Introduction to Part I

Introduction

Throughout this book, we will make allusions to various aspects of the lifecycle of insects, as well as their anatomy, physiology, and ecology. As a result, it is helpful to have had exposure to this information before reading the book. One way to address this is to ask you to take a whole entomology course where this information will be discussed in detail prior to reading this book. Some of you, in fact, have had such a course. But most people find ways to avoid taking courses in entomology either as a result of having no interest in insects (we will change that!), or a level of fear that mitigates against the study of the subject. So, we have to get creative.

Rather than engage in a lengthy aside every time some point of entomological interest arises in subsequent chapters, it seems more productive to lay out all of the entomology you need to know in order to successfully navigate through the rest of the book. Chapters 1-6 do just that. Ideally, you will read Chapters 1-6 and receive this helpful instruction before continuing on to the later chapters where it will be assumed that you have this background. In order to facilitate your understanding, we have chosen an approach which we hope is likely to have greater resonance with people who do not intend to become entomologists. We will first discuss where insects and humans fall on the Tree of Life and then cover basic entomological information by comparing insect and human systems, highlighting their similarities and differences. Human systems are at least somewhat familiar to you, and what you know about humans, thus, provides an anchor that will help you process what you need to know about insects. So, with that in mind, let’s begin with a basic consideration of what humans do to survive and reproduce. In other words, what sorts of functions must we carry out in order to live and reproduce? Before we conveniently provide you with an answer, please take a crack at answering the question yourself. You might even go so far as to make a list. Well, we can dream, anyway. Once you’ve created your list, either on paper or in your head, please continue to Chapter 1. You will discover that humans and insects face many of the same challenges in trying to eke out an existence on planet earth. You will also find that humans and insects have developed different ways of negotiating those challenges. Nonetheless, there are enough similarities that you shouldn’t get lost in the discussion. And if you do, just think about how humans work. It will give you a great reference point from which to understand insects.

It is also useful to note that insects are the most numerous and diverse groups of animals on Earth. There are over 900,000 species of insects that have been identified, named, and bar-coded. Further- more, scientists estimate that there may be as many as ten million more species of insects worldwide. We simply haven’t yet found, identified, and named all of them! But because there are so many insects occupying so many ecological niches, you can expect that there will be variation among insects in how they conduct basic processes like breathing, reproduction, digestion, and so forth. Just think of all of the variation that we see among mammals or even people as far as these processes occur! To a large extent, you can deduce elements of the life habits of an insect from its structure. In other words, form follows function. We will make note of examples of this as we move through the material. It helps to reinforce basic principles and it will prompt you to start to think analytically about how and why insects do the things they do, and how this is similar and different to how humans accomplish these analogous processes.

To help facilitate you in this process, we will first review where humans and insects are placed on the Tree of Life. Next we will consider the necessary tasks that both humans and insects have to complete in order to survive and prosper as a species, as well as the relevant organ systems that allow them to accomplish these tasks. These will be the topics of Chapters 2-6:

• Breathe (respiratory and circulatory systems)

• Get energy (food, drink) and digest it (digestive and excretory systems)

• Grow and develop (endocrine system)

• Monitor and respond to the environment (nervous system and companion sensory organs)

• Reproduce (reproductive and endocrine systems)

Part I cover photo credit:

CC0 Public Domain Entomological Society of London

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