245 RESEARCH NOTE Report on the occurrence and biology of Thalassodes pilaria Guen Øe (Lepidoptera: Geometridae) on litchi (Litchi chinensis Sonn.) in Bihar, India VINOD KUMAR 1* , P. V. RAMI REDDY 2 and AJIT KUMAR DUBEDI ANAL 1 1 National Research Centre for Litchi, Mushahari, Muzaffarpur, Bihar - 842002, India 2 Indian Institute of Horticultural Research, Hessaraghatta Lake, P.O., Bengaluru - 560089, India *E-mail: vinod3kiari@yahoo.co.in Litchi or lychee (Litchi chinensis Sonnen) is one of the most important subtropical fruit trees of the family Sapindaceae. The translucent, flavoured aril or edible flesh of the litchi is popular as a table fruit in India, while in China and Japan it is preferred in dried or canned state. India is the second largest producer of litchi in the world after China with an area and production of 82,000 ha and 555,000 tonnes, respectively during 2012-13 (DAC, 2013). Pests are one of the major constraints affecting production and quality of litchi. In recent years, a change in pest dynamics has been observed in litchi (Kumar et al., 2011). The occurrence of a green looper, identified as Thalassodes pilaria (Lepidoptera: Geometridae) was recorded on litchi trees in Bihar state during scouting surveys of farmer fields. The moths are commonly called Big emerald. The population of the pest was monitored in a fixed plot at National Research Centre for Litchi (NRCL) Experimental Farm during 2012. The mean number of insects (count) per 100 leaves was recorded. Rearing of the pest was done in laboratory on litchi leaves at a temperature of 28 – 1C, relative humidity 70 – 5% and photoperiod 12:12 h L:D conditions. The young larvae (1 st and 2 nd instars) were collected from field and reared in the laboratory in Petri dishes (18 cm diam.). The pupae were transferred to insect rearing jar (8.5 cm  8.5 cm  15 cm) for emergence of adults. A filter paper disc with a cotton swab dipped in honey was kept in each rearing jar. Morphometric measurements of different stages were taken and biology was studied. Insect morphology was studied with the help of a stereo- binocular microscope. The data on looper counts were subjected to analysis of variance (ANOVA) after square root transformation. The least significant differences (LSD) between means at 5% significance level (P = 0.05) and the standard error (SE) of means were computed. The diagnostic symptoms of damage and characteristics of the pest as well as summaries of studies conducted to assess the occurrence of pests in litchi are described. The larvae of T. pilaria fed on tender foliage and resembled a green stick similar to the midrib of leaves or thin shoots that served as a camouflage for the pest (Fig. 1). Studies on the biology of the pest revealed that larvae were green resembling to colour of young leaves which gradually changed to darker green as the leaves became older. The dimensions of fully grown larvae (last instar) were approximately 2 mm wide and 3.6-4.3 cm (mean 3.86 – 0.109) long. The width of head capsules in last instar larvae were 1.4-1.6 mm (mean 1.52 – 0.055). The pupae were 1.4-1.7 cm (mean 1.54 – 0.047) long and the adults with fully spread wings were 2.7- 3.0 cm (mean 2.83 – 0.047) wide. The developmental period from larva to adult was completed in 18-23 days (mean 20.11 – 0.962), out of which the larval period was 9-13 days (mean 10.89 – 0.981), the pupal period was 6-7 days (mean 6.67 – 0.272) and adult period was 2-3 days (mean 2.56 – 0.192). The adults, however, failed to mate in the laboratory (temp. 28 – 1 C, RH 70 – 5%, and 12:12 h L:D. The newly formed pupa was greyish brown in colour. The adult moth had sea-green colour wings which were semitransparent having fine white lines (Fig. 2). Fore wing was broad, triangular and leading edge was yellowish brown, crossed by two distinct w hite lines and a number of faint transverse marks which was also white. The distinct fine white lines continued up to terminal edge of hind wings, converging to form a W  way along length. The hind wings had an angular margin. Underside of the moth was greenish white. Legs and antennae were yellowish brown. The first half of antennae was feathery while second half was threadlike. The period of occurrence of this pest was from July to December. The peak infestation was observed from 15 th September to 15 th October that coincided with the occurrence of another geometrid pest of litchi, Perixera illepidaria GuenØe. During September and October 2012, Pest Management in Horticultural Ecosystems, Vol. 19, No. 2 pp 245-247 (2013)