Docstoc

The Heat Is On

Document Sample
The Heat Is On Powered By Docstoc
					                              The Heat Is On
"Integrated pest management (IPM) is an effective and environmentally sensitive approach to
pest management that relies on a combination of common-sense practices. IPM programs use
current, comprehensive information on the life cycles of pests and their interactions with the
environment. This information, in combination with available pest control methods, is used to
manage pest damage by the most economical means, with the least possible hazard to people,
property and the environment. IPM programs take advantage of all pest management options
possible, including, but not limited to, the judicious use of pesticides. " - EPA definition.

Basically, this means that multiple tactics are utilized together to form an effective strategy for
the management of pests. This concept has evolved into a 12-point comprehensive IPM system.
One of these components is physical pest management. Physical controls are those direct or
indirect measures, such as heat, cold, humidity, sound, energy and inert gases that are utilized to
destroy pest populations outright or make their environment unsuitable for their entry, dispersal,
reproduction or survival.

The use of higher temperature (heat) as a non-chemical alternative to fumigation has been a
feasible treatment for stored product insect control in the food industry since the early 1900's.
Today's consumer attitude toward chemicals in general, along with subsequent restrictions, i.e.
methyl bromide and FQPA, have provided a challenge to the control of stored product insects in
various food processing facilities. Heat can be used effectively, efficiently and economically as a
space treatment for many food-processing facilities. The future of heat treatments will likely be a
solution for various localized insect problem areas that are inaccessible for cleaning, i.e. block
walls or inadequately designed equipment. Confining heat to a specific zone while the rest of the
facility stays in operation, possibly with preventative maintenance and/or cleaning activity, is a
cost effective approach.

During the filming of the recently released Physical Pest Management Practices training video a
"verification study" of an earlier heat parameter was conducted. Practical research was conducted
in 1994 by this author which suggested a minimum temperature, time and humidity parameter
effective for control of some stored product insects. Insects used in this study were various stages
of Tribolium castaneum (red flour beetle), Blattella germanica (German cockroach) and
Trogoderma variable (warehouse beetle), provided by the University of Nebraska-Lincoln,
Department of Entomology. The results of this research indicated a temperature of 120 - 125° F.
at 25 - 30% relative humidity for 20 - 30 minutes was suggested as the lowest guideline to
achieve stored product insect mortality. This research was conducted to provide information
clarifying the minimum parameter it takes to achieve mortality while minimizing damage to
property and/or equipment. Since this 1994 research, different insect species, different
environments, different incubators/cages and different technical assistance have been utilized, all
with similar results. Following is a summary of this "verification study".

The objective was to capture, on film, insects’ response to slowly increasing temperature. This
experiment, conducted on June 15, 2000, produced a series of observations verifying conclusions
from the 1994 research study. These observations have been captured on film in the
aforementioned video. Another video titled Dance to Death has been produced capturing the
more specific insect response to slowly increasing temperature.



                                                                                                      1
                              The Heat Is On
Kansas State University, Department of Grain Science and Industry provided the insects. All
insects were held for seven days following death to assure the initial observations of mortality.

Experiment #1
Twelve adult cigarette beetles, twelve adult confused flour beetles, twelve adult sawtoothed grain
beetles and two adult German cockroaches were exposed to slowly increasing temperature
starting at 90° F. and stopping at 125° F. for a forty-five minute period at 26 - 28% humidity.
These particular insects were selected to measure additional species’ heat tolerance, especially
the cigarette beetle. The temperature and humidity levels were selected to mirror a typical heat
treatment.

Observations
Overall insect mortality was 100% and temperatures varied with insect. The lethal temperatures
for the cigarette beetles were 104 - 106° F. and they seemed lethargic from the beginning and
were removed from any further filming. The lethal temperatures for the German cockroaches
were 112 - 114° F. with the lethal temperatures for the sawtoothed grain beetles in the 116 - 118°
F. range. The lethal temperatures for confused flour beetles were a little higher in the 118 - 120°
F. range.


