Seasonal incidence, host plants and efficacy of some insecticides against Myllocerus maculosus Desb. infesting hybrid sorghum.
An outbreak of Myllocerus maculosus [M. undecimpustulatus var. maculosus] caused severe damage to sorghum at Gwalior, Madhya Pradesh, India, in the rainy season of 1980. Laboratory and field studies carried out in the same year showed that adults fed on 8 other plant species. Of these, nutgrass (Cyperus rotundus), horse-purslane (Trianthema portulacastrum), kankua (Commelina benghalensis), barnyard millet (Echinochloa crus-galli) and sandhor (Bothriochloa pertusa) were new food-plant records for the pest. Adult populations were observed from the 1st week of July to the last week of August and reached peak numbers (3.0 weevils/plant) in the 3rd week of July. The curculionid damaged all plants of the variety CSH 5 grown and 23.21-92.48% of their leaves. Spray applications of 0.1% carbaryl, 0.1% UC-51762 [thiodicarb] or 0.04% monocrotophos caused 80-100% mortality of adults infesting leaves.