Pseudothysanoes multispinatus. Photo by You Li.

Dr. Andrew Johnson of the Hulcr Lab at the University of Florida has finally found his white whale. After years of looking for Psuedothysanoes multispinatus, a bark beetle last observed by any scientist in 1974, Johnson finally found some while looking for ripe loquat fruit on the UF campus.

P. multispinatus is a member of the micracidini. Like many of the clade, it typically feeds on drier material than most bark and ambrosia beetles. This species is exclusive to basswood, at least among the three occasions to date on which it has has been observed.

The first known specimens, gathered in the 1930’s, reside in the Smithsonian’s Museum of Natural History while the ones from the 1970’s are in the Florida State Collection at DPI. The seven beetles already prepared by Johnson will be added to UF’s substantial collection of bark and ambrosia beetles.

But there may be more. A twig of basswood sits in a covered jar on Johnson’s desk. Rows of tiny holes line the bark.

Johnson says that these beetles always form a single hole per gallery. Each gallery contains two adult females and a single male with spikes covering its back, who usually blocks the entrance. About twenty beetles are likely still living and feeding inside of the twig. Johnson hopes to capture more samples as they mature and emerge, and possibly breed an additional generation.

Photo by Allan Gonzalez

Dr. Mike Wingfield, founder of the Forestry and Agricultural Biotechnology Institute at the University of Pretoria, visited the University of Florida’s School of Forest Resources and Conservation to deliver a lecture during the John Gray lecture series. In his lecture on the global threats of invasive forests pests, Dr. Wingfield bemoaned the tendency of the European Union’s open borders to allow invasive insects to move around without quarantines or inspections.

Ironically, only days later Business Insider reported that emergency talks are being held in Britain due to the realization that after Brexit all British wooden shipping pallets will be treated as imports and likely refused at the new border due to the threat of introducing wood-boring pests to Europe.

Moving untreated wood from one location to another is a frequent cause of bark and ambrosia beetle introductions, including the emerald ash borer, which continues to spread across the US primarily through firewood.

The UF/IFAS SFRC Forest Entomology lab advocates for a global system of sentinel gardens that would provide early warnings of threats from invasive wood-boring pests.

Xylosandrus crassiusculus. Photo by the Hulcr Lab

One of the most essential sources for information about North American Xyleborini has recently been updated. Demian Gomez, a PhD candidate in the Hulcr Lab, has reviewed our web-based guide to the North American members of the Xyleborini tribe of bark beetles and updated it to reflect the latest understanding of their taxonomy. Broken or outdated links have also been replaced.

Among the total of sixty species of Xyleborini in North America, thirty are invasive and five are known to be serious forest pests.

Gomez has authored and co-authored several papers on Xyleborini taxonomy and has been establishing himself as an authority on North American ambrosia beetles. His research and revisions to the online guide have been enabled in part by grants from the National Sciences Foundation and our collection of 160,000 specimens of bark and ambrosia beetles.

Small lopsided fruit from greening-infected citrus tree. UF/IFAS File Photo.

Ambrosia beetles are not typically found in citrus trees, but Dr. Andrew Johnson of the Hulcr Lab at the University of Florida recently helped Lauren Diepenbrock of the Florida Extension Service to identify an exception. The cooperation between Diepenbrock and Johnson was reported by The Orlando Ledger.

Euplatypus compositus was identified as a culprit in the death of a commercial grove of orange trees in Hernando, Florida, which had been weakened by citrus greening and excessive rain. E. compositus is a native ambrosia beetle which is attracted to trees that are already stressed or dying.

Johnson has identified tens of thousands of samples of bark and ambrosia beetles on behalf of the Hulcr Lab. His expertise is available to any other scientists or forest professionals who require assistance identifying bark and ambrosia beetles.

Photo courtesy of USDA Forest Service.

As Spring approaches, our team is preparing to launch a study on monitoring of the black turpentine beetle in Gainesville, Florida. The black turpentine beetle is a native bark beetle which is frequently a pest of stressed or injured pine trees. It is particularly effective at attacking non-native pines, raising concern over potential effects of any future introduction to new habitats.

Simon Ernstsons will conduct trapping and test a variety of semiochemicals at a site on the University’s campus in order to develop an effective lure. The work has been funded by Synergy Semiochemicals.

Photo by T.H. Atkinson, University of Texas at Austin.

Researchers here in the Hulcr Lab have recently been able to confirm the identity of a platypodid beetle, found in an unexpected place, colonizing an unexpected host.

Sangamesh Hiremath of TK posted photos on Frass and Noodles (our lab’s Facebook Group for bark and ambrosia beetle researchers) of beetles found attacking live rubber trees in Kerala, India. Dr. Andrew Johnson and Dr. You Li were both able to confirm that the species is Euplatypus parallelus, which has not previously been observed in India.

Parallelus does not typically attack live trees and is not host-specific, according to Dr. Johnson.

“It’s just a generous ambrosia beetle, so [it may feed on] really anything,” Johnson says. “It seems to attack live rubber trees sometimes but normally dead trees.”

The beetles appeared following weather that likely stressed the rubber trees badly. Between June and August of 2018, Kerala received heavy rains “leading to one of the worst flood situations after a century,” Hiremath wrote on Facebook. “Heavy rainfall coupled with low sunshine hours and depletion of nutrients from soil (laterite soil) leading to acidity might have caused a severe stress in the rubber trees, thus creating a congenial breeding ground” for parallelus.

Native to South America and possibly Florida, parallelus is an invader in the Indian subcontinent. In 2003 it was described on stressed, wilting trees in Bangladesh.