investigation (Wurtman et a!., 1968; Reiter and Sorrentino, 1970). Among several indolie compounds produced by the pineal is melatonin, a presumptive hormone which exhibits anti-gonadotropic activity in the rat and other mammals. Early work demonstrated that melatonin reversed the persistent estrus induced in rats by continuous lighting (Wurtman et al., 1964); injections of the indole decreased...

the grain aphid, sitobion avenae (hemiptera: aphididae) is one of the injuriously important pests of wheat and praon volucre (hymenoptera: braconidae) is one of its major parasitoids in iran. in this research, thermal requirements of the grain aphid and its parasitoid were evaluated at six constant temperatures (10, 15, 20, 25, 27.5 and 30 °c), 60 ± 5 % relative humidity and a photoperiodicity ...

biological characteristics and population growth parameters of diaeretiella rapae (hym.: braconidae) on russian wheat aphid, diuraphis noxia (hem.: aphididae) were investigated at five constant temperatures (10, 15, 20, 25 and 27.5 ?c), 60±5% rh and a photoperiodicity of 16:8 h (light:dark). developmental period of immature stages of d. rapae was the lowest at 25 ?c (11.23±0.144 days) and highe...

in vitro pollen germination and also pollen tube growth dynamics in different pollination treatments under controlled temperature, humidity and photoperiodicity were studied regarding four cultivars (‘shastomi - e - do’, ‘ebrahim - e - kalajah’, ‘sefid - e - rezaeeieh’ and ‘razi’) under self and under cross-pollination along with three superior genotypes (‘269’, ‘416’ and ‘464’) of apricot. fol...

ladybird beetles are of a special standing in aphid biological control. they attack different aphid species and play an important role in suppressing aphid populations. one of the most conspicuous coccinellids namely hippodamia variegata, occurs in such different crops as alfalfa and vegetables. life history parameters of this predator at 25 ± 1 ?c and 16:8 (l: d) photoperiodicity were evaluate...

MELATONIN (N-ACETYL-5-METHOXYTRYPTAMINE) IS A HORMONE PRODUCED DURING THE HOURS OF DARKNESS BY THE PINEAL GLAND. From very low daytime levels an increase in plasma melatonin occurs in the evening, peaking between 01:00-05:00h, and becoming barely detectable again by about 09:00-10:00h Secretion in many animals is truly photoperiodic, that is it is influenced by the length of the day/night cycle...

The Concept of Internationalism: PROFESSOR E. B. Scientific Apparatus and Laboratory Methods: KRUMBHAAR......................................... 73 Location of Thiamin and Riboflavinin Wheat The White Dwarfs: PROFESSOR W. J. LUYTEN .................. 79 Grains: DR. G. FRED SOMERS and MARY H. CooScientific Events: LIDGE. A Cylinder Guide for Use i&t Plate Assay of The New York Botanical Garden; ...