparents' swimming pool.
Huntington testified about the insects in the trunk of Anthony's car and at the scene where her daughter was found. 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."
The morning also included a long period -- about 45 minutes -- in which the jury was sent outside the courtroom by Judge Belvin Perry while the attorneys argued over prosecutors' objection about whether Huntington was going to testify specifically about the stain its expert said was on the carpet in the Anthony car trunk.
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.
Haskell testified last week that he found only a small number of bugs on the toddler's remains in the woods and on paper towels inside Casey Anthony's trunk. He also said that insects related to decomposition were found along with decomposition fluid on paper towels in the trunk.
Haskell estimated that the child's remains were inside the trunk for at least three days.
Huntington testified Friday that the only flies he found inside the trash bag taken from Anthony's trunk were those usually found in household garbage and not the ones attracted to the early stages of decomposition.