Studies on the outcomes of pesticide exposure on bumble bees have traditionally evaluated the pesticides individually. Poorly known is the effect of simultaneous exposure to multiple pesticides, which has high likelihood in agricultural landscapes. Four experiments were conducted to determine if simultaneous exposure to sub-lethal doses of the insecticide Assail^® (30% acetamiprid) and the fungicide Orbit^® or Tilt^® (41.8% propiconazole) would cause detrimental effects on survival and colony productivity of the common eastern bumble bee, Bombus impatiens (Cresson) (Hymenoptera: Apidae). Survival of workers exposed to propiconazole was marginally reduced (Experiment 1), whereas gyne production increased in colonies exposed to acetamiprid (Experiment 2). There was a trend for fewer larvae and workers in colonies exposed to acetamiprid and a mixture of acetamiprid and propiconazole (Experiment 3). Higher wax moth infestations and densities were observed in colonies exposed to the mixture of acetamiprid and propiconazole (Experiment 4). In conclusion, exposure to the two pesticides resulted in variable outcomes in B. impatiens. Synergy between acetamiprid and propiconazole was explained as an indirect effect of enhanced wax worm infestation. We found an increased level of wax worm infestation in colonies exposed to a mixture of Assail and Tilt compared to colonies not exposed to Assail or Tilt (control) or exposed only to Assail. While this study does not provide evidence that B. impatiens are at high risk when simultaneously exposed to field rates of these two pesticides, we suggest that wild blueberry growers practice integrated pest management as a means of reducing any amount of risk to these important bumble bees.

Agonoscena pistaciae Burckhardt & Lauterer (Hemiptera: Aphalaridae) is the most important pest of pistachio trees in Iran and the world. Anthocoris minki pistaciae Wagner (Hemiptera: Anthocoridae) is a predator of A. pistaciae. Biological characteristics of this predatory bug were determined at three constant temperatures (17, 26 and 30 ± 2°C), 55 ± 5% R.H., and a photoperiod of 16:8 h (L:D). Data were analyzed by age-stage, two-sex life table to assess the variable developmental rates. Pre-adult developmental time of this predator at 17, 26 and 30°C were 24.5, 15.2 and 14.2 d, respectively. Adult longevities were 61.8, 51.9 and 43.7 d for males, and 60.3, 49.2 and 43 d for females at 17, 26 and 30°C, respectively. Fecundity at 17, 26 and 30°C were 50.3, 51.9 and 41.6 eggs/female, respectively. Intrinsic rates of increase (r) were 0.0707, 0.1042 and 0.1102 d^–1 at 17, 26 and 30°C, respectively. The mean generation time (T) was 27.3 d (the shortest time) at 30°C and 42 d (the longest time) at 17°C. The net reproductive rate (R₀)_, the age-stage-specific fecundity (f_xj), age-specific fecundity (m_x) and age-specific maternity (l_xm_x) at 26°C were higher than those at 17 and 30°C. This research suggests that this predator can retain higher population densities at 26°C than at the other temperatures tested. Results of this study provide the biological basis for using A. minki pistaciae in a biological control program against A. pistaciae in pistachio orchards.

The use of non-conventional methods in the management of stored product insect pests is gaining popularity, particularly due to problems associated with chemical control. The effect of ozone on Sitophilus oryzae (L.) (Coleoptera: Curculionidae), an internal feeder of stored wheat and other grains, was investigated using dose-response experiments. Eggs, immature stages within wheat kernels, and adults were exposed to an ozone concentration of 200 ppm for 6, 18, and 30 h. Insect life stages were placed at a depth of 5, 15, and 25 cm in wheat filled in PVC pipes. Effect of ozone on S. oryzae life stages was evaluated as the percent mortality of treated eggs, immature stages, and adults. Egg mortality was recorded as the percentage of eggs that failed to hatch 10 d after treatment (DAT), and mortality in immature stages was recorded as the percentage of immature insects that failed to develop into adults 28 DAT at 28°C. Mortality of adults was recorded as the percentage that died 0, 1, and 2 DAT. Egg mortality at the 5 cm depth in wheat exposed to ozone for 30 h was significantly higher than the mortality when exposed for 18 h. When the three depths were compared, at 18 h and 30 h exposure times, fewer adults emerged from immature insects placed at 5 cm compared with insects placed at 15 or 25 cm depths. Adult mortality in insects placed at the 5 cm depth for all exposure times was significantly higher than at 15 and 25 cm at 2 DAT. Findings from this study suggest that ozone may be an effective fumigant; however, mortality of S. oryzae life stages is dependent on the exposure time, depth of occurrence in the wheat mass, or post treatment time (DAT).

Assertions that first-instar pentatomids “do not feed” are pervasive in the literature. Recent research using rifampicin-resistant marked bacteria demonstrated that first-instar southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae), ingest from green bean. The technique of electropenetrography (EPG), coupled with histology, has allowed researchers to elucidate feeding behavior within plant tissue, and recordings of several species (including N. viridula) have shown that internal stylet probes of adults and late-instar nymphs may terminate in xylem as well as in seed endosperm, inner pod wall, or stem parenchyma. The seeming contradiction regarding “feeding” could be explained if first instars were simply hydrating from plant tissue to maintain water balance. In this study, first-instar N. viridula were supplied with either water or green bean, and subsequently given a traditional rearing diet (green bean and peanut) from second instar onward. We noted aggregations of first instars forming on water wicks and on beans along the carpellary bundles and at both tips. Availability of food (green bean) in first instar did not affect subsequent development. Using EPG, we recorded first-instar N. viridula probing on soybean leaves and found the primary waveform to be xylem ingestion. Probing and ingestion behavior did not differ between first instars previously exposed to high and moderate humidity conditions. We conclude that these insects ingest from xylem, but nutrients other than water are not required in the first instar for successful nymphal development.

The khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), is an important pest of stored wheat worldwide. Nanoparticles have become one of the most promising new tools for insect pest management in recent years. This laboratory study was conducted to evaluate the insecticidal efficacy of three commercially available nanoparticles [silicon oxide (SNPs), aluminium oxide (ANPs) and zinc oxide (ZNPs)] against T. granarium at 50, 100 and 200 mg kg^–1. The efficacy of SNPs, ANPs and ZNPs on wheat, barley, rice, white maize and yellow maize was assessed after 1, 3, 5 and 7 d of exposure. Corrected mortality of T. granarium was significantly affected by nanoparticle types, application rates, grain types, and the insect developmental stages. SNPs and ANPs were more effective than ZNPs, where 100% mortality of second instars was obtained at the highest concentration. Mortality of second instars on wheat treated with SNPs, ANPs or ZNPs at the rate of 200 mg kg^–1 was significantly higher than other concentrations. Insecticidal efficacy of all nanoparticles at the rate of 200 mg kg^–1 against second instars was significantly higher on barley and wheat than those on rice and maize. First, second and third instars exposed to all nanoparticle types at the rate of 200 mg kg^–1 were more susceptible than fourth and fifth instars and adults. Female adults exposed to wheat treated with all nanoparticles at the rate of 200 mg kg^–1 stopped reproduction completely. The results demonstrate that commercially available SNPs and ANPs can be used as eco-friendly management strategy of T. granarium; however, further studies under commercial storage conditions are required.