Investigation on the Biological Characteristics and Thermal Requirements of Egg Parasitoid Trichogrammatoidea bactrae on Eggs of Cotton Pink Bollworm
Sahil D. Meshram
College of Agriculture, Nagpur, Maharashtra, India.
Prabhulinga Tenguri *
ICAR- Central Institute for Cotton Research, Nagpur, Maharashtra, India and ICAR-National Bureau of Agricultural Insect Resources, Bengaluru, Karnataka, India.
V. K. Biradar
Agricultural Research Station, Tharsa, Nagpur, Maharashtra, India.
Shivaji H. Thube
ICAR- Central Institute for Cotton Research, Nagpur, Maharashtra, India.
Babasaheb B. Fand
ICAR- Central Institute for Cotton Research, Nagpur, Maharashtra, India.
Madhu T. N
ICAR- Central Plantation Crops Research Institute, RS Vittal, Karnataka, India.
Vivek Shah
ICAR- Central Institute for Cotton Research, Nagpur, Maharashtra, India.
Rachna Pande
ICAR- Central Institute for Cotton Research, Nagpur, Maharashtra, India.
V. Chinna Babu Naik
ICAR- Indian Institute of Rice Research, Hyderabad, Telangana, India.
*Author to whom correspondence should be addressed.
Abstract
The biological traits and thermal needs of Trichogrammatoidea bactrae Nagaraja was assessed on the eggs of the Pink bollworm, Pectinophora gossypiella to predict the ideal temperature for the release of the parasitoid. A card with 300 P. gossypiella eggs was offered to T. bactrae adults in a 5:1 ratio at temperatures 18, 20, 22, 24, 26, 28, 30, 32, 34 and 36 oC. All developmental stages of T. bactrae were monitored at each temperature, however, no parasitism or development occurred at temperature 36°C. The highest parasitism rate was observed at 28°C (76.03%), and emergence rates exceeded 85.65% between 18 and 30°C. Temperature variations affected both the development duration and adult longevity, with higher temperatures leading to shorter development times and reduced lifespan. The highest proportion of female offspring was recorded at 20°C (73.67%). The total heat requirement for complete development was calculated to be 136.98 degree-days (K), with a lower threshold temperature identified at 11.75°C.
Keywords: Biological control, cotton, Trichogrammatoidea bactrae, thermal requirements, pink bollworm, Pectinophora gossypiella