~ 706 ~ Journal of Entomology and Zoology Studies 2019; 7(5): 706-710 E-ISSN: 2320-7078 P-ISSN: 2349-6800 JEZS 2019; 7(5): 706-710 © 2019 JEZS Received: 07-07-2019 Accepted: 09-08-2019 VK Bhamare Department of Agricultural Entomology, College of Agriculture, Latur, Maharashtra, India RD Dhembare Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India AS Ingale Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India KV Deshmukh Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India SH Shelke Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India Correspondence VK Bhamare Department of Agricultural Entomology, College of Agriculture, Latur, Maharashtra, India Impact of abiotic factors on population dynamics of Thysanoplusia orichalcea (Fabricius) and Mocis undata (Fabricius) infesting sole sunflower and sunflower intercropped with pigeonpea VK Bhamare, RD Dhembare, AS Ingale, KV Deshmukh and SH Shelke Abstract The investigations conducted at Research Farm of Department of Agricultural Entomology, College of Agriculture, Latur (VNKMV, Parbhani) during kharif-2017 revealed that Thysanoplusia orichalcea (Fabricius) and Mocis undata (Fabricius) were major semilooper pests observed on sunflower and sunflower intercropped with pigeonpea. The peak population of T. orichalcea was exhibited on sole sunflower and sunflower intercropped with pigeonpea during 35 th (3.2 larvae per quadrat) and 34 th SMW (2.6 larvae per quadrat), respectively. The larval population T. orichalcea infesting sole sunflower indicated a positive correlation with rainfall, maximum temperature and beforenoon relative humidity, whereas number of rainy days showed negative correlation with larval population. T. orichalcea larval population infesting sunflower intercropped with pigeonpea demonstrated a positive correlation with rainfall and afternoon relative humidity while, negative correlation with number of rainy days. The population of M. undata reached to its peak on sole sunflower and sunflower intercropped with pigeonpea during 33 th (1.6 larvae per quadrat) and 31 st SMW (1.0 larva per quadrat), respectively. The larval population of M. undata infesting sole sunflower indicated a positive correlation with rainfall and beforenoon relative humidity, whereas number of rainy days, minimum temperature and afternoon relative humidity showed negative correlation with larval population. The larval population of M. undata infesting sunflower intercropped with pigeonpea evidenced a positive correlation with rainy days and minimum temperature while, negative correlation with rainfall, beforenoon and afternoon relative humidity. Keywords: Thysanoplusia orichalcea, Mocis undata, population dynamics, abiotic factors Introduction Sunflower, Helianthus annus Linnaeus (Family Compositae or Asteraceae) is photo- insensitive crop, grown across the globe primarily for its seeds, oil and meal. It is not only cultivated as an ornamental plant but also fulfills the demand of feed and fuel. The sunflower oil is high in unsaturated fatty acids, vitamin E and plant sterols and; low in saturated fatty acids (Bonos et al., 2011) [5] . Sunflower is well known for its phytoremediation potential as efficiently remove pollutants from soil and water (Luqueno et al., 2014) [13] . Worldwide, sunflower is cultivated over an area of more than 26.20 million hectares in about 70 countries with 47.34 million tonnes of production and 1806.7 kg per ha of productivity during 2016 (FAOSTAT, 2018) [6] . In India, sunflower is cultivated on an area of 0.40 million hectares with 0.33 million tonnes of production and 830 kg per hectare of productivity during 2016 (FAOSTAT, 2018) [6] . In Maharashtra, sunflower is grown on an area of 0.61 lakh hectare with 27.67 thousand tonnes of production and 407 kg per hectare of productivity during 2014-2015 (Anonymous, 2015) [1] . Sunflower is referred as high-risk crop because of potential losses from insects, diseases, weeds and birds (Knodel et al., 2015) [12] . In India sunflower is damaged by more than fifty insect-pests. Among them, defoliating semiloopers play significant role in vegetative stage of crop. Thysanoplusia orichalcea (Fabricius) and Mocis undata (Fabricius) are reported as regular and key pests of sunflower in Marathwada region of Maharashtra state. The loss in seed yield due to defoliators was estimated to the tune of 58.06 per cent per ha in a rain fed Kharif sunflower (Suhas et al., 1996) [17] .