Morphological, Biological and Ecological Studies of the Mycophagous Ladybird Psyllobora vigintiduopunctata L. (Coleoptera: Coccinellidae) on Powdery Mildew Fungi in the Coastal Region of Syria

Ghydaa Hasan Younes, Mohammad Ahmad, Nawal Ali

Abstract


The coccinellid tribe Psylloborini is comprised of obligate consumers of powdery mildew fungi (Ascomycota: Erysiphales). The 22-spotted ladybird, Psyllobora vigintiduopunctata L. (Coleoptera: Coccinellidae) has been considered as one of the most important powdery mildew consumers in the coastal region of Syria. Adults and larvae of this native species were active from early April until the end of November on powdery mildew infected plants in this region. The biology of P. vigintiduopunctata fed on many powdery mildew species was observed under constant environmental conditions [temperature: 25±2ºC, relative humidity: 70±5%, and photoperiod: 12: 12 (L: D) h]. Mean dimensions of the first instar larvae measured 1.99×0.65 mm and weighted 0.25±0.08 mg, increased to 5.51×1.78 mm in its size, and weighted 5.91±0.81 mg in the forth instar. The developmental period of the immature stages from egg to adult was 21.97±1.89 days when reared on Phyllacctinia guttata (Wallr.: Fr.) Lev/. on black mulberry (Morus nigra L.) leaves, and the mean fecundity was reached to 109.44±77.61 eggs/female. The average leaf surface area of M. nigra infected by P. guttata from which the larvae of P. vigintiduopunctata removed visible powdery mildew hyphae through consumption during the entire larval stage was 28.08±5.94 cm²/leaf, and decreased to 16.43±2.98 cm²/leaf when the larvae fed on Uncinula necator (Schw.) Burr. on Grape (Vitis vinifera L.). These observations indicated that P. vigintiduopunctata may be considered as a good biological control candidate against many powdery mildew fungi.

Keywords


Psyllobora vigintiduopunctata, powdery mildew fungi, predator, biological control, Syrian Coast

Full Text:

PDF

Refbacks

  • There are currently no refbacks.