In a search for high-quality jute (Corchorus olitorius) fibre using phenotypic marker(s), a single plant from CRIJAF accession OIJ 154 was isolated on the basis of its unique red-tinted pale green stem, which becomes crimson red at maturity, and was given a code name, PPO4. Progenies from this selection bred true with respect to morphological characters. It has a slightly lower height at maturity, but has comparable yield and a higher harvest index when compared to the most popular high-yielding variety JRO 524. In spite of having lower chlorophyll per unit weight of leaf tissue, the photosynthetic rate per unit chlorophyll, the relative growth rate of PPO4 was higher than JRO 524. A composite analysis of quality parameters indicated that the genotype is of higher grade (between TD2 and TD3) with very fine (1.5 tex) fibre of high tensile strength (19.7 g/tex). The lignin content (ca 14%) of the fibre was also less than that of JRO524 (ca 17%) under standard assay conditions. This plant type, with distinct morphological markers, could be utilized in breeding programmes for the genetic improvement of jute.

Some aspects of the reproductive behaviour of the tossa jute defoliator, Acraea terpsicore (L.), were studied. The insect mated only once. A horny material was deposited on the female's genital aperture after mating. Mating began on the day of emergence and lasted for 7 days on 10% sucrose solution. Maximum number of matings was on the third day after emergence. Within the day, over 95% of matings was between 0600 and 1800 hr with a peak between 1200 and 1800 hr. Eggs were also laid mainly between 0600 and 1800 hr during the day with a peak between 1500 and 1800 hr. Oviposition which started on the day of emergence lasted for 7 days on 10% sucrose with a peak on the second day. The presence of the male, after mating had occurred, did not significantly affect the number of eggs laid. Adults emerged between 0600 and 1800 hr but mostly before mid-day. Peak emergence for males occurred earlier than that for females. Behavioural activities in courtship, mating, oviposition, and adult emergence, are described.