Development of leaf silvering in squash cultivars infested by silverleaf whitefly

Abstract

The silverleaf whitefly Bemisia tabaci biotype B is one of the most harmful insect pests for agricultural and vegetable crops. Beside the direct damage, it transmits pathogenic virus and induces plant physiological disorders, such as the squash silverleaf disorder. In this research we evaluated the development of leaf silvering in squash cultivars submitted to artificial infestation of B. tabaci biotype B. An experiment was conducted under field conditions, in Campinas, São Paulo State, Brazil, during the season [2003][2004]. The germplasm (Cucurbita spp.) comprised of seven cultivars of summer squash and nine of bush squash. The experiment used a complete randomized blocks design, with 16 treatments (cultivars) and five replications. Each plot consisted of two plants. The artificial infestation was done when the plants emitted the third pair of leaves, by transplanting soybean plants infested with silverleaf whitefly between the squash plots. The leaf silvering was evaluated every two or three days, using a rating scale varying from 1 (no symptom) to 5 (leaves completely silvered). The highest level (5.0) was observed in 'Baianinha', 'Golden Delight', 'Caravela' and 'Arlika', while 'novita' (2.5), 'Atlas' (2.0) and 'Atlanta AG-303' (1.5) showed light symptoms, indicating that these have low sensibility to this physiological disorder.

Relationship Between Bemisia tabaci and Aphis gosspyii Infestations with Certain of Plant Diseases, Plant Enzyme Activities, Dissection Structures and Natural Enemies on Squash Plant.

“…A little infestation of B. tabaci individuals caused physiological disorders (silvering squash leaf SSL) which reducing transpiration and photosynthesis. Similarly, numerous studies also demonstrated that the association between the feeding of B. tabaci individuals and the squash leaf silvering disease (Paris et al, 1987 andLourenção et al, 2011).…”

“…The whitefly, Bemisia tabaci and cotton aphid, Aphis gosspyii are caused severe damages to squash crop, Cucurbita pepo L.. They cause direct damage by continuous sucking of plant xylem (Bleicher et al, 2000) and silver leaf disease (Lourenção et al, 2011), sooty mold development and mosaic virus disease as an indirect damage (Nagata et al, 2005), that reduce plant productivity. The silvering leaf appearance due to separation of the upper epidermis from the palisade mesophyll resulting in altered reflection of light (Jimenez et al, 1995 andBurger et al, 1988).…”

Evaluation of a low-cost staining method for improved visualization of sweet potato whitefly (Bemisia tabaci) eggs on multiple crop plant species

“…The sweet potato whitefly ( Bemisia tabaci ) (Hemiptera: Aleyrodidae) is an agricultural pest of global significance with a wide host range that includes many crop species [ 1 – 3 ]. At high population densities, B. tabaci cause damage to crops through several mechanisms: the removal of phloem sap and direct damage to leaf tissues, inducing disorders from the injection of saliva into the phloem, and excreting honeydew that can cause secondary infections and interfere with photosynthesis [ 4 – 6 ]. In zucchini for example, yield losses of 25–100% have been reported from direct damage under high levels of B. tabaci infestation [ 7 ].…”

Efikasi Cendawan Entomopatogen Lecanicillium Lecanii Terhadap Bemisia Tabaci (Hemiptera: Aleyrodidae) Pada Kedelai

“…tabaci berkembang biak optimal pada temperatur yang tinggi di atas 26 o C dan kelembaban relatif 60%. Perkembangan serangga di lapangan dimulai pada bulan Juni dan populasi optimal terjadi pada bulan Agustus (Hilje & Morales, 2008;Lourencao et al, 2011). Seekor imago betina mampu memproduksi telur hingga mencapai 160 butir dalam setahun yang terdiri 11-12 generasi (Musa & Ren, 2005).…”