Residual Efficacy and Field Performance of Thiacloprid
(Calypso®) Against Whiteflies in Melons
John C. Palumbo, F.J. Reyes, C.H. Mullis, Jr., A. Amaya, and L. Ledesma, L. Carey
Department of Entomology, Yuma Valley Agricultural Center
Abstract
Studies were conducted to compare the residual field efficacy of Calypso,
compared with soil applications of Admire and foliar sprays of Provado and
Actara. The results demonstrate that several insecticide product uses are being
developed that offer melon growers management alternatives for controlling
whiteflies comparable to what they have experienced with Admire. Calypso
showed excellent promise as a foliar, post-planting spray with good residual
activity. Two spray applications provided good whitefly control and excellent
crop and melon quality. Although we saw a measurable impact on some natural
enemies, the compound is supposedly very safe to honeybees. Overall, when
directed at low adult and immature densities, Calypso provided 14-21 days of
residual control and was capable of preventing yield and quality losses in spring
melons. These studies also emphasize, that like the IGRs, these foliar
neonicotinoids should be used when whiteflies densities are low and beginning
to build. This compound may be available as early as 2002.
Introduction
Over the past several years, whiteflies have not caused significant problems for melon growers because of the
availability of imidacloprid (Admire®). This class of chemistry (neonicotinoids) has activity against many sucking
insect pests and has good systemic activity in the plant. Thus it is appropriate for soil applications in some crops.
The systemic activity of Admire against insects may vary depending on the crop, formulation, and application
method.
Unfortunately, Provado, the foliar formulation of imidacloprid, has poor residual efficacy against
whiteflies and is not labeled for use on melons. Recently, there has also been a release by the agrochemical
industry of several new products within the neonicotinoid chemistry that have shown activity on whiteflies and
aphids in vegetables. These compounds are toxicologically similar to Admire, but differ in their route of activity.
Thiamethoxam (Actara) is similar to Admire, and has shown promising activity when applied as a foliar spray.
Thiacloprid (Calypso) is the most recent nicotinoid compound to be developed, and similar to imidacloprid, the
compound has a favorable environmental profile and activity against a number of sucking pests, including
whiteflies. It has good persistent translaminar activity as a foliar spray, and has shown residual efficacy comparable
to acetamiprid and Actara against whiteflies. The purpose for this study was to compare the residual field efficacy
of Calypso, compared with soil applications of Admire and foliar sprays of Provado and Actata.
_____________________
This is a part of the University of Arizona College of Agriculture 2001 Vegetable Report, index at:
http://ag.arizona.edu/pubs/crop/az1252/.
Methods and Materials
Spring Melons 2000:
The objective of this study was to examine the residual activity of two new
chloronicotinyl compounds against whitefly on melons relative to standard Admire soil applications, and
Capture/Thiodan and Applaud sprays. Cantaloupe plots ‘Mission’ were established at the Yuma Agricultural
Center on March 14 and managed similarly to local growing practices. Plots consisted of four 80-inch beds, 60 ft
long with a 15 buffer between each plot. The study was designed as a randomized complete block design (4
replicates/treatment) with the program treatments applied to melons in the following manner: 1) Admire at plant at
16 on Mar 14;
2) Provado at 3.75 oz/acre on May 2, May 23;
3) Calypso 4SC at 1.5 and 3.0 oz /acre on
May 2, May 23;
4) Actara at 4.0 and 5.5 oz/acre on May 2, May 23;
5)Catrure (5.0 oz) and Thiodan (32 oz)
May 2, May 23; and 6) Applaud at 8 oz/acre on May 2. Admire was applied at planting at 3" sub-seed line prior
to seed placement in 20 GPA. The foliar treatments were applied with a hydraulic sprayer delivering 36 GPA at 60
psi, using 5 - TX18 ConeJet nozzles per bed. Whitefly populations were assessed by estimating immature and adult
densities at 3, 7, 14 and 21 days following each application. We estimated the effects of the spray treatments on
population densities by making whole plant counts. This entailed removing the leaves from 3 locations on the
primary vine (crown, midvine, and terminal) of 5-8 plants within each replicate. Whitefly density counts on each
leaf were estimated under magnification. These data provide both seasonal growth rates of the population and
efficacy estimates relative to the residual activity of each treatment. Vacuum samples were taken on 6 June to
estimate natural enemy abundance. Melon yields and quality were estimated beginning on June 20. The number of
total netted fruit and the percentage of the total that were size 9 and 12 melons were estimated for yields. Quality
was measured by estimating the sooty mold contamination on individual melons and by using a foliage rating (0-4;
0=vine collapse, 4= clean, healthy leaves and vines) to assess the amount of damage to the foliage from whitefly
feeding.
Spring 2001:
The study was similar to the previous year with the exception that a different formulation of
Calypso (240SL) was evaluated. Cantaloupe plots ‘Del Rio’ were established at the Yuma Agricultural Center on
March 26 and managed similarly to local growing practices. Plots consisted of four 80-inch beds, 60 ft long with a
15 buffer between each plot. The study was designed as a randomized complete block design (4 replicates/treatment)
with the program treatments applied to melons in the following manner: 1) Admire at plant at 16 oz/acre; 2)
Calypso 240SL at 3.0and 6.0 oz /acre; 3) Actara at 3 oz/acre; and 4) Fulfill at 2.75 oz/acre. Two foliar sprays
were applied on May 9 and 31. Applications and whitefly assessments were similar to the spring 2000 study.
Results and Discussion
Whitefly population pressure was low-moderate during both years of this study, but differences among the
management approaches were observed. In general, Calypso and Actara, provided adequate seasonal whitefly
control comparable to the Admire standard in 2000. All the foliar compounds provided good adult knockdown and
reduction in egg deposition (Fig 1), where Actara, Calypso, and Capture/Thiodan appeared to provide a solid 14-d
residual compared with the untreated check following each application. This was particularly apparent at the high
rates of Calypso and Actara. In the 2001 study, the new 240SL formulation of Calypso provided excellent residual
control of eggs and small nymphs compared with the untreated control. Actara at 3.0 oz and Fulfill provided
significantly weaker suppression of eggs and nymphs (Fig 5).
Immature colonization following the foliar sprays showed a somewhat similar trend. In 2000, Actara appeared to be
the quickest acting on small nymphs following treatment (Fig 2), and appeared to provide the best residual. Calypso,
at both rates, appeared to provide significantly better suppression of large and red-eyed following the first
application, but all compounds provided significant residual control following the 2nd spray. The ultimate measure
of preventing whitefly colonization is the estimate of eclosed pupae. The high rates of Actara and Calypso contained
the fewest eclosed pupae following the 2nd spray, comparable to Admire (Fig 3). In 2001, following 2 applications
21 days apart, Calypso provided significantly better suppression of whitefly large nymphs and pupae when
compared with the other treatments (Fig 6). Both rates were equally effective in suppressing the build up of large
nymphs. Calypso was comparable to Admire in preventing whitefly colonization.
Fruit quality in 2000 was most consistent in the plots that provided good residual suppression of whiteflies (Fig 4).
Significant sooty mold contamination on both foliage and fruit was prevented in the Calypso and Actara treatments,
and were comparable to the standard Admire treatment. Again this is correlated to the level of residual consistent
provided by each compound. In 2001, yield effects were not observed among the treatments due to the late
establishment of whiteflies. However, a vine decline due to high soil temperatures and whitefly infestation resulted
in significant treatment effects (Fig 7). Again, melons sprayed with Calypso maintained the most vigorous vines
and canopies through the harvest period.
In conclusion, this study shows the residual efficacy of Calypso against whiteflies in spring melons. When
compared to Provado, the compound is significantly more efficacious, with more consistent residual activity.
Calypso appears to be comparable to applications of Actara at higher rates, but significantly more efficacious
compared to Actara at 3.0 oz. Overall, when applied at low adult and immature densities applications, Calypso
provided 14-21 days of residual control and was capable of preventing yield and quality losses in spring melons.
These studies also emphasize, that like the IGRs, these foliar neonicotinoids should be used when whiteflies
densities are low and beginning to build.
Acknowledgment
Funding for this research was provided by the following sources: California Melon Research Board Project
PAL-99 and PAL00, Aventis CropScience, Bayer Corporation and Novartis Crop Protection.
Figure 1. Whitefly adult abundance and egg densities relative to foliar sprays treatments,
Yuma Ag Center, 2000. Arrows indicate spray applications (see text for treatments)
Adult Abundance
#2
#1
50
45
40
35
Adults/ leaf
50
Actara - 4.0 oz
Actara - 5.5 oz
Provado
Calypso - 3.0 oz
Calypso - 1.5 oz
Applaud (1 spray only)
Capture/Thiodan
Admire (at planting)
Untreated
30
25
45
40
35
30
25
20
20
15
15
10
10
5
5
0
Prespray
3
DAT
7
DAT
14
DAT
21
DAT
7
DAT
14
DAT
21
DAT
0
Egg Densities-Terminal Leaves
2
Eggs / cm / Leaf
45
#1
45
#2
40
40
35
35
30
30
25
25
20
20
15
15
10
10
5
5
0
Apr 28
Pre-spray
May 9
7 DAT
May 16
14 DAT
May 23
21 DAT
May 30
7 DAT
June 6
14 DAT
June 13
21 DAT
0
Small Nymphs-Midvine leaves
2
Eggs / cm / Leaf
10
#1
#2
10
8
8
6
6
4
4
2
2
0
0
Apr 28
Pre-spray
May 9
7 DAT
May 16
14 DAT
May 23
21 DAT
May 30
7 DAT
June 6
14 DAT
June 13
21 DAT
Large and Red-eyed Nymphs- Midvine leaves
#1
5
4
2
Mean / cm / Leaf
6
3
#2
6
Actara 4.0 oz
Actara 5.5 oz
Provado
Calypso 3.0 oz
Calypso 1.5 oz
Applaud
Capture/Thiodan
Admire at planting
Untreated
5
4
3
2
2
1
1
0
0
Apr 28
Pre-spray
May 9
7 DAT
May 16
14 DAT
May 23
21 DAT
May 30
7 DAT
June 6
14 DAT
June 13
21 DAT
Figure 2. Whitefly small and large nymph densities relative to foliar sprays treatments, Yuma Ag Center, 2000.
