Incidence of infection by Neozygites fresenii (Nowakowski) Batko in the cotton aphid, Aphis gossypii Glover was monitored biweekly during the summer of 2002 in a cotton field in Bamberg County, SC. (33°22′02″N, 81°12′14″W). Five treatments were evaluated to determine the effects of insecticides on incidence of N. fresenii: acetamiprid, dicrotophos, thiamethoxam, imidacloprid, and control. Aphids were sampled by taking 24 leaves from 12 cotton plants from each plot and placed into 30-ml screw cap vials filled with 70% ethanol. Fungus infection in aphids, numbers of aphids, percentage of winged aphids, and fungus infection in winged aphids were determined from aphids for each plot.

The highest fungus infection occurred on July 12 and 16. Acetamiprid treated plots had infection levels of N. fresenii lower than other treatments. Cotton aphid numbers in acetamiprid and thiamethoxam plots were significantly lower than in the dicrotophos treatment and untreated plots. None of the treatments caused reductions in percentage of winged aphids or in infection levels by N. fresenii in winged aphids.

In the last decade, the wheat stem sawfly [Cephus cinctus Norton (Hymenoptera: Cephidae)] has resurged as an important pest of wheat in the Canadian prairies and continues to be a chronic pest in the Northern Great Plains of the USA. Ecological and management studies to determine egg and larval infestation, damage and parasitoid attack rates, require laborious dissections of stems collected at various spatial scales. We used a statistical simulation study to determine the minimum number of stems required to estimate these response variables at the level of a sub-sample (e.g., within a plot). The number of stems required to estimate sawfly cutting damage and parasitoid attack to larvae was strongly and negatively related with the response variable. At moderate to high levels of sawfly pressure where the stems cut by larvae exceeds 40%, it is possible to reduce stem counts to 50 stems; however, in the 10% cutting range, up to 200 stems are needed for accurate estimates. These values were similar for sample size required to estimate larval parasitism but egg infestation of stems, when levels surpass 70%, can be determined with as few as 30 stems.

With the introduction of an invasive pest ant species, Paratrechina sp. nr. pubens, it has become imperative to develop novel control technologies. There is currently no published research concerning dinotefuran and novaluron against pest ants. Paratrechina sp. nr. pubens workers and brood were exposed to baits containing dinotefuran and novaluron at varied concentrations. Liquid bait amended with dinotefuran was applied in the laboratory against P. sp. nr. pubens. Mean percent mortality of P. sp. nr. pubens was typically higher as the concentration increased at both three (F  =  7.28; df  =  28; P < 0.001) and seven (F  =  7.28; df  =  28; P < 0.001) d post-treatments. Three day observations of the lowest concentration (0.00006%) indicated a significantly lower efficacy than the highest two concentrations. LD₅₀ and LD₉₀ values at three and seven d post treatment showed a poor fit to the model (df  =  1; χ²  =  7.20; P < 0.01, df  =  1; χ²  =  7.09; P < 0.01, respectively). The use of dinotefuran was highly efficacious against P. sp. nr. pubens, and is recommended for further laboratory research and initial field research. Corn grit bait amended with novaluron was applied in the laboratory against P. sp. nr. pubens workers and brood. At four wk results did not reveal significant differences among concentrations with active ingredient and controls (F  =  1.504, df  =  3, 27, P  =  0.239). Results of the study were inconclusive regarding the efficacy of novaluron against P. sp. nr. pubens. The findings of this study emphasize the difficulties in maintaining incomplete colonies of P. sp. nr. pubens that contain brood under laboratory settings.

The sweetpotato whitefly, Bemisia tabaci (Gennadius) is a worldwide pest in diverse agroecosystems. There are numerous species of predators and parasitoids that are associated with this pest. Climate and species of vegetation can dramatically affect the distribution and incidence of these natural enemies. A field survey was conducted to determine the incidence of the primary natural enemies of B. tabaci in 10 vegetable crops in Egypt. Fifteen species of natural enemies of B. tabaci were observed, including 5 species of predators and 10 species of parasitoids. Coccinella septempunctata L. was the most commonly found predator, and it was found in four of the crops. The parasitoids consisted of four species of Encarsia and six species of Eretmocerus which represents 71% of the known aphelinid parasitoid species of B. tabaci in Egypt. Eretmocerus aegypticus Evans and Abd-Rabou was the most commonly encountered parasitoid species; it was found in five of the crops. To date, this species has only been reported in Egypt. These results help define the diversity of natural enemies of B. tabaci among vegetable crops.

Formica perpilosa Wheeler is a serious economic ant pest on table grapes grown in the Coachella Valley, California, and Hermosillo, Sonora, Mexico. This ant aggressively tends hemipteran pests, such as the vine mealybug, Planococcus ficus Signoret, and disrupts natural control by predators and parasitoids. Efforts are underway to develop control measures against F. perpilosa using granular bait, yet little is known about the colony life cycle or foraging characteristics of this ant. We studied the seasonal activity, mating behavior, and density and spatial characteristics of F. perpilosa nests in vineyards as well as its foraging and recruitment behavior. Nests were active from early February to mid-October. Mating flights occurred in early August and again in the first two weeks of September and new colonies were founded by a single queen. F. perpilosa rapidly colonized a new, non-infested vineyard with ca. 9% of the vines infested after 1.5 y. In September the proportions of infested vines at 5, 20, and 30 y old vineyards were 18.6, 21.8, and 16.2%, respectively. This ant is seasonally polydomous and nest density increased ca. two-fold at the 5 and 20-year old vineyards between February and September. Foraging and recruitment primarily occurred up to 6.39 m from a home nest. The implications of these studies for controlling F. perpilosa using low-toxic bait delivery systems are discussed.

Field experiments were conducted to determine establishment of fall armyworm, Spodoptera frugiperda (J.E. Smith), infestations on whorl stage sorghum when larvae in different stages were reared on either sorghum foliage or wheat germ based diet and artificially inoculated onto the plants. No differences were observed in numbers of larvae per plant on days 1, 2, 6 or 12 after infestation when plants were inoculated with third instar larvae reared on sorghum foliage or wheat germ diet. Inoculations using first or third instars at day 1, 6 or 12 after infestation were not compared because of non-significant interactions. However, at day 2 after infestation and when first instar larvae were used, the mean numbers of larvae per plant were greater when inoculations were made at 7:00 am and 1:00 pm than at 6:00 pm, whereas when third instar larvae were used a greater number of larvae was on the infested plants when inoculated at 7:00 am than at 1:00 pm or 6:00 pm. For experimentation, it is better to inoculate whorl stage sorghum with first or third instar fall armyworm larvae reared on either sorghum foliage or wheat germ diet during early morning than later during the day to obtain suitable survival of larvae to successfully establish infestations of this pest.