Biological Control with Insects: The Hydrilla Tuber Weevil

http://edis.ifas.ufl.edu/ ( Publisher's URL )
MISSING IMAGE

Material Information

Title:
Biological Control with Insects: The Hydrilla Tuber Weevil
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 137"

Record Information

Source Institution:
University of Florida Institutional Repository
Holding Location:
University of Florida
Rights Management:
All rights reserved by the submitter.
System ID:
IR00004566:00001


This item is only available as the following downloads:


Full Text

PAGE 1

SS-AGR-137 Biological Control with Insects: The Hydrilla Tuber Weevil 1 Ted D. Center, F. Allen Dray, and Vernon V. Vandiver, Jr.2 1. This document is SS AGR 137, 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. ( Bagous affinis Hustache Coleoptera: Curculionidae: Erirhinae: Bagoini) Host : Hydrilla verticillata (L.f.) Royle (hydrocharitaceae) The genus Bagous is cosmopolitan and includes at least 130 species, 33 of which are present in the United States. B. affinis has been reported only from India and Pakistan, and its host range is restricted to hydrilla. Females deposit their eggs on hydrilla tubers and stems or moist wood, but apparently not on submersed material. Eggs hatch after 3 to 4 days and neonates crawl through the soil in search of tubers. Larvae generally feed and pupate within a single tuber. However, if a tuber is destroyed larvae will search for a new tuber. There are four instars, and total duration for the larval stage is 8 to 14 days (at 27C). Pupation usually occurs within the tuber, but can also take place in moist wood. Duration of the pupal stage is 4 to 6 days (at 27C). Newly emerged (teneral) adults remain inside the tuber for 2 to 3 days while their exoskeletons harden. Some females oviposit within 2 to 7 days of emergence, others appear to develop flight muscles upon emergence. Females do not simultaneously have flight muscles and eggs, but histolize their flight muscles and form eggs within 8 days of flight. Females produce up to 649 (average 232) eggs over an average lifespan of 128 days. Males live an average 149 days. Overall, adult longevity ranges up to 272 days. Adults B. affinis are most active at night and burrow into the soil or hide among dried hydrilla or other materials when not active. Adults eat hydrilla tubers, but the damage caused by adult feeding is apparently inconsequential relative to the larval destruction of tuber populations. Larvae attack tubers up to 10 cm deep in the soil, and have reportedly infested high percentages of the tubers present in small ponds in their native range. Neither larvae nor adults are able to withstand submergence for more than a few days.

PAGE 2

Biological Control with Insects: The Hydrilla Tuber Weevil 2 Bagous affinis has been released at several sites in Florida. Unfortunately, permanent populations have not become established.