MISSISSIPPI STATE Most of Mississippi's weather in 2000 did more harm than good for the state's farmers -- until December.

After four relatively mild winters, entomologists predict significant insect mortality from the cold. The state climatologist reported December temperatures were among the coldest in reported history.

"The east-central Mississippi area posted the second coldest average temperature for December since we started keeping records in 1895," said Charles Wax, professor and head of geosciences at Mississippi State University. "The average temperature in 2000 was 36.1 degrees. The previous coldest average had been 36.6 in 1963."

Wax said temperatures got as cold as 11 degrees and four days did not get above freezing.

"A total of 24 days dropped to freezing or below in December," he said. "Rainfall was below normal at 2.42 inches, compared to the normal average near 6 inches."

Blake Layton, Extension entomologist, said wet conditions combined with the cold are more detrimental for insects than dry, cold weather. Sudden drastic temperature drops and extended extreme cold also are ideal for killing insects.

"Boll weevils have probably been the main victims of the cold weather. At this point, we've probably had about 95 percent mortality and because of the boll weevil eradication program, we didn't have many weevils going into the winter anyway," Layton said.

"The past four winters have been no help in the eradication process, but this year should be a drastically different story," he said.

Layton cited research that predicts 30 percent mortality in dry conditions when temperatures reach 15 degrees for six hours, 85 percent when temperatures reach 10 degrees for six hours and 100 percent mortality when it drops to 5 degrees for six hours.

"If it's wet, there is significant mortality when it just reaches 20 degrees for six hours," he said.

Layton said other insect pests knocked back by the cold include stink bugs and fall armyworms.

"Fall armyworms never overwinter in Mississippi, but remain relatively close in Texas and Florida during mild winters. This year should push them even further away, and make it take longer in the season for them to reach us," he said.

Evan Nebeker, another MSU entomologist, has watched Ips and southern pine beetle populations in recent years. Mississippi pine trees had significant Ips damage in 2000, largely because of drought-stress making trees more susceptible.

"Both the Ips and the southern pine beetle populations should be reduced from this winter's temperatures," Nebeker said.

The southern pine beetle has been a major problem in Alabama, prompting increased concern for Mississippi.

"The southern pine beetle is cyclic, and we are due for an outbreak," Nebeker said.