Experiment #2
Twelve adult drugstore beetles, twelve adult confused flour beetles, twelve adult sawtoothed
grain beetles and two adult German cockroaches were exposed to slowly increasing temperature
starting at 90° F. and stopping at 125° F. for a forty-five minute period at 26 - 28% humidity.
The drugstore beetles were substituted for the wimpy cigarette beetles for this "retake" shoot.

Observations
Again the overall insect mortality was 100% and temperatures varied with insect. The lethal
temperatures for the drugstore beetles were 104 - 106° F. while the lethal temperatures for the
German cockroaches were higher in the 112 - 114° F. range. The lethal temperatures for the
sawtoothed grain beetles were 116 - 118° F. with the lethal temperatures for confused flour
beetles slightly higher at 118 - 120° F. Experiment #2 mortality started at 104° and ended at 120°
F., the same as #1.


Experiment #3
Another filming was conducted duplicating #2 using different cameras and photography
techniques. The experiment and observations were identical.


Summary
More research is needed, especially in the hot air application itself, of plant-wide "space" and/or
specific equipment-wide "local" heat treatments. Previous research has shown and now has been
verified that death will result when stored product insects (the insects themselves, not the
environment the insects are within) are exposed to temperature of 120 - 125° f. at 25 - 30%
humidity for 20 - 30 minutes. This is a heat parameter that is not only effective but will minimize
structural and/or equipment degradation of a food plant.


                                                                                                    2
                              The Heat Is On
Other insect species such as Gibbium aequinoctiale (spider beetle) and larger cockroaches have
been exposed to this heat parameter, all with similar mortality results. Insects have a variety of
responses to a sudden rise in temperature, but the most obvious is behavioral, as they simply try
to get out of there. They can also have a physiological response, such as evaporative cooling to
lower their body temperature. Although water represents about 70% of the body weight of most
insects, insects can tolerate a temporary loss of 20 to 30% of this moisture for brief periods. In
this heat stressed state they may appear to be dead. Usually the least thermo-tolerant tissue in the
insect's body becomes the weak link. Overall, the insect's water intake must equal the insect's
water loss from both excretion and transpiration. This is known as the Critical Transition
Temperature or CTT. Above the CTT, insects will die quickly. With a temperature of 120 - 125°
f. at 25 - 30% humidity for 20 - 30 minutes, insects die of moisture loss. Experienced heat
treatment professionals maintain that heat-induced mortality is equal to temperature plus time. A
lethal temperature may have little meaning without time - that underlines the necessity of
keeping the environment at a proper temperature sustained long enough to ensure overall
effectiveness of the heat treatment. This filming experiment not only verifies historical
information but provides additional information; more insect species, different genetics, different
environment, different incubator/cages, different technical assistance, all with similar results.
Indeed, heat is a feasible treatment for stored product insect control in the food industry, today
and for generations to come.




Ole Dosland
Director of Technical Training and Education
Copesan
Brookfield, Wisconsin

Before joining Copesan in 1997, Ole has accrued nearly 30 years of
experience in the quality assurance, food protection and pest
management aspects of the food industry. He spent ten years each                          with
Ralston Purina Company and IAMS Pet Food Company before he was a Food Protection
Specialist for ConAgra, Inc. starting in 1990. Ole frequently conducts pest management,
sanitation and food safety seminars for various food industry clients and Copesan Partners. He is
currently a member of Copesan’s Technical Committee and is active in providing Heat
Treatment Educational Workshops, customized for food industry companies.

Copesan is an alliance of regional pest management companies that are united as a single entity
for the sole purpose of providing quality pest solutions to businesses with locations throughout
North America. For more information about Copesan and our service capabilities, please contact
Copesan’s corporate headquarters: 3490 N 127th St, Brookfield, Wisconsin, 53005, (262) 783-
6261, or visit Copesan’s official web site at www.copesan.com.




                                                                                                   3

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:6
posted:11/12/2011
language:English
pages:3