Apr 7, 2011 – Holing Up In The Winter
QUESTION:
I am hiring on my first tech and writing my SOP's, which have led me to ask some questions of how I do things. Is there a difference between dormancy and hibernation, and if so would it be a waste of time to exterior bait C/C during winter quarterlys?
ANSWER:
We tend to use some terms that may be interchangeable, but in this case we really have 3 terms to look at - dormancy, hibernation, and aestivation (sometimes spelled estivation). Hibernation refers to a period of inactivity in the winter (bears hibernate), aestivation refers to that inactivity in the summer (gophers often aestivate), and dormant refers more to an extended period of time when the animal (or plant) is inactive, but activity may resume at any time due to circumstances. For example, seeds of weeds may lay dormant for years in dry conditions, and then be activated when rains fall and begin to sprout. Bed bugs may be dormant in a structure when no food is available, but then spring to activity when people return and the triggers of carbon dioxide and heat bring them back to feeding. So, yes, hibernation and aestivation are regular cycles in the biology of living things, while dormancy may be more of a forced period of inactivity.
Since you are in Utah you likely enjoy pretty cold winters, and very, very few arthropods will be active outdoors for these months. Nearly all of them go into some level of hibernation, with their ability to move severely restricted by the cold temperatures. Warm winter days might be sufficient to activate some of them, so we could find ants suddenly wandering around if you had some extended spring-like days in January, but this would be the exception I think. Using bait products during the cold months probably would be mostly ineffective, since there would be so few bugs around to take advantage of this food resource. By the time you get a general re-emergence of those hibernating bugs the bait may no longer be effective or palatable to the pest. Rain or snow could have washed it away or turned it to mush, or the active ingredient may have degraded sufficiently to not kill the bug even if it did feed on it.
Winter is a great time to do other projects that are good pest management. This could be the time to focus on things like exclusion - sealing openings and gaps around the exterior that would admit rodents, bats, or crawling bugs later in the year. Exclusion is every bit a part of pest "management" as is the spraying of pesticides. It may be a good time to re-evaluate the exterior and landscaping, and point out those circumstances in a yard that encourage the presence of many pests. Maybe firewood should be moved away from the structure, piles of landscape debris or discarded household items could be disposed of to eliminate pest harborage, dense shrubbery could be trimmed properly to expose the soil, branches too near to or touching the structure can be trimmed away. All of this is habitat modification, and it is also important in reducing pest problems.
Winter is also a great time for Horticultural controls, such as the applications of dormant sprays (there's that darned word "dormant" again), such as horticultural oils or fungicides. These are critical products to use during late winter months to control many plant diseases as well as to kill over-wintering (hibernating) arthropod pests such as aphids, scales, mites, and many other plant-feeding pests that leave eggs or pupae or early stages of nymphs on the bark of trees and shrubs. Winter is also a good time to do soil injections of systemic insecticides such as imidacloprid, which then will move up the dormant tree and be present in the foliage when it begins to sprout, killing aphids and beetles and other plant feeders before their populations get damaging.
Pesticide applications can be dramatically reduced in the winter in cold regions, and your experience will tell you whether or not many active pests are there in Dec. thru February, or later in the northern states. You can focus instead on preventing pests from entering, including Fall applications around the exterior to kill over-winter guests like stinkbugs, cluster flies, ladybird beetles, etc. You also can concentrate on rodents, as these often are more actively attempting to get inside during harsh weather.
I am hiring on my first tech and writing my SOP's, which have led me to ask some questions of how I do things. Is there a difference between dormancy and hibernation, and if so would it be a waste of time to exterior bait C/C during winter quarterlys?
ANSWER:
We tend to use some terms that may be interchangeable, but in this case we really have 3 terms to look at - dormancy, hibernation, and aestivation (sometimes spelled estivation). Hibernation refers to a period of inactivity in the winter (bears hibernate), aestivation refers to that inactivity in the summer (gophers often aestivate), and dormant refers more to an extended period of time when the animal (or plant) is inactive, but activity may resume at any time due to circumstances. For example, seeds of weeds may lay dormant for years in dry conditions, and then be activated when rains fall and begin to sprout. Bed bugs may be dormant in a structure when no food is available, but then spring to activity when people return and the triggers of carbon dioxide and heat bring them back to feeding. So, yes, hibernation and aestivation are regular cycles in the biology of living things, while dormancy may be more of a forced period of inactivity.
Since you are in Utah you likely enjoy pretty cold winters, and very, very few arthropods will be active outdoors for these months. Nearly all of them go into some level of hibernation, with their ability to move severely restricted by the cold temperatures. Warm winter days might be sufficient to activate some of them, so we could find ants suddenly wandering around if you had some extended spring-like days in January, but this would be the exception I think. Using bait products during the cold months probably would be mostly ineffective, since there would be so few bugs around to take advantage of this food resource. By the time you get a general re-emergence of those hibernating bugs the bait may no longer be effective or palatable to the pest. Rain or snow could have washed it away or turned it to mush, or the active ingredient may have degraded sufficiently to not kill the bug even if it did feed on it.
Winter is a great time to do other projects that are good pest management. This could be the time to focus on things like exclusion - sealing openings and gaps around the exterior that would admit rodents, bats, or crawling bugs later in the year. Exclusion is every bit a part of pest "management" as is the spraying of pesticides. It may be a good time to re-evaluate the exterior and landscaping, and point out those circumstances in a yard that encourage the presence of many pests. Maybe firewood should be moved away from the structure, piles of landscape debris or discarded household items could be disposed of to eliminate pest harborage, dense shrubbery could be trimmed properly to expose the soil, branches too near to or touching the structure can be trimmed away. All of this is habitat modification, and it is also important in reducing pest problems.
Winter is also a great time for Horticultural controls, such as the applications of dormant sprays (there's that darned word "dormant" again), such as horticultural oils or fungicides. These are critical products to use during late winter months to control many plant diseases as well as to kill over-wintering (hibernating) arthropod pests such as aphids, scales, mites, and many other plant-feeding pests that leave eggs or pupae or early stages of nymphs on the bark of trees and shrubs. Winter is also a good time to do soil injections of systemic insecticides such as imidacloprid, which then will move up the dormant tree and be present in the foliage when it begins to sprout, killing aphids and beetles and other plant feeders before their populations get damaging.
Pesticide applications can be dramatically reduced in the winter in cold regions, and your experience will tell you whether or not many active pests are there in Dec. thru February, or later in the northern states. You can focus instead on preventing pests from entering, including Fall applications around the exterior to kill over-winter guests like stinkbugs, cluster flies, ladybird beetles, etc. You also can concentrate on rodents, as these often are more actively attempting to get inside during harsh weather.
