The present invention relates to novel compacted granular larvicidal feed premix compositions of N[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide, a method for their preparation and an improved method for the control of larvae utilizing these compositions.

BACKGROUND OF THE INVENTION 
The control of fly larval infestation is important in agricultural in order 
to avoid the illnesses and economic losses associated with such insect 
pest infestation. A method of controlling fly larval by direct application 
to the larval breeding medium is widely known in the industry. The method 
involves such direct utilization of the compound, 
N[[4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide, sold under the 
tradename of DIMILIN.RTM. insecticide, a registered trademark of Duphar BV 
of Amsterdam, Holland (hereinafter referred to as diflubenzuron, the 
generally recognized generic chemical name). 
Due to the effectiveness of diflubenzuron when used against fly larvae, the 
search for a more beneficial manner to control such fly larvae has spurred 
and continues to spur new research efforts. One attractive method for fly 
larvae control is to utilize diflubenzuron in feeds for controlling fly 
larvae in excreted feces. This method is commonly referred to as 
feed-through application. For instance diflubenzuron at levels of 0.5 to 
1.0 mg/kg animal body weight, has been mixed directly into the feed of 
calves and dairy cattle and has shown effective control of house fly and 
face fly larval in the feces (R. W. Baker et al, J. Georgia Entomol. Soc., 
11 (1976) 1: 67-71 and R. W. Miller, J. Economic Entomol. 67 (1974) 5: 
697). 
In addition to this direct feed addition method, diflubenzuron has been 
encapsulated and tested for insecticidal activity, F. W. Knapp et al., 
Symp. Int. Meeting Controlled Release Soc. (Academic Press, 1980), as well 
as being applied in mineral blocks and delivered in a sustained-release 
bolus form (U.S. Pat. No. 4,166,107, issued to J. A. Miller et al on AUg. 
28, 1979). 
SUMMARY OF THE INVENTION 
The present invention relates to novel compacted granular feed premix 
compositions containing diflubenzuron. These granular feed premix 
compositions provide enhanced larvicidal effectiveness and fly control of 
surprisingly low doses of diflubenzuron. 
It is an object of the present invention therefore to provide novel such 
compacted granular feed premix compositions with improved larvicidal 
effectivness and fly control. 
It also is an object of the present invention to provide a method for 
preparing the novel compacted granular feed premix compositions of the 
invention. 
These and further objects of the present invention will become more 
apparent by the more detailed description of the invention provided 
herein. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates to compacted granular feed premix 
compositions comprising, on a weight basis, about 0.5% to 84.0% 
diflubenzuron; about 0% to 10% whole dried whey; about 0% to 2% water and 
the remainder of a compactable, insoluble carrier to total the composition 
of 100%. 
Compactable, insoluble carriers suitable for use in the compositions of the 
present invention include clays and mineral salts, such as CaSO.sub.4, 
BaSO.sub.4 or other mineral salts, CaCl.sub.2. The preferred carrier, 
however, is CaSO.sub.4 dihydrate. Preferred compacted granular premix 
compositions of this invention have a granular particle size of 10 mesh to 
100 mesh, with a particle size range of 20 mesh to 60 mesh being 
preferred. 
This invention also relates to methods for the preparation of these 
compacted granular compositions. It unexpectedly has been discovered that 
compositions of the present invention, prepared by the compaction and 
granulation process of the invention, provide compositions which provide 
effective control of larvae when administering doses in animal feeds of 
diflubenzuron at rates as low as 0.025 mg/kg of animal body weight. 
Surprisingly, the compacted granulated compositions of the invention are 
more efficacious than diflubenzuron alone, the uncompacted composition or 
an alfalfa feed premix of diflubenzuron administered in animal feed for 
the feed through control of fly larvae and resulting fly control (see 
Table I). This invention also provides an improved method for controlling 
fly larvae and flies in the feces of animals. This is accomplished by 
orally administering, in an animal feedstuff or feed supplement, 
sufficient quantities of the present compositions to provide about 0.025 
mg/kg to 10 mg/kg per animal per day of diflubenzuron. 
TABLE I 
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% Fly control obtained by various feed through compositions 
4.0% Compacted 
4.0% granular 
Diflubenzuron 
Alfalfa premix 
CaSO.sub.4 premix 
Day 0.5 mg/kg/day a.i. 
0.5 mg/kg/day a.i. 
0.5 mg/kg/day a.i. 
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7 64.5 44.0 85.6 
14 84.5 69.5 97.0 
21 76.5 97.5 100.0 
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The compositions of the invention may be administered by addition to animal 
feeds, protein concentrates or supplements and other feed ingredient 
compositions such as vitamin or mineral supplements. 
The feed premix compositions of the present invention may readily be 
prepared by compacting a mixture of the compactable carrier and 
diflubenzuron. Alternatively, an appropriate amount of water may be 
sprayed onto the carrier and mixed until homogeneous, and then 
diflubenzuron is added, mixed with the homogeneous mixture and the 
resulting blend compacted on serrated compaction rolls. The compacted 
blend is then ground to the desired particle size range of about 10 to 100 
mesh, with a preferred range of 20 to 60 mesh. This is then packaged. 
Material of smaller particle size is recycled through the compaction 
procedure and reground in order to obtain the optimum particle size, while 
larger particles also may be recycled or merely reground.

The compositions of the invention are further illustrated by the following 
non-limiting examples. 
