Larvae of the Southern pine coneworm, Dioryctria amatella (Hulst) (Lepidoptera: Pyralidae), were collected monthly during the growing seasons of 1996 and 1997 from loblolly pine, Pinus taeda L., seed orchards in Alabama, Florida, Georgia, South Carolina, and Virginia, and examined for pathogenic microorganisms. One fungus, Beauveria bassiana (Bals.) Vuill, a granulosis virus (Baculoviridae: Eubaculovirinae), and a protozoan (phylum Microspora) were found. Five larvae from three localities were infected with B. bassiana, 37 larvae from six localities were infected with the granulosis virus, and 69 larvae from 5 locations were infected with the microsporidian. Laboratory trials confirmed that B. bassiana and the granulosis virus caused coneworm mortality. B. bassiana isolates from all three locations were equally virulent to late instar larvae. Spores of the unidentified microsporidian are free, elongate oval, binucleate and contain 13-14 turns of an isofilar polar filament. The primary sites of infection were the Malpighian tubules and the silk glands. The microsporidian was found in 2 to 51% of larvae sampled. It caused 100% mortality in early instar larvae allowed to feed on artificial diet contaminated with 3 × 10³ or 4.5 × 10³ spores. More work is needed to determine the importance of these pathogens in regulating populations of southern pine coneworms or their potential utility in an IPM program.

Liriomyza trifolii (Burgess) is an important leafmining pest of numerous ornamental and vegetable crops. The pest is attacked by many species of parasitoids which inflict heavy mortality in the absence of insecticides. The functional response, as well as parasitoid-induced mortality, of one major parasitoid, Diglyphus intermedius (Girault), was estimated over a range of densities of third instar L. trifolii at 25-27°C in the laboratory. The functional response of D. intermedius was given by the equation Y = Kp·n₂·(1-exp(-n₁/Kh)) where Y, the rate of parasitism, is the number of hosts parasitized per day; Kp is a constant of 7.3908 hosts parasitized per parasitoid-day; n₁ and n₂ are the densities of leafminer larvae and parasitoid adults (numbers/cm² leaf area), respectively, and Kh is a constant of 0.0144 leafminer larvae/cm² leaf area. The relationship between host and parasitoid density and parasitoid-induced host mortality was given by Z = Cp·n₂·(1-exp(-n₁/Ch)) where Z, the rate of parasitoid-induced mortality, is the number of leafminer larvae killed per day; Cp is a constant of 9.2064 hosts killed per parasitoid-day and Ch is a constant of 0.0165 leafminer larvae/cm² leaf area. The observed rate of parasitism at a particular parasitoid density was always lower than the observed rate of parasitoid-induced host mortality at that density. Lower leafminer larval densities resulted in increased multiple oviposition by D. intermedius. When eggs of the parasitoid were placed at increasing densities on leafminer larvae in artificial mines, the number of parasitoid eggs surviving to adulthood decreased while the number of individuals surviving per host tended to remain at about one.

Studies were conducted during 1996-1999 to evaluate damage to citrus leaves by the Texas citrus mite, Eutetranychus banksi(McGregor), and its impact on leaf longevity in irrigated citrus. Natural mite infestations were followed in a citrus orchard (‘Rhode Red Valencia’) under irrigation management, and damage to leaves and leaf abscission were assessed periodically. The number of feeding stipples per cm² on the upper leaf surface was used as an index of feeding damage. A variable ‘mite-days’ [average number of mites per leaf multiplied by the number of days of infestation] was used to characterize infestation densities over time. Increases in average numbers of stipples per cm² per leaf (Y) across different mite-day values (X) were described by the equation Y = 44.08 0.59X (r²= 0.57). A model including temperature was marginally better. The final mean density of feeding stipples on infested leaves for the 1996, 1998 and 1999 evaluation periods averaged 327, 134 and 873 per cm², respectively, with an overall mean of 470. Leaf life from the date of full expansion until abscission averaged 443, 387 and 380 days for the respective periods, with an overall average of 399 days. The observed life of the leaves was typical to what has been observed in Florida citrus. Overall, no significant negative relationship was found between leaf life and mite damage. The study indicated that damage by Texas citrus mites to ‘Valencia’ citrus leaves promoted little or no premature leaf abscission in irrigated trees.

