Bactericera cockerelli
Encyclopedia
Bactericera cockerelli, also known as the potato psyllid, is a potato/tomato psyllid
Psylloidea
Psylloidea is a superfamily of true bugs, including the jumping plant lice and others which have recently been classified as distinct families....

 native to southern North America. As its name suggests, it is commonly found on potato and tomato crops, where feeding of the nymphs causes a condition called psyllid yellows
Psyllid yellows
Psyllid yellows is a disease of potatoes infested by the potato/tomato psyllid, Bactericera cockerelli. The symptoms are a marked yellowing of the leaves, an upright appearance to the leaves, with severe cases resulting in early death of the plant. Tuber initiation and growth is affected. Many...

, presumed to be the result of a toxin.

The pest has caused significant loss in potato yields during periods of major population increase. Maximum potato yield loss appears to be related to infestations occurring early in the growing season, or on crops with a significant leaf canopy by summer. The psyllids are not heat tolerant and it is thought they survive summer temperatures in crops with sufficient leaf canopy through summer to offer shade.

The nymphs are very small and inconspicuous, feeding on the underside of leaves. Both nymphs and adults feed in the phloem
Phloem
In vascular plants, phloem is the living tissue that carries organic nutrients , in particular, glucose, a sugar, to all parts of the plant where needed. In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Greek word "bark"...

.

The host range is reputed to be very wide, with many species from up to 20 genera recorded. Breeding hosts are generally recognised as being restricted primarily to Solanaceae
Solanaceae
Solanaceae are a family of flowering plants that include a number of important agricultural crops as well as many toxic plants. The name of the family comes from the Latin Solanum "the nightshade plant", but the further etymology of that word is unclear...

, including important crop and common weed species, and a few species of Convolvulaceae
Convolvulaceae
Convolvulaceae, known commonly as the bindweed or morning glory family, are a group of about 60 genera and more than 1,650 species of mostly herbaceous vines, but also trees, shrubs and herbs.- Description :...

, including bindweed
Bindweed
Bindweed may refer to:* Convolvulaceae , a family including about 60 genera and more than 1,650 species** Calystegia , a genus of about 25 species of flowering plants...

 and sweet potato
Sweet potato
The sweet potato is a dicotyledonous plant that belongs to the family Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. Of the approximately 50 genera and more than 1,000 species of...

.

Zebra chip
Zebra chip
Zebra chip, also known as papa manchada and papa rayada, is the term for both an as-of-yet unidentified pathogen and the disease it causes in potatoes and their derivative products. Potato chips exposed to the Zebra chip pathogen develop unsightly black lines resembling the stripes of zebras that...

 is a recently diagnosed disease of potatoes associated with psyllid infestation and caused by species of the gram-negative bacterium, Candidatus Liberibacter
Candidatus Liberibacter
Candidatus Liberibacter is a genus of gram-negative bacteria in the Rhizobiaceae family. The term Candidatus is used to indicate that it has not proved possible to maintain this bacterium in culture. Detection of the liberibacters is based on PCR amplification of their 16S rRNA gene with specific...

. The tubers frequently have discolouration which becomes more clear during frying of chips. This disease causes very significant losses to farmers when it occurs as the potatoes are not suitable for making into chips or fries.

Researchers at the Agricultural Research Service
Agricultural Research Service
The Agricultural Research Service is the principal in-house research agency of the United States Department of Agriculture . ARS is one of four agencies in USDA's Research, Education and Economics mission area...

 (ARS) are searching for better methods to control the potato pest. Pesticides are usually used to control the potato psyllid population, however, it is difficult to predict the movement and migration of the psyllid in order to prevent outbreaks. ARS researchers are trying to isolate the compound that female psyllid excrete to attract males. They will then synthesize the compound and place it on tapes around potato farms in order to attract males. Attracting the males will indicate to potato farmers that the insects are colonizing their fields and farmers can then plan pesticide treatments as needed. The goal of this research is to develop a psyllid-specific monitoring tool to allow farmers to use pesticides only when they are needed. http://www.ars.usda.gov/is/pr/2010/100514.htm
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