Search Results (3)

The energy requirement for biosynthesis plays an important role in an organism’s life history, as it determines growth rate, and tradeoffs with the investment in somatic maintenance. This energetic trait is different between painted lady (Vanessa cardui) and Turkestan cockroach (Blatta lateralis) due to the different life histories. Butterfly caterpillars (holometabolous) grow 30-fold faster, and the energy cost of biosynthesis is 20 times cheaper, compared to cockroach nymphs (hemimetabolous). We hypothesize that physiologically the difference in the energy cost is partially attributed to the differences in protein retention and turnover rate: Species with higher energy cost may have a lower tolerance to errors in newly synthesized protein. Newly synthesized proteins with errors are quickly unfolded and refolded, and/or degraded and resynthesized via the proteasomal system. Thus, much protein output may be given over to replacement of the degraded new proteins, so the overall energy cost on biosynthesis is high. Consequently, the species with a higher energy cost for biosyntheses has better proteostasis and cellular resistance to stress. Our study found that, compared to painted lady caterpillars, the midgut tissue of cockroach nymphs has better cellular viability under oxidative stresses, higher activities of proteasome 20S, and a higher RNA/growth ratio, supporting our hypothesis. This comparative study offers a departure point for better understanding life history tradeoffs between somatic maintenance and biosynthesis. Full article

The paralysis behavior of some ponerine ants when foraging may be important for food storage and colony development. However, how workers invest in paralysis under different prey circumstances is often overlooked. Here, we report the prey-foraging behavior and paralysis behavior of Harpegnathos venator under different food supply conditions. Solitary hunting was the main foraging mode of H. venator, with occasional simple collective hunting. Nymphal cockroaches with high activity were the most attractive to H. venator. In the experiment, we found that the stings of H. venator completely paralyzed the cockroaches. The stinging time was significantly longer at a higher prey activity level and for larger cockroaches. In addition, there was no significant difference in the stinging time of H. venator for different prey densities. The results showed that the longer similar cockroaches were stung, the longer it took for them to revive and move. These results are helpful for further understanding the behavioral mechanism underlying the food storage of live prey by predatory insects. Full article

The Turkestan cockroach, Blatta lateralis (Walker) is an invasive urban pest prevalent throughout the Southwestern United States. Despite the presence of this cockroach in peridomestic areas, there is limited information on strategies that can be utilized by pest management professionals (PMPs) to effectively manage populations of this pest. We evaluated the efficacy of dry residues of liquid insecticides commonly used for household and structural insect pest control: Tandem (0.10% thiamethoxam, 0.03% lambda-cyhalothrin), Transport GHP (0.05% acetamiprid, 0.06% bifenthrin), Temprid SC (0.10% imidacloprid, 0.05% beta-cyfluthrin), Demand CS (0.06% lambda-cyhalothrin), Talstar P (0.06% bifenthrin), and Phantom (0.5% chlorfenapyr) on three different substrates against Turkestan cockroach nymphs. Except for Phantom and Talstar P, all insecticide formulations killed 100% of the cockroaches on concrete, 89–100% on tile, and 77–100% on wood within 4 days. The rate of cockroach mortality varied according to the substrates to which they were exposed. Temprid SC and Transport GHP killed cockroaches faster on tile than wood. Tandem provided a faster mortality rate than Transport GHP and Temprid SC on concrete. Demand CS and Tandem killed cockroaches at similar rates on the three substrates. This study provides information to guide PMPs in their selection of insecticide formulations for the management of Turkestan cockroach infestations. Full article