Over 10 billion tons of trade goods enter the US every year. Most of the cargo comes into our ports in container ships. The containers have plenty of room for insect stowaways. One of the unintended consequences of global trade is the transportation of insect species to new continents. North American insect pests are shipped from the US to other countries with US trade goods. Foreign insect pests are shipped into North America by foreign trade.
New insect pests may cause enormous economic damage. Preventing the pest insects from entering the US, or quickly eradicating them if they do arrive is a constant battle carried out by State and Federal Regulatory agencies. Recently, I toured the Nevada Department of Agriculture, Plant Industry Division, in Reno, NV and talked to some of my fellow entomologists working the front lines of this effort.
Entomologist Jeff Knight oversees an extensive survey program for early detection of insect pests. Entomologists deploy traps throughout the state and inspect areas that are at high risk for important pests. Part of this effort includes a collection of about 300,000 insect specimens. Taxonomists compare the features of the insects collected in their surveys to the features of known specimens in their collection. The proper curation, labeling and maintenance of the collection is a key part of the effort. If an insect is improperly identified, it could lead to an unnecessary commitment of resources or it could lead to a failure to eliminate a pest before it becomes established.
For example, the Red Palm Weevil can destroy palm trees, and was recently found in California. If not contained, this weevil could wipe out the iconic palm trees in parts of California and Las Vegas, Nevada. If a foreign pest, such as the red palm weevil, is found in a neighboring state, it will trigger a series of alerts and heightened pest survey activity. Many insect pests are transported unknowingly by people moving plants or wood or as stowaways in their vehicles. A pest such as the red palm weevil could easily hitch a ride from Southern California to Las Vegas. Jeff has acquired some specimens of red palm weevil to be used for identification purposes and to show to landscapers and nurserymen so they can be alert for their presence.
Many insects can only be easily identified in their adult stage. In many cases, the larval features have not been studied enough to find consistent characters that will distinguish closely related insects. Larval taxonomy is more difficult because features and coloration may change drastically as the larvae molt from one stage to the next. For this reason, it is often necessary to collect suspect larvae and keep them in a rearing room to allow them to become adults. In the future. DNA bar-coding or other genetic techniques may be available for larva identification. Until that time, the larvae must be kept alive and develop into adults before their identity can be confirmed.
These efforts at protecting our economy and our environment from invasive foreign insects are accomplished by a skeleton crew of dedicated experts on limited budgets. If the efforts are working, then the economic and environmental damage is limited and the public may wonder why these programs are necessary. It is only when the pest gets the upper hand and runs rampant that the public gets a sense of the importance of this work.
Top Left: Pinned Specimens of Red Palm Weevil. Note the color variation.
Right: Agriculturalist Robert Little holds a rearing jar for insect larvae to develop into adults.
Bottom Left: The Insect Collection Room contains about 300,000 insect specimens. The tables are for processing traps, pinning and curating the Insects. Jeff Knight (far left, plaid shirt) discusses his program with visiting scientists.
