The Asian citrus psyllid, Diaphorina citri, is a sap-sucking, hemipteran bug in the family Psyllidae.It is an important pest of citrus as it is one of only two confirmed vectors of the serious citrus disease, Huanglongbing abbreviated as HLB or greening disease. It is widely distributed in southern Asia and has spread to other citrus growing regions. The Asian citrus psyllid originated in Asia but it is now also found in parts of the Middle East, South and Central America, Mexico and the Caribbean. In the United States, this psyllid was first detected in Florida in 1998 and is now also found in Louisiana, Georgia and South Carolina.
The Asian citrus psyllid is a four-millimeter-long brown insect that feeds on the stems and leaves of citrus trees. The adult pysllid is about four millimetres long with a fawn and brown mottled body and a light brown head. It is covered with a whitish, waxy secretion which makes it look dusty. The fore wings are broadest at the back and have a dark edging around the periphery with a pale gap near the apex. The antennae are pale brown with black tips. It typically adopts a head down, tail up posture as it sucks sap.
Psyllid nymphs are found on new shoots of citrus trees. As they feed, they produce a toxin that causes the plant tips to die back or become contorted, preventing the leaves from expanding normally. Of more importance is the fact that they are vectors for the bacteria that causes one of the most devastating of citrus diseases, Huanglongbi ng. This is also called as citrus greening disease. The Asian citrus psyllid can fly short distances and be carried by the wind. However, a main way the Asian citrus psyllid spreads throughout the state is by people transporting infested plants or plant material. The Asian citrus psyllid feeds on all citrus trees, including orange, lemon, lime, mandarin, pomello, kumquat, grapefruit and tangerine trees. It also feeds on some relatives of citrus, like orange jasmine and curry leaves.
Citrus greening is one of the most serious citrus plant diseases in the world. It is also known as Huanglongbing (HLB) or yellow dragon disease. Once a tree is infected, there is no cure. While the disease poses no threat to humans or animals, it has devastated millions of acres of citrus crops throughout the United States and abroad. The disease was first described in 1929 and first reported in China in 1943. It has seriously affected Taiwan since 1951. The African variation was first reported in 1947 in South Africa , where it is still widespread. The disease has affected crops in China , Taiwan, India
This disease is distinguished by the common symptoms of yellowing of the veins and adjacent tissues; followed by yellowing or mottling of the entire leaf; followed by premature defoliation, dieback of twigs, decay of feeder rootlets and lateral roots, and decline in vigor; and followed by, ultimately, the death of the entire plant. Affected trees have stunted growth, bear multiple off-season flowers, and produce small, irregularly-shaped fruit with a thick, pale peel that remains green at the bottom. Fruit from these trees tastes bitter. ACP nymphs can only survive on the new flush tips of citrus. Because they produce a toxin, the flush tips die back or become twisted and the leaves do not expand normally. HLB causes asymmetrical blotchy mottling of leaves. Fruit from HLB-infected trees are small, lopsided, poorly colored, and contain aborted seeds. The juice from affected fruit is low in soluble solids, high in acids and abnormally bitter. The fruit retains its green color at the navel end when mature, which is the reason for the name citrus greening disease . The fruit is of no value because of poor size and quality. There is no cure for the disease and rapid tree removal is critical for prevention of spread.
“The [Asian citrus psyllid] is of grave concern because it can carry the disease huanglongbing (HLB), also known as citrus greening,” the California Department of Food and Agriculture, or CDFA, said in a press release . “All citrus and closely related species are susceptible hosts for both the insect and the disease. There is no cure once a tree becomes infected.”
University of Florida estimated that between 2007 and 2012, the state lost 6,600 jobs, direct revenue of $1.3 billion and indirect revenue of $3.6 billion due to citrus greening disease.
This disease has caused continued mayhem in the citrus industry year after year. Since the psyllid arrived in Southern California in 2008, the citrus nursery industry has been in a tizzy! Florida, the world’s largest orange grower after Brazil , will harvest 121 million boxes of the fruit in the season that began Oct. 1, 2013 the fewest since 1990, the U.S. Department of Agriculture estimates.
Let us take a look at the below news article:
Florida Orange Juice Industry Squeezed by Citrus Disease
December 26, 2013
An insect — no bigger than the head of a pin — is wreaking havoc on the Florida orange industry. The Asian citrus psyllid is responsible for spreading citrus greening across the state, all of which is under quarantine for the disease. Citrus greening, also known as Huanglongbing, causes oranges to turn green, grow misshapen, and take on a sour taste. Infected citrus trees normally die within a few years.
Already, the forecasts for orange harvests in Florida are down. According to the December data by the United States Department of Agriculture, Florida orange production is expected to be 3 percent lower than November’s numbers. Hale Groves, a florida based citrus grower , says that the citrus industry in Florida accounts for more than 75,000 jobs, and is worth $10 billion annually. In the U.S., citruses, including oranges, grown in Florida supply 70 percent of the market, and is second only to Brazil in terms of growing oranges. Florida’s dominance in the orange juice market is even more impressive, with the state producing 90 percent of the U.S.’s supply.
Recognizing the severity of impact a devastated orange market can produce, the USDA announced a multi-agency response. ”USDA listened to the citrus industry’s request for more urgency and greater coordination on the response to HLB and is implementing an emergency response structure,” Secretary of Agriculture Tom Vilsack said in a statement To jump start this initiative and affirm our commitment to industry, USDA is also providing $1 million to be used in support of research projects that can bring practical and short-term solutions to the growers in their efforts to combat this disease.” Companies, like the Coca-Cola Company and PepsiCo, Inc.will feel the impact of a limited orange market as well. This year, the USDA expects 121.0 million boxes of oranges will be produced by Florida. If this is the case, it will be a 9 percent year-over-year decrease.
PepsiCo, so far, does not appear to have been affected. ”The chilled juice business as well, both in terms of base Tropicana as well as the innovation that we have with Tropicana Farm stand and Trop50, all continue to perform well,” the company’s Executive Vice President and CFO Hugh Johnston said in PepsiCo’s 2013 third quarter earnings call. In 2012, the U.S imported 2.3 billion in oranges and orange-related products with the top supplier being Brazil. It is possible that imports will offset any issues for corporations, leaving the growers to be the main sufferers of the damaging effects of citrus greening.
Florida, however, isn’t the only orange juice market that has recently experienced issues. Coca-Cola, the parent company of Minute Maid and Simply Orange, incurred losses in 2012 due to Brazilian orange juice. The company discovered in 2011 that carbendazim residues were in orange juice Coca-Cola was importing from Brazil. Carbendazim is a fungicide not registered for use in the U.S. As a result, the company had to purchase additional Florida orange juice, which costs more than Brazilian. Charges to Coca-Cola during the nine months ended September 28, 2012 associated with the changes totaled $21 million.
HLB can kill a citrus tree in as little as five years, and there is no known cure. The only way to protect trees is to prevent spread of the HLB pathogen in the first place, by controlling psyllid populations and removing and destroying any infected trees. Conventionally used toxic pesticides have been of little help. In this scenario of growing despair, Termirepel™ a product by C Tech Corporation can prove to be a worthy solution. Termirepel™ which by nature is a non-toxic, non-hazardous and eco-friendly termite aversive is also highly effective against a host of other insects and pests. It works by the mechanism of repellence, through which it will work at protecting the trees from this deadly pathogen by repelling the vector i.e. psyllid from the citrus trees. This will in turn contain the spread of the pathogen among the trees. Termirepel™ is available in the form of a liquid concentrate that can be diluted in a favorable medium and sprayed on the trees as well as around them.