Comparative Biologies of the Cryptic, Sympatric Species, Trupanea bisetosa and T. nigricornis (Diptera: Tephritidae) in Southern California

The biologies of the sympatric, cryptic species, Trupanea nigricornis (Coquillett), a flower head-infesting fruit fly attacking a wide range of hosts in 8 tribes, 33 genera, and at least 71 species of Asteraceae, and T. bisetosa (Coquillett), an oligophage attacking only 6 hosts in 4 genera of the tribe Heliantheae, are described and compared. A major biological distinction between these species was their ovipositional behavior, whereby females oviposited different numbers of eggs at different sites in different developmental stages of flower heads of their hosts. The larvae of these species showed minor differences in their feeding behaviors, and their puparia were formed and located similarly in host flower heads. Development from egg to adult under field conditions lasted up to 35 d for each species. These species showed subtle differences in their courtship and mating behaviors, and substantial differences in the daily timing of courtship

Cancer risks from arsenic in drinking water.

Ingestion of arsenic, both from water supplies and medicinal preparations, is known to cause skin cancer. The evidence assessed here indicates that arsenic can also cause liver, lung, kidney, and bladder cancer and that the population cancer risks due to arsenic in U.S. water supplies may be comparable to those from environmental tobacco smoke and radon in homes. Large population studies in an area of Taiwan with high arsenic levels in well water (170-800 micrograms/L) were used to establish dose-response relationships between cancer risks and the concentration of inorganic arsenic naturally present in water supplies. It was estimated that at the current EPA standard of 50 micrograms/L, the lifetime risk of dying from cancer of the liver, lung, kidney, or bladder from drinking 1 L/day of water could be as high as 13 per 1000 persons. It has been estimated that more than 350,000 people in the United States may be supplied with water containing more than 50 micrograms/L arsenic, and more than 2.5 million people may be supplied with water with levels above 25 micrograms/L. For average arsenic levels and water consumption patterns in the United States, the risk estimate was around 1/1000. Although further research is needed to validate these findings, measures to reduce arsenic levels in water supplies should be considered

Nanoparticle-induced neuronal toxicity across placental barriers is mediated by autophagy and dependent on astrocytes

The potential for maternal nanoparticle (NP) exposures to cause developmental toxicity in the fetus without the direct passage of NPs has previously been shown, but the mechanism remained elusive. We now demonstrate that exposure of cobalt and chromium NPs to BeWo cell barriers, an in vitro model of the human placenta, triggers impairment of the autophagic flux and release of interleukin-6. This contributes to the altered differentiation of human neural progenitor cells and DNA damage in the derived neurons and astrocytes. Crucially, neuronal DNA damage is mediated by astrocytes. Inhibiting the autophagic degradation in the BeWo barrier by overexpression of the dominant-negative human ATG4BC74A significantly reduces the levels of DNA damage in astrocytes. In vivo, indirect NP toxicity in mice results in neurodevelopmental abnormalities with reactive astrogliosis and increased DNA damage in the fetal hippocampus. Our results demonstrate the potential importance of autophagy to elicit NP toxicity and the risk of indirect developmental neurotoxicity after maternal NP exposure

Descriptions of Immature Stages of Trupanea nigricornis and T. bisetosa (Diptera: Tephritidae) from Southern California

The immature stages of the sympatric, cryptic species Trupanea nigricornis (Coquillett), a flower head-infesting fruit fly that attacks a wide range of hosts in the Asteraceae in southern California, and T. bisetosa (Coquillett), an oligophagous congener that attacks only a few hosts in the tribe Heliantheae, are described and illustrated. Detailed examination with the aid of scanning electron microscopy of the eggs, all 3 instars, and puparia of this taxonomically closely allied generalist and specialist revealed many similarities and very few differences, for instance, most puparia of T. nigricornis were shorter and narrower than those of T. bisetosa. Therefore, major differences in the host-plant specificities of these cryptic, possibly sibling, species were not reflected by substantial morphological differences among their immature stages

Ovipositor ultrastructure and oviposition behavior of the cryptic and sympatric species, Trupanea Nigricornis (Coquillett), a polyphage, and the narrowly oligophagous T. Bisetosa (Coquillett) (Diptera: Tephritidae)

Volume: 109Start Page: 385End Page: 39