Red imported fire ant, Solenopsis invicta Buren, was studied to determine if it preys on eggs, fourth-instar larvae, and pupae of the Asian tiger mosquito, Aedes albopictus (Skuse), under laboratory and field conditions. Fire ant workers removed eggs, larvae, and pupae from dampened filter paper and larvae and pupae from standing water. In experiments for a 12-hour period during daytime hours in the field, as many as 71.1% of the eggs were removed (mean = 15.8%, n = 50), while during the same period during nighttime hours, as many as 78.2% of the eggs were removed (mean = 16.1%, n = 50). As many as 97.2% of the eggs were removed during a 24-hour period, (mean = 40.8%, n = 50), and as many as 96.8% of the eggs were removed during a 48-hour period (mean = 30.8%, n = 50). Under field conditions, red imported fire ants removed some larvae and pupae from 96% of the experiments (n = 25, range = 60–100%) with larvae and pupae exposed on dampened filter paper for 12 hours and from 60% of experiments (n = 25, range = 10–100%) with larvae and pupae in standing water for 24 hours. In the laboratory (n = 20), 100% of Asian tiger mosquito larvae and pupae were removed from dampened filter paper within 60 minutes, 45% of larvae were removed from standing water within 24 hours following a 48-hour period of food and water deprivation (n = 5), and 100% of all larvae were removed from standing water within 48 hours without 48 hours of food and water deprivation (n = 3).

‘Candidatus Liberibacter solanacearum’ is the putative causal agent of zebra chip disease of potato, Solanum tuberosum L., and is transmitted by the potato psyllid, Bactericera cockerelli (Sulc). Much work has been done on the association of Liberibacter with the potato psyllid and several laboratories currently use polymerase chain reaction (PCR) to test for the bacterium. We have been testing for the bacterium in individual and composite samples of B. cockerelli as part of an ongoing investigation of the incidence of ‘Ca. L. solanacearum’ in potato psyllids collected in various parts of the US. Here we report that the bacterium can be reliably detected by using conventional and quantitative real-time PCR of nucleic acid extracts prepared from composite samples of one psyllid from a Liberibacterinfected colony combined with either one, two, three, four, five, nine, 14, 19, or 29 psyllids from a Liberibacter-free psyllid colony. This ability makes it possible to more easily test large numbers of psyllids for the presence of ‘Ca. Liberibacter solanacearum’. This, in turn, will aid efforts to predict the threat of developing serious zebra chip disease as a result of psyllid infestations in potato fields.

Potato psyllid, Bactericera cockerelli (Sulcen), nymphs were treated with extracts of Annona muricata L., Carica papaya L., Euphorbia dentate Michx, Thuja occidentalis L., Sapindus saponaria L., and Azadirachta indica A. Juss. (neem) as a commercial check in the laboratory. At 72 hours, most potato psyllid nymphs died (98 and 100% mortalities) from A. muricata extract from seeds, at concentrations of 2,500 and 5,000 ppm, respectively, followed by A. indica oil that caused 91 and 100% mortality at concentrations of 2,000 and 2,500 ppm, respectively. A. muricata seed extract was the most effective insecticide in the study.

We report the susceptibility of a green plant bug, Creontiades signatus Distant, a pest of cotton, Gossypium hirsutum L., and other crops in South Texas, to malathion and other cotton insecticides using the adult vial test, and an oral “floral foam” assay for systemic insecticides, when active eradication of boll weevil, Anthonomus grandis grandis Boheman, has been in effect for six seasons in the Rio Grande Valley of Texas. Field-collected green plant bugs exhibited malathion tolerance ratios of 1.68 to 4.83 when compared to unexposed plant bugs reared in the laboratory for six generations. The associated 95% C.l.'s for LC₅₀ values did not overlap following six consecutive paired (field versus laboratory) assays from November 2006 to October 2009. The greater tolerance ratios and LC₅₀ values may be the result of an average of 18 to 20 applications of ultra-low volume (ULV) malathion applied in the process of boll weevil eradication in cotton fields. Field-collected green plant bugs also had larger LC₅₀ values when exposed to acephate using an adult vial test compared to the laboratory strain, but the 95% C.l.s did not overlap. All other organophosphate, pyrethroid, carbamate, neonicotinoid, and flonicomid insecticides were very toxic against field- and laboratory-reared green plant bugs. The floral foam method of diluting non-acetone soluble insecticide active ingredients into honey-water worked well as an assay technique with the exception that mortality should be observed at 72 instead of 48 hours.

