Field experiment was conducted at Sugarcane Research Station, Melalathur, Tamil Nadu Agricultural University, during 2002 to 2005 in Randomized Block Design, in three replications to study the effect of intercrops and plant extracts on the activities ofTrichogramma chilonis against sugarcane shoot borer,Chilo infuscatellus (Snellen) in late planted sugarcane crop during summer months. The inter crops were sown on 3rd day after planting.T. chilonis @ 2.5 cc/ha were released at two intervals (weekly and fortnightly) in the treatment plots from 30th to 75th day after planting. The cane crop was sprayed with 5% tomato extracts +T.chilonis @ 2.5 cc/ha at fortnightly interval release recorded the lowest cumulative shoot borer incidence of 8.08% with the highest shoot borer reduction of 70.83% and 43.30% respectively over untreated check and existing practices ofT. chilonis @ 2.5 cc/ha at fortnightly interval, followed by cane inter cropped with Soybean (5:1) + 71chilonis @ 2.5 cc/ha at fortnightly interval release, in which 8.27% of shoot borer incidence with next highest shoot borer reduction of 70.14% and 41.96%, respectively recorded over untreated check and the existing practices ofT. chilonis @ 2.5 cc/ha at fortnightly interval release. The lower incidence of shoot borer in the above treatments was due to higher parasitization of 32.86% and 30.15% respectively during March-June. The highest sugar yield of 12.45 t/ha was obtained from cane yield of 96.12 t/ha with CCS% of 12.94 in cane crop sprayed with 5% tomato extracts +T. chilonis @ 2.5 cc/ha at fortnightly interval, followed by cane intercropped with Soybean (5:1) +T. chilonis @ 2.5 cc/ha at fortnightly interval in which, the next higher sugar yield of 12.16 t/ha was obtained from cane yield of 94.18 t/ha with CCS of 12.91 %. The above two treatments recorded the additional sugar yield of 15.42% and 13.40%, respectively over existing practices ofT. chilonis @ 2.5 cc/ha at fortnightly interval and 43.90% and 39.87% additional sugar respectively over untreated control. However, cane inter cropped with Soybean (5:1) +T. chilonis @ 2.5 cc/ha at fortnightly interval scored the highest CB ratio of 1:2.77 followed by CB ratio of 1:2.71 in cane sprayed with 5% tomato extract +T. chilonis @ 2.5 cc/ha at fortnightly interval.