What was found
UNEVENTFUL FLIGHT FROM SMF UNTIL ALERT. LEVEL AT FL310 APROX 2 30 INTO FLIGHT. COST INDEX 200 GAVE US .837MACH. GOT TRI-TONE AND MASTER WARNING LIGHT, WITH "LWR AFT CRG FIRE". DECLARED EMERGENCY AND DIVERTED TO CLOSEST FIELD KTUL. 13MIN FROM DECLARATION TO TOUCHDOWN. STOPPED ON RWY18L MID-FIELD. ALL ENGINE AND APU FIRE BOTTLES WERE DISCHARGED. ALSO, BOTH LOWER CARGO FIRE BOTTLES WERE EXPENDED. EGRESS WAS VIA 1L. SLIDE DEPLOYED NORMALLY, AND BOTH CREW AND 1 JUMPSEATER SAFELY EGRESSED THE A/C. REMOVED CARGO FROM LOWER CENTER AND AFT CARGO COMPARTMENTS. FIRE DEPT PERFORMED INSPECTION AND DID NOT FIND ANY EVIDENCE OF SMOKE OR FIRE. NO EVIDENCE OF SMOKE AND FIRE IN ANY OF THE CARGO REMOVED. DURING OFF LOAD FOUND A SWARM OF "LADY BUGS" IN BOTH COMPARTMENTS SUSPECT SMOKE DETECTORS CONTAMINATED BY THE BUGS. ALSO PERFORMED TROUBLESHOOTING IAW MD10-30 FIM 26-14-00-810-802 AND FOUND ALL SMOKE DETECTORS OPERATING NORMAL. AIRCRAFT DISINSECTION PROCESS WAS PERFORMED IN CENTER AND AFT LWR CARGO COMPARTMENTS IAW MM 12-22-01-2-99 PRIOR TO R&R OF SMOKE DETECTORS. NO MORE EVICENCE OF LADY BUGS PRESENT.