'Entomological Society of America (Arthropod Management Tests)'
Abstract
Atherigona soccata (Rondani) (Diptera: Muscidae) is one of the most important pests
of sorghum, Sorghum bicolor (L.) Moench, in Asia, Africa, and the Mediterranean Europe. Exploitation
of cytoplasmic male sterility (CMS) for hybrid production has resulted in considerable narrowing
of the genetic base and may increase the vulnerability of this crop to insect pests. Therefore, we studied
the expression of different mechanisms of resistance in sorghum to A. soccata in CMS (A) and
maintainer (B) lines of 12 genotypes under Þeld and greenhouse conditions. The CMS lines of
A. soccata-resistant genotypes were preferred for oviposition (78.5 versus 71.5% plants with eggs) and
suffered greater deadheart incidence (47.6 versus 41.6%) than the corresponding maintainer lines,
whereas such differences were not apparent in CMS lines belonging to the susceptible genotypes (92.7
versus 92.3% plants with eggs and 75.6 versus 74.6% deadhearts) under multichoice Þeld conditions.
Similar differences also were observed under controlled conditions in the greenhouse. The larval
period (9.0 versus 8.8 d) and pupal mortality (18.4 versus 13.4%) were greater on maintainer lines than
that on the CMS lines in the resistant group. The male and female pupal weights, fecundity, and
antibiosis index were greater on the CMS than on the maintainer lines. The maintainer lines showed
better recovery resistance than the CMS lines, but no such differences were observed in tiller
deadhearts. The differences in susceptibility to A. soccata were greater in the A. soccata resistant CMS
and maintainer lines than in the CMS and maintainer lines belonging to susceptible genotypes.
Conversion of A. soccata-resistant genotypes into alternate less susceptible cytoplasmic backgrounds
may be undertaken for developing sorghum hybrids with stable resistance to A. soccata
