There is extensive literature available on food pests. Scientific articles deal with specific parts of pest problems. Some of them are available on the Internet and you can also see pictures and descriptions of each pest there. You can use the animals’ Latin names as keywords.
Determination books with detailed keys are available. The authors of this book have had the pleasure of using Professor Herbert Weidner’s keys, which exists in several versions.
The latest (7th) edition is: Weidner, Herbert & Udo Sellenschlo (2010). Vorratsschädlinge und Hausungeziefer: Bestimmungstabellen für Mitteleuropa. Spektrum Akademischer Verlag, Heidelberg. (350 pages).
For mites in food you can use the book: Hughes, A. M. (1976). Mites of stored food and houses. Min. Agr. Fish. Food. Tech. Bull. 9, London. (400 pages). (Key for the determination of mites. Difficult.).
Your local authorities can provide information and sometimes also provide help when it comes to pests.
Extermination with poison
You can exterminate with poison yourself or you can leave the task to an exterminator. Make sure to check the qualifications of any exterminator, as there are different demands to the qualifications required to take this title in different countries. The addresses of the persons or companies which carry out commercial pest control can be found on the Internet under the search term pest control. Some forms of pest control may only be made by persons and firms that have special licenses to perform such extermination. When you are dealing with poisons: read the label (which can also be viewed on the website) or contact the authorities.
There are general guidelines and rules to import of animals, insects and plants. They are primarily designed to prevent pests in plants, but some of the species mentioned in this book are also mentioned in the so-called quarantine lists. Quarantine lists from virtually every country in the world can be found in different databases on the Internet. For example the PQR database from EPPO, which is freely downloadable. Species listed on quarantine lists shall not be imported into that country. The so-called list II species are also undesirable, but may be introduced by agreements of extermination etc. There may in fact be a huge gap between official requirements and what is done in practice. The trend is towards more stringent requirements as import countries may require more than the official requirements, never less. As evidence that the requirements for specific food pests are met, some countries require that the product is accompanied by an international phytosanitary certificate.
One can examine whether food pests mentioned in this book can cause allergic reactions to people. This is done on the Internet at “Allergome – A Database of Allergenic Molecules,” on www.allergome.net. Here it is possible to search the Latin pest names.
Colouration of small, pale animals
It is not very difficult to make decent microscope preparations for examination under a high resolution light microscope. You will need a colouration, called Hoyer’s medium. It is prepared according to the following recipe:
- 30 g Arabic gum
- 50 ml distilled water
- 20 ml glycerol
- 200 g chloral hydrate
Dissolve the gum in the distilled water. It may take several days, but moderate heating and a magnetic stirrer speed up the process. Let it happen in a flask with a stopper so the water does not evaporate along the way. Next, the last two ingredients are added and when the chloral hydrate is dissolved you filter the fluid through a tea strainer to remove the coarsest impurities from the Arabic gum lumps. The mixture should be stored in a bottle with a stopper (not rubber or cork) and is stable for many years. The bottle should be labelled with “corrosive” and “toxic”.
Whenever you make a preparation, start by placing a drop of the mixture on a glass slide. The tip of a needle is dipped into the drop and is moved so that the insect is affected by the tip and adheres thereto. The insect is placed in the drop and a glass slide is placed on top. You can heat gently on the preparation to remove any air bubbles. The preparation can now be examined under a high resolution microscope, but it is better to allow it to stay a few days if necessary at 50 ° C, which can kill any insects. If you want to store the preparation in a box, it should be surrounded with clear nail polish.
Insects in water or glycerine can be applied directly to Hoyer’s medium, but insects in alcohol or lactic acid should be washed first. A drop of alcohol in the mixture causes the material to escape to the sides, and lactic acid precipitates in decorative shapes, which complicates any observations. Preparations with Hoyer’s medium are, as far as we know, unlimited durable and good to use when insects must be determined properly with a high resolution microscope – especially when using phase contrast.