EXAMPLE 1 
Preparation of compacted granular larvicidal premix compositions 
Water (200 g) is sprayed into CaSO.sub.4 (9.335 kg) while blending the 
mixture. After ten minutes, diflubenzuron (465 g,) is added, and blending 
is continued until the mixture is homogeneous. A portion of this mixture 
(5.0 kg) is compacted using 2" compaction rolls, with a roll speed of 5.5, 
a feeder speed of 1.5 and pressure of 1500 psig. 
The resulting compacted material is ground, and the ground material 
classified on a shaker equipped with two sieves (20 and 60 mesh), to give 
the desired compacted granular premix composition. Material less than 60 
mesh is blended with 2.5 kg of the remaining mixture, and the compaction, 
grinding and classification steps repeated. This is continued through 
three cycles or until greater than 90% of the original mixture is 
converted to the preferred particle size. Material greater than 20 mesh is 
ground and classified directly into the preferred size range. 
EXAMPLE 2 
Efficacy of compacted granular larvicidal feed premix compositions 
Twenty-one Hereford steers weighing approximately 250 to 450 kg each are 
provided with 1.0 kg of dairy concentrate daily plus free choice silage 
and water ad libitum. Each steer individually housed is acclimatized to 
these conditions and observed until all animals are consuming the 
silage-concentrate mixture and their manure appears normal. 
Then the compacted granular feed premix is added to the daily ration of 
concentrate and fed daily for 14 days at the different rates indicated in 
Table II. Two manure samples (200 g) are collected from each animal on 
days 0, 4, 7 and 14 after treatment commences. Each sample is seeded with 
25 WHO strain house fly first instar larvae and the number of pupae and 
emerged adult flies are recorded. 
The results of these experiments, which are summarized in Table II below, 
demonstrate the improved efficacy of the compacted granular premix 
compositions of the invention compared to diflubenzuron alone and a 
diflubenzuron and CaSO.sub.4 mixture which has not been compacted and 
granulated. 
EXAMPLE 3 
Water (200 g) is sprayed onto CaSO.sub.4 (5.67 kg) while blending the 
mixture. After ten minutes diflubenzuron (4.122 kg) is added and the 
blending continued until the mixture is homogeneous. One-half of this 
mixture (5.0 kg) is compacted using a two inch compaction rolls, with a 
roll speed of 5.5, a feeder speed of 1.5 and pressure of 1500 psig. 
The resulting compacted material is ground and classified in a shaker 
equipped with two sieves (20 and 60 mesh), to the desired particle size. 
Material less than 60 mesh is blended with 2.5 kg (one-half of remaining) 
mixture and compacted/ground/classified. This is continued through three 
cycles or until greater than 90% of the original mixture is converted to 
the preferred particle size. Material greater than 20 mesh is ground and 
classified directly into the preferred particle size range. 
TABLE II 
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Average % pupae recovered* 
Average % fly control* 
Rate 
Day Day Day Day Day Day Day 
Treatment mg/kg 
0 4 7 14 4 7 14 
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A Controls None 
91 93 87 83 -- -- -- 
B 0.05 
87 43 46 51 97 97 95 
C 0.10 
83 30 10 17 99 100 100 
D 0.25 
86 9 1 2 100 100 100 
E 0.50 
92 4 1 2 100 99 100 
F Diflubenzuron 0.10 
92 93 73 61 95 82 89 
G Diflubenzuron + CaSO.sub.4 not as 
0.10 
83 78 35 57 88 97 83 
compacted granular premix 
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*Average of three animals per group and two samples per animal. 
EXAMPLE 4 
Diflubenzuron (12.6 g) is blended with 9.874 kg CaSO.sub.4 and mixed. 
One-half of this uncompacted blend (5.0 kg) is compacted using a two inch 
compaction rolls, with a roll speed of 5.0, a feeder speed of 2.5 and a 
pressure of 1500 psig. 
The resulting compacted material is ground and classified on a shaker 
equipped with screens ranging from 12 to 60 mesh. Material less than 60 
mesh is blended with 2.5 kg (one-half of remaining) original blend and the 
compaction/grinding/classification cycle repeated. This sequence is 
continued for at least three cycles or until greater than 90% of the 
original blend is converted to the desired particle size range. Material 
greater than 12 mesh is ground/classified directly into the preferred 
particle size range. 
EXAMPLE 5 
Water (200 g) is blended with 9.335 kg CaCl.sub.2 and mixed. To this 
mixture, 465 g of diflubenzuron is added, and blending is continued until 
the mixture is homogeneous. A portion of this uncompacted blend (5.0 kg) 
is compacted using two inch compaction rolls, with a roll speed of one 
roll speed 7.0 and pressure of 1000 psig. 
The resulting compacted material is ground and classified as described in 
Example 4. Again at least three cycles of blending/compaction/grinding and 
classification are used. 
EXAMPLES 6-8 
Compositions which have been or can be prepared in accordance with the 
present invention are listed below. The components are thoroughly blended, 
and this blended composition is transferred to a holding bin that feeds a 
set of serrated rolls (e.g. Fitzpatrick chillsonator). The composition is 
fed to the rolls and compacted into a ribbon of materials. Thereafter, it 
is granulated and sieved for size, with the procedure repeated, if 
necessary, to obtain the appropriate mesh sizes. 
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PREMIX COMPOSITIONS 
% (w/w) 
Components Example 6 Example 7 Example 8 
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diflubenzuron 
41.2 55.5 83.33 
(95-100% technical) 
whey 2.0 4.5 8.0 
water 1.5 0.5 0.0 
CaSO.sub.4 dihydrate 
55.3 39.0 8.67 
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