A two-part study related tree pollen dehiscence and thrips population dynamics in the field, and directly evaluated effects of pine pollen deposition on Frankliniella spp. (Thysanoptera: Thripidae) reproduction on tobacco, Nicotiana tabacum L. (Solanaceae), under laboratory conditions. Ambient pollen and thrips were monitored in Tift County, GA, USA, from early spring to late summer/early fall from 2005 to 2008. Correlation analyses were conducted using weekly means of thrips collected on sticky traps compared to weekly pollen counts from a Burkard air sampler and pollen deposition sheets. There were significant positive correlations between pollen and thrips counts on later dates, suggesting that if a relationship exists between pine pollen dehiscence and thrips population dynamics, it will be delayed. Over all years combined, the first spring time peak in Frankliniella fusca (Hinds) counts on sticky traps occurred at 227 accumulated degree days (dd) after the first peak in pine pollen, approximately the dd required to complete a single F. fusca generation. Two subsequent thrips peaks occurred at approximately one and two F. fusca generations following the first peak. After 10 weeks following the final peak in pollen, there appears to be no more effect of pollen on thrips population dynamics. A tobacco leaf, lightly dusted with Slash pine [Pinus elliottii Engelmann (Pinaceae)] pollen to mimic natural deposition, showed a significant increase in the number of offspring produced per Frankliniella occidentalis (Pergande) and F. fusca female. The total offspring produced increased five-fold in F. fusca and 22-fold in F. occidentalis in 15 days on the pollen-treated leaves over the untreated leaves.

The objective of the test was to determine the efficacy of selected insecticide application techniques for suppressing TSWV symptomatic plants and season-long suppression of TBW and THW population densities on flue-cured tobacco. The trial was conducted at the University of Georgia Bowen Research Farm in Tift County, Georgia. Plots were 3 rows wide (44-in row spacing) by 30 ft long and were separated on each side with an untreated border row and on each end with a fallow alley 6 ft wide. The experiment was designed in a RCB with 13 treatments and 3 replications. The tobacco was transplanted on 14 April into Tift sandy loam soil at a rate of 7000 transplants per acre. A pre-plant application of Prowl and Spartan herbicides and Lorsban Advanced insecticide (for soil insect pest control) was applied several days prior to transplanting. No other pesticides were applied except the selected insecticide treatment options evaluated in this study. The plots were irrigated twice during the season. Plots were periodically inspected for insect pest infestation throughout the season by observing each plant (54 plants per plot) for live insects. The plots were observed weekly for symptomatic TSWV plants, a disease that is vectored by certain thrips species. Forty-eight hours prior to transplanting, five insecticide treatments were applied as tray drench treatments (TD) in the greenhouse using 6.7 oz of water per 242 cell tray and then rinsed off the foliage and into the root zone with water. Four additional insecticide treatments were applied in the transplant water (TPW) in 2 oz of water per transplant (109 gpa). On 18 May and 3 Jun, three foliar insecticide treatments were applied using a CO2 pressurized sprayer with 3 TX-12 nozzles down a single row delivering 22.8 gpa at 40 psi. All plants in each plot (54 plants per plot) were sampled weekly for TSWV symptomatic plants and on 18 and 25 May and 1, 10, and 15 June for TBW and THW densities. The TSWV and insect count data were subjected to ANOVA and means were separated using the Waller-Duncan Kratio t Test at P = 0.05.

come a major new invasive pest species in North America. It was first detected on Wisconsin soybeans during the summer of 2000. By the end of the 2001 growing season, soybean aphid populations were observed from New York westward to Ontario, Canada, the Dakotas, Nebraska and Kansas and southward to Missouri, Kentucky and Virginia. By 2009 it had been detected in most of the soybean-producing states in the U.S. On September 10 and October 1, 2002, during monthly field sampling of soybeans at the Georgia Mountain Research and Education Center in Blairsville, Ga., several small colonies of soybean aphids (eight to 10 aphids per leaf) were collected. Aphid identification was verified by Susan Halbert, Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Gainesville, Fla. Soybean aphids have been observed on soybeans in Union County, Ga., (Blairsville) every year since 2002 and in several other Georgia counties in recent years. The presence of soybean aphids in Georgia represents a new state record for this invasive soybean pest that is being regulated through USDA/APHIS personnel. The source of the initial aphid infestation in North America is not known. This pest is native to China but has spread along the western Pacific and has been reported from Korea to the Philippines. In early 2000, the soybean aphid also was introduced into New South Wales and Queensland, Australia.

Transgenic lines of soybean, Glycine max (L.) Merrill, expressing a synthetic cry 1A gene from Bacillus thuringiensis Berliner (Bt), were evaluated in replicated field trials in 1999–2002 for suppression of lepidopteran pests and the resultant crop injury. Velvetbean caterpillar, Anticarsia gemmatalis Hübner, soybean looper, Pseudoplusia includens (Walker), and green cloverworm, Hypena scabra (F.), population densities were essentially absent throughout the growing season in each year of the study in each of the Bt lines evaluated compared with moderate (5–10 larvae per row-m) to heavy (15–20 larvae per row-m) populations in the isogenic and parental lines serving as soybean controls. Significant A. gemmatalis larval population reductions were observed in the Bt entries compared with the nonBt entries in each year of this study. The P. includens larval densities were significantly lower in Bt entries in the 3 yrs of this study when population densities were abundant, whereas H. scabra were lower in the Bt lines in the 2 yrs of this study when this species was present. Cumulative defoliation in nonBt soybean entries exceeded 95% in some years compared with 0.0–1.6% in the transgenic lines containing Bt. Yields of the transgenic soybean lines were equal to or higher than the non Bt lines examined in each year of this study. It appears that these Bt transgenic soybeans provide superior season-long control of the common lepidopteran pests on soybeans in the southern U.S., resulting in reduced defoliation levels and potentially higher yields compared with equivalent cultivars that lack the Bt trait.

Several transgenic lines of soybean, Glycine max (L.) Merr., expressing a synthetic cry1A gene from Bacillus thuringiensis (Bt), were examined in replicated field trials in 2003-2007 for suppression of naturally occurring population densities of lepidopteran pests and the resultant crop injury that they caused. Bt soybean and negative controls (isogenic segregants and parental lines) were evaluated against velvetbean caterpillar, Anticarsia gemmatalis (Hubner); soybean looper, Pseudoplusia includens (Walker); and green cloverworm, Hypena scabra (F.). Population densities of these lepidopteran species were essentially absent in each of the Bt soybean entries evaluated throughout the growing season in every year of the study compared with moderate (5-10 larvae per row-m) to large (20-30 larvae per row-m) peak population densities in the negative control soybean entries. These lepidopteran populations caused significant plant injury in the non-Bt soybean plots, ranging from 53% defoliation in 2003 to 17.5% in 2007, compared with <1.5% defoliation (mostly 0.0% defoliation) in the Bt soybean plots. When two or three foliar insecticides were applied in August or September, as lepidopteran populations approached or exceeded economic threshold levels, pest populations were suppressed and defoliation was minimal in the treated non-Bt entries similar to results in Bt soybean. Soybean 100-seed weights and harvested yields were similar between the Bt and non-Bt entries each year of this study. It seems that Bt transgenic soybean provides excellent season-long control of lepidopteran pests and have yields equal to the standard cultivars examined in this study. Once available to producers, this Bt technology has the potential to provide an effective insect pest management option similar to that being used in Bt cotton, Gossypium hirsutum L., and Bt corn, Zea mays L., and enhance the sustainability and profitability of soybean production in the southern region where lepidopteran pests cause annual economic losses to the crop.