The mating behavior of sterile, laboratory-reared, male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), was evaluated in field-cage mating competition tests with wild flies after exposing the laboratory males to ginger root oil extract. Without exposure to ginger root oil, sterile males obtained 12.6%, 69.0%, and 72.8% of the total matings with wild females when present in 1:1, 5:1, and 10:1 ratios of sterile males to wild males, respectively. Sterile males, exposed to ginger root oil for 3 h, 1 d before mating trials, in a 1:1 ratio with wild males, achieved 62.3% of the matings with wild females. These data suggest that exposure to ginger oil can elevate sterile male mating competitiveness to a similar degree as elevated ratios of sterile to wild males. Incorporating the use of ginger root oil extract into sterile release programs may thus increase the effectiveness of the sterile insect technique, and/or allow a reduction in the number of sterile flies that are released.

The seasonal abundance of various life stages of Diaprepes abbreviatus (L.), was monitored in separate years in adjacent irrigated and non-irrigated citrus plantings, as well as thickets of Brazilian-pepper located near Poinciana, FL in Osceola County. Adult emergence, estimated by weekly catches in cone-shaped ground traps, occurred throughout the year with a peak in mid-June in both citrus and Brazilian-pepper plantings. Onset of adult emergence coincided with an increase in soil moisture and temperature. Trap counts were highest when soil water potential increased to 3-5 centibars at a depth of 15-30 cm and soil temperature averaged 22-24EC. In the non-irrigated citrus planting, the adult emergence peak was of shorter duration, but of greater magnitude, compared to the irrigated planting. Although the alternate host, Brazilian-pepper, produced fewer weevils than did citrus, the seasonal emergence pattern was virtually the same.

Adult abundance within the citrus plantings was also monitored weekly using modified Tedders traps. The number of adults captured approximated the number caught in ground traps. Adult number caught weekly changed seasonally, particularly in the fall when adult populations were the highest. Ground traps caught a larger number of adults in the spring. The number of egg masses collected weekly in the tree canopy and the number of neonates caught weekly beneath the tree canopy were both correlated with the number of adults captured weekly in modified Tedders traps. These data suggest that adults caught in modified Tedders traps provide a reliable indicator for estimating the seasonal abundance of all life stages within a citrus planting. Larvae of different instars, pupae, and teneral adults were recovered from the soil rhizosphere after periodic tree removal. No diseased or parasitized life stages were observed in the study. Most life stages were present in the soil at each sample date, but the proportion of larvae in various instars changed seasonally. The implications of this study for understanding the population dynamics of D. abbreviatus are discussed in relation to current and future IPM strategies.

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.

Arthropod ground predators were sampled with pitfall traps in Florida sugarcane fields. More red imported fire ants, Solenopsis invicta Buren, were caught in pitfall traps than all other predators combined. Sugarcane harvesting did not affect pitfall trap catches of arthropod ground predators. However, replanting reduced arthropod catches for five to six months. These data show that for most of its three to five year crop cycle, Florida sugarcane is a stable ecosystem at ground level for arthropod ground predators.

Fopius ceratitivorus Wharton is a recently discovered braconid parasitoid of the Mediterranean fruit fly (= medfly), Ceratitis capitata (Wied.). Unlike other parasitoids previously used in medfly biological control, F. ceratitivorus was originally collected from medfly in its purported region of origin, east Africa. Shipments of Ceratitis spp. pupae from Kenya to a newly constructed quarantine facility in Guatemala yielded both F. ceratitivorus and its congener F. caudatus (Szèpligeti). Only the former species was successfully colonized through the use of medfly infested coffee berries. In the process of colonization it was determined that F. ceratitivorus oviposited into the eggs and recently hatched larvae of medflies and completed development in the hosts’ puparia. This is a relatively rare behavior among fruit fly parasitoids and, because tephritid eggs near the surface of fruits are particularly vulnerable to attack, one that might contribute to its success as a biological control agent.

