Accession Number : AD0704692

Title :   PHOTOPERIODIC REGULATION OF DEVELOPMENT AND BEHAVIOR OF IXODES RICINUS L. LARVAE AND NYMPHS FROM DIFFERENT POPULATIONS AND ITS CHANGES OWING TO AGE OF THE TICKS,

Corporate Author : NAVAL MEDICAL RESEARCH UNIT NO 3 CAIRO (EGYPT) DEPT OF MEDICAL ZOOLOGY

Personal Author(s) : Belozerov,V. N.

Report Date : 1969

Pagination or Media Count : 2

Abstract : The report presents the results of further study on the photoperiodic reaction mechanism in T. ricinus larvae and nymphs. Diapause in larvae of this species is very similar in different populations. The diapause state, manifested as delay of metamorphosis in engorged larvae, occurs prior to feeding and is based on long-day photoperiodic reaction rates. After engorgement, diapause is either fixed or reactivated on the basis of long-day reaction rates. In both cases, darkness is equivalent to a short-day and low temperatures do not influence the reaction. Differences in the photoperiodic reaction threshold (critical day length at 18C in Leningrad larval population is equivalent to 17-18 light hours while in the Moldavian larval population it is 15-16 light hours per 24 hrs) are very important ecologically and provide for adaptation to specific conditions during the seasonal cycle of the larvae. (Author)

Descriptors :   (*TICKS, LIFE CYCLES), (*LIFE CYCLES, *PHOTOPERIODISM), LARVAE, NYMPH, POPULATION, ECOLOGY, TEMPERATURE, LIGHT, INGESTION(PHYSIOLOGY), AGING(PHYSIOLOGY), DIURNAL VARIATIONS, USSR

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE