Daniel R. Suiter

Preliminary Genetic Analysis of a Recently-Discovered Invasive True Bug (Hemiptera: Heteroptera: Plataspidae) and Its Bacterial Endosymbiont in Georgia, USA

A true bug (Hemiptera: Heteroptera: Plataspidae), previously known only in the Old World from India and Pakistan to China, Korea, Japan and Malaysia to Australia, was discovered in mid-October 2009 in several northeastern counties in Georgia (USA). Specimens of the stinkbug were submitted by professional pest control operators and county agents following homeowner complaints of the large number of insects migrating from kudzu killed by recent frosts. The insect was identifi ed using morphological characters as the bean plataspid, Megacopta cribraria (F.) (Hemiptera: Plataspidae), by J.E. Eger, Jr. (Dow AgroSciences, Tampa, FL). The identifi cation was confi rmed by entomologists at North Dakota State University and the USDA-ARS Systematics Laboratory (Washington, DC). Genomic DNA was extracted using methods of Jenkins et al. (2009, Ann. Entomol. Soc. Am. 102: 380 395) from 3 specimens collected in northeast Georgia. The cytochrome oxidase subunit I (COI) gene fragment was then a mplified and sequenced according to Jenkins et al. (2009). The COI s equences from all 3 specimens were identical, indicating a single female line age. When these sequences were subjected to a GenBank Blast search (Altschul et al.1990. J. Mol. Evol. 215: 403 410), M. cribraria (GenBank # AY627332) was the closest match (11 base differences out of 789 total bases or 98.6% identity). A γ-Proteobacterium, Candidatus Ishikawaella capsulata (Hosokawa et al. 2006. PLOS Biol. 4: e337. DOI: 10.1371/journal.pbio.0040337), reportedly lives in the posterior midgut of plataspid stinkbugs and appears to be necessary for normal growth and development. It also has been implicated in increased fecundity (Fukatsu and H osokawa. 2002, Appl. Environ. Microbiol. 68: 389 396). The female bean plataspid,

Activity of bifenthrin, chlorfenapyr, fipronil, and thiamethoxam against Argentine ants (Hymenoptera: Formicidae).

ABSTRACT Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thiamethoxam. After 2 h, the number of fipronil-treated ants unable to walk out of test arenas did not differ from control ants. Median lethal time (LT50) after topical treatment was lowest in the bifenthrin treatment, followed by thiamethoxam, chlorfenapyr, and then fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30°C, with topically treated ant corpses serving as donors. There was low to moderate horizontal activity in bifenthrin and chlorfenapyr treatments, with no temperature effect in bifenthrin treatments and a positive temperature effect in chlorfenapyr treatments. Mortality in the fipronil treatments was highest and was positively correlated with temperature. Thiamethoxam treatments did not differ from controls at 10°C, but mortality increased with temperature. To evaluate contact activity, either all of 20% of the ants in a cohort were exposed to insecticide-treated pine needles. In both tests, mortality was highest in fipronil and bifenthrin treatments, followed by thiamethoxam, with lowest mortality in chlorfenapyr treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control. Mortality data suggest that lack of recruitment rather than repellency account for this result.

Evaluation of Control Measures for Black Carpenter Ant (Hymenoptera: Formicidae)

Abstract Current control methods for the black carpenter ant, Camponotus pennsylvanicus (De Geer), include the use of remedial and preventative residual sprays as well as toxic baits. We evaluated the acceptance of three baits (Maxforce, Niban, and Baygon) to field colonies of the black carpenter ant in the spring and fall. Maxforce bait granules were more readily accepted than either Niban or Baygon bait granules in the spring. A change in food preference from protein to sugar by the black carpenter ant appeared to reduce the number of Maxforce bait granules removed in the fall, resulting in no differences in bait acceptability. The longevity of Dursban 50W and Tempo 20WP were evaluated in the summer and fall on painted wood panels. Panels aged outside for 15 d under prevailing weather conditions exhibited increased LT50 values. For each sampling period, panels aged on the south face (in the sun) exhibited less insecticidal activity (i.e., large LT50 values) than panels on the north face (shaded; small LT50 values). At each sampling period, Tempo 20WP provided smaller LT50 values than Dursban 50W. Because of changing dietary preferences, our data highlight the importance of using various bait types for carpenter ant control. Moreover, the application of residual spays should be made to locations protected from direct sunlight.

Activity of Bifenthrin, Chlorfenapyr, Fipronil, and Thiamethoxam Against Red Imported Fire Ants (Hymenoptera: Formicidae)

ABSTRACT Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Both immobilization and mortality occurred most quickly with bifenthrin, followed by thiamethoxam, chlorfenapyr, and fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30°C, with three ratios of topically treated donor ant corpses to live recipients (5, 10, or 20% donors). Bifenthrin had the greatest horizontal activity of the chemicals tested. For chlorfenapyr, the only treatments having higher mortality than controls were the highest percentage donors at either 10 or 30°C. Horizontal activity of fipronil was temperature dependent only with the highest proportion of donors and was lower than that of bifenthrin but higher than that of chlorfenapyr or thiamethoxam. Mean mortality due to thiamethoxam was similar to that with chlorfenapyr. Significant mortality occurred in all of the 20 and 30°C thiamethoxam treatments, but none of the 10°C treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control bridge. Mortality data suggest that a reduction in recruitment rather than repellency account for this result.

Deterrency and Toxicity of Essential Oils to Argentine and Red Imported Fire Ants (Hymenoptera: Formicidae)

Laboratory assays were conducted to evaluate deterrency and contact toxicity of six essential oils to the Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren. In choice tests, both Argentine ants and fire ants crossed barriers treated with multiple rates of basil, citronella, lemon, peppermint, or tea tree oil less frequently than paired control barriers. Eucalyptus oil did not prevent movement of either species at any of the rates tested. In continuous exposure assays, citronella oil killed 50% of Argentine ants in 34.3 min and was the only treatment to cause 100% Argentine ant mortality after 24 h. Argentine ant mortality after 24 h was 89.8% with peppermint oil and 85.7% with tea tree oil, with the remaining treatments having mortality not significantly different from the control. Only citronella oil caused significant mortality of red imported fire ants, with 50.6% of the ants being dead after 24 h of continuous exposure.

German Cockroach, Blattella germanica (L.) (Blattaria: Blattellidae), Feeding Activity in Apartment Kitchens

German cockroach, Blattella germanica (I), distribution within two low-income apartment kitchens was determined by monitoring feeding activity with capacitive proximity sensors for four consecutive...