The root weevil, Diaprepes abbreviatus (L.), is a major pest of Florida citrus. When neonate larvae hatch from egg masses in the citrus canopy and drop to the soil surface before burrowing down to the roots for feeding, they are vulnerable to ant predation. However, neonates are reported to produce a chemical repellent that lasts up to four days and reduces ant predation by about 40%. We assessed the daily pattern of neonate drop from egg masses under laboratory conditions (24°C, 70% RH, L:D = 12:12), examined the role of ants as predators of neonates (<48 h post hatch) on the soil surface in three citrus groves in central Florida, and tested for chemical repellency in the field by comparing predation rates on 5-day versus 1-2 h old neonates. Neonate drop was not well synchronized within or among egg masses, occurred during all hours of the light and dark phases, and extended over 5 to 23 h (mean = 11.97, SE = 0.866) for individual egg masses (n = 29). However, the drop rate was highest during the second half of the light phase (52.4%) and lowest during the second half of the dark phase (8.0%). Predation occurred in 104 of 199 replicates (52.3%) in the three groves with a total of 475 of the 3980 larvae (11.9%) removed by predators within 20 mins. Predation pressure varied within and among groves, and involved eight ant species (Hymenoptera: Formicidae) and a single predation event by a nymph of the big-eyed bug, Geocoris floridanus Blatchley (Hemiptera: Lygaeidae). For data pooled among groves, the red imported fire ant, Solenopsis invicta Buren, was responsible for 29.5% of the predation, Pheidole moerens Wheeler 27.8%, Dorymyrmex reginicula (Trager) 9.7%, Brachymyrmex obscurior Forel 8.8%, Dorymyrmex bureni (Trager) 8.6%, Cardiocondyla emeryi Forel 8.0%, Paratrechina bourbonica Forel 4.8%, and Pheidole morrisi Forel 2.5%. In our test for age-dependent chemical repellency, a total of 2620 of the 3840 neonates (68.2%) were preyed upon within 30 mins but the predation rate on old versus young neonates did not differ at 68.8% and 67.7%, respectively. In this experiment, 368 of the predation events (14.0%) were observed directly with P. moerens responsible for 62.5%, S. invicta 25.3%, C. emeryi 10.1%, B. obscurior 1.4%, Cardiocondyla wroughtonii (Forel) 0.5%, and D. bureni 0.3%. We conclude that ants are important predators of Diaprepes neonates in central Florida citrus groves and have potential for a conservation biological control program.

Neotermes phragmosus n. sp. is described from the imago and soldier castes. The imago head capsule of N. phragmosus has a distinctly phragmotic and concave frons. Plesiomorphic characters of N. phragmosus unique among the Kalotermitidae include partial separation of the otherwise fused first and second marginal teeth of the left imago/worker mandible, long subcosta and radius, and increased number of antennal articles in both imagos and soldiers. This species is confined to the xeric coastal habitats of southeastern Cuba.

Three legume species with potential as cover crops in citrus groves were studied for their effect on the developmental biology of the Diaprepes root weevil, Diaprepes abbreviatus (L.) in greenhouse studies. All 3 cover crops were hosts for the Diaprepes root weevil. Cajanus cajan (pigeon pea) was a superior host for development of D. abbreviatus compared with citrus rootstocks. C. cajan appeared to be allelopathic; the root mass of uninfested citrus was greatly reduced when grown in association with C. cajan compared with citrus grown alone. Association of citrus with C. cajan or Arachis pintoi (perennial peanut) reduced chlorophyll fluorescence, a measure of photosynthesis, compared with citrus associated with Crotalaria pallida (rattlebox) or with another citrus seedling. When grown in close association with A. pintoi, citrus produced the same amount of root mass as citrus seedlings grown alone. Infestation with larval D. abbreviatus reduced chlorophyll fluorescence of citrus by 26%. None of the 3 legume species tested reduced the feeding damage caused by D. abbreviatus to citrus. Larvae reared in pots with A. pintoi, associated with citrus or alone, gained weight at the same rate as larvae reared on the citrus rootstocks alone. Larvae recovered from pots containing C. pallida associated with citrus weighed significantly more than larvae reared on citrus alone. C. cajan appears to be particularly inappropriate as a cover crop because of its positive effect on larval growth and reduction of citrus root mass. None of the 3 legume species tested had a negative effect on D. abbreviatus or on feeding damage.