June 2012 archive

Pest of the Month January 2012 – Bacterial Leaf Spot of Hibiscus

 Host: Hibiscus and others, most commonly Hibiscus rosa-sinensis L. Distribution: Particularly in high rainfall areas like Kurtistown on the Big Island Symptoms: Lesions from 2-10 mmin diameter, usually surrounded by a two-color border (black next to tan-colored necrotic center and purplish-red next to the black)  Dispersion:  Primarily by splashing or windblown rain.  Infects through wounds …

Continue reading

Pest of the Month November 2011 – Sugarcane Weevil

Hosts: Sugarcane, palms (coconut, betelnut), papaya Distribution: Most of Micronesia and Hawaii.  Native to New Guinea. Symptoms: Tunnels in the interior of the stem.  The entrance is usually plugged with plant fibers.  In coconuts, the stem is weakened to the point of palm failure in high winds.  In betelnut, the weevils frequently bore near the …

Continue reading

Pest of the Month October 2011 – Ohia Psyllid

 Ohia Psyllid (several native Hawaiian species of the Family Psyllidae) Host: Ohia  Distribution: Native to Hawaii Symptoms: Circular, conical, or convex galls on leaves, particularly new growth Management:  Biological control by other native species (Sympiesis sp.)  Because the ohia psyllids are native insects, avoid the use of pesticides as they or their parasites could become …

Continue reading

Pest of the Month September 2011 – Bacterial Leaf Blight of Panax

Host: Panax Symptoms: Lesions on young leaves have a water-soaked appearance.  Mature lesions have dried brown centers and dark-colored or black margins.  Lesions are sometimes surrounded by diffuse purplish or reddish halos.  Blighted leaves may curl and drop prematurely. Spread by: Splashing water or windblown rain. Management:  When propagating, use pathogen-free plant material.  Do not …

Continue reading

Pest of the Month August 2011 – Chinese Rose Beetle

 Distribution:  Originally from Japan and Taiwan.  Widespread through southeast Asia and Pacific Islands Hosts: Over 250 plants.  Wide variety o f ornamentals and cultivated crops. Damage: Lace-like or shot with holes appearance on leaves caused by adults Management:  Insignificant biological control.  Green muscardine fungus destroys many larvae and adults during wet season.  Pesticides not noted. Per …

Continue reading

Pest of the Month July 2011 – Coconut Mealybug

Distribution:  North, Central, and South America, Europe, Asia, Oceania, and Africa. Hosts:  Dracaena, sago palm, Heliconia, avocado, banana, orchids, palms (dwarf date, Washingtonia, Chamaedorea, queen palm, & Rhapis), Coffea spp., Citrus spp., potato, & ginger Damage:  Adult females and immatures feed on sap.  Honeydew secretions may lead to black sooty mold, which can result in …

Continue reading

Pest of the Month June 2011 – Lightning Injury to Plants

Affects:  Any plant, particularly tall-standing, erect plants (like trees and palms) Symptoms include:  rapid wilting or collapse of plants or stems in combination with structural damage or carbonization (burning) of the internal stem tissues, premature mass dropping of green fruit, burns or strange scars on plants or organs, roots appear blackened or cooked, interior plant …

Continue reading

Pest of the Month May 2011 – Giant Palm Weevil (Pest Alert)

Distribution: from South Carolina south to the Florida Keys and west toTexas.  Native to Florida. Hosts: Canary date palm, date palm, sabal palm, fishtail palm, coconut, latan palms, royal palm, and Washingtonia spp.  Stressed, damaged, pruned, and recently transplanted palms are the most susceptible.  Symptoms: General decline of young fronds, older fronds may begin to …

Continue reading

Pest of the Month April 2011 – Broad Mite

Hosts:  Guava, macadamia, mango, and Plumeria Distribution: All of the major Hawaiian islands, Australia, Asia, Africa, North America, South America, and the Pacific Islands Damage:  Terminal leaf and flower buds become cupped and distorted, reduction in photosynthesis, corky brown areas between the main veins on the underside of leaves. Management:  Biological control through locally occurring …

Continue reading

Pest of the Month March 2011 – Spiraling Whitefly

Hosts:  Recorded on 38 genera of plants from 27 plant families and over 100 different species.  Common on avocado, breadfruit, citrus, coconut, kamani, Indian banyan, macadamia, mango, palm, paperbark, plumeria, sea grape, and tropical almond. Distribution: Native to Central American and the Caribbean region.  First reported in Hawaii in 1978 and is now present on …

Continue reading