Studies were conducted to determine if predation versus scavenging versus scavenging on insecticide-killed prey affected brown recluse spiders, Loxosceles reclusa. Indicators of possible effects were measured by weight change and survival. Live house crickets, Acheta domesticus, used as prey, were exposed to one of four treatments: live (untreated control), Spinosad or pyrethroid insecticide treated surface, or freeze-killed (scavenging control) and made available to spiders for twenty-four hours once/week for eight weeks. Spiders fed pyrethroid-killed crickets had significantly lower survival than did spiders utilizing crickets exposed to all other treatments. L. reclusa had significantly greater weight gain feeding as predators than as scavengers.

The common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer is a key pest throughout all pistachio producing regions of Iran. Pest management depends primarily on the application of chemical insecticides. The lack of compatibility between natural enemies and pesticides is the main concern to ecologists in the integrated management of psylla. The susceptibility of the fifth instar nymphs of A. pistaciae from five populations of the Kerman province and third instar larvae of the lady beetle species, Oenopia conglobata L., were examined against three commonly used insecticides: acetamiprid, spirotetramat and hexaflumuron, using the spraying tower method. Probit regression analysis was conducted on mortality data at various insecticide concentrations using the POLO-PLUS program to estimate LC₅₀ values. Resistance ratio data revealed that usage of pesticides has led to resistance in the psylla population of Rafsanjan. The results showed that the Rafsanjan psylla population (with LC₅₀ values of 40.55, 43.65 and 95.10 mg a.i. L^-1, for acetamiprid, spirotetramat and hexaflumuron, respectively) was the most resistant and the Anar population (with LC₅₀ values of 11.92, 24.13 and 81.06 mg a.i. L^-1 for acetamiprid, spirotetramat and hexaflumuron, respectively) was the most susceptible based on the LC₅₀ ratios of insecticides. The LC₅₀ values of acetamiprid, spirotetramat and hexaflumuron for the coccinellid predator O. conglobata in the Rafsanjan population were estimated to be 8.76, 5218.33 and 2268.81 mg a.i. L^-1, respectively. The predator was more susceptible to acetamiprid and more tolerant to spirotetramat and hexaflumuron than the psylla A. pistaciae.

The Black Hills are a mountain island surrounded by prairie on the eastern edge of the Rockies. The ant fauna of this area is known only from collections in the southern Black Hills and surrounding plains. To assess ant biodiversity and activity levels in the northern Black Hills, ants were collected monthly from April through September 2016 at two sites (1250 m ponderosa pine – common juniper forest and 2060 m aspen-pine forest). At each site, collections were made by opportunity collections and using 40 pitfall and 50 baited traps along perpendicular transect lines. We collected a total of 6180 ants. At the lower elevation, we identified nine genera consisting of 21 species in comparison to the higher elevation where we found only seven genera consisting of 13 species. Fourteen species and three genera were unique to the lower site while six species and one genus were unique to the higher site. Species accumulation graphs and richness estimates based on incidence data suggest more than 67% of the total number of species were collected at each of the sites. Diversity and evenness averages over the season are not significantly different between the two sites. Some of the species we collected are new records for South Dakota, with one well outside its known range.

In June 2015, a huge, adult butterfly feeding aggregation of thousands of individuals in seven species, dominated by Asterocampa celtis (northern-race Hackberry Emperor), occurred in Douglas and Jefferson Counties, Kansas. This aggregation differed in species composition from smaller aggregations in the same observation area in 1970–1971. A rare A. celtis melanic form was in both the 1970 and 2015 aggregations. Vehicles killed thousands of butterflies in the 2015 aggregation. This study also summarizes data on local population sizes of A. celtis and Asterocampa clyton (Tawny Emperor) in the U.S. and provides new adult food records obtained from eight of the butterfly species in the aggregations.

The present study was undertaken to analyze the resistance status of Culex pipiens pipiens (C. p. pipiens) to the chlorpyrifos insecticide in Tunisia. Three mosquito populations of C. p. pipiens were collected from three districts of Tunisia between 2003 and 2005. Results obtained here showed that all populations were resistant to used insecticide and the level of resistance varied widely between the samples. The resistance ratios at LC₅₀ (RR₅₀) to chlorpyrifos ranged from 8.75 to 455. A synergism study showed that resistance to chlorpyrifos was affected (SR₅₀ > 1, p < 0.05) by piperonyl butoxide (Pb), indicating the involvement of P450 oxidases detoxication in the recorded resistance of sample #1. However, esterases and/or glutathione S-transferase (GST)-mediated detoxication were not involved. Bioassays showed that resistance to chlorpyrifos and propoxur was correlated, suggesting an insensitive acetylcholinesterase (AChE 1). The highest frequencies of the resistant phenotypes ([RS] and [RR]) (0.74) were detected in the most resistant sample (#1). Five esterases were detected in the studied field samples. The esterase C1 encoded by the Est–1 locus and four esterases encoded by the Ester super locus: A1, A2–B2, A4–B4 (or A5–B5, which has the same electrophoretic mobility) and B12.

Culex pipiens is considered the potential vector of West Nile virus outbreaks that have affected Tunisia. The objective of the present study was to evaluate the fenitrothion insecticide resistance status of Culex pipiens pipiens in three populations of insects from three Tunisian states. Standardized method bioassays were conducted to shed light on fenitrothion susceptibility status in field Culex pipiens pipiens populations.The cross-resistance between fenitrothion and propoxur, and the polymorphism of over-produced esterases and AChE 1 were also investigated. Resistances to fenitrothion were moderate and low in sample # 2 and 3 (12.9 and 7.2, respectively). The highest resistance ratio was observed in populations collected in Northern Tunisia (sample # 1) with a rate of 60.9 fold at the LC₅₀ level. The use of a synergist suggested the non-involvement of CYP450, esterases and/or glutathione-S-transferase in resistance of Culex pipiens pipiens to the tested insecticide. However, the biochemical investigation of detoxification enzymes using starch electrophoresis showed the involvement of four esterases, including A2-B2, A4-B4 (and/or A5–B5), B12 and C1. The fenitrothion resistant populations were highly resistant to propoxur indicating the possible involvement of their common target site (AChE 1) in the recorded resistance. Our results are particularly interesting to update the information base for rational deployment of the existing tools for mosquito's control.