First Report of Chagas Disease Vector Species Triatoma sanguisuga (Hemiptera: Reduviidae) Infected with Trypanosoma cruzi in Delaware.

In July and October 2023, two live triatomine bugs were found inside a home in New Castle County, Delaware. The bugs were identified as Triatoma sanguisuga, the most widespread triatomine bug species in the United States. Triatoma sanguisuga is a competent vector of Trypanosoma cruzi, the causative agent of Chagas disease. The two specimens were tested via real-time PCR (qPCR) for infection with T. cruzi, and one of the specimens was positive. Despite T. sanguisuga being endemic to the area, attainment of accurate species identification and T. cruzi testing of the bugs required multiple calls to federal, state, private, and academic institutions over several months. This constitutes the first report of T. sanguisuga infected with T. cruzi in Delaware. In addition, this is the first published report of T. sanguisuga in New Castle County, the northernmost and most densely populated county in Delaware. New Castle County still conforms to the described geographic range of T. sanguisuga, which spans from Texas to the East Coast of the United States. The T. cruzi infection prevalence of the species has not been studied in the northeastern United States, but collections in southern states have found prevalences as high as 60%. The Delaware homeowner's lengthy pursuit of accurate information about the vector highlights the need for more research on this important disease vector in Delaware.

Oviposition response of green lacewings (Neuroptera: Chrysopidae) to aphids (Hemiptera: Aphididae) and potential attractants on pecan.

Pecan foliage is attacked by three species of aphids [Monellia caryella (Fitch), Melanocallis caryaefoliae (Davis), and Monelliopsis pecanis Bissell], resulting in damage that can reduce tree nut yield. In this study, we assayed the ovipositional response of the green lacewing Chrysoperla rufilabris (Burmeister) to M. caryella and M. caryaefoliae at high and low aphid densities and the development of C. rufilabris larvae when fed solely on each of the three pecan aphid species. During 2004 and 2005, combinations of attractants and food sprays were applied to pecan trees in an orchard to monitor green lacewing ovipositional response. We found that C. rufilabris laid more eggs on seedling trees infested with the M. caryella (at both high and low densities) than on seedlings infested with M. caryaefoliae. Development of C. rufilabris was unaffected by aphid species. At least one attractant/food spray treatment applied to trees in an orchard significantly increased green lacewing oviposition for three of the five treatment dates over both years. These results show that larvae of C. rufilabris will consume all aphid species attacking pecan, even though female ovipositional response can differ for aphid species. It is likely that combinations of attractants and food sprays can be used to enhance green lacewing populations in orchards.

Effect of Steinernema glaseri-infected host exudates on movement of conspecific infective juveniles.

The entomopathogenic nematode's decision to infect a host is paramount because once the decision is made it is irrevocable; nematodes that invade a host either develop and achieve reproductive success, or they die. Entomopathogenic nematodes that have a cruiser foraging behavior, such as Steinernema glaseri, follow host-associated cues to locate insects to infect. Most of the host finding and infection dynamics research has focused on the infective juvenile nematodes' responses to cues from live insects such as host-associated volatiles and host contact cues. Few studies focus on how previously infected hosts influence infective juvenile infection behaviors. We investigated how exudates from nematode-infected hosts affect the behavior of S. glaseri infective juveniles. We hypothesized that the infective juvenile's behavioral response to cadavers would change as the state of a nematode-infected host changes during pathogenesis. We examined the effect of exudates collected from infected hosts on infective juvenile locomotory behavior. We detected no effects on nematode repulsion or attraction from exudates produced within the first 48h post-infection. We observed repulsion from accumulated exudates during the 3-48, 3-72, 3-120, and 3-144h intervals. Repulsion from exudates was observed during the 48-66, 72-90, and 120-138h intervals in experiments evaluating daily exudate emissions. The repellent effect of infected host exudates may result in an infective juvenile discriminating between suitable and unsuitable hosts.