A study was conducted to correlate tree pollen dehiscence and thrips population dynamics in the field. Ambient pollen and thrips trap count data were collected in Tift Co., Georgia, USA, from early spring to late summer/early fall in 2005, 2006, 2007 and 2008. Correlation analyses were conducted by year, as well as for overall years combined using weekly means of pollen and thrips from the same week, or one-, two-, three-, fourand five-weeks offset with the pollen week advancing while the thrips week remained stationary. With the exception of 2006, analyses suggested a significant positive correlation between pollen and thrips counts. Correlations varied in strength depending on the weekly data alignment and year. Significant, positive correlations occurred after a two-week time lag in 2005, a one-to-two-week offset in 2007, and a two-to-four-week offset in 2008. Results overall showed a positive correlation between pollen and thrips counts after a two week offset, i.e. thrips populations increased two weeks following an increase in pollen dehiscence. Introduction Thrips populations are known to fluctuate seasonally, presumably in reaction to changing host availability, temperatures and other factors (Lewis 1973). Two important crop pests in the southeastern USA that exhibits seasonal population fluctuations are the tobacco thrips (Frankliniella fusca (Hinds)) and western flower thrips (Frankliniella occidentalis (Pergande)). Tobacco thrips populations increase significantly in the spring, peaking sometime in April to June (Riley and Pappu 2000, Groves et al. 2003, Riley and Pappu 2004). Some seasonal factors referenced as inducing changes in thrips populations include temperature (Lowry et al. 1992), photoperiod (Whittaker and Kirk 2004, Chaisuekul and Riley 2005), humidity (Kirk 1997), and availability of nutritious hosts for food and oviposition (Lewis 1973, Mound and Teulon 1995).

A series of replicated field experiments was conducted with vegetable soybean (edamame), Glycine max (L.) Merrill, to assess the impacts of cultivars, planting dates, and insecticidal controls on insect pest abundance, crop damage and yield potential. The velvetbean caterpillar, Anticarsia gemmatalis Hübner, was the most common lepidopteran defoliator in this study, causing heavy defoliation in some years when left untreated. Other lepidopterans observed included the soybean looper, Pseudoplusia includens (Walker), and the green cloverworm, Hypena scabra (F.). Stink bugs, primarily the southern green stink bug, Nezara viridula (L.), also caused seed damage in some cultivars when left untreated. Stink bug damage exceeded expectations on edamame seeds when exposed to moderate stink bug densities (≤3 bugs per 25 sweeps). Other arthropods that were commonly observed included threecornered alfalfa hoppers, Spissistilus festinus (Say), grasshoppers, Melanoplus spp., and the potato leafhopper, Empoasca fabae (Harris). Arthropod infestations on edamame were similar to reported pest problems on conventional soybeans being produced for oil and meal. Midseason applications of the insecticides diflubenzuron plus l-cyhalothrin reduced insect pest populations, percentage of arthropod-induced defoliation and percentage of seeds damaged by stink bugs, but had little effect on edamame yields. Most defoliation and seed damage occurred during R5 development when seeds were approaching full size, thus only minimal yield reductions were noted. However, seed quality of the untreated vegetable soybeans would be unacceptable for the consumer. Total fresh green yields ranged from 2343–11,895 kg ha−1, depending on year, cultivar and planting date, whereas fresh green seed yields ranged from 1208–6,119 kg ha−1. Early-maturing edamame cultivars planted in April had fewer insect pests and less damage than the cultivars planted later. Avoidance of insect pests is an important production consideration for insect management, especially critical in an organic production system. The fresh green seed yields produced during this study demonstrate that this emerging alternative crop has the potential for economic success in the southern region, assuming that the arthropod pests are effectively managed to maintain acceptable edamame quality and yield.

Two soybean varieties (an early-maturing Group V and a later-maturing Group VII) and two cotton varieties (a conventional and a transgenic Bacillus thuringiensis Berliner [Bt]) were grown in adjacent replicated large field plots at two locations for 3 growing seasons. The abundance of commonly-observed lepidopteran pests within these two crops was observed weekly throughout each growing season. The green cloverworm, Hypena scabra (F.); soybean looper, Pseudoplusia includens (Walker), and; velvetbean caterpillar, Anticarsia gemmatalis Hubner, preferred soybeans over cotton at all six test sites. The bollworm complex, Helicoverpa zea (Boddie) and Heliothis virescens (F.), preferred soybeans at one site, cotton at two sites, and no crop preference at three sites. There was no difference in the seasonal mean abundance of the pests between the two soybean maturity groups. A few varietal differences were noted on soybeans on specific sampling dates; however, they occurred when insect numbers were low. Populatio...

