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1999 Rangeland Grasshopper Outbreak Forecast

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1999 Rangeland Grasshopper Outbreak Forecast Powered By Docstoc
					Non-target Effects:
  Reducing Risks
Risks for Different Groups of
    Non-target Organisms




 Source: Food and Agriculture Organization of the UN, 2003
      Environmental Profile
                         Carbaryl      Malathion   Diflubenzuron
                         CAR           OP          BU (IGR)

Human toxicity
   (WHO/EPA class)       II (Moder.)   III (Low)   Unlikely to be toxic

Fish toxicity            Moderate      Low         Low

Aquatic invertebrate
   toxicity              Low           Moderate    High

Mammalian toxicity       Moderate      Low         Low

Toxicity for birds and
    reptiles             Low           Moderate    Low

Toxicity for honey bee   High          High        Low

Toxicity for other
    non-target arthr.    High          Moderate    Moderate
Half-Life in Soil
Malathion:        1-25 D
Carbaryl:         7-28 D
Diflubenzuron:    3-4 D
DDT:              2-15 YR!


Half-Life in Water
 Malathion:        <7 D
 Carbaryl:         10 D
 Diflubenzuron:     3D
 DDT:              28-56 D
HAZARD to NON-TARGETS

Hazard = Toxicity X Exposure

Toxicity: LD (LC)50 – intrinsic
    characteristic of a chemical

Exposure: Dose rate [and Persistence]
 TOXICITY to MAMMALS
               Oral LD50
of active ingredients for rats (in mg/kg):
Malathion –          2,100 (1,000-10,000)
Carbaryl –             450 (250-850)
Diflubenzuron – >4,640

               Dermal LD50
of active ingredients for rats (in mg/kg):
Malathion –          >4,000
Carbaryl –           >2,000 (rabbit)
Diflubenzuron –      >10,000
       HAZARD to MAMMALS
                                   (rats)

                                                  Insecticides
                                      (active ingredient and trade name)
Parameter
                                    Malathion      Carbaryl    Diflubenzuron
                                    Fyfanon         Sevin          Dimilin
Oral Toxicity (LD50 mg/kg)            2,100          450           >4,640
Relative Toxicity                     2.2x          10.3x           1.0x
Exposure (oz and [g a.i./ac])        8 [227]       16 [100]         1 [7]
Relative Exposure                     32.4x         14.3x           1.0x
Hazard (Rel. Tox. x Rel. Exp.)        71.3          147.3            1
Hazard relative to Diflubenzuron      ~70x          ~150x            1x
             HAZARD to BIRDS

                                                   Insecticides
                                       (active ingredient and trade name)
Parameter
                                    Malathion       Carbaryl    Diflubenzuron
                                    Fyfanon          Sevin          Dimilin
Oral Toxicity (LD50 mg/kg)         1,485* [167**]    >2,000         3,763
Relative Toxicity                  2.5x [22.5x]       1.9x           1.0x
Exposure (oz and [g a.i./ac])         8 [227]       16 [100]         1 [7]
Relative Exposure                      32.4x         14.3x           1.0x
Hazard (Rel. Tox. x Rel. Exp.)       81 [729]         27.2            1
Hazard relative to Diflubenzuron   ~80x [~700x]       ~30x            1x


          * - mallard ducks
          ** - pheasants
HAZARD to GAME BIRDS
Malathion:         LD50 167 mg/kg
Carbaryl:          LD50 2,000 mg/kg
Diflubenzuron:     LD50 3,763 mg/kg

Applied at recommended dose rates, the area of
      1 square foot will receive:
Malathion:        5.3 mg
Carbaryl:         2.3 mg
Diflubenzuron:    0.16 mg

To pick up a 50% lethal dose, a 2 ¼ - lb bird
      should consume all vegetation on:
Malathion:         32 square feet
Carbaryl:          900 square feet
Diflubenzuron:     ½ acre
                HAZARD to FISH
                (brown, rainbow, and cutthroat trout)


                                                 Insecticides
                                     (active ingredient and trade name)
Parameter
                                   Malathion      Carbaryl    Diflubenzuron
                                   Fyfanon         Sevin          Dimilin
Toxicity (LC50 mg/L)                  0.1            1.3           240
Relative Toxicity                   2,400x         184.6x          1.0x
Exposure (oz and [g a.i./ac])       8 [227]       16 [100]         1 [7]
Relative Exposure                    32.4x         14.3x           1.0x
Hazard (Rel. Tox. x Rel. Exp.)      77,760         2,639.8          1
Hazard relative to Diflubenzuron   ~80,000x       ~2,600x           1x
How to Reduce the Risks?
Hazard = Toxicity X Exposure


Use insecticides      RAATs!!!
with lower toxicity
                      Observe buffers around
                          water bodies
                      Do not overdose
                      Appropriate formulation
                      Protect bees
Is Dimilin Dangerous
   for Honey Bees?
       Dimilin and Honey Bees
Citrus pest control: (Schroeder et al., 1977)
Six consecutive applications of Dimilin at 140 g a.i./acre
       each, approximately at a monthly intervals.
No difference in brood numbers between treated and
       untreated hives.
No detectable diflubenzuron residues in honey.


Cotton pest control: (Robinson, 1979)
Eight consecutive applications of Dimilin at 57 g. a.i./acre
       each, at one week intervals.
No difference in treated/untreated brood ratio.
No change in brood developmental rate.
No detectable residues of diflubenzuron in wax, pollen or
       honey.
     Dimilin and Honey Bees
                Conclusion:
Repeated exposure of bee colonies to six
to eight, consecutive Dimilin applications
of 57 to 140 g a.i./acre presented no hazard
to adult honey bees or to their brood.

For comparison:
In grasshopper control, a single Dimilin
application at a rate of 7 g a.i./acre is used.
This reduces the hazard by 64 to 120 times.
Insecticides and Bees
Extremely toxic to honey bees and should not be
applied to blooming crops or weeds:
      Carbaryl (EC and ULV formulations)
      Malathion ULV

To minimize hazard to bees, should be applied only
during late evening:
      Malathion EC

Relatively safe to bees and can be applied at any
time:
      Diflubenzuron

                   Excerpt from: Honey bee poisoning by
                   chemicals: signs, contributing factors, current
                   problems and prevention – Johansen, 1980
 Insecticides and Bees
    Which formulation is better?

Worst                                     Best




Wettable   Micro-         Oil-based   Water-based
Powder     Encapsulated   ULV         EC


                            Source: Johansen, 1980

				
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posted:12/9/2012
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