DDT Resistance in an Italian Strain of Musca domestica L.

1952 ◽  
Vol 42 (4) ◽  
pp. 761-768 ◽  
Author(s):  
C. Mary Harrison
Keyword(s):  
Musca Domestica ◽  
Resistant Strain ◽  
Toxicity Tests ◽  
Comparative Toxicity ◽  
Ddt Resistance

1. Flies of 9–10 and 16–19 days old were more susceptible to DDT than 4–5-day-old flies. Female flies were less susceptible than males, and large flies less susceptible than small flies to residual deposits of DDT. It is clearly important that flies used in comparative toxicity tests should be standardised for age, sex and size.2. The strain Torre in Pietra was 3·6 times more resistant to dry deposits of DDT on Essex board than the Roma strain, but this resistance declined after culturing the strain in the laboratory for 22 generations.3. The DDT-resistant strain (Torre in Pietra) was as susceptible as the non-resistant (Roma) strain to deposits of γ BHC on Essex board but was slightly resistant to pyrethrins.4. The DDT resistance of the Torre in Pietra strain was increased readily by selection, yet a similar selection with DDT on the Roma strain was unsuccessful. This failure in the Roma strain may be due to the purity of the stock.

The behavioural responses of three different strains of Musca domestica (Diptera: Muscidae) to Alfacron bait in the laboratory

1992 ◽  
Vol 82 (4) ◽  
pp. 471-478 ◽  
Author(s):  
Z.A. Freeman ◽  
D.B Pinniger
Keyword(s):  
Musca Domestica ◽  
Resistant Strain ◽  
Behavioural Responses ◽  
Components Of Resistance ◽  
Minute Period ◽  
Proboscis Extension ◽  
Number Of Visits ◽  
Time Spent Feeding ◽  
Different Strains ◽  
Cage Test

AbstractA study was carried out to investigate the behavioural components of resistance in the Standlake strain of Musca domestica Linnaeus. The flies were collected from a poultry unit where azamethiphos spray-on-bait (Alfacron), had been regularly used to control the fly population. A no-choice laboratory cage test was used to observe the responses of the Standlake resistant strain to baits and compare it with two other strains namely, Sparsholt resistant and Cooper susceptible. The baits used were, Alfacron, sugar and analytical grade azamethiphos, sugar alone, and a blank target as control. Only female flies were used, each strain was exposed separately to each bait over a 50 minute period and the responses were recorded with a datalogger. The responses (per fly) recorded during each test period were: the number of visits to a bait; the time spent on a bait; the number of feeds and time spent feeding on the bait defined as the number of proboscis contacts and the length of time of proboscis contact with the bait. Knockdown of flies was recorded at the end of each test. All strains showed differences in their responses to baits. The Standlake strain showed the greatest difference to responses to Alfacron, with inhibition of proboscis extension when flies landed on the bait and a lower proboscis contact when extended, resulting in fewer flies being knocked down by Alfacron than by the sugar and azamethiphos bait. This suggested that inhibition of feeding on the Alfacron bait by the Standlake strain was caused by formulation components or contaminants and not the active insecticide ingredient, azamethiphos.

Inheritance of DDT dehydrochlorination and of a mechanism restricting uptake of DDT in the mosquito Aedes aegypti

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 357-360 ◽  
Author(s):  
H. R. Rathor ◽  
R. J. Wood
Keyword(s):  
Resistant Strain ◽  
Parental Strain ◽  
Susceptible Strain ◽  
In Vitro Assays ◽  
Pesticide Resistance ◽  
Life Stages ◽  
Ddt Resistance ◽  
Clear Relation

Crosses and backcrosses were made between the T8 dichlorodiphenyltrichloroethane (DDT) resistant strain and NS susceptible strain. Each generation was tested for resistance, for internal levels of DDT and dichlorodiphenyldichloroethylene (DDE) (thus "DDT uptake" (DDT + DDE) and percentage DDT dehydrochlorination in vivo), and for DDT dehydrochlorination in vitro, both at the larval and adult stages. The patterns of inheritance of uptake and dehydrochlorination were different. At both life stages, dehydrochlorination (both in vivo and in vitro) was intermediate in the F1, reverting to or exceeding the parental strains in the backcrosses except in adult tests on the backcrosses to the susceptible strain where it remained intermediate. Uptake increased very substantially in the F1 compared with either parental strain and was also high in the backcrosses. This was interpreted as being due to the disruption of an uptake-restricting mechanism in T8 brought about by outcrossing. Larval resistance in the various generations was correlated significantly with dehydrochlorination, both in vivo and in vitro but bore no clear relation to uptake. Resistance in adults was found not to be correlated significantly with either. Key words: DDT dehydrochlorination, pesticide resistance, DDT uptake, DDT resistance, dehydrochlorination in vivo and in vitro assays.

The inheritance of DDT-resistance in the cattle tick, Boophilus microplus

1962 ◽  
Vol 13 (5) ◽  
pp. 984 ◽  
Author(s):  
BF Stone
Keyword(s):  
Resistant Strain ◽  
Reference Strain ◽  
Boophilus Microplus ◽  
Autosomal Gene ◽  
Cattle Tick ◽  
Adult Females ◽  
Ddt Resistance ◽  
High Level ◽  
Multiresistant Strain

Adults of a DDT-resistant strain of the cattle tick from central Queensland were crossed with adults of a susceptible reference strain, by means of cardboard mating boxes glued to the skins of cattle. F1, backcross, and F2 larvae were tested for resistance to DDT by enclosure of larvae in filter paper packets impregnated with oil solutions of pp'-DDT. F1 and backcross engorged adult females were tested for resistance by injection with oil solutions of pp'-DDT. There was no evidence of departure from a 1 : 1 ratio in the backcrosses or from a 1 : 2 : 1 ratio in the F2, and there was little difference between the compositions of the F1 reciprocal crosses or among the backcrosses derived from them. Therefore DDT resistance in this strain was considered to be due to a single, incompletely recessive, autosomal gene. Engorged nymphs of the resistant strain moulted later in vitro than nymphs of the susceptible strain, and resistant engorged adult females detached from the host later than susceptible engorged adult females. After 13 generations of DDT-free culturing of a multiresistant strain, the percentage of homozygous DDT-resistant ticks in the strain had fallen from a high level to about 55%. This figure remained constant for a further 10 generations.

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