Sixty-five soybean, Glycine max (L.) Merr., breeding lines containing the stink bug resistant 'IAC-100' in their pedigrees were evaluated for their resistance to stink bug, primarily southern green stink bug, Nezara viridula L., feeding in replicated field trials from 2001 to 2005. Plots were sampled throughout the season for stink bug abundance, and, at harvest, seed samples were rated for stink bug-induced kernel damage. Individual seeds were categorized as having none, light, moderate, or heavy damage plus 100-seed wt and plot yields were determined. Both ground cloth and sweep net sampling procedures were used to compare stink bug densities between the soybean entries. Stink bug densities varied between years; however, in the years when populations exceeded four per row-meter or six per 25 sweeps, there were more damaged soybean seeds (>25%) in the entries with higher stink bug numbers. During the first 2 yr of evaluations, the mean stink bug-damaged soybean seeds ranged from 10.0 to 38.2%. From these differential responses, 28 entries were selected for continued study in 2003-2004. In 2003, stink bug-damaged soybean seeds were low, with damage ranging from 2.9 to 18.2%. In 2004, stink bug damage ranged from 8.8 to 53.2%. From these 28 lines, 12 entries were selected for an advanced field screening trial in 2005, including the IAC-100 and 'Hutcheson'. Damaged soybean seeds ranged from 18.5 to 54.1% among these 12 entries in 2005, under heavy stink bug pressure. From these evaluations, four breeding lines with either Hutcheson X IAC-100 or IAC-100 x 'V71-370' in their genealogy were identified as possible breeding material for future soybean stink bug resistance cultivar development.

Sixty-five soybean, Glycine max (L.) Merrill, breeding lines containing 'IAC-100' in their pedigrees were evaluated for their resistance to lepidopteran defoliation in replicated field trials during 2001-2005. Three soybean cultivars, IAC-100 (with resistance to stink bug [Hemiptera: Pentatomidael feeding), 'Dillon', and 'Hutcheson', also were included in the evaluations. The percentage defoliation among these 68 entries ranged from 4.3 to 28.3% in 2001 and from 35.0 to 99.0% in 2002. Lepidopteran caterpillars, primarily Anticarsia gemmatalis Hiibner, but also some Pseudoplusia includens (Walker) and Hypena scabra (F.), peaked at 14.3 per row-meter on 11 September 2001 and at 39.7 per row-meter on 22 August 2002. Twenty-six entries with better resistance potential, plus two cultivars, were selected for continued evaluations in 2003 and 2004. Defoliation ranged from 23.3 to 56.7% among the 28 entries in 2003 and from 16.3 to 42.5% in 2004, with peak caterpillar densities of 20.3 per row-meter on 17 September 2003 and 14.5 per row-meter on 8 September 2004. From these differential responses, 12 entries were included for advanced resistance evaluations in 2005. The breeding line entries 52 (IAC-100 X V89-1301), 23 (IAC-100 X V89-1301), and 14 (IAC-100 X V71-370), plus entry 37 (IAC-100) had lower defoliation rankings during all 5 yr of this study, with the entry having the lowest defoliation ranked 1 and the entry with highest defoliation ranked either 68, 28, or 12, based on the number of entries evaluated each year. The overall mean rankings of these four entries over the 5 yr of this study were 4.4, 3.0, 4.2, and 4.6, respectively. A fifth entry, 30 (IAC-100 x V71-370), was in the top group with lower defoliation in 4 yr of this 5-yr study, and it had an overall mean ranking of 5.6. A sixth entry, 35 (Hutcheson X IAC-100), had moderate resistance (overall ranking of 19.2) compared with the standard Hutcheson (30.8 ranking of a possible highest ranking of 40.8). Entry 35 also yielded as well as the standard cultivars evaluated in the study. These lines will provide excellent sources for future soybean germplasm and varietal resistance development.

