Insect-pests of ber (Ziziphus mauritiana Lam.) as influenced by abiotic factors in arid region of Rajasthan

Indian jujube known as ber (Ziziphus mauritiana Lam.) is an extremely drought hardy and native fruit of India. It is a dominant component of the natural vegetation in the Indian “Thar desert”. Though as many as 130 species of insect pests have been recorded in India, only few species have attained the pest status and cause substantial economic damage to ber. However, a total of 10 insect-pests feeding on ber were recorded from hot arid region of Rajasthan. Out of these, two insects viz., Ber fruit fly (Carpomyia vesuviana Costa) and stone weevil (Aubeus himalayanus Voss) were recorded as major pests on this crop with infestation varying from high to very high degree, whereas two insects (Ber butter fly, Tarucus theophrastus (Fabricius) and thrips, Scirtothrips dorsalis (Hood)) were recorded as moderate pests. As many as six insect pests viz., grey weevil, Myllocerus dentifer (Fabricius), M. blandus Faust, Amblyrrhinus poricollis Schoenherr; leaf webber, Synclera univocolis; bark eating caterpillars, Indarbela sp and termite, Odontotermes sp were recorded as minor pests. The incidence of fruit fly (C. vesuviana) and stone weevil (A. himalayanus) were recorded on ber from October to February. The damage of leaf feeder’s viz., ber butterfly, leaf webber, thrips and grey weevils damage was more during June to September. The high mean percent incidence of fruit fly was recorded on gola (16.77%) than seb (10.36%) but stone weevil incidence was found reverse to fruit fly (more in seb, 15.43 % than gola, 09.62 %). Correlation of fruit fly and stone weevil with maximum and minimum temperatures was found negative, which indicated that decrease in temperatures increased the population of the pest. Correlation between the pest (fruit fly & stone weevil) population and maximum and minimum R.H. was found positive correlation