​Pigeon Pea [Cajanus cajan (L.)]: New Promising Host of Lac [Kerria lacca (Kerr)] in Southern Rajasthan

Background: Lac is a resin secretion of insects [Kerria lacca (Kerr)], which are commercially cultivated through ages. Lac cultivation has its roots in India and a major source of economy to the local populace. Though different lac hosts have been recorded in Rajasthan, but it is not cultivated commercially. Pigeonpea crop could be utilized for encouraging lac cultivation in the region and yield losses can be compensated by additional income received from lac resin. Methods: The experiment on “Studies on Economics and Yield Attributing Parameters of Lac Cultivation on Yield of Pigeonpea, Cajanus cajan (L.) in Southern Rajasthan” was conducted on Rangeeni strain of lac insect in Baisakhi season at lac insect gene bank cum garden situated at Department of Entomology, Rajasthan College of Agriculture, MPUAT, Udaipur during 2019-20 and 2020-21 respectively. The life cycle of Rangeeni strain of lac insect were studied on pigeonpea sown in last week of August in plot size measuring 2 × 10 sq m during Baisakhi season of both year. Result: The study revealed that the mean initial settlement density of lac insect on pigeonpea ranged from 67.53 to 84.20 with 4.27 to 5.27 (per sq. cm) mature female cell density during successive years. The mean per cent settlement was found to be the maximum (91.78 and 91.15%) at lower portion of the pigeonpea plant during respective years. The duration of sex differentiation ranged from 48.23 to 49.10 days for both successive years. The benefit cost ratio was also higher (1.95 and 2.09) in lac inoculated experiment then the sole seed crop (control) of pigeon pea (1.84 and 1.35) in season 2019-20 and 2020-21, respectively. All the parameter revealed that pigeon pea is economically efficient host for the Rangeeni strain of lac in agro-climatic region of southern Rajasthan.

Extent and Pattern of Natural Occurrence of Lac Insect (Kerria lacca) and their Host Plants in different Agro-Climatic Zones of Bihar

Surveys were conducted in 28 districts of Bihar for occurrence of natural population of lac insect; Kerria lacca Kerr (Hemiptera, Tachardiidae), and abundance of its host plant. Naturally occurring lac insect was observed in 18 districts in varied proportion mostly on Ficus religiosa, Ficus benghalensis and rarely on Ziziphus mauritiana and Butea monosperma. Majority of insects were found dead but at few places good live population were noticed. Natural occurrence of lac insect was found highly vulnerable to human interventions, high temperature and parasitoids and predators. Out of 17 districts of south Bihar, falling under zone III, 10 districts were found rich in naturally surviving lac insect. Lac insects in scattered manner were also observed in many districts of Northern Bihar but occurrence and population densities were very low. Survey revealed the abundance of lac host and natural population of lac insects in various districts of zone III (58%) of Bihar. These findings could open a new window for introduction lac cultivation in these areas for livelihood support to resource poor farmers, especially during off-agricultural season.