N some respects, the mutagenic action of the mustards on Drosophila resembles I that of X-rays. Both are nonspecific in their effects (AUERBACH and ROBSON 1946), each induces an approximate five-to-one ratio of recessive lethals to visible deletions (SLYZINSKA and SLYZINSKI 1947), the same stage of spermatogenesis appears to be sensitive to both mutagens (AUERBACH 1953) and breaks are induced a...

EEKEEPERS have long been familiar with a poor type of brood which due to its €5 scattered appearance is sometimes called “shot brood”. An explanation for this character was given by MACKENSEN (1951). MACKENSEN inseminated several queens with semen of their brothers, and by brood viability studies obtained a 1: 1 ratio between high (close to 100%) and low (close to 50%) viable brood. He suggeste...

the effect of host diet on developmental time, fecundity and life-table parameters of bracon hebetor (say) (hymenoptera: braconidae) against the mediterranean flour moth ephestia kuehniella (zeller) was studied in the laboratory condition at 26 ± 1 °c, 65 ± 5% relative humidity and a photoperiod of 16l:8d h. the diets used were rice, barley, corn and wheat flours. the developmental time (egg to...