Jacobiasca lybica (Bergevin and Zanon)
(Also known as Empoasca lybica)
Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Cicadellidae.
Common name: Cotton jassid.
Geographical distribution: Mediterranean basin, Arabia, India, East, South and North Africa.
Morphology: Female about 3 mm in length; body pale green. The wings project beyond the abdomen; forewings greenish, hindwings transparent. Head, pronotum and metathoracic shields with white spots.
Host plants: Cotton, grapevines and many Solanaceae.
Economic importance: This jassid is a serious pest of grapes; the presence of 0.5–1 nymphs/ leaf in mid-summer induces damage symptoms and reductions in the soluble solids. The pest pierces grape cells and sucks their contents. Infested leaves change color, appear scorched and often curl downwards. Severe attacks result in massive shedding of leaves, exposing them to the sun, thus causing berry “scalding”, reducing grape quality and quantity. In addition, such injury reduces the plant nutrient reserves for the following season. The pest also seriously damages solanaceous crops, such as pepper, potatoes and tomatoes, its injury being especially severe on eggplants. Beets, beans and cotton may also be attacked.
Life cycle: Females, which often inhabit the lower side of leaves, insert their eggs, about 50-80/female, into leaf veins or stalks. The emerging nymphs develop within about 3 weeks through 5 instars and the adults may live for several months. They require about 280 day degrees for development and the threshold of development is around 10-12°C. Depending on the region, the pest annually raises 5–8 overlapping generations.
Monitoring: Pest presence can be monitored and its population levels estimated by adult catches in yellow traps and by direct counts of nymphs on a random sample of leaves.
Plant resistant: Hirsute cotton varieties are little attacked by this pest.
Chemical control: Organophosphates and the carbamate carbaryl have been used to control the pest, the sprays being directed at the underside of leaves, which the pest prefers.
Biological control: Natural enemies include various predators, such as Chrysoperla carnea, Scymnus sp. (Coccinellidae), and Syrphidae. The mymarid parasitoid Anagrus atomus attacks the eggs of the pest.
Delrio, G., Lentini, A. and Serra, G. 2001. Spatial distribution and sampling of Jacobiasca lybica on grapevine. IOBC/wprs Bulletin 24: 211-216.
El Shafie, H.A.F. and Basedow, T. 2003. The efficacy of different neem preparations for the control of insects damaging potatoes and eggplants in the Sudan. Crop Protection 22: 1015–1021.
Kisha, J.S.A. 1978. The relative efficiency of foliar sprays and granular insecticides in control of the jassid Empoasca lybica on eggplant. Annals of Applied Biology 89: 451-457.
Klein, H.Z. 1948. Notes on the green leafhopper, Empoasca lybica, Berg. (Hom. Jassid.) in Palestine. Bulletin of Entomological Research 38: 579-584.
Klerks, W. and van Lenteren, J.C. 1991, Natural enemies of Jacobiasca lybica (Homoptera: Cicadellidae): A review with an annotated bibliography. Agricultural University, Department of Entomology, Amsterdam, pp. 54.