Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Fecundability”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources
PubMed1994

Survival, fecundity, and egg fertility of Culicoides variipennis (Diptera: Ceratopogonidae) fed on calves inoculated with ivermectin.

Female Culicoides variipennis were fed at 1-18 days postinoculation on calves treated with a commercial injectable formulation of ivermectin at the recommended rate of 200 micrograms/kg of body weight. There were no significant differences between treated and untreated animals in the survival rate of the flies at 24 h and 48 h postinoculation and the number of eggs produced per living female. There was a significantly greater mean hatch rate of eggs from flies fed on the untreated animals (65.8%) than those fed on the treated animals (52.8%). The recommended use rate of ivermectin does not appear to provide significant mortality for female C. variipennis, nor affect egg deposition or hatch rate sufficiently to reduce vector populations.

Animals↗
PubMed1994

Effects of ivermectin on survival, fecundity, and egg fertility in Culicoides variipennis (Diptera:Ceratopogonidae).

Colonized female Culicoides variipennis were fed through an artificial membrane on sheep blood meals containing 0-1.0 microgram/ml of ivermectin. Significant mortalities were present at 48 h postfeeding, with probit analysis yielding an LC50 of 0.35 microgram/ml and a slope of 4.12. All dosages caused significant decreases (P < 0.01) in egg production and sporadic decreases in egg hatch, with no eggs produced at 1.0 microgram/ml. There was a negative linear correlation (r2 = 0.91) between dose rate and number of eggs produced per living female. An inoculation of ivermectin at the recommended dosage of 200 micrograms/kg of body weight would not produce the serum concentration that could be expected to have noticeable effects on bloodfeeding C. variipennis.

Animals↗
PubMed1996

Diel oviposition and fecundity of Anopheles oswaldoi in Trinidad, West Indies.

The diel oviposition periodicity of wild-caught Anopheles oswaldoi collected from the forest-ecotone habitat in Valencia, Trinidad, was studied in the laboratory by recording the performance of egg-laying individuals and a colony at 2-h intervals. Oviposition was almost exclusively nocturnal, with 95.3% of eggs and 91.3% of oviposition occurrences being observed during the scotophase. During the rest of the day, only 4.7% of eggs (8.7% occurrences) were recorded after dawn (0600-0800 h). Wild-caught females engorged on human blood under laboratory conditions matured, on average, 61.1 +/- 32.3 follicles (range 56-135). Ranges of 50-69, 70-89, 90-109, and > 110 follicles were matured by 12, 4, 4, and 3 gravid females, respectively. These findings provide vector operators with a window of time to maximize the impact of insecticides on An oswaldoi populations.

Animals↗
PubMedDate not supplied

[Evolution of fecundity in the Valencian community during the 1975-1990 period].

BACKGROUND: To study the evolution of specific cases of fertility by age groups in the Autonomous Region of Valencia, between 1975 and 1990, and compare this development with the evolution on a national level. METHODS: The specific fertility rates were calculated for seven 5-year age groups within the female fertility period (15-49 years). The number of births per age of mother (Natural Movement of the Spanish Population) has been used and the denominator is the female population calculated be geometrical interpolation from the figures provided by different censuses and electoral roles for each one of the age groups. The study period is 1975 to 1990. RESULTS: The evolution of the fertility rate in the Autonomous Region of Valencia is declining in all age groups except the 30-34 year age group, where fertility showed a slight increase at the end of the eighties, the same as in the rest of the country. Worthy of mentioned is the 15-19 year old group, with figures below the national level, and the 25-29 year old group, where the figures are greater than for the rest of the country as a whole. On a province (county) level, the development is similar to what has been described above. Alicante has the highest figure out of the three provinces (counties) for women in the 15-19 and 35-39 year age ranges. CONCLUSION: The evolution of the fertility rate in the Autonomous Community of Valencia is similar to the development in the rest of the country, a slight increase being detected in women in the 30 to 40 year group, which is similar to what has happened in other European countries.

Adolescent↗
PubMed1996

Life-cycle, longevity and fecundity of Blomia tropicalis (Acari: Glycyphagidae) in a tropical laboratory.

In the present study on the life-cycle of Blomia tropicalis, freshly laid eggs were observed until they developed into adults; the development periods between stages were recorded. The eggs took an average of 22.9 +/- 6.4 days to develop to adults. For longevity experiments, newly emerged adults were kept at 25 degrees C and observed until they died. There was no significant difference in longevities of the different sexes (p = 0.053). Production of eggs by mated females were monitored until egg production stopped and the female died. Mated females and males survived an average of 32.2 +/- 15.4 and 30.9 +/- 17.7 days respectively. The difference in longevity of the mated females, and males was not significant (p = 0.747). Longevity of the mated females was found to be significantly (p < 0.05) shorter than unmated females.

Animals↗
PubMed1997

Effect of the plant Azolla pinnata on survival, growth rate, fecundity and hatchability of egg-masses of Biomphalaria alexandrina snails.

Data indicated that Azolla pinnata plants variously reduce the growth rate of Biomphalaria alexandrina snails expressed as net increase in shell diameter (direct or indirect exposure). The plant density played an important role in this respect. The higher the plant density was the lower the growth rate and vice versa. Too, indirect exposure of newly hatched B. alexandrina resulted from exposed treated eggs reduced the growth rate of these snails. Data revealed that direct and/or indirect exposure to the abnormal high density (50,000 plants/L) resulted in complete kill of B. alexandrina snails after two weeks from continuous exposure. Snails exposed directly to Azolla at 50,000 and 25,000 plants/L failed to lay eggs. On the other hand, sanils exposed to 10,000 plants/L laid few eggs, resulted in low reproductive rate (57.94) compared with unexposed ones (110.6). The same trend of results was recorded with hatchability of Biomphalaria eggs.

Animals↗
PubMed1998

Effect of female size on fecundity and survivorship of Aedes aegypti fed only human blood versus human blood plus sugar.

We determined whether size, an indirect measure of teneral energy reserves, modifies the fitness advantage (sigma survival x egg production/female/day) conferred to female Aedes aegypti (L.) maintained on human blood over cohorts fed human blood plus sugar. Different sized females were obtained by rearing them at different larval densities and with different amounts of food per larva. Each female in 4 treatment groups of 23 mosquitoes each was maintained in a separate cage. A 10% sucrose solution was provided ad libitum to mosquitoes in the sugar-plus-blood treatments and water to the blood only groups. Eggs deposited and survival were monitored daily for each mosquito until all had died. Within a size category, survival of mosquitoes in different treatments was not different and mosquitoes fed only human blood laid more eggs than those fed blood plus sugar. The numbers of eggs laid by small mosquitoes fed human blood alone and large mosquitoes fed human blood plus sugar were not different. Mosquitoes fed only human blood had higher net replacement and intrinsic rates of growth than similar sized mosquitoes fed blood plus sugar. Female Ae. aegypti fed only human blood, regardless of the variation in size that we studied and thus energy reserves at emergence, had a fitness advantage over those fed a diet that included sugar.

Aedes↗
PubMed1994

[Fecundity and embryonal development of Romanomermis culicivorax].

Romanomermis culicivorax (Ross and Smith, 1976) eggs completed the late preparasite curling phase of their embryo development in an average time of 11 days and at a temperature of 25 +/- 2 degrees C. It was also observed that female R culicivorax specimens laid 312 eggs in 13 days, when male and female specimens were placed in a substrate of distilled water with a pH = 4.5.

Animals↗