Population dynamics of the purple scale, Lepidosaphes beckii (Hemiptera: Diaspididae) and its parasitoid Aphytis lepidosaphes (Hymenoptera: Aphelinidae) as a new threat pest on mango trees in Egypt

Abstract

The purple scale, Lepidosaphes beckii (Newman) (Hemiptera: Diaspididae) is one of the most important pests attacking mango. The present paper includes population dynamics of the purple scale, L. beckii and its parasitoid. Dynamics of L. beckii and its parasitoid on mango trees was carried out in Giza, governorate, during 2009 and 2010. Only one parasitoid recorded in this work was Aphytis lepidosaphes Compere (Hymenoptera: Aphelinidae). Statistical analysis of the effect of weather factors on the population of L. beckii and its parasitoid during the two years under consideration was explained. The results indicated that maximum and minimum temperatures was significant on the population of L. beckii and its parasitoid, A. lepidosaphes while percent of relative humidity it is nonsignificant. As well as obtained results over both years indicated the occurrence of three generations per year for L. beckii on mango in Giza.

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

“…Also, the present study revealed that L. beckii was recorded all over the year infesting leaves of navel orange, mandarin and lemon trees showing one to three peaks of activity during 2019 and 2020 years. These results are partially in agreement with those obtained by Aly (2011), Draz et al (2011), Belguendouz et al (2015), Zaabta et al (2020), Agagna et al (2022) and Esmaeili et al (2022); they reported that L. beckii exhibited three peaks of activity in mango and citrus orchards in Egypt, Algeria and Iran. Also, in Egypt, Moustafa (2012) and El-Amir et al…”

“…Also, the present result is near to the results of Stathas et al (2015) and Zaabta et al (2020); they recorded two to three peaks of A. lepidosaphes activity on L. beckii infesting citrus orchards in Greece and Algeria. According to Aly (2011), there was no parasitism by A. lepidosaphes on L. beckii during the months of January, February and March. These findings support the present study; which revealed that there was no record of parasitism percentages on L. beckii by A. lepidosaphes during these months, especially during the second year.…”

“…The purple scale, Lepidosaphes beckii (Newman) ( Hemiptera: Diaspididae) is one of the most important armored scale insects infesting citrus trees in Egypt and many parts of throughout the tropical and subtropical regions (Danzig & Pellizzari, 1998, Magro & Hemptinne, 1999, Claps et al, 2001, Foldi, 2001, Draz et al 2011, Moustafa, 2012, Belguendouz et al (2015, Stathas et al, 2015, El-Husseini et al, 2018, Zaabta et al, 2020, Agagna et al, 2022and Esmaeili et al, 2022. It is a polyphagous species; where, it had been reported almost on 176 genera (belonging to 83 families) of plants (Davidson & Miller, 1990, Aly, 2011and Garcia et al, 2016. All stages of L. beckii are present in the orchards all around the year; so, it gives a sequent of overlapping generations (Fadamiro et al, 2008).…”

“…Because of the small size of insects and the characteristics of their bodies, biological aspects of insects are depending on climatic factors especially temperature degrees and thermal fluctuations (Chown & Nicholson, 2004). According to Aly (2011), Draz et al (2011), Moustafa (2012) and El-Amir et al (2020), weather factors especially temperature degrees mainly determine the growth rate in L. beckii, the parasitoid, A. lepidosaphes and the predator, C. bipustulatus. On another hand, synchronizations between insect pests and their natural enemies determine their efficacy as biological control agents against the pest (Ghanim, 2003).…”

Data on ecology of the purple scale Lepidosaphes beckii (Newman) on citrus in Greece

“…Smirnoff () states that the scale completes 4 annual generations in Morocco. Aly () reported three to four generations of L. beckii per year in Egypt and Gill () three to four generations per year in California. Females lay about 170 eggs when settled on leaves and 250–300 eggs when settled on fruits (Bodenheimer, ).…”