Historic note

Group Title: Research Report - University of Florida Central Florida Research and Education Center ; 90-07
Title: Bioassay of two new insecticides, CGA-183893 and CGA-184699, against Liriomyza trifolii (Burgess)
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00075873/00001
 Material Information
Title: Bioassay of two new insecticides, CGA-183893 and CGA-184699, against Liriomyza trifolii (Burgess)
Series Title: Research Report - University of Florida Central Florida Research and Education Center ; 90-07
Physical Description: Book
Language: English
Creator: Leibee, Gary L.
Savage, Kenneth E.
Publisher: University of Florida, Central Florida Research and Education Center
Publication Date: 1989
 Record Information
Bibliographic ID: UF00075873
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 122930305

Table of Contents
    Historic note
        Historic note
        Page 1
        Page 2
Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida

Central Science
rm" ILibrary

University of Florida JAN 11 1990


Sanford, Florida

Research Report SAN 90-07 December 1989


Gary L. Leibee and Kenneth E. Savage

The insect growth regulators CGA-183893 and CGA-184699 (Ciba-Geigy
Corporation) were compared with cyromazine (Ciba-Geigy Corportation) against the
larval stage of Liriomyza trifolii (Burgess) using a leaf-dip technique in the
laboratory. All compounds were evaluated at 6 ppm, the app. LC50 value for
cyromazine on L. trifolii using this leaf-dip technique (Leibee, unpublished
data). Cowpeas in the primary leaf stage were exposed to L. trifolli adults for
24 hrs in an infestation cage. Immediately after removal from the infestation
cage the leaves and part of the stem were submersed for 5 seconds into the
appropriate solutions and the excess solution shaken off. X-77 (Chevron Chemical
Co.) was added to the leaf-dip solutions at the rate of 8 oz per 100 gallons to
improve wetting of the plants. The untreated checks were dipped in water
containing only X-77. Twenty plants were used for each treatment with each plant
considered a replication. The treated plants were maintained at 25+10 C and a
12-hr photoperiod in growth rooms. Leafmines were counted about 5 days after
dipping. About one day before the larvae began to exit the leaves the primary
leaves were excised and placed in plastic petri dishes with covers. The petri
dishes contained filter paper to absorb excess moisture to prevent the emergent
larvae and pupae from drowning. The leaves were left in the Petri dishes one
week to allow all the larvae to exit and pupate. The puparia were removed from
the Petri dishes, counted, and placed into plastic pill cups. The puparia were
maintained at 25+10 C and a 12-hr photoperiod for two weeks to allow the adults
to emerge and die. The adults were sexed, counted, and returned to the pill cups
for storage. Larval mortality was calculated for each plant by using the
following formula: % larval mortality (m-p)/m x 100 where m number of mines
or larvae in the plant and p number of pupae reared from the plant. To account
for mortality that occurred in both the larval and pupal stages (hereafter
referred to as total mortality), the following formula was used: % larval-pupal
mortality (m-a)/m x 100 where m is the same as above and a the number of
adults reared from the plant. Pupal mortality was calculate by using the
following formula: % pupal mortality (p-a)/p x 100 where a and p are same as

Larval, pupal, and total mortality are presented in Table 1. Cyromazine
at 6 ppm produced about 50% mortality in the larval and pupal stage, which is
in agreement with the results of previous studies (Leibee, unpublished data).
CGA 183893 at 6 ppm was much more active than cyromazine in that almost all the
larvae were killed and no adult emergence occurred from the few remaining
puparia. CGA 184699 caused statistically no more mortality than in the untreated
check in the larval stage, but caused significant mortality in the pupal stage.

I .

Table 1. Activity of CGA-183893 and CGA-184699 compared
with cyromazine on Liriomyza trifolii larvae in cowpea.

% Mortality
Treatment Larval Pupal Total

Untreated check (water + X-77) 5.4 c 3.8 b 9.6 d

CGA-183893 25WP at 6ppm 99.1 a 100.0 2 100.0 a

CGA-184699 50EC at 6ppm 7.2 c 41.7 a 46.0 c

Cyromazine (96.8% technical)
at 6ppm 51.9 b 49.8 a 73.9 b

'Means within each column followed by the same letter are not
significantly different at the 1% level by DMRT. ANOVA was
performed on transformed (arc sine) data.

2Not included in statistical analysis because 20 plants
(replicates) containing a total of 563 mines yielded a total
of 7 pupae from 4 plants.

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