Why Thrips?

Thrips are unbelievably small insects. Yet, they cause millions of dollars of damage annually to United States vegetable crops, attacking most everything from onions to basil, to peanuts and snapbeans. Adult thrips (both singular and plural - "thrip" is not a word) are just barely visible to the naked eye, measuring about 1/32 inch. Immature thrips are even smaller. Besides being small, thrips are elusive. Finding and observing them on a plant is difficult.

However, because

the damage thrips inflict is so disproportionate to their size,
detecting them in a crop is difficult due to their elusive behavior, and
management practices are dependent on which species are present,

being able to tell the different species apart is critical!

Thrips belong to the insect order Thysanoptera, and are closely related to the order Homoptera, which contains the leafhoppers and aphids (Stannard, 1986). There are over 500 thrips species in the United States, which are divided into eight families (Palmer, et al., 1989; Stannard, 1968). Of these, seven members of two families, the Thripidae and the Phlaeothripidae, are covered in this program, including the most comnmon species of vegetable thrips in the US. A table illustrating the postion of the thrips in the animal kingdom is given below. Data on the numbers of North America species come from Arnett, 1985.

Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Thysanoptera

Suborder: Tubulifera

Family Phlaeothripidae (Tube-tailed Thrips Family: 348 North American species)

Suborder: Terebrantia

Family Aeolothripidae (Predaceous Thrip Family: 57 North American species)

Family Merothripidae (Jumping Thrips Family: 4 North American species)

Family Heterothripidae (Tree Thrips Family: 20 North American species)

Family Thripidae (Thrips Family: 246 North American species)

This knowledgebase contains information for identifying and managing the thrips commonly infesting vegetable crops in the US. The impetus for developing this knowledgebase was the introduction of the melon thrips Thrips palmi Karny, into the vegetable growing area around Homestead, FL in 1990.

Since 1985, Glade Crop Care, Inc. has actively surveyed for thrips to define the distribution of vectors of tomato spotted wilt virus. In one of our surveys we identified the melon thrips, the first such reported occurence in the US. This thrips spread througout south Florida over the next few years, and we decided to assist others in making the correct identification of this pest and other thrips pest species.

Our purpose for developing this knowledgebase is simple: to provide growers, consultants, extension agents and other agricultural professionals information they will need to determine the presence of this devastating pest along with other thrips infesting vegetables. Hopefully, this information will increase the number of informed practitioners, and result in accurate identification, responsive control practices and a more sustainable agriculture.