Newly eclosed adult bollworm, Helicoverpa zea (Boddie), feeds on carbohydrate from plants and other exudates before dispersal and reproduction. The objective of this study was to determine whether or not this nocturnal behavior could be used to attract the insect to a feeding-based attracticide mixed with a toxicant. Commercially-formulated abamectin (Agri-mek 0.15EC) was evaluated as a toxicant mixed with a 2.5 M sucrose solution against bollworm adults, relative to toxicity, mortality, gustatory and proboscis-extension response, and reproduction. Sublethal doses of abamectin at 0.05, 0.1, 0.25, and 0.5 mg litre^-1 fed to laboratory-reared females within 24 hours of emergence significantly reduced by 10–73% the percentage of eggs that hatched as compared to females fed sucrose only. Mating frequency was significantly inhibited by 2–70% at 0.25 mg litre^-1 or more. A detailed examination of the effect of abamectin on toxicity, mortality, gustatory and proboscis-extension response, and reproduction of laboratory-reared and feral bollworms showed a potential exists for the use of this insecticide in a feeding-based adult control system. The dramatic decrease in fecundity and inhibition of mating frequency show a premise for the use of abamectin as a toxicant for suppression of bollworm adults.

Differences in susceptibility to insecticides based on adult insect sex indicate that males are more susceptible than females. Hence, it may be necessary to sex the insects before a bioassay is conducted, but this activity is tedious, takes time, and this manipulation might cause harm to the insects. Monitoring the evolution of resistance to the neonicotinoid insecticides in field whitefly populations is important and usually based on adult exposure to these toxicants. The aim of this study was to correlate the susceptibility to thiamethoxam with sex in susceptible populations of Bemisia tabaci (Genn.) B-Biotype and Trialeurodes vaporariorum (West.). Five-day-old males, females, and a mixture of female and male (80:20) adults were evaluated to determine log doses-Probit lines for this insecticide. In B. tabaci, the CL₅₀ ranged of 1.4 mg [lA] L^-1 to 2.8 mg and the relative proportion RR50 ranged from 1.0 to 2x. The CL₉₅ ranged from 12.3 to 16.7 mg and the RR95 values varied from 0.8 to 1.0x. In T. vaporariorum, the CL₅₀ fluctuated from 14.2 to 30.3 mg and the value of RR50 between 1.0 and 2.1x. The CL₉₅ ranged of 180.4 to 314.0 mg and the RR₉₅ from 1.0 to 1.7x. In both species, no differences were found between insect sex and susceptibility to thiemathoxam. Hence, to conduct bioassays with thiamethoxam on these species, the use of one sex or the other is irrelevant.

The identification of Cx. stigmatosoma and Cx. thriambus is sometimes confused in Mexico. Intraspecific differences in spiracular apodeme on Cx. stigmatosoma larvae and chaetoaxy on siphon of Cx. thriambus are reported and illustrated here. Based on specimens from recent collections, we include distribution, ecologic, medical importance, and taxonomic notes, and additional collection records in Mexico are documented for both species.

Tamarind (Tamarindus indica L.) is an economically important crop in the dry tropical region of Western Mexico. During more than one decade, damage caused by a borer insect in tree branches and trunk have been observed. Until recently, the taxonomy and generalities of this pest were unknown. In this brief review, current knowledge of the tamarind borer is presented. The insect is a large beetle, 18 to 33 mm, glossy, of fusiform black- or brown-colored body with yellow/black alternate sections in tarsus and antennal segments. The adult is characterized by extremely long antennae as long as or longer than the body of the beetle. Each elytra has two yellow spots. The larvae are cerambyciform, whitish in color, and its head is wider than the rest of the body. The insect was identified as Trachyderes (Dendrobias) mandibularis Dupont. In this region, the borer has been observed affecting only tamarind, in spite of other hosts such as Mexican lime, orange, and mango. The borer attacks young plants and adult trees. Its control consists of cultural practices (irrigation and fertilization) to reduce damage. For infested trees, pruning of damaged branches is recommended and then killing the larvae to break its life cycle. The application of insecticides (painted) to the trunk of the trees is a preventive measure to control the borer.