Would you like to guess how many bugs are in your home? In the fall of 2017 researchers from the California Academy of Sciences published a survey of the bugs in 50 homes in and around Raleigh, North Carolina. The researchers took 10,000 samples from basements, bedrooms, kitchens, and attics. They identified 579 species from the 304 families of arthropods known to science. Arthropods include insects, mites and, spiders.
The researchers found ants, carpet beetles, gall midges, and cobweb spiders in 100% of the homes. In many of the houses, they found booklice, dark-winged fungus gnats, cellar spiders, scuttle flies, and dust mites. Misha Leong who was the lead author of the study says that most homes contain hundreds if not thousands of individual arthropods.
It is interesting that as people move toward buying organic and buying in bulk, they are increasing the bugs in their homes. Indian meal moths, for example, can contaminate oatmeal or chew through a sweater. They lay eggs in our food and closets, and the larvae chew through packaging leaving a mess of silk and frass (waste) behind. If we use the food quickly enough we eat the eggs, and since they don’t hurt us, we don’t even know they are there.
The reality is that we have and will always have lots of bugs in our homes. Many of them are beneficial to us. Booklice, for example, eat fungi and mold. Spiders eat insects and other harmful agents including flies and mosquitoes. Harmful spiders like the black widow and brown recluse are rare. Studies have also shown that many of our chronic diseases are related to our failure to be exposed to biological diversity. Leong says, “Rooms with more kinds of arthropods may be healthier rooms.”
It is easy for humans to minimize the design that is needed for life to exist on Earth. How do you feed massive numbers of birds, especially in the spring when winter has taken away most of their food sources, and their food needs are maximized as they lay eggs and feed baby birds? In the past scientists have shrugged their shoulders and imagined that there are food sources we don’t recognize that fill this gap until the summer season generates sufficient seeds and insects to sustain the growing populations. Similar problems exist for many other animals like bats that depend on insects for their nutritional needs.
In the April 2017 issue of Scientific American (page 84), there is an interesting report about previously unknown migrations of insects. We have known about monarch butterflies for some time, but this study by British researchers shows that migrations of insects are massive. Over southern Britain alone there are 3.3 trillion insects migrating. That is an average of 3200 tons of bugs moving through the skies over Britain every year. The study also reports that similar patterns have been observed in Texas, India, and China.
The complexity of this migration is astounding. Insects don’t live long enough for one bug to complete the migration. Researchers found that in some cases six generations were involved to complete a migration. The insects do not just get randomly blown about. They travel in a well-programmed pattern taking advantage of wind direction and speed. The elevation at which they fly to get the strongest support for their journey is carefully chosen. For a number of reasons, spring migrations are different from fall migrations.