The thrips-borne tomato spotted wilt tospovirus is a serious economic threat to Georgia's flue-cured tobacco crop. Two thrips vectors, Frankliniella fusca (Hinds) and F. occidentalis (Pergande), are commonly encountered on tobacco foliage and blooms, respectively. Yellow sticky traps were monitored after a 48-h field exposure from March through June in 2003–2005 to assess thrips movement and species composition in the tobacco farm scape. During March each year there were similar numbers of F. fusca and the flower thrips complex [F.occidentalis, F. tritici (Fitch) and F. bispinosa (Morgan), combined] captured on sticky cards. During April, May and June, the flower thrips complex steadily became more abundant comprising around 60, 70, and 95% of the trap capture, respectively. Thrips vector species were captured throughout the entire sampling period. In April and May, F. fusca captures on stick traps related to F. fusca population densities on tobacco foliage. Some sampling periods had differences in thrips captures relative to a north, south, east, or west orientation, with each direction having the highest thrips numbers at least once each season. However, the overall seasonal mean capture was higher on the eastward direction all 3 yrs and on the westward direction on 2 of the 3 yrs, compared to the southern and northern directions. In a time-of-day study, very few thrips were captured between 1830 h and 0,700 h the following morning. Thrips movement increased in midmorning and peaked during midafternoon. It appears that sticky cards can be used to monitor early colonization of thrips species in tobacco fields plus monitor thrips movement throughout the day, thus providing information on when potential vectors arrive and move within the field. Sticky trap monitoring provides an alternative to direct plant observation for predicting thrips abundance on tobacco foliage and the need for thrips controls.

The relative impacts of early season thrips exclusion (cages) and thrips suppression (pesticides) on tomato spotted wilt (family Bunyaviridae, genus Tospovirus, TSW) Tospovirus infection in flue-cured tobacco, Nicotiana tobaccum L., were examined in field trials in 2001-2004. There were fewer TSW symptomatic plants when plants were covered by exclusion cages for 6 wk than when they were uncaged or caged for 2 or 4 wk after transplanting. Plant height, leaves per plant, and total leaf weight per plant were lower in TSW symptomatic plants compared with nonsymptomatic plants for the uncaged plus 2- and 4-wk caged duration treatments but not different when caged 6 wk. Weekly acephate (Orthene) foliar sprays for 2 or 4 wk after transplanting reduced thrips populations for up to 5 wk after transplanting, whereas the 6-wk sprays had lower thrips populations for up to 8 wk. TSW was lower in both the 4- and 6-wk acephate treatments than in the untreated. A tray drench application of imidacloprid (Admire) reduced thrips populations in early season plus lowered the percentage of TSW compared with no tray drench treatment. The tobacco thrips, Frankliniella fusca (Hinds), was the predominate thrips species on tobacco foliage, and 1.9-4.9% tested positive for nonstructural TSW protein. The imidacloprid tray drench treatment and 6-wk acephate foliar sprays had lower densities of the tobacco-adapted form of Myzus persicae (Sulzer). Suppressing early season thrips populations with foliar acephate or imidacloprid tray drench are management option that can effectively reduce the incidence of TSW in flue-cured tobacco plus suppress aphids.

The red imported fire ant, Solenopsis invicta Buren, has been reported to contribute to the biological control of key arthropod pests in soybean, Glycine max (L.) Merrill, and other crops. Solenopsis invicta also has been implicated as a major disrupter of biological control and a direct crop pest associated with reduced yields. In 2000 and 2001, fire ant foraging, survival of sentinel lepidopteran eggs and pupae, seasonal abundance of common foliage-dwelling soybean arthropods, and crop yield were assessed under three different fire ant suppression treatments at two test sites in Tift Co., GA. The treatments included an untreated control, hydramethylnon ant bait, and hydramethylnon bait in combination with the broad spectrum insecticide chlorpyriphos. Fire ant foraging was reduced in the chemically-treated plots in comparison to the control, based on fire ant numbers on hot dog baits after a 1-h field exposure in the early morning. Survival of soybean looper, Pseudoplusia includens Walker, eggs in 2000 and corn earworm, Helicoverpa zea Boddie, eggs in 2001 was lower in the untreated plots after a 24-h field exposure, where S. invicta foraging rates were high. Soybean looper pupal survival was 34 and 88% lower on foliage and the ground, respectively, in the control compared to those with reduced fire ant foraging. The seasonal abundance of foliage-dwelling soybean arthropods was primarily unaffected by the fire ant suppressing treatments. However, in 2001, green cloverworms, Hypena scabra F., and spiders were significantly lower (38.6 and 40.5%, respectively) in the chlorpyriphos plus hydramethylnon bait treatment in comparison to the other treatments. Season-long suppression of fire ants had no effect on soybean yield. The results of this study suggest that S. invicta, at naturally-occurring levels, is an active predator on some common soybean lepidopteran pests.