The Evil Weevil
By Brian Cabrera

 For many people, a great way to relax is to sit in the shade of a tiki hut and sip a few cold drinks. Along with palm trees swaying in the breeze, the tiki hut brings to mind the image of taking it easy without a care in the world. However, even these temples of relaxation can’t escape the harsh realities of life _ some of them of the insect kind.

 A LEAKY TIKI

 In early 2005, I heard from a pest control company in the Tampa area that was dealing with a puzzling problem. A homeowner had a custom-built tiki hut and started finding piles of dust on the chairs and tables under the thatch roof. During his inspection, the technician looked above from where the dust was piling up and found several holes in the stalks of the palm fronds, which made up the thatch. The holes were definitely made by some type of borer but the technician was unable to find any insects.

Instead of going away empty-handed, he collected some frass and took a few pictures of the holes. He then took the samples and pictures to the Pinellas County Extension office in Largo for identification. The extension agent there did not recognize the frass nor could he make an educated guess as to what type of insect was making the holes. So he e-mailed me photos of the oval-shaped holes in the stalks.

The holes appeared too large to be made by true powderpost beetles and their shape was not characteristic of false powderpost or anobiid beetles. The oval holes were consistent with those made by long-horned beetles which belong to the family Cerambycidae. A familiar member of this group is the Old House Borer. However, without any insect specimens, I was unable to determine what was infesting the tiki hut.

 As for control, I told the technician that it should be treated as a wood-infesting beetle infestation. The tricky part was that the thatch roof was made of numerous palm fronds and not solid pieces of wood, so spot treating could be a lot of work. In addition, there was no way of knowing how many fronds were infested. Fumigation was also an option but the dosage needed could not be determined without knowing the identity of the pest.

 Another suggestion was to apply a heat treatment by wrapping the roof in heavy black plastic to bake the insects. A target rate of 130oF for 60 minutes (the standard rate for some commercial heat treatments) inside the palm frond stalks would be needed. This could be reached fairly quickly because the stalks aren’t very thick or dense. Of course, the temperatures would have to be monitored and such a treatment would be experimental.

WANTED DEAD OR ALIVE

 Whatever treatment was being considered, the most important step was to find out what was infesting the thatch. The pest control company said it would send me specimens if and when they found any.

 A few weeks later they found some beetles and mailed them to me. The beetles were a little strange looking and definitely were not long-horned beetles. These were sent to the Florida Department of Agriculture’s Division of Plant Industry. A few days later I received a report that they were fungus weevils. These insects are in the beetle family, Anthribidae. This particular fungus weevil was identified as Phoenicobiella chamaeropis which I will refer to from now on as the ’Tiki weevil.’ 

MYSTERY WEEVIL

 Unfortunately, there’s not much information on tiki weevils other than they’re found throughout Florida and the Bahamas and the larvae bore into the leaf stems of Sabal palmetto. It’s not known whether they reinfest the stems. This lack of knowledge adds to the challenge of treating infestations.

 Tiki weevils are about a half inch long. They have a gray body speckled with black and light-colored spots. Tiki weevils are sexually dimorphic _ which means the males and females look different. Females have short antennae while the males have antennae that are about twice as long as the body. The underside of the male’s antennae is also covered with short bristly hairs.

 THAT’S NOT ALL, FOLKS

 Since I first became aware of the tiki weevil, I have known of at least five other infestations including one in the thatched roof of a chickee (a raised platform structure used by the Seminoles and Miccosukees). On the day I started writing this article, I got a call from a pest control company that was dealing with a tiki weevil problem in a 60’ by 40’ tiki bar and restaurant. Oval-shaped exit holes were visible in the palm frond stalks 15 feet up from the floor. The owners complained of large amounts of dust and shavings falling below where people were eating and drinking. This could pose a public health problem as well as drive away customers.

 Besides the tiki weevil, I have encountered one other tiki hut pest. A tiki hut builder had a customer who was finding holes and frass in his hut. The builder sent me a few damaged palmetto frond stalks. While examining them, I noticed the holes were round rather than oval so I suspected they might not have been made by tiki weevils. While cutting open the stalks I found most of them were packed tightly with frass but saw no signs of insects.

 I almost came up empty-handed but finally I found the culprit. Deep inside one stalk I found a false powderpost beetle. In this case the species was Xylopsocus capucinus, which I had seen before infesting some Bishop’s wood branches and a gigantic Christmas wreath. This species is known to infest a variety of hosts including bamboo, mango, tamarind, and Ficus, so it wasn’t surprising they were in the palmetto stalks.

 NOW YOU KNOW

 Tiki weevils are not very common, but since I have identified several infestations over the last two years, I thought it would be a good idea to let the pest control industry know about them. And because tiki huts and chickees are growing in popularity, there is the possibility that we might be seeing more infestations. Even though there is no standard control treatment for these pests at this point, at least someone will know the pest they’re dealing with.

 So the next time you’re kicking back at a tiki hut, take a look above you. If you see some holes, it might be a good idea to cover your drinks.

 Cabrera is assistant professor of entomology and extension specialist, University of Florida, Fort Lauderdale Research and Education Center.

Cutlines: A male “Tiki hut” weevil, Anthribidae, left, (note the long antennae), and right, a female “Tiki hut” weevil.