DPI's Bureau of Entomology, Nematology and Plant Pathology (the botany section is included in this bureau) produces TRI-OLOGY six times a year, covering two months of activity in each issue. The report includes detection activities from nursery plant inspections, routine and emergency program surveys, and requests for identification of plants and pests from the public. Samples are also occasionally sent from other states or countries for identification or diagnosis.

Highlights

Following are a few of the notable entries from this volume of TRI-OLOGY. These entries are reports of interesting plants or unusual pests, some of which may be problematic. See Section Reports for complete information.

Foliar symptoms of Raffaelea lauricola (laurel wilt) on Persea borbonia (red bay tree)
Photograph courtesy of Bud Mayfield, FDACS Division of Forestry

Persea borbonia (red bay) - Raffaelea lauricola, laurel wilt. The laurel wilt pathogen vectored by Xyleborus glabratus, redbay ambrosia beetle, is capable of attacking and killing red bay and several other members of the laurel family including sassafras, pondspice, spicebush and camphor-tree. Commercially, the biggest concern is the apparent susceptibility of many varieties of avocado, most of which are grown in Miami-Dade County.

Persea humilis Nash. - silk bay, scrub bay. The three species of Persea native to Florida are all very similar in general appearance. Unfortunately, like all of its close relatives, the silk bay is theoretically susceptible to the laurel wilt disease rapidly being spread by the redbay ambrosia beetle. To date, no infected plant of this species has been found.

Lycium carolinianum (Christmas berry)
Photograph and copyright courtesy of Roger Hammer/Wildflowers of the Everglades, Atlas of Florida Vascular Plants

Lycium carolinianum Walt. - Christmas berry, Carolina desertthorn, lycium. This species is a spiny, salt-tolerant, evergreen shrub to 2 m tall, found in coastal areas, including shell mounds and the edges of salt marshes and brackish swamps, from South Carolina to Florida and west to Texas and Mexico.

Phoradendron leucarpum (oak mistletoe)
Photograph courtesy of Betty Wargo, Atlas of Florida Vascular Plants

Phoradendron leucarpum (Raf.) Reveal & M.C.Johnst. - oak mistletoe. This evergreen subshrub, up to 1 m in diameter, is a hemi-parasite, taking water and nutrients from its host tree, but also carrying out photosynthesis. Only one other species in this genus occurs in Florida, P. rubrum, the mahogany mistletoe. It is a rare, parasitic plant found only in far South Florida, distinguished from oak mistletoe by its lemon-yellow to orange fruit.

Carthosilvanus vulgaris (Grouvelle)
Photograph courtesy of M.C.Thomas, DPI

Carthosilvanus vulgaris (Grouvelle). Specimens were collected in a blacklight trap at the Port Manatee Forestry Terminal by Customs and Border Patrol. This is a Neotropical species not previously known from the United States; the collection is a continental record. This beetle is not of economic importance. It lives under bark and feeds on fungi. (Dr. Michael C. Thomas.)

Orius tristicolor (White) minute pirate bug. Found on Helianthus debilis, beach sunflower or dune sunflower in Tierra Verde, FL. This is the second catch for the tiny predator (usually no more than 3 mm long) in the landscape in Florida. It is intercepted regularly on produce from Western states. This is a county record for Pinellas. (Dr. Susan E. Halbert.)

Root galling caused by Meloidogyne javanica (Javanese root-knot nematode) on Solanum viarum (tropical soda apple)
Photograph courtesy of J. Lotz and J. A. Brito, DPI

Solanum viarum (tropical soda apple) - Meloidogyne javanica (Treub, 1885) Chitwood, 1949, the Javanese root-knot nematode was found infecting the roots of this noxious weed during a survey by DPI staff. Roots were heavily infected and deformed by prominent and bead-like galls. Root-knot nematodes have broad host ranges and are very damaging pathogens of many agronomic and horticultural crops including most row and vegetable crops, fruit trees and ornamental plants.

Miscanthus sinensis (zebra grass, Chinese silver grass) - Pratylenchus zeae Graham, 1951, a root lesion nematode was found infecting the roots of this ornamental grass. Nematode-infected roots showed dark lesions on their surface. Morphological and molecular (rDNA) analyses were used for species identification. As this ornamental grass becomes more popular in Florida, its pests may become more economically important.

Colletotrichum dracaenophilum (stem rot) on Dracaena sanderiana (lucky bamboo)
Photograph courtesy of T. Schubert, DPI

Dracaena sanderiana (lucky bamboo) - Colletotrichum dracaenophilum, stem rot. This stem pathogen has probably been introduced into the United States by way of the vast quantities of lucky bamboo propagative material imported from Asia.

Hibiscus syriacus (rose-of-Sharon) - Thielaviopsis basicola, root rot. The black root rot pathogen is more commonly found on hollies and pansies, but has a wide host range. It prefers wet, cool soils and can be very difficult to manage after soils are infested. NEW HOST RECORD.

Suriana maritima (bay cedar) - Rhizoctonia sp., root rot. Collected from a nursery in Palm Beach County on 12 January 2009. NEW HOST RECORD.

Patti J. Anderson, Ph.D., managing editor
Wayne N. Dixon, Ph.D., editor