Study Of Karyotype And Chromosome Behavior On Cell Division Of The Diplonevra Peregrina (Wiedemann)(Diptera: Phoridae)

Diplonevra peregrina（Wiedemann）is the first species of binomial nomenclature phoridrecords in China. Their larvae are saprophagous or necrophagous, and have a important roleon genetic control, medicolegal expertise and so on.Chromosome preparations were made from cerebral ganglion of the third instar larvaeand pupal gonad of D. peregrina with air dry method. Karyotype study on mitosis and meiosisof D. peregrina provided evidence for the further research on the classification system,genetic control and medicolegal expertise. The main results showed as follows:（1）It was reared D. peregrina using simple feeding over a long period of time. Thewhole life history was divided into four distinct stages, namely egg, larva, pupa, adult. Aftermating, the females started to lay eggs. After24hours, the larvae broke out from shell andlooked for food. The larval development period was divided into three instars. At24~26℃,the first and second instar larvae lasted for1~2days, the third instar larvae lasted for3~4days.The late of the third instar larvae were found hidden dry places when they were ready topupate. Initially the pupae were orange and soft, then gradually darkened and hardened, andfinally turned to be redish brown. Two or three days later, a pair of redish brown respiratoryhorns emerged on the head position of the pupae after pupation. After12~15days, adult brokeout from puparium, namely the emergence.（2）D. peregrina had a diploid number of eight chromosomes, the first three pairs ofautosomes were metacentris, the fourth pair of sex chorosomes was heterotypic, Xchromosome was metacentrics, Y chromosome was telocentric.（3）Through observing on cerebral ganglion of the third instar larvae in the mitosis of D.peregrina, the fourth chromosome pair in the middle prophase compared with the other threechromosome pairs of thin lines was stained deeply, short and thick morphology, and compactstructure, which should be sex chromosomes. In the metaphase of mitosis, the phenomenon ofhomologous chromosomes synapsis could be observed obviously.（4）In meiotic pachytene of spermatocytes and oocytes, autosomes and sex chromosomescould be observed obviously. In diplotene, homologous chromosomes had obviouslychiasmatic phenomenon. In diakinesis, homologous chromosomes formed end to endconfigurations.（5）In meiotic diplotene of spermatocytes and oocytes, the sex chromosomes stained byGiemsa were deeper than autosomes. The silver staining showed the sex chromosomesabsorted more silver than autosomes.