Arrows indicate spray applications (see text for treatments)
Eclosed Pupae - Midvine leaves
#1
#2
2
Eclosed pupae / cm / Leaf
1.8
1.5
1.2
0.9
1.8
Actara 4.0 oz
Actara 5.5 oz
Provado
Calypso 3.0 oz
Calypso 1.5 oz
Applaud
Capture/Thiodan
Admire at planting
Untreated
1.5
1.2
0.9
0.6
0.6
0.3
0.3
0.0
0.0
Apr 28
Pre-spray
May 9
7 DAT
May 16
14 DAT
May 23
21 DAT
May 30
7 DAT
June 6
14 DAT
June 13
21 DAT
Eclosed Pupae - Crown leaves
#2
6
6
5
5
4
4
3
3
2
2
1
1
2
Eclosed pupae / cm / Leaf
#1
0
0
Apr 28
Pre-spray
May 9
7 DAT
May 16
14 DAT
May 23
21 DAT
May 30
7 DAT
June 6
14 DAT
June 13
21 DAT
Figure 3. Whitefly eclosed pupae densities estimates relative to Foliar sprays treatments,
Yuma Ag Center, 2000. Arrows indicate spray applications
Foliage Rating
4 = Clean foliage;
Contamination Index
4.0
3.5
3 = Light sooty mold; 2 = Mod. sooty mold; 1 = Heavy sooty mold; 0 = Vine collapse
a
ab
4.0
a
ab
bc
ab
3.5
cd
cd
3.0
3.0
2.5
2.5
e
2.0
2.0
1.5
1.5
1.0
1.0
Actara
4.0 oz
Actara
5.5 oz
Provado
3.75 oz
Calypso
3.0 oz
Calypso
1.5 oz
Applaud
8.0 oz
Capture
Thiodan
5.1/32 oz
Admire
16 oz
Untreated
Check
Sooty Mold Contamination
100
100
a
% Contaminated Fruit
90
90
80
80
70
70
60
60
50
40
30
50
bc
40
cd
30
de
20
10
0
e
Actara
4.0 oz
Figure 4.
Actara
5.5 oz
Provado
3.75 oz
e
e
Calypso
3.0 oz
Calypso
1.5 oz
e
Applaud
8.0 oz
Capture
Thiodan
5.1/32 oz
20
e
10
Admire
16 oz
Foliage and fruit quality relative to whitefly control, YAC, Spring 2000
0
Untreated
Check
Egg Densities (Terminal Leaves)
#1
#2
12
Admire
Actara
Fulfill
Calypso - low
Claypso- -High
Untreted
9
2
Eggs / cm / Leaf
12
6
9
6
3
0
3
May 7
Pre-spray
May 16
7 DAT
May 23
14 DAT
May 29
20 DAT
Jun 7
7 DAT
June 12
14 DAT
June 20
21 DAT
0
Small Nymphs (Mid-vine leaves )
12
12
#2
9
9
6
6
3
3
2
Small nymphs / cm / Leaf
#1
0
May 7
Pre-spray
May 16
7 DAT
May 23
14 DAT
May 29
20 DAT
Jun 7
7 DAT
June 12
14 DAT
June 20
21 DAT
0
Figure 5. Whitefly immature densities relative to foliar sprays treatments, Yuma Ag Center, 2000.
Arrows indicate spray applications
Large Nymphs (Mid-vine Leaves)
#1
2
Eggs / cm / Leaf
6.0
4.5
#2
Admire
Actara
Fulfill
Calypso - low
Claypso- -High
Untreted
6.0
4.5
3.0
3.0
1.5
1.5
0.0
May 7
Pre-spray
May 16
7 DAT
May 23
14 DAT
May 29
20 DAT
Jun 7
7 DAT
June 12
14 DAT
June 20
21 DAT
0.0
Eclosed Pupae (Mid-vine Leaves)
#2
2.0
2.0
1.5
1.5
1.0
1.0
0.5
0.5
2
Small nymphs / cm / Leaf
#1
0.0
May 7
Pre-spray
May 16
7 DAT
May 23
14 DAT
May 29
20 DAT
Jun 7
7 DAT
June 12
14 DAT
June 20
21 DAT
0.0
Figure 6. Whitefly immature densities relative to foliar sprays treatments, Yuma Ag Center, 2000.
Arrows indicate spray applications
Foliage Rating
3 = No vine decline;
2 = light-moderate vine decline; 1 = moderarte-heavy vine decline; 0 = complete vine collapse
Contamination Index
3.0
2.5
a
3.0
a
2.5
b
b
2.0
2.0
1.5
1.5
c
1.0
c
0.5
0.0
1.0
0.5
Admire
16 oz
Figure 7.
Actara
3.0 oz
Fulfill
2.75 oz
Calypso
Low
Calypso
High
Rating of vine decline asscoiated with treatment effects; YAC, Spring 2001
Untreated
Check
0.0