[StBernard] Freezing temperatures unlikely to effect major insect populations

[Westley Annis]

Freezing temperatures unlikely to effect major insect populations
Print NOLA Community By NOLA Community 
on February 06, 2014 at 6:45 AM, updated February 06, 2014 at 6:55 AM

The recent record-breaking low temperatures are not likely to have a major
effect on many insect populations. Many insects were overwintering during
the period Louisiana experienced this weather. This means their metabolism
was slowed down and they were in protected places. Thus, the cold would have
little effect on the normal densities of these insects.

In addition, some insects have ethylene glycol - antifreeze - in their body
fluids that helps them withstand cold. For example, the Hessian fly can
freeze solid, then thaw out and continue its life cycle.

As for other insects, the boll weevil overwinters in protected areas.  And,
the cold probably did not hurt mosquitoes.

If a freeze occurs after insects have come out of overwintering, then many
will die. However, such a freeze would also injure many plants.

We do not expect to see as many carpenter bees as we did last year.

Insects that have become accustomed to the mild conditions also may have
been killed. Sugarcane borers overwintering on top of the soil could have
been killed, but those in the soil would have survived. Sweet potato weevils
in sweet potatoes on top of the soil would probably have been killed while
those in sweet potatoes under the soil would survive.

Generally, insects are very well adapted to their environment. They are well
equipped for the species to survive the extremes of their environment such
as record cold.

Individuals may be killed, but the species will probably survive. Weather
factors that are important in mortality of insects include temperature,
moisture, the interaction of temperature and moisture, and other factors.

For further information contact Alan Vaughn, County Agent, Plaquemines/St.
Bernard Parish at (504) 433-3664 or (504)278-4234.