As humans, we can detect the temperature of the outside environment, and our bodies respond to it. However, is this true for insects?
Insects can feel the cold. Similarly, insects can feel hot temperatures as well. It is important to note that exposure to cold temperatures does not inflict discomfort on insects, but can cause them to become inactive or die.
This article will explain the interaction between insects and changing temperatures. Additionally, the intricacies of the insects’ nervous system and its ability to react and adapt will be explained.
What Temperature Is Ideal for Insects’ Survival?
The optimal environmental temperature for an insects’ survival is anywhere from 25°C to 32°C (77°F to 89.6°F). At this rate, all bodily functions can be carried out as usual. All essential body functions must be carried out in order for the insect to maintain homeostasis.
At any temperature above 35°C (95°F), a temperature that is considered suboptimal, the rate at which the species reproduces will be negatively affected. As temperatures climb toward 42°C (107.6°F), mobile insects will begin to seek shelter from the heat.
How Do Insects React to Temperature Changes?
As temperature strays further, in either direction, from the 25°C to 32°C (77°F to 89.6°F) range, the rate at which the population increases will decrease. In other cases, mobility declines, and movement eventually ceases.
The worst possible outcome, death, comes at temperatures as low as -25°C (-13°F) or as high as 62°C (143.6°F). This scenario could mean death for merely one individual insect or the entirety of the population.
Additionally, non-fatal increases in temperature can adversely affect the rate at which reproduction rates. The egg-to-adult survival rate is generally positively changed as a result.
How Does the Cold Weather Affect Insects?
It is common to see a notable decrease in the number of insects that inhabit your home as the cooler seasons come around. For most insects, the temperature change is a matter of life or death. While some insects simply die off, others can make instinct-based changes to survive.
It is important to note that a large number of insect species will have already completed the bulk of their life span at the point in which the cold weather comes around. For most insects, the reproduction and regeneration of their population are reliant on their survival. If an insect has successfully reproduced at some point within its lifetime, its purpose is considered fulfilled, and its mission in life is complete.
When Does the Cold Weather Become Fatal?
For insects, extreme climatic conditions can be defined as any temperature greater than 50°C (122°F) or lower than 15°C (59°F). At these temperatures, the insects’ survival is at risk.
Since insects’ cells are made up mostly of water, they are capable of freezing and eventually dying. Therefore, it is freezing rather than a decrease in temperature alone that can be fatal to the insect.
Many insects have developed their own unique ways to adapt to sudden drops in temperature in order to survive. There are various measures that insects can take to either survive the winter months or prepare their eggs and younger population for the springtime.
In colony insects such as bees or termites, their main priority is to protect their queen at all costs. In the case of decreased temperatures, the same holds true. Bee populations can be found hiding out in their hives during the winter while ants seek shelter underground.
How Do Insects Adapt to Cold Temperatures?
When it comes to preparing for the winter months, different types of insects may carry out any of the following responses:
- Freeze Tolerance
The reproduction of crickets is one prime example of the species’ ability to adapt to cold temperatures. While a significant portion of the population will die out as a result of the drop in temperature due to changing seasons, the eggs remain. The cricket’s eggs are built to survive the harsh winter months and eventually hatch in the spring. The egg provides the cricket both shelter and food throughout these conditions.
Unlike crickets, some insects adapt to the colder months by going into hibernation. When insects undergo hibernation during the winter, it is known as diapause. During diapause, the insect goes into a dormant state, slowing its metabolism and conserving its energy to use when temperatures rise again.
The monarch butterfly is, perhaps, the most well-known migrating insect species. After migrating south toward warm weather, the monarch butterfly prepares the next generation for springtime. In preparation for the warmer months, the monarch butterfly reproduces and eventually dies after reaching its sunny destination.
In some insects, the makeup up their tissue may be capable of withstanding cold temperatures. These same insects can produce their own natural antifreeze.
One insect that is capable of creating a natural ice repellant is the wooly bear moth caterpillar. Thanks to the natural antifreeze, the formation of damaging ice clusters are avoided. Once the insect successfully unthaws as the warm weather approaches, the insect is able to return to its usual activities.
The Insect Nervous System
Similar to that of most arthropods, insects’ nervous systems are fairly simple. The insects’ nervous system has two main systems- a brain and a central nervous system. The dorsal brain is linked to a ventral nerve cord that is made up of segmental ganglia. These paired ganglia segments run along the midline of the insects’ abdomen and the thorax.
Within the insects’ nervous system lies a network of neurons. Neurons work as a superhighway of specialized cells that work to generate electrical impulses that move in depolarization waves along the membrane of the cell. Each of the individual nerve cells connects to one another via synapses or junctions.
The nerves are simply bundles of dendrites. Each bundle serves a specific region, whereas the larger bundles or ganglion. Each ganglion is capable of using interconnected neurons to control motor outputs and process sensory information.
For example, the thoracic ganglia control the locomotion of body regions such as the legs and wings. The segmented ganglia have a greater influence than the brain on overt behavior such as mating, feeding, and locomotion.
Do Insects Have a Sense of Touch?
Because there are many bundles of dendrites in every body region, the insect has a sense of feeling in all of those areas. The afferent or sensory neurons work directly with the sense organs to carry information toward the central nervous system.
The efferent or motor neurons are triggered by sensory stimuli in the environment, prompting the appropriate reaction. These neurons can be found within the peripheral nervous system. The peripheral nervous system is located within the epidermis, making it a barrier between the insects’ internal organs and the outside environment.
A category of sensory organs called mechanoreceptors controls the insect’s sense of touch and feel. The basic functions of the mechanoreceptors include detecting vibrations, movements, and other sudden changes or disturbances.
Insects can feel cold temperatures. While the insect’s body can detect temperature changes, no discomfort is inflicted on the insect.
Due to the nature of the insects’ central nervous systems, they can detect sensory changes and adapt to those changes promptly and appropriately. For example, if the insect’s nervous system detects a sudden temperature change, it will relocate immediately if it is a mobile insect.