Traps, attractants, targets and
insecticides for house flies
Christopher J. Geden
USDA, ARS, CMAVE
Traps, attractants, targets and
insecticides for house flies
1)Trap height
1)Fresh vs. fermenting sugar baits
2)Insecticide-treated targets
3)Status of imidacloprid resistance
4)Pyriproxyfen and endosulfan for fly
control
Topic 1: Trap height
In a previous DWFP project, the Terminator was identified
as the most effective jar trap for house flies. Outcomes:
publication and issuance of a NSN for the Terminator.
____________________________________________
Trap
Mean catch
% catch
____________________________________________
Terminator
12,323.0a
100.0
Final Flight
2,166.5b
17.6
Victor Fly Magnet
1,287.0c
10.4
Monster Flies-Be-gone
883.0c
7.2
ISCA
276.8d
2.2
Advantage
202.5d
1.6
Fermone Big Boy
132.8d
1.1
Squeeze & Snap
79.3d
0.6
Oak Stump (blue trap)
15.5e
0.1
____________________________________________
Geden, C. J., D. E. Szumlas and T.W. Walker. 2009. Evaluation of
commercial and field-expedient baited traps for house flies, Musca
domestica L. (Diptera: Muscidae). J. Vector Ecol. 34: 99-103
House flies tend to fly low to the ground. At what
height should the traps be placed?
Effect of trap height on house fly collections in
Terminator traps
6000
Flies/trap/day
5000
4000
3000
2000
1000
0
Low (0.25 m)
Med (0.9 m)
High (1.7 m)
Trap height
The traps work best when placed on the ground or suspended just above
Data from research of graduate student Melissa Doyle
Topic 2: fresh vs. fermenting molasses
The attractant used in the Terminator is a combination
of trimethylamine, indole/skatole, and z-9-tricosene.
Effective, but stinky!
Does fermentation increase attractiveness of molasses?
Background
• Flies have been observed to be attracted to molasses since antiquity.
• In previous years, blackstrap molasses was found to be as attractive as
the bait used in Terminator traps.
• Flies also visit a variety of fermenting food sources in the field.
Hypothesis: That flies use volatile products from fermentation such as
ethanol and CO2 as stimuli indicating the presence of sugar sources.
2 Methods:
• Molasses with and without live yeast placed in field and monitored for 4
days.
• Molasses allowed to ferment indoors for 1 or 2 days then placed in the
field and compared with fresh molasses.
Effect of fermentation of molasses on attractiveness to house flies
1000
Flies/trap/day
800
600
400
200
0
Unfermented
24 hr ferment
48 hr ferment
Flies were more attracted to unfermented than to fermented molasses, at
least in jar traps. Do the high CO2 levels associated with primary
fermentation deter flies from entering the traps?
Data from research of graduate student Melissa Doyle
Topic 3: Insecticide-treated targets for fly control/interception
In an ongoing project, visually attractive targets have been tested for their
ability to intercept and kill dispersing flies. The most attractive configuration
consists of adjoining bands of alsynite fiberglass and blue fabric with peak
reflectance at 460 nm. Joe Declaro and Phil Koehler are also developing a
trap that takes advantage of this color preference.
In 2008, a perimeter of targets provided
significant protection of a large structure (calf
barn) from fly invasion from surrounding
breeding sites. Target performance improved
substantially when an olfactory lure (Farnam fly
attractant) was added.
Treated targets, 2009: Low apparancy targets using
olfactory lures
Questions:
• Can an olfactory fly attractant be used in a
low-apparency attract-and-kill device?
• Are kill rates in such a device higher than in
a conventional jar trap baited with the same
attractant?
• Can the attractant be conserved by a slower
release method?
Attractant delivery using conventional Captivator jar traps
• Buckets (containing nothing or attractant in Captivator
traps or slow-release devices) were wrapped with camo and
tied at top and bottom to prevent fly entry.
• Netting was treated with imidacloprid/sugar solution,
allowed to dry.
• Pans were placed below targets to collect killed flies.
Geden – USDA, ARS, FL
Fly collections from insecticide-treated, camouflage-covered
targets and from uncovered Captivator traps.
____________________________________________________
Device
Mean flies/day
____________________________________________________
Camo-covered chick waterer w/ attractant
2219.6 (466.9)a
Camo-covered Captivator w/attractant
2189.7 (555.0)a
Camo-covered bucket, no attractant
1298.4 (286.7)b
Captivator control (no camo cover)
1137.5 (238.0)b
____________________________________________________
Results:
• Treated targets with attractant collected 2x more flies than jar
traps or targets without attractant.
• Targets were easy to service, no handling of smelly liquids
• Treated camouflage netting without attractant was surprisingly
effective. The complex pattern may present a visually attractive
target to the flies.
Topic 4: Imidacloprid resistance
Imidacloprid for fly control first appeared in ca. 2002 as a scatter
bait. The bait’s success gave rise to other application methods
that may increase the likelihood of resistance development,
despite the fact that neonicotinoids represent “new chemistry”
with low risk of cross-resistance from other insecticide classes.
