Ground-dwelling ants (Hymenoptera: Formicidae) were sampled at 29 sites in 26 counties in Georgia with pitfall traps, leaf litter extraction, visual searching, and bait stations. We found 96 ant taxa including nine species not previously reported from Georgia: Myrmica americana Weber, M. pinetorum Wheeler, M. punctiventris Roger, M. spatulata Smith, Pyramica wrayi (Brown), Stenamma brevicorne (Mayr), S. diecki Emery, S. impar Forel, and S. schmitti Wheeler, as well as three apparently undescribed species (Myrmica sp. and two Stenamma spp.). Combined with previous published records and museum records, we increased the total number of ground-dwelling ants known from Georgia to 144 taxa.

The effect of drought stress on the resistance of sweetpotato roots to sweetpotato weevil (SPW), Cylas formicarius (Fab.), was studied in 1997 and 1998 in two genotypes (“Beauregard” and “Excel”) with different SPW susceptibility. Storage roots produced under drought or normal conditions were tested for adult feeding, oviposition, larval survival and pupal weight in the laboratory under no-choice and free-choice test conditions. The levels of sweetpotato resin glycoside and caffeic acid in the periderm tissue of the roots were also determined. Drought-stressed roots received significantly more SPW eggs under no-choice and free-choice conditions and more feeding punctures under free-choice conditions than non-stressed roots in 1997. Larval survival rate was significantly lower on drought-stressed roots. A significant drought effect on feeding, oviposition and larval survival was absent in 1998. Drought stress had no effect on sweetpotato resin glycosides content in both years, but significantly reduced the content of caffeic acid in 1997. Genotype had a significant effect on SPW feeding in 1997 and on feeding and oviposition in 1998 under free-choice test conditions, where Beauregard was preferred for both feeding and oviposition. Beauregard also supported a significantly higher larval survival rate compared with Excel. Resin glycosides or caffeic acid contents were similar for the two genotypes in 1997, while higher level of resin glycosides was detected in Excel than in Beauregard in 1998. The interaction between drought stress and genotype was significant for adult feeding under free-choice conditions and for larval survival, indicating a different response between the two genotypes.

A survey for parasitoids of the whiteflies, Bemisia tuberculata Bondar, Trialeurodes variabilis Quantaince, T. vaporariorum (Westwood), Aleurotrachelus socialis Bondar, Tetraleurodes sp., Aleuroglandulus malangae Russell and Aleurodicus sp., was conducted in 6 cassava growing regions of Colombia and Ecuador. In Colombia, the degree of infestation was predominantly high (>29 whiteflies/cm²) for A. socialis, B. tuberculata and T. variabilis in all cassava growing regions. In Ecuador, levels of infestations were high for Aleurodicus sp., A. socialis, B. tuberculata, Tetraleurodes sp. in the coastal region, and for T. vaporariorum in the Highlands. The parasitoid fauna of the whiteflies appeared to be more diverse in Colombia than in Ecuador. Eleven species of parasitoids representing 5 genera, 4 families and two superfamilies, as well as 1 hyperparasitoid, were collected from the cassava growing regions of Colombia and 4 species were collected from Ecuador. The parasitoids, Amitus macgowni Evans and Castillo, Encarsia sp., E. hispida De Santis, E. pergandiella Howard, E. bellottii Evans and Castillo, E. luteola group, E. sophia (Girault and Dodd), E. strenua group, Eretmocerus sp., Metaphycus sp. and Euderomphale sp., were collected. There were notable differences in parasitism among the different geographic regions and whitefly species. In general, Eretmocerus was the dominant genus in Colombia and Ecuador, followed by Encarsia sp. We found A. macgowni in regions characterized by high temperatures and bimodal rainfall. Percent parasitism per region surveyed ranged from 3 to 25% in Colombia and from 12 to 21% in Ecuador.

Phymastichus coffea (LaSalle) is an African parasitoid of adults of the coffee berry borer Hypothenemus hampei (Ferrari) that has been introduced to Mexico and other Central and South American countries for the biological control of this important pest. The present study assessed the host specificity of this parasitoid in the laboratory. We tested the acceptance and parasitism of P. coffea on five species of bark beetle adults commonly found in coffee plantations of Mexico: Hypothenemus crudiae, H. plumeriae, H. eruditus, Scolytodes borealis and Araptus fossifrons. As a control, we used adults of H. hampei‘ the natural host. P. coffea parasitized and successfully completed its life cycle in H. crudiae and H. eruditus, as well as in H. hampei. The degree to which bark beetles were attacked by P. coffea was estimated by percent of parasitism, which was 64% for H. hampei, 14% for H. crudiae, and 6% for H. eruditus. The risk of potential deleterious effects of the parasitoid on non-target organisms in coffee agroecosystems is discussed.

The final instars of Eurytoma nodularis and E. heriadi are described and illustrated. Morphological structures of diagnostic value are discussed. The most salient character shown by the mature larvae of these two species lies in the mandibles, which are simple (unidentate), a feature that, according to current knowledge, is only shared with E. verticillata.

Eretmocerus rui n. sp. imported from Hong Kong and released against Bemisia (tabaci group) in Florida is described. This thelytokous species was recovered after release, but it is unknown if it is established in Florida.

Four commercial sex pheromones and virgin females were tested as attractants for male fall armyworm (FAW), Spodoptera frugiperda with Scentry Heliothis traps in sorghum fields in Chiapas, Mexico. We observed significant differences among the lures tested. Pherotech, virgin females, and Scentry lures elicited different responses from Chemtica and Trece lures. In another experiment performed in Michoacán, Mexico, we found that Scentry Heliothis traps baited with Chemtica lures placed at 1.5 m above ground caught significantly more males than traps placed at a height of 2 m. In contrast, the capture of S. frugiperda males with bucket traps placed at 1 m height was not significantly different from that of traps placed at 1.5 and 2 m height. When baited with pheromone, Scentry Heliothis traps caught more non-target insects than bucket traps. Apidae was the most prevalent family of non-target insects caught in both experiments.

Traps in field plots assessed attraction of the cabbage looper moth, Trichoplusia ni (Hübner), to lures emitting synthetic chemicals identified as the pheromone of the male; linalool, p-cresol and m-cresol. Male and female cabbage looper moths were captured in traps baited with racemic linalool, but significantly greater numbers of both sexes were captured in traps baited with the 3-component blend. Virgin and mated female cabbage looper moths were captured, with up to 5 spermatophores per female in mated ones. Pheromone was dispensed from polypropylene vials, and numbers of moths captured in traps increased with the size of the hole in the vial lid, up to the maximum 25-mm diameter hole tested. Rates of release of pheromone from vials with 25-mm diameter holes in the laboratory decreased from 4 to 3 milligrams per h over a four-week duration. This is the first evidence in the field of cabbage looper response to the chemicals identified as pheromones of the male.

After a nematode application, mole crickets (Orthoptera: Gryllotalpidae: Scapteriscus spp.) are frequently assayed to confirm nematode establishment and infectivity. However, the standard soap flush was suspected of providing false negatives under field conditions. Thus, we examined the effect of several potential flushing solutions on the survival and infectivity of Steinernema scapterisci Nguyen and Smart (Nematoda: Steinernematidae) as well as flushing ability under field conditions. Seventy percent of S. scapterisci died in lemon dish detergent solution, confirming that assays for nematode infection of soap-flushed mole crickets are likely to be inaccurate. When sampling for mole crickets in areas where S. scapterisci has been applied, a potential alternative to the standard soap drench is a dilute permethrin drench.

Antrusa curtitempus, Chorebus liliputanus, C. propediremptum, and C. vicinus, four new species of Dacnusini from the Iberian Peninsula, are described, illustrated, and compared with allied species. Keys for their discrimination are provided. The taxonomic rehabilitation of the genus Antrusa is proposed.

The influence of Ischnodemus variegatus feeding on photosynthesis and growth of the invasive semi-aquatic grass, Hymenachne amplexicaulis, was investigated in field and greenhouse environments. In the field, carbon dioxide assimilation of infested plants was approximately 35% less than that of non-infested plants, and the rate of assimilation was related to I. variegatus density. The relative growth rate of infested plants in the greenhouse was 77% of that of non-infested plants, and biomass of infested plants was significantly less than for non-infested plants 79 days after infestation. The value of I. variegatus as a fortuitous biological control agent of H. amplexicaulis is discussed.

