Insects can suffer from fractures in their exoskeletons in their lifetimes. Aside from fractures, they can also suffer wear and tear related cracks in the exoskeleton. Insects are tiny, but they are very resilient. This holds because, during the migration season, many insects can travel by flying for hundreds and thousands of kilometers. For example, Schistocera gregaria is one such insect that flies for days on end in the search for a new habitat. The wings of insects are the parts of insect bodies that are the most prone to getting injured. Their wings are stable, as they can make them whizz through the air, carrying the entire bodyweight of the insect. However, the wings are also the most prone to injury and wear and tear due to its constant use.
Locusts need to resist putting extra stress on their wings, but since they are so small and they are insects, the question of their “correct” bodily functions doesn’t even come into place. Locust wings get damaged, but they somehow remain as small defects and do not turn into large cracks. This can be a result of either a very touch wing membrane or the mechanism of wing veins as crack-restricting barriers.
Insect Wing Membranes
Insect wing membranes may differ. However, we will take a look at the wing membrane of the Schistocera gregaria, the insect that travels thousands of kilometers during the season of migration in search of habitat. Scientists have conducted studies to examine the bodily structure of these locusts carefully. According to their studies, the wing membrane of this insect is about 1.7 to 3.7 µm, which is extremely thin. Then how do the insect’s wings not crack when so much pressure is added to it?
Aside from this, the wing membrane is made up of untraceable amounts of chitin, a very minimal amount of water, and an amorphous cross-linked with proteins. These are all contained in the epicuticle, many of which come together to form the wing membrane. Along the wing, there is no indication of a clear pattern of stiffness. Any stiffness that researchers even find combines to create flexibility in the movement of the wings. It is a result of something called “stressed skin,” which is what the wing membrane acts as for the insect. However, despite knowing all of this, it has not yet known how strong or weak the wing membrane is.
There are two kinds of veins, i.e., longitudinal and cross-sectional veins. These veins in locusts are what divide the wings into parts. The longitudinal veins are hollow and long, with a diameter of about 100 to 150 µm. However, as they reach the ends of the wing, the width gets smaller. They help to provide stiffness to the wing and contain veins, hemolymph, and trachea. The cross-sectional veins don’t have a very uniform shape in comparison to longitudinal ones. They also do not contain hemolymph. While the longitudinal veins play a much more significant role in wing movement, cross-sectional veins are also important.