Biological Control with Insects: The Alligatorweed Thrips

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Material Information

Title:
Biological Control with Insects: The Alligatorweed Thrips
Physical Description:
Fact sheet
Creator:
Center, Ted D.
Publisher:
University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication:
Gainesville, Fla.
Publication Date:

Notes

Acquisition:
Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
Publication Status:
Published
General Note:
"Revised: May 2002"
General Note:
"SS AGR 135"

Record Information

Source Institution:
University of Florida Institutional Repository
Holding Location:
University of Florida
Rights Management:
All rights reserved by the submitter.
System ID:
IR00004564:00001


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SS-AGR-135 Biological Control with Insects: The Alligatorweed Thrips 1 Ted D. Center, F. Allen Dray, and Vernon V. Vandiver, Jr.2 1. This document is SS AGR 135, one of a series of the Department of Agronomy, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Revised: May 2002. Please visit the EDIS Web site at http://edis.ifas.ufl.edu. 2. Ted D. Center, Research Entomologist, USDA Agricultural Research Service, Invasive Plant Research Laboratory, Fort Lauderdale, FL 33314; F. Allen Dray, Ecologist, USDA Agricultural Research Service, Invasive Plant Research Laboratory, Fort Lauderdale, FL 33314; and Vernon V. Vandiver, Associate Professor and Extension Aquatic Weeds Specialist, Fort Lauderdale Research and Education Center, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611. The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean. ( Amynothrips andersoni O'Neill Thysanoptera: Phlaeothripidae) Host : Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) The adult alligatorweed thrips is shiny and black in color. The female is only about 2.1 mm long while the smaller male is about 1.7 mm long while the smaller male is about 1.7 mm long. Two forms exist, a short-winged (brachypterous) and a long-winged (macropterous) form. Only the macropterous form is capable of flight. The females undergo a 4 day pre-ovipositional period after which they deposit their eggs on or behind hairs present in leaf axils on stem nodes of alligatorweed. Females lay an average of about 200 eggs. The newly placed eggs are yellowish or amber and become reddish as the embryo matures. The eggs hatch in about 7 days and produce a larva. Two distinct larval stages eventuate. Larvae are active and feed by piercing meristematic tissues with their mandibular and maxillary stylets. Scarified lesions are produced along the margins of the young leaves which cause the leaves to distort and curl. The larvae often aggregate within these curled leaves which provide excellent hiding and feeding sites. As with other species of thrips, A. andersoni development progresses through a pre-pupal stage before attaining the pupal stage. The total generation time is about 28 days, and the adults live up to four months. On floating alligatorweed, A. andersoni has difficulty competing with the alligatorweed flea beetle which rapidly defoliates the plants. The thrips thrives on rooted alligatorweed, however, which usually is not heavily attacked by flea beetles. The feeding activity of the larvae causes stunting of leaf growth, but thrips populations are sporadic and their distribution seems limited. Some evidence indicates that predators may suppress thrips populations as does resource competition from flea beetles. However, the impact of this insect on alligatorweed, particularly the rooted form, has never been evaluated.