Posts tagged ‘weevils’
Our lab has had an eventful joint ECN/ESA 2014 meeting and presentation/poster schedule of activities. Most presentations are now posted. Great meetings – even won recognition for our Twitter contributions.
1. Neil Cobb, Katja Seltmann & Nico Franz. 2014. The current state of arthropod biodiversity data: Addressing impacts of global change. Presentation.
A running post with links to literature and on-line resources, presentations, identification support, and other information accompanying The Weevil Course 2014 (second installment) held from August 05-13 at the Southwestern Research Station in Portal, Arizona. Course related photos are posted on Flickr here.
1. Links to key course/identification resources
- Link to Weevil Resources
- Link to Curculionoidea on BugGuide
- Link to WoNA – Weevils of North America
- Link to AmbrosiaSymbiosis – Resources
2. Miscellaneous course presentations
- Anderson – Diversity of Curculionoidea
- Hulcr – Bark & Ambrosia Beetles, I – Introduction
- Hulcr – Bark & Ambrosia Beetles, II – Classification & Characters
- Hulcr – Bark & Ambrosia Beetles, III – North American Taxa
- O’Brien – Weevils Invasive to North America
- Franz – Images of Vegetable & Grain Weevils
- Franz – Images of Turf & Pasture Weevils
- Franz – Weevil Relationships: from Diagnostics to Homology
- O’Brien & Anderson – Specialized Weevil Traps
- Franz – Introduction to, and plans for, “WoNA”
What occurs to you when you hear the name Guatemala? Thirty-odd years of ‘civil war‘? The land of the Maya civilization? The famous Spanish colonial city Antigua? Or perhaps the 37 volcanoes for those who are geology-oriented? For we entomologists, it is beetles and bugs! But we have seen more than that during our recent field trip to the beautiful land of Guatemala. We drove across the country and collected in nine departmentos (states) in about 15 days (Fig. 1). This is a brief account of the trip.
The unique and complex geological history and biogeographic constituents of Guatemala have attracted us to make it our destination. We wanted to collect specimens of weevils in the Exophthalmus genus complex. We were hoping to find species that may have an affinity to Caribbean lineages. Because it was possibly historically connect to part of the land masses in the Caribbean, Guatemala seems the right place for finding our weevils.
The trip was joined by ASU Franz Lab Postdoc Guanyang Zhang, Graduate Student Andrew Jansen, and Manuel Barrios, a guatemalteco (Guatemalan), who is a student of molytine leaf litter weevils and currently pursuing a PhD degree at the Universidad Nacional Autónoma de México (UNAM).
Weevil natural history news from Gamboa, Panama. We are continuing to look for weevils that can be observed feeding and reproducing in the field. One such opportunity is starting to develop because we discovered a fallen palm tree of the species Oenocarpus mapora which is very common on the Cerro Pelado at Gamboa. On the fallen log we first spotted two specimens of Metamasius hemipterus, and today a female of the South American palm weevil Rhynchophorus palmarum. The female was feeding, possibly also hiding, near the central core of the broken off stem. A short video of this female is available here. We will monitor the log for more dryophthorid weevils and possible mating activities.
Post in development..
This morning I had an opportunity to revisit an interaction that was part of my graduate thesis research; i.e. the reproductive association of Carludovica “Panama hat palms” and acalyptine weevils in the genus Systenotelus.
Carludovica plants are members of the Cyclanthaceae and are common along roads and trails in and around Gamboa, Panama. The development of the flowering process is short (essentially lasting 24 hours) and highly predictable – one can observe an inflorescence’s spathes opening and detaching during the night prior to the main flowering event. Having spotted one such plant yesterday night at the “Frog Pond”, I arrived at the fully opened and extended inflorescence of C. palmata at 5:30 am on the following morning.
Sometimes, especially in open habitats where Carloduvica plants receive high sun exposure, leaf-cutter ants and stingless bees will find the inflorescences early and cut off the staminodes, thereby reducing the attractiveness of the inflorescence and intensity of the weevil-attracting scents. This was not the case with this inflorescence, however. Likely more than 300-500 weevils pertaining to four acalyptine species arrived during this morning. I managed to record about 2.5 hours of close-up weevil feeding and reproductive behavior under very good conditions. A short 1-minute video (shot with a point-and-shoot camera) is posted here.
Of primary interests to me was filming the behavior of Systenotelus stockwelli – possibly for the first time. Presently three species are recognized in the genus Systenotelus, of which S. stockwelli is the smallest and also that which most closely resembles weevils in the related genus Perelleschus in terms of general shape. However, unlike Perelleschus, Systenotelus weevils a not pollinators of Carludovica, and instead of primarily feeding on the fleshy red pulp, the larvae are seed predators. Hence the evolution of Perelleschus and Systenotelus marks a transition from weevils being largely beneficial to being detrimental to the plant’s reproductive success.
Only about 15-20 individuals of S. stockwelli arrived at the inflorescence, at least 30 minutes after other species of Azotoctla, Ganglionus, and Perelleschus had arrived. Both females and males of S. stockwelli are quite active in the first 1-2 hours following arrival. I was able to observe and film multiple instances of feeding, probing and drilling oviposition sites, mating attempts, copulatory courtship, mate guarding, male-to-male conflicts, male-to-female conflicts, and oviposition.
In the next few days we hope to find more inflorescences of C. palmata around Gamboa, and also dissect fruits which contain the weevil larvae (mostly of Perelleschus, according to initial samples). We are also looking for other weevils that can be observed feeding and reproducing at sites that can be carefully observed and recorded on video.
Evening update. I revisited the inflorescence after 8 pm today. The staminodes were on the ground and in a state of rotting. Only Ganglionus, Perelleschus, and very small species pertaining to an undescribed genus (though often identified as Phyllotrox – which is not typically on cyclanths) were present, in lower numbers, and not on the surface layer.
My second semester as a graduate student has been spent conducting research with the Smithsonian Tropical Research Institute in Panama. Since February, I have been dividing my time between working in STRI’s Insect Collection in Panama City and traveling around Panama collecting insects. In the Collection I’ve been making an interactive identification key to the 29 currently described Panamanian genera of weevils in the subfamily Conoderinae, available shortly in SCAN. This has been possible thanks to the collecting of Henry Stockwell in the 1970s and 1980s, whose large collection of conoderines contains numerous undescribed species.