Diflubenzuron recommendations

For protection of domestic cattle, feeds should contain <0.05 mg diflubenzuron/kg FW. Cottonseed may be added to cattle diets provided that diflubenzuron concentrations in the seed do not exceed 0.2 mg/kg FW and that cottonseed composes <17% of the total diet bulk (Gartrell 1981). Diflubenzuron causes biochemical upset, as judged by lowered testosterone levels in chickens and rats (USEPA 1979), altered glutathione 5-transferase activity in mouse liver (which adversely affects the ability to detoxify foreign substances by way of conjugation Young et al. 1986), and disrupted hydroxylamine activity in human infants (USEPA 1979). Additional research seems needed on biochemical alterations induced by diflubenzuron. No diflubenzuron criteria are currently recommended for protection of avian and mammalian wildlife. All data available suggest that wildlife species are about as tolerant to diflubenzuron as are domestic poultry and livestock however, the wildlife database seems inadequate for practicable criteria formulation. 

Birds seem comparatively resistant to diflubenzuron acute oral LD50 doses exceed 2000 mg/kg body weight (BW) dietary concentrations <4640 mg/kg FW are tolerated for at least 8 days and forest birds seem unharmed by recommended diflubenzuron application procedures to control pestiferous insects, except for a possible loss in fat reserves. Intraspecies differences in ability to metabolize diflubenzuron are probably large different strains of domestic chickens show significant differences in ability to accumulate and retain this compound. 

Criteria now recommended for protection of various species include the following dietary loadings, in mg/kg FW ration, of <0.05 for human health, <0.05 for livestock, <1 for honey bees, and <5 for poultry seawater concentrations <0.1 pg/L for estuarine crustacean larvae and, for all aquatic life, restricted or prohibited use of diflubenzuron in saltmarsh mosquito breeding areas and on agricultural lands less than 5 km from coastal areas. No criteria are available or proposed for protection of avian and mammalian wildlife against diflubenzuron, probably because of an incomplete toxicological database. 

With the related compound PH 60-38, (III), a comparable but smaller effect of the particle size on the apparent rate of degradation in soils was observed as is illustrated in Table 1 The influence of the type of soil on the rate of degradation of diflubenzuron is much less important, because with five agricultural soils and three hydrosoils, including the soil types recommended by the EPA and the German BBA, the variation in the halflife was only a factor of approximately two. 

However, under more natural conditions, e.g. according to the methods recommended in the EPA Guidelines the rate of the photochemical degradation was found to be very low h.) In other experiments washing off of diflubenzuron from plant leaves with high amounts of simulated rainfall was found to be negligible All these results point to a high... 

Diflubenzuron has very low systemic side effects, if absorbed through the skin. The exposed area should be thoroughly washed with soap and water. Eyes should be washed with copious amounts of room-temperature water for 15 min in cases of eye contamination. If small amounts are ingested, no treatment is needed. Low toxicity is seen in nontargeted species. Symptomatic treatment is recommended. 

Since diflubenzuron toxicity seems to be similar in both insects and cmstaceans, extreme care must be taken when this compound and other chitin synthesis inhibitors are used for insect control in areas where aquatic crustaceans occur. Otherwise, ecological instability may result, with consequences for feeding, metabolism, growth, reproduction, and survival of numerous nontarget organisms. Specifically, diflubenzuron use in salt marsh mosquito breeding areas or on agricultural lands less than 5 km from coastal areas is not recommended because of concerns that runoff may reach the adjacent estuaries, which are the primary hatcheries... 

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