In an consumer orientated world where poisons are applied to enhance crop yields there are a myriad of unforeseen and generally unwanted side effects.
The designed loss is mass, the reduction in numbers of insects competing for food.
The objective loss is two-fold. 1. The mass as designed and 2. The unforeseen consequences of a rapid change to the proportions of other insects.
The subjective loss has as many arguments as their are effects. The most obvious is that other insects and animals will be deprived of food and this will continue along the food chain as each consumer species goes hungry. Some will suffer direct poisoning designated for other insects.The two most newsworthy reports refer to the birds and the bees.
Some birds suffer directly from a shortage of insects to feed whilst all may and suffer from eating poisoned insects and seeds,
The study team said the insecticide is probably coating seeds that the birds like to eat, as well as leaching into both water and soil around the sprayed areas. https://www.redorbit.com/news/science/1113188610/farmland-bird-population-declines-insecticides-071014/
Bees die directly from the poisons.
In this article we discuss the potential effects of both the lethal and sub-lethal impacts of insecticide use in agro-ecosystems on pollination services by bees. https://www.sciencedirect.com/science/article/pii/S1439179110001623
Other small creatures are susceptible to general pesticides
Argument of fundamental resources
Background
Looking at the environment it's clear that variety or diversity is an important factor as well as quantity. Not only would it be increasingly boring with less choice but more likely to suffer from catastrophic failure of one of a few large resources.
Resources.
Whereas plants and animals use the Sun, wind, water and earth (if one were to fail > the end) plants get most of their energy from the sun directly. Animal take most it from the plants and other animals. Many cold blooded creatures take a significant amount from the sun, which is why crocodiles are a bit slow to until they warm up. Insects also slow down significantly when they are cold so it will be easier to swat a fly in the autumn indoors if you don't have central heating.
From the smallest bacteria, fungi, mosses, vegetables and seeds, through insects and other small creatures, birds, fish, reptiles and other mammals, humans eat them all. I'm sure you have heard of people eating ants, bees, snails, and whales.
insects have a great range for food. Many suck blood from mammals, eat each other, eat decaying flesh and even living tissue where available. Maggots, which are the young form of some insects, are actively used to eat putrefying skin in humans to clean out infectious tissue. https://www.ncbi.nlm.nih.gov/pubmed/12547878
The demise of insects
Prior to chemical poisoning insects most often died in the food chain, and from the cold; now that has been disrupted by insecticides.
As cultivated plants are the major resource for energy from food for humans, it is not surprising that crops are guarded and protected from insects. Whereas it is fairly easy to ward of birds and fence off rabbits and deer, it is more difficult to keep insets off food crops. This is becoming a greater problem for three reasons
- The amount of plants humans consume, including those for other animals so we can eat them and crops for other uses than food such as cotton, silk and corn and sugar which are also used for fuel. Even trees are under sustain degradation from human and consumption.
- The selective breeding to make crops sweeter and more delicate has made them a prime target for other creatures. I even have mice eating my onions and chillies.
- The application of poisons, including those that are genetically modified to kill off one species, impacts upon another, which has a feed back on insect populations, (foxes and rabbits) both in variety and mass, locally and globally.
The Unintended and Unwanted Effects
Any change in one resource impacts upon other consumers, and whereas it is all but impossible to calculate the impact of the loss of one insect on the future of the human race or of the impact of the human race on the sun, these impacts do exist.
In our short killing spree as a single human consumer we can see the benefits of crop management. In the longer course of generations of co-operative exploitation of resources we have become susceptible to large scale changes in the environment, some brought about by the use of insecticides, poisons to kill insects. But as noted there are side effects.
Insects prey on each other and so the demise of one may mean that another starves and in doing so we loose that insects benefit.
There are numerous way to control insects, for example: In industrialised agriculture the farmer sprays whole areas and kills of many insects, a large proportion of which would have been beneficial. A general chemical insecticide, could kill both greenfly and ladybirds, yet ladybirds eat greenfly.
In organic agriculture farmers will breed or buy ladybirds to keep down the number of greenfly. On small endeavours like mine I tried spraying them with soapy water to get them off the leaves and at one point shook the plant, whence so many fell off onto newspaper I rolled it up and burnt them. Not a nice thing to do but it was a simple choice, tomatoes or no tomatoes or buy tomatoes from someone who undoubtedly did far more damage.
So the argument is not an absolute moral one, about what is better for the environment, but how to treat the environment in such a way that we minimise any long-term damaged so that we can continue to exploit it.
Altogether a very selfish attitude, and the only was you can actively reduce insecticide use is to grow or buy organically produced products and not just for food but organic cotton for clothes. Just remember this is not a moral undertaking, people will still suffer, animals will be bred for consumption and most people will have other things they prefer to are about.
But note that before humans were such prolific consumers and almost wild, the not plant based wildlife mass was 100%.
According to an article ( in The Independent 4th May 2014, by Ian Johnston), it is now less than 5%, 40% human and 55% animals we consume.
See https://rogerlovejoy.net/blog/space.php/and-so-said/dusk-of-the-wild