Sensitivity to imidacloprid in colony and field-collected house flies
Strain
n
LC90 (µgg-2 ) (95% CI)
RR90b
Slope (SE)
Susc. colony
1,920
65 (52-89)
-
2.3 (0.2)
UF 05-06c
1,760
143 (122-173)
2.2*
2.2 (0.1)
UF 07 c
2,160
446 (369-555)
6.8*
1.7 (0.1)
Gilchrist
1,920
346 (273-462)
5.3*
1.7 (0.1)
Lafayette
2,160
23.7*
1.6 (0.1)
Okeechobee
1,920
3.1*
1.9 (0.1)
1,550 (1,276-1,941)
202 (159-274)
A recent survey found imidacloprid resistance in all populations
tested. In one case, resistance was high enough that product failure is
imminent. There is a critical need for new active ingredients for fly
control.
Data from Kaufman et al. 2009, Insecticide resistance in house flies
collected from Florida dairies. Pest Management Sci. (in press)
Pyriproxyfen
• Discovered in the early 1980’s
• JH analogue
• Low mammalian toxicity (acute oral
LD50>5000)
• Breaks down rapidly in soil and
water
• Discovered in early 1980’s
• Early work indicated some potential
for tsetse, stable flies, house flies.
Pyriproxyfen (continued)
Trade names: Knack, Nylar, Sumilarv,
Nyguard
• Main targets: Homoptera, fleas,
mosquitoes
• For mosquitoes and flies in the US, the
only EPA-registered product is Nyguard,
with only adults listed. Face flies are on
the label but not house flies. The label
does not include application as a larvicide.
• Outside the US, Sumilarv is sold in
granular and liquid formulations as a
larvicide for mosquitoes and flies.
•
In a recent paper, Devine et al. observed substantial control of Aedes
aegypti by treating mosquito resting sites with pyriproxyfen and
allowing the mosquitoes to transfer the ppx to larval habitats. Could a
parallel approach be effective against house flies?
Pyriproxyfen test 3: Young flies exposed continuously
to treated filter paper suspended in cages; flies allowed
to oviposit in media after 6 days.
600
Progeny/ 5 females
500
Adults
Pupae
400
300
200
100
0
Control 0.0012
0.006
0.03
0.15
0.75
3.75
% Pyriproxyfen
When flies were held continuously in cages with treated filter paper, fecundity
was reduced, but only at 125X the label rate.
Fly progeny/ 5 females
Pyriproxyfen test 4: Young flies given treated sugar as
sole food source for 3 days then given normal food;
groups of 5 flies allowed to oviposit after 7 days.
400
350
300
250
Pupae
200
Adults
150
100
50
0
Control
0.001
0.033
0.01
0.33
0.1
% Pyriproxyfen
However, flies given ppx in a dry sugar bait had reduced fecundity at lower doses.
Still no effect on emergence success of flies from pupae of treated groups.
Pyriproxyfen test 7: similar to test 6 (3 ml topical larvicide
trt, 350 eggs), except using wild flies.
350
Pupae
Adults
No. pupae & adults
300
250
200
150
100
50
0
Control
0.0012
0.006
0.03
0.15
0.75
3.75
% Pyriproxyfen
Results with wild flies were essentially the same as those with insecticidesusceptible colony flies, except 2 flies emerged from pupae at the lowest
dose.
Summary, preliminary pyriproxyfen tests:
___________________________________________
PPX shows promise for fly control
• It is a potent IGR against house fly immatures
• Little to no evidence of tolerance in wild flies
• Although there is little effect on fly adults during short
exposures, incorporation into baits reduces fecundity,
as does frequent contact with a treated surface over
longer time frames.
Endosulfan
Developed in the 1950’s
• Organochlorine
• High mammalian toxicity (acute oral
LD50 35 mg/kg)
• GABA-gated chloride channel
antagonist
• ATPase inhibitor
• Broad spectrum
• Trade names: Benzoepin, Endocel,
Parrysulfan, Phaser, Thiodan, Thionex
• Most uses have been banned, but….
•
Avenger ear tags containing 30% endosulfan were introduced in 2007 for
fly control on cattle (but not soldiers!). Marketed as “new chemistry”, the
tags are highly effective against insecticide-resistant horn fly populations.
100.0
Mortality of insecticide-susceptible house flies after a
1hr exposure to Endosufan
% Mortality
80.0
4 hr
24 hr
60.0
40.0
20.0
0.0
Control
0.009
0.028
0.084
0.253
0.758
% Endosulfan
Adult house flies were highly susceptible to endosulfan (Thionex) when
exposed to filter paper treated at the label rate for control of Homoptera on
cotton. There was no recovery of flies between 4 and 24 hr after exposure.
Mortality of house flies after varying periods of
exposure to 0.76% Endosulfan
100.0
4 hr
24 hr
Mortality
80.0
60.0
40.0
20.0
0.0
Control
1 min
5 min
10 min
20 min
40 min
Exposure time
Even at a high dose, a substantial exposure time to endosulfan was required
Mortality 4 hr after exposure to endosulfan
100.0
Mortality
80.0
60.0
Susceptible
Wild
40.0
20.0
0.0
Control
0.009
0.028
0.084
% Endosulfan
0.253
0.758
Summary, preliminary endosulfan tests
______________________________________
• Endosulfan is highly toxic to insecticidesusceptible and wild house flies.
• Some evidence for higher recovery rates
in wild flies
• Use as a residual treatment would rapidly
lead to resurgence of resistance.
• Are there targeted applications that would
allow use of this old-school insecticide in
ways that would be safe and not lead to
rapid resistance development?