This study investigated biological activity of chloroform extract of dry Lantana camara ‘Mozelle’ leaves against the eastern subterranean termite, Reticulitermes flavipes (Kollar), an important structural pest. Repellent activity was assessed using a paper-disc choice test and a sand arena choice test. Antifeedant and toxic properties were assessed using a no-choice paper test and a topical application method. In the choice tests, significantly fewer termites made contact with treated paper-discs at test concentrations ≥0.016 mg/cm² (equivalent to 0.0023 wt:wt) or tunneled into treated sand at test concentrations ≥0.125 mg/g, compared with control. In the no-choice tests, termite feeding activity was significantly reduced and termite mortality was greatly increased in treatments than control. Exposure to filter paper treated at 0.212 and 0.106 mg/cm² (equivalent to 0.03 and 0.015 wt:wt) resulted in >90% mortality and 78% reduction in feeding, and ≈52% mortality and 40% reduction in feeding, respectively. Top-dorsal application led to >60% mortality at 4 μg/termite. This study showed that the chloroform leaf extract of L. camara had excellent repellent and moderate toxic and antifeedant activities.

Prewinter copulation, sperm storage, and oocyte development in overwintering adult Megacopta cribraria (F.) was examined in Alabama (Lee Co.). Microscopic examinations of the spermathecae and ovaries were made in females and of the testes in males that were collected approximately weekly from September 2013 through March 2014. The results indicated that approximately 15% of females mated before entering winter dormancy and sperm was stored in their spermatheca for up to seven months, oocytes in mated overwintering females proceeded to postblastoderm stage before the onset of spring feeding and mating in March, all of the overwintering males had sperm in their testes, and the ratio of females gradually increased in populations during overwintering. This study indicates that both males and females are capable of reproductive dormancy. The biological significance of these life cycle aspects is discussed from the viewpoints of invasiveness and adaptation.

The earliest description of the discontinuous gas exchange cycle (DGC) in lepidopterous insects supported the hypothesis that the DGC serves to reduce water loss (hygric hypothesis) and facilitate gaseous exchange in hyperoxia/hypoxia (chthonic hypothesis). With technological advances, other insect orders were investigated, and both hypotheses were questioned. Thus, we conducted a meta-analysis to evaluate the merit of both hypotheses. This included 46 insect species in 24 families across nine orders. We also quantified the percent change in metabolic rates per °C change of temperature during the DGC. The DGC reduced water loss (−3.27 ± 0.88; estimate ± 95% confidence limits [95% CI]; p < 0.0001) in insects. However, the DGC does not favor gaseous exchange in hyperoxia (0.21 ± 0.25 [estimate ± 95% CI]; p = 0.12) nor hypoxia, but did favor gaseous exchange in normoxia (0.27 ± 0.26 [estimate ± 95% CI]; p = 0.04). After accounting for variation associated with order, family, and species, a phylogenetic model reflected that metabolic rate exhibited a significant, non-zero increase of 8.13% (± 3.48 95% CI; p < 0.0001) per °C increase in temperature. These data represent the first meta-analytic attempt to resolve the controversies surrounding the merit of adaptive hypotheses in insects.

The emergence and dissemination of multidrug resistant bacterial pathogens necessitate research to find new antimicrobials against these organisms. We investigated antimicrobial production by eastern subterranean termites, Reticulitermes flavipes, against a panel of bacteria including three multidrug resistant (MDR) and four non-MDR human pathogens. We determined that the crude extract of naïve termites had a broad-spectrum activity against the non-MDR bacteria but it was ineffective against the three MDR pathogens Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Acinetobacter baumannii. Heat or trypsin treatment resulted in a complete loss of activity suggesting that antibacterial activity was proteinaceous in nature. The antimicrobial activity changed dramatically when the termites were fed with either heat-killed P. aeruginosa or MRSA. Heat-killed P. aeruginosa induced activity against P. aeruginosa and MRSA while maintaining or slightly increasing activity against non-MDR bacteria. Heat-killed MRSA induced activity specifically against MRSA, altered the activity against two other Gram-positive bacteria, and inhibited activity against three Gram-negative bacteria. Neither the naïve termites nor the termites challenged with heat-killed pathogens produced antibacterial activity against A. baumannii. Further investigation demonstrated that hemolymph, not the hindgut, was the primary source of antibiotic activity. This suggests that the termite produces these antibacterial activities and not the hindgut microbiota. Two-dimensional gel electrophoretic analyses of 493 hemolymph protein spots indicated that a total of 38 and 65 proteins were differentially expressed at least 2.5-fold upon being fed with P. aeruginosa and MRSA, respectively. Our results provide the first evidence of constitutive and inducible activities produced by R. flavipes against human bacterial pathogens.

Julian R. Golec, Xing Ping Hu, Charles Ray, and Norman E. Woodley (2013) Strongygaster triangulifera (Diptera: Tachinidae) as a Parasitoid of Adults of the Invasive Megacopta cribraria (Heteroptera: Plataspidae) in Alabama. Journal of Entomological Science: Vol. 48, No. 4, pp. 352-354. doi: http://dx.doi.org/10.18474/0749-8004-48.4.352