Mark Deyrup

A review of the ants of the Florida Keys

A new survey of the ants of the Florida Keys increases the known fauna from 30 to 83 species. An annotated list provides data on habitats, collection sites, and location of vouchers. Solenopsis corticalis Forel, Leptothorax torrei (Aguayo) and Monomorium ebeninum Forel are new records for the U.S. The fauna includes 27 exotics and 31 species native to the southeastern Coastal Plain; most of the remaining species are Antillean. There are 2 possibly endemic species. The proportion of known exotics (33%) in the fauna is the highest for any area in the U.S. There is evidence that populations of certain exotics are increasing with increasing disturbance of remaining native habitats. Species diversity in the Keys is probably limited by 1) limited habitat diversity, 2) lack of easy access to the rich ant fauna of the Neotropics, and 3) unsuitability of the climate and habitats for many species found farther north.

AN UPDATED LIST OF FLORIDA ANTS (HYMENOPTERA: FORMICIDAE)

Abstract A list of ants of Florida published in 1989 is replaced to accommodate 49 additional species now known from Florida, and 34 name changes in species already on the 1989 list. Currently, 218 species of ants are reliably reported from Florida.

Necrodols: Anti-insectan terpenes from defensive secretion of carrion beetle (Necrodes surinamensis)

Two compounds recently isolated from the defensive gland ofNecrodes surinamensis, α-and β-necrodol, first representatives of a new category of monoterpenes (the necrodanes), are shown to be repellent to ants and other insects and irritating to cockroaches and flies. The compounds doubtless play a defensive role inNecrodes. The possible long-range applied significance of research on insect repellents is discussed.

North American Lauraceae: Terpenoid Emissions, Relative Attraction and Boring Preferences of Redbay Ambrosia Beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae)

The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were positively correlated with attraction, and EAG analyses confirmed chemoreception of terpenoids by antennal receptors of X. glabratus.

Temporal Analysis of Sesquiterpene Emissions From Manuka and Phoebe Oil Lures and Efficacy for Attraction of Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae)

ABSTRACT Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-borer that vectors the fungal agent (Raffaelea lauricola) responsible for laurel wilt. Laurel wilt has had severe impact on forest ecosystems in the southeastern United States, killing a large proportion of native Persea trees, particularly redbay (P. borbonia) and swampbay (P. palustris), and currently poses an economic threat to avocado (P. americana) in Florida. To control the spread of this lethal disease, effective attractants are needed for early detection of the vector. Two 12-wk field tests were conducted in Florida to evaluate efficacy and longevity of manuka and phoebe oil lures, and to relate captures of X. glabratus to release rates of putative sesquiterpene attractants. Two trap types were also evaluated, Lindgren funnel traps and sticky panel traps. To document lure emissions over time, a separate set of lures was aged outdoors for 12 wk and sampled periodically to quantify volatile sesquiterpenes using super-Q adsorbant and gas chromatography-mass spectroscopy analysis. Phoebe lures captured significantly more X. glabratus than manuka lures, and sticky traps captured more beetles than funnel traps. Phoebe lures captured X. glabratus for 10–12 wk, but field life of manuka lures was 2–3 wk. Emissions of &agr;-copaene, &agr;-humulene, and cadinene were consistently higher from phoebe lures, particularly during the 2–3 wk window when manuka lures lost efficacy, suggesting that these sesquiterpenes are primary kairomones used by host-seeking females. Results indicate that the current monitoring system is suboptimal for early detection of X. glabratus because of rapid depletion of sesquiterpenes from manuka lures.

Brachymyrmex patagonicus (Hymenoptera: Formicidae), an Emerging Pest Species in the Southeastern United States

Abstract Brachymyrmex patagonicus Mayr is a recently introduced species that is well established in the Gulf Coast region of the United States. This species is abundant in Georgia, Florida, Alabama, Mississippi, and Louisiana and has spread into other states. It has become a nuisance pest with occasional large infestations occurring in homes, hospitals, and other businesses. Brief descriptions and illustrations of all castes, biological and economic importance, and known distribution in the United States are given.

ARTHROPOD FOOTPRINTS IN THE SANDS OF TIME

Arthropod distribution in Floridas sandy uplands shows some obvious patterns. Arthropods endemic to Florida scrub are concentrated on the Lake Wales Ridge, apparently a long-term refuge. Scrub areas to the north apparently lost diversity, as some species that must have migrated through there from southwestern North America are now only in southern scrubs. The more recently formed Coastal Ridge was apparently colonized by the remnant fauna of north Florida, not by Lake Wales Ridge species. North Florida scrubs have few known endemics, but there are probably many endemics in sandhill habitats. Expansion and contraction of sandhill areas may explain some faunal patterns. Rapid destruction of Floridas upland habitats demands prompt research.

A preliminary list of the ants of Florida

A list is given of ants known to occur in Florida. Except for widespread species the known distribution by counties is recorded. Species which require further study are listed in an appendix. This list is preliminary to a book which will treat fully the ant fauna of the state.

Xyleborus glabratus, X. affinis, and X. ferrugineus (Coleoptera: Curculionidae: Scolytinae): Electroantennogram Responses to Host-Based Attractants and Temporal Patterns in Host-Seeking Flight

ABSTRACT The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-boring insect that vectors the mycopathogen responsible for laurel wilt, a lethal vascular disease of trees in the Lauraceae, including avocado (Persea americana Mill.). Effective semiochemical-based detection and control programs for X. glabratus will require an understanding of the chemical ecology and host-seeking behaviors of this new invasive pest. This study 1) presents an electroantennography (EAG) method developed for assessment of olfactory responses in ambrosia beetles; 2) uses that new method to quantify EAG responses of X. glabratus, X. affinis, and X. ferrugineus to volatiles from three host-based attractants: manuka oil (essential oil extract from Leptospermum scoparium Forst. & Forst.), phoebe oil (extract from Phoebe porosa Mex.), and wood from silkbay (Persea humilis Nash); and 3) documents temporal differences in host-seeking flight of the sympatric Xyleborus species. Field observations revealed that X. glabratus engages in flight several hours earlier than X. affinis and X. ferrugineus, providing a window for selective capture of the target pest species. In EAG analyses with X. glabratus, antennal response to phoebe oil was equivalent to response to host Persea wood, but EAG response elicited with manuka oil was significantly less. In comparative studies, EAG response of X. glabratus was significantly higher than response of either X. affinis or X. ferrugineus to all three host-based substrates. Future research will use this EAG method to measure olfactory responses to synthetic terpenoids, facilitating identification of the specific kairomones used by X. glabratus for host location.

Student Symposium: Alternatives to Chemical Control of Insects: Pollen-Feeding in Poecilognathus Punctipennis (Diptera: Bombyliidae)

Females of the bombyliid fly Poecilognathus punctipennis (Walker) feed avidly on pollen of Commelina erecta L. and Tradescantia roseolens Small (Commelinaceae). The front tarsi rapidly rake pollen from slits in the sides of the anther and transfer the pollen to the tip of the proboscis. Specialized tarsal hairs may assist in pollen collection. Pollen appears to be mixed with a liquid as it is transported the length of the proboscis. The stomach of pollen-collecting flies is distended with pollen. Pollen was also found in stomachs of females of Geron sp. Several types of evidence suggest that P. punctipennis females are specialized to exploit pollen of Commelinaceae, especially T. roseolens. There is no evidence that the plants have a coevolved symbiosis with the flies.