Tips for using the nymphal key

 

Many of these tips may also be helpful for the adult key.

Tools

To effectively identify nymphal grasshoppers using this key there are several tools that you will need. Some type of magnification will be required to see some of the smaller characteristics, particularly on the early instars. The best choice is a dissecting microscope of 7 to 20 power magnification, however, even a hand lens of 5 or greater power will do if that is all that is available and you have good light. You will probably also want a good pair of forceps to manipulate your specimens. The third item which will be very helpful is a micrometer or some other precision measuring device. You will be working with sub- millimeter measurements so a simple ruler will be very difficult to use for this purpose .

Specific tips for using this key

One of the difficulties in identifying nymphal grasshoppers is the variability between different instars of the same species. This key is set up so that each instar of each species stands alone as a separate entity. If you are identifying a sample containing many grasshoppers of different sizes and colors the first step you should take is to sort them into groups of similar size, color and physical characteristics. Grasshoppers which look alike and are of the same size will most likely be of the same instar and species. Groups of grasshoppers which look alike or similar but are of different sizes may be the same species but different instars, or they may be entirely different species. It is best to start your identification with a single group of grasshoppers which look similar and are of the same size (instar). Once you have determined the species of this group you can check the text or the species fact sheet to verify your identification and to determine if other instars of the same species look similar or different.

Instar - a most useful feature

When making an identification with the key, one of the easiest and most productive steps to narrow your search is to determine the instar of your specimens. An accurate determination and choice of a single correct instar will eliminate approximately 80% of the remaining entities from the list. If you have a sample which contains many specimens of more than one instar which show enough similarity that you suspect they may be the same species, the key will allow you to select multiple instars. Sometimes it is helpful once you have determined and chosen the instar of a specimen to also select the instars before and after your specimen. Then look at the list of Entities Remaining to see if any of the specimens in the remaining list match any of your other specimens. If they don't match anything else you can de-select the additional instars to remove them from the list.

Body length and hind femur length - also very useful

Another easy way to narrow your search is to use the features "Body Length" and "Hind Femur Length" (found under "Hind Leg"). To use these features you will need an accurate measuring device as mentioned above. The measurements in these two features come from the measurements in Dr. Pfadt's book, and although they generally work well to narrow the choices, we have found that sometimes they will eliminate the correct species due to some variability of size within a species. If you are narrowing down a selection and your prime suspect disappears from the remaining list after using one of these measurements, it might be preferable to use other features to continue your search.

You can skip around in the key

One of the benefits of a Lucid key is that it is not necessary to start at the top and go down the list of features in order. They can be chosen in any order you want. Any particular feature may be more or less useful in the identification of a species. Choose the easy ones first.

Looking at the photos

This key is highly dependant on graphics and photos. To see a much broader, side-by-side view of photographs in Entities Remaining without so much scrolling, click the Images tab at the bottom of the Entities Discarded window. Notice though that this will hide the Entities Discarded window.

It's not necessary to check every feature and state

In some cases, if you have a short list of specimens remaining, but have not addressed all the features, it may be easier to check your specimen against information associated with these remaining species by reading the species information attached to each entity. It also may help to look at the species fact sheet. Almost everything found in this key, including the photos, can be found in the species fact sheets for the respective species. This can sometimes be a faster way to make an identification, than trying to find a feature that will discriminate among the remaining specimens. If your specimen does not look similar to any of the specimens remaining, you can use the strategy of unselecting states one by one, or "playing" with the key, to find the best matching species.