Seasonal Activities of Lepidosaphes beckii and Its Associated Natural Enemies in Response to Habitat Environment

Document Type : Original Article

Authors

Plant Protection Research Institute. Agricultural Research Centre, Dokki, Giza, Egypt

Abstract

The purple scale, Lepidosaphes beckii (Newman) ( Hemiptera: Diaspididae) is one of the most important armored scale insects infesting citrus trees in Egypt. The present study was conducted aiming to a better understand the seasonal activities of L. beckii and its associated natural enemies, Aphytis lepidosaphes Compere (Hymenoptera: Aphelinidae) and the predator, Chilocorus bipustulatus (L.) (Coleoptera: Coccinellidae) in response to habitat environment (host plant species and certain weather factors) during two successive years (2019 and 2020) in Dakahlia governorate, Egypt. The obtained results indicated that  L. beckii is present in the orchards all around the year infesting leaves of navel orange, mandarin and lemon trees showing one to three peaks of activity yearly. A. lepidosaphes recorded one to two peaks of activity (as parasitism%) on L. beckii adults in navel orange, mandarin and lemon orchards; while C. bipustulatus exhibited one to three peaks (as predatism%) on the pest stage. A. lepidosaphes and C. bipustulatus act in density-dependent reactions; where statistical analysis showed that there were good synchronizations between L. beckii and populations of these natural enemies. L. beckii population was significantly higher in navel orange orchards followed by mandarin and lemon orchards, respectively. On the contrary, the activities of studied natural enemies were mostly higher in significant values in lemon orchards followed by mandarin and navel orange orchards, respectively. So, it can be concluded that the relatively low population levels of L. beckii in lemon orchard may be attributed to the relatively high activities of the recorded natural enemies, and vice versa. The daily temperature degrees had mostly high significant positive effects on the activities of L. beckii and both A. lepidosaphes and C. bipustulatus; while the daily means of relative humidity had mostly insignificant effects on them.

Keywords

Files

Share

How to cite

Statistics