LIFE-HISTORY OF BITTACOMORPHA CLAVIPES (FABRICIUS) (DIPTERA, PTYCHOPTERIDAE) IN AN OZARK SPRING, USA

A population of Bittacomorpha clavipes was studied in an Ozark spring from July 1987-August 1988. Measurement of larval head capsules (N=4,5 44) showed B. clavipes has four distinct larval instars. Seasonal dist ribution of immature and adult life stages suggests that this populati on has an asynchronous, non-seasonal, multivoltine life history with a t least three cohorts. First instar larvae and pupae were collected du ring all months except December through March and December through Feb ruary, respectively. Adults and larval instars II-IV were collected th roughout the year. Larval recruitment generally paralleled adult fligh t periods, and the presence of adults during all months sampled indica tes a correlation with ovipositional periods. The life history documen ted here for B. clavipes suggests that limiting factors for growth and reproduction are not seasonally dependent for this population.