Dieldrin Resistance Research Articles

Correction—Inheritance of Dieldrin Resistance in the Housefly

Correction—Inheritance of Dieldrin Resistance in the Housefly

Genetics of resistance to dieldrin in Lucilia cuprina Wied.

IN an earlier study1 on the inheritance of dieldrin resistance in Lucilia cuprina, involving a cross between susceptible females and a single resistant male, F2 and back-cross ratios, obtained by employing the discriminating dose technique2,3, indicated that dieldrin resistance in this insect can be explained in terms of a single gene. Information is now presented from reciprocal crosses between resistant and susceptible strains. The discriminating dose method was again utilized, with the results shown in Tables 1 and 2. The data from the F2 and back-cross ratios suggest a simple Mendelian interpretation, even though the F1 and F2 data conform to a polygenic pattern, namely, intermediate resistance in F1 progeny with both parental types in the F2.

Colonization and Production of a Dieldrin-Resistant Strain of Anopheles quadrimaculatus Say1

A dieldrin-resistant field strain of Anopheles quadrimaculatus Say from Cleveland, Mississippi, has been established under insectary production. Three-day-old females show high dieldrin resistance; 60-minute exposures to 0.8% through 8% dieldrin- Risella oil papers result in less than 10% mortality in 24 hours, while 480-minute exposures to 4% papers killed only 50%. Susceptible females are killed by 60-minute exposures to 1.6% dieldrin-Risella oil papers.

Genetics of dieldrin resistance in Lucilia cuprina Wied.

IN a comprehensive paper on insecticidal resistance in anopheline mosquitoes Davidson1 demonstrated that resistance to dieldrin in Anopheles gambiae is due to a single gene, partially dominant. In this work the discriminating dose technique, supported by Milani2, for genetical studies on insecticidal resistance in insects was utilized.

Resistance of Anopheles aquasalis curry to dieldrin in Trinidad.

WORK at the Ross Institute with Anopheles gambiae revealed that dieldrin resistance is due to an allele of a single gene. When tested with papers impregnated with a mineral oil solution of this insecticide, the heterozygotes for this allele can withstand 0.4 per cent dieldrin for 1 hr. and the homozygotes for this resistant allele can withstand 4.0 per cent dieldrin for 1 hr.

The Resistance of Strains of D. melanogaster to DDT and Dieldrin

1. The level of DDT-resistance of eighteen strains of D. melanogaster collected from ten localities in Europe, Africa, Asia and North and South America was tested by exposure to 4 per cent DDT test paper prepared by the WHO in Geneva. The level of dieldrin resistance of eleven strains of five localities was tested by exposure to 0.8 and 0.4 per cent dieldrin test paper. 2. The total average mortalities of these strains after exposure for varying times were almost linear when plotted on normal logarithmic section paper. The expression of resistance to DDT and DL is, therefore, normally distributed in populations. 3. From the results of analyses of variance using numbers of dead flies 25 hours after exposure to DDT, DL and control test papers, significant differences in resistances to both insecticides were observed between localities and between strains. Significant differences between strains but not between localities were found in resistance to desiccation. 4. Cross-resistance between DDT and DL was observed; it was concluded that these resistances are the result of different genetic systems of which some factors are common to both.

Dieldrin-resistant cattle ticks, Boophilus microplus (Canestrini) in Queensland

Infestation by cattle ticks in a herd a t Mt. Gravatt, near Brisbane, in southern Queensland, could not be controlled by repeated spraying of the cattle with 0.05 per cent. w/v dieldrin. Ninety-eight per cent. of engorged females of this strain, which fell from an artificially infested beast in the 48 hr following spraying with 0.05 per cent. w/v dieldrin, laid normal batches of viable eggs. Spraying cattle with 0.05 per cent. w/v "Diazinon", however, readily controlled infestation by this strain. Laboratory concentration-response tests on a culture of the dieldrin-resistant ticks indicated that the median lethal concentration of dieldrin for the larvae was over 2000 times higher than for those of a reference strain. There was also strong evidence from laboratory tests of dieldrin resistance in the engorged adult female ticks.

Adult fly production from garbage can sites and privy pits in the lower Rio Grande Valley.

SummaryStudies were conducted in the lower Rio Grande Valley of Texas to determine the importance of fly production from privy pits and garbage can sites. House fly production from dieldrin-treated privies was shown to exceed greatly that found in untreated privies. Dieldrin resistance in M. domestica appeared to influence house fly breeding in privies more so than any other single observed factor, the emergence of M. domestica apparently increasing concurrently with the development of the resistance. The increased production of house flies in treated privies presents an important and immediate problem in the future prevention and spread of enteric diseases. Abandoned privy pits produced more flies than did garbage can sites but approximately 50 per cent of the emerging flies were Sarcophaga spp.At garbage can sites approximately 96 per cent of the flies produced were Phaenicia pallescens. Fly emergence was greater at “approved” can sites than at “non approved” sites, indicating that proper garbage handling within the containers is vital in preventing fly breeding in garbage containers.