In California U.S.A., 238 named species of the insect Order Thysanoptera, in 87 genera and eight families, are listed as having been found in this state. Inspection of museum collections indicates many undescribed species of thrips exist. Little is known of the host plants of native California thrips species, due to imprecise collecting methods such as sweep netting swaths of mixed vegetation. At least 40 (∼17%) of the listed species in California are introduced from other parts of the world. Two terebrantian families (Adiheterothripidae and Fauriellidae), and one genus (Orothrips) in a third terebrantian family (Aeolothripidae), have a remarkably disjunct distribution between California and the European Mediterranean region.

Laboratory bioassays enabled us to determine the mortality of Argentine ant (Linepithema humile [Mayr]) workers, and red imported fire ant (Solenopsis invicta Buren) workers exposed to sodium hydrogen carbonate (NaHCO₃, sodium bicarbonate). The median lethal concentration (LC₅₀) of NaHCO₃ for Argentine ants was 5.64 mg per cm² after 5 d exposure and 3.96 mg per cm² after 6 d. Cumulative mortality for Argentine ants exposed to 28 mg NaHCO₃ per cm² was 89.5% on day 6. Workers of both species were exposed to concentrations of 9.92, 17.70, or 152.00 mg NaHCO₃ per cm² in separate tests. Mortality of Argentine ants was significantly higher than that of fire ants following exposure to 9.92 mg NaHCO₃ per cm², while mortality for the two species did not differ following exposure to the two higher concentrations. Mortality of both species treated with the highest concentration exceeded 99% at 6 d. In tests with equivalent amounts of sodium in NaHCO₃ and NaCl treatments, mortality for fire ants exposed to NaHCO₃ was about 46% after 6 d. Mortality for fire ants exposed to NaCl was about 15% and was similar to that for untreated ants. Argentine ants were provided sugar water baits containing a range of NaHCO₃ concentrations. Argentine ant mortality after 6 d exposure to 5% NaHCO₃-sugar water treatment was about 50%. Mortality was not higher for workers exposed to higher concentrations of NaHCO₃ in sugar water baits. Enzymatic dysfunction caused by unfavorable increases in internal pH is the most likely explanation for worker mortality following exposure to NaHCO₃.

The Asian citrus psyllid, Diaphorina citri Kuwayama, was discovered in Florida in 1998. It can be one of the most serious pests of citrus if the pathogens that cause citrus greening disease (huanglongbing) are present. Citrus greening recently has been reported in Brazil by Fundecitrus, Brazil. The establishment of D. citri in Florida increases the possibility that the disease may become established. Diaphorina citri can be separated from about 13 other species of psyllids reported on citrus. The biology of D. citri makes it ideally suited to the Florida climate. Only two species, D. citri and Trioza erytreae (del Guercio), have been implicated in spread of citrus greening, a disease caused by highly fastidious phloem-inhabiting bacteria. The disease is characterized by blotchy mottle on the leaves, and misshapen, poorly colored off-tasting fruit. In areas where the disease is endemic, citrus trees may live for only 5-8 years and never bear usable fruit. The disease occurs throughout much of Asia and Africa south of the Sahara Desert, on several small islands in the Indian Ocean, and in the Saudi Arabian Peninsula. Transmission of citrus greening occurs primarily via infective citrus psyllids and grafting. It is transmissible experimentally through dodder and might be transmitted by seed from infected plants and transovarially in psyllid vectors. Citrus greening disease is restricted to Citrus and close citrus relatives because of the narrow host range of the psyllid vectors. Management of citrus greening disease is difficult and requires an integrated approach including use of clean stock, elimination of inoculum via voluntary and regulatory means, use of pesticides to control psyllid vectors in the citrus crop, and biological control of psyllid vectors in non-crop reservoirs. There is no place in the world where citrus greening disease occurs that it is under completely successful management. Eradication of citrus greening disease may be possible if it is detected early. Research is needed on rapid and robust diagnosis, disease epidemiology, and psyllid vector control.

