An insect expert has given his verdict on when insects would have first appeared on the bodies of the Cooper twins.

Dr. Jason Byrd told the murder trial jury yesterday that the period of ?colonisation? would have been from between late afternoon on March 13 and late afternoon on March 15, 2005.

The court heard that he came to this three-day timeframe by examining eggs deposited by two species of flies and looking at the stages they had reached in their lifespan.

Regular updates from the Bermuda Weather Service on hourly temperatures and rainfall also played a part in working out how long insects had been on the twins? bodies, discovered in a bad state of decomposition on Abbot?s Cliff on April 13, last year.

The twins were last seen alive on March 13, a jury has been told.

Their murder trial ? which has now entered its third week ? has already heard the prosecution claim that defendant Kenneth Burgess launched a violent baseball bat attack on the brothers at an apartment in Devonshire in the early hours of March 13. Co-accused Dennis Alma Robinson held the door to prevent escape, prosecutors allege.

Dr. Byrd, from the University of Florida, told the court that insects could smell a dead body very quickly.

He said that insects would normally ?skeletonise? a body from the head down, however, parts that were badly injured, such as open wounds, would be targeted first.

The skin would have to be broken, the court heard, and bruising would not be enough to alter the ?head down? colonisation process.

Dr. Byrd said he attended Abbot?s Cliff after the bodies were discovered and spent a few hours on the remote ledge digging up leaves and soil to find the oldest insects in the area. The jury saw detailed photographs showing insects on the remains and clothing of the twins.

Courtenay Griffiths, for Burgess, said the insect expert had been given a scenario by Police ? stating the twins had last been seen alive between 4 and 6 a.m. on March 13 ? when he arrived on the Island to work on the case.

The court heard how the expert?s report said insects could have been on the twins? bodies from the afternoon of March 13, but were definitely there from the afternoon of March 15.

Under cross-examination from John Perry QC, for Robinson, Dr. Byrd confirmed insects would not attack live tissue.

Dr. Byrd said the pattern of colonisation started at the heads of both Jahmal and Jahmil Cooper.

He said this could be consistent with head traumas in both cases.

Mr. Perry said in both cases insects had not attacked other parts of the body away from the heads.

The barrister added: ?That seems to imply that there must have been trauma to the head and not to the rest of the body.? The witness agreed.

Burgess, 33, of Hamilton Parish, and Robinson, 34, of Southampton, both deny murdering the twins on March 13, last year.

The trial, before Chief Justice Richard Ground, continues.