Application of bait spray to non-host sorghum plants bordering host plants of melon flies, Bactrocera cucurbitae Coquillet, is a common practice for melon fly control in Hawaii. In a field study conducted in 2003 in Hawaii, we first asked whether GF-120 Fruit Fly bait spray applied to sorghum plants that bordered only two (opposite) sides of a patch of cucumbers was as effective in protecting cucumbers against melon flies as similar spray applied to sorghum plants that bordered all four sides of a cucumber patch. Second, we asked whether mature melon fly females carrying a high egg load but deprived of protein during the previous 24 h were more responsive to bait spray than mature females having continuous access to protein. Color-marked melon fly females were released outside of patches of sorghum-bordered cucumbers. We found no significant differences between two-sided and four-sided patches of sorghum or between protein-deprived (for 24 h) and protein-fed (continuously) mature females in percentages of released females that found cucumbers in bait-sprayed plots. Moreover, none of these percentages was significantly less than percentages of released females that found cucumbers in unsprayed plots, indicating an overall ineffectiveness of bait spray application. During the 24 h after alighting on cucumbers, released females that were captured alive on cucumbers and placed in cups with cucumbers laid on average almost as many eggs (insignificantly fewer) when taken from bait-sprayed plots as when taken from unsprayed plots. An overriding factor may have been the presence of just a narrow swath of sorghum (arising from a single row of plants), which may have permitted females easy access to cucumbers and masked potential differences among treatments. Bait spray applied to broader swaths of sorghum may be more effective.

Larval tissues of Anastrepha suspensa (Loew) (Diptera: Tephritidae) were examined to determine the optimal tissue and stage for chromosomal preparations and to determine the karyotype. Tissues were dissected in saline, stained in 2% aceto-orcein for 45 minutes, and squashed on a coverglass by thumb pressure. The compound eye imaginal discs from 6-day-old larvae yielded the best preparations of dividing cells. Mitotic figures also can be obtained from larval brain tissue, ventral nerve cord, and leg imaginal discs. In larvae 6 days old, many cells in the tissues examined were dividing. Cell division appears to be synchronized in the different tissues examined, with most cells in interphase or dividing at the same time during all instars. The male is heterogametic (XY) and the female is homogametic (XX). The chromosome number is 12 (10 autosomes XX or XY). There are 3 pairs of subtelocentric and 2 pairs of submetacentric chromosomes. The X chromosome is subtelocentric and the Y chromosome is submetacentric. The two X chromosomes tend not to pair like the other chromosomes, and in males the Y chromosome often sticks to the short arm of the X chromosome.

Two new members of the widespread Neotropical genus Zammara Amyot & Serville, Zammara olivacea n.sp. from Columbia and Zammara medialinea n.sp. from Venezuela are described.

Xylem-feeding leafhoppers have evolved several behavioral and physiological adaptations to utilize xylem fluid of variable composition, including polyphagy and high assimilation efficiency. They also display high vagility coupled with excellent visual acuity. We investigated the spectral frequency responses of the nymphal stages of three leafhopper species: Homalodisca coagulata, H. insolita, and Oncometopia nigricans. Under laboratory conditions, the nymphs of H. coagulata and O. nigricans discriminated spectra and were highly attracted to hues of yellow, with safety yellow being the most attractive. The nymphs of H. insolita were also attracted to yellow hues, but were more attracted to cream yellow. In the laboratory, maximum jumping distances of third instar H. coagulata, H. insolita, and O. nigricans were 68.0, 49.7, and 39.2 cm respectively, when provided a target. The fifth instars of H. coagulata, H. insolita, and O. nigricans had maximum jumping distances of 78.8, 29.2, and 45.5 cm, respectively. Additionally, all nymphal stages of H. coagulata dispersed up to 10 meters after three days under field conditions when released into an outdoor grass-covered arena. The neonates of H. coagulata, H. insolita, and O. nigricans survived on average, 83.5, 70.5, and 83.0 h without plant feeding, respectively.

A new species of mydas fly, Nemomydas dominicanus is described from two males collected from the Dominican Republic, the first record of this genus from Hispaniola. A new record for Baliomydas cubanus (Curran) is noted for the Dominican Republic.