Jerome Goddard’s research while affiliated with Mississippi State University and other places

Ticks and tick-borne diseases are of increasing concern in the United States, and understanding tick behavior could be crucial to limiting the exposure of humans and other animals to ticks. Here, we wanted to understand the drivers of questing and burrowing in Amblyomma americanum and A. maculatum. We used a factorial design to assess the effects of substrate (sand, soil, and rock), temperature (16° and 22° C), tick species (A. maculatum and A. americanum), and competition (homogenous or heterogenous mixture of ticks in the arena) on tick behavior in laboratory arenas. Questing varied significantly between tick species, with 61% of A. americanum questing compared to 35% of A. maculatum. Substrate similarly affected questing, with most ticks questing in the arenas with sand (83%) compared to arenas with rock (35%) or soil (25%). Burrowing behavior was also influenced by substrate; every tick in the arenas with rock (100%) and nearly all in the arenas with soil (98%) exhibited burrowing, whereas only 10% burrowed in sand. A. americanum traveled longer distances than A. maculatum (23 ± 2.8 cm vs 9.7 ± 2.3 cm). The disparity in laboratory behavior between sand and rock/soil substrates might warrant further consideration in a field setting, as understanding factors that inhibit host-seeking behaviors of ticks can inform management of public spaces and potentially help mitigate tick-exposure.

Microenvironmental factors affect ovipositional choices and behavior in ticks. In this study, engorged female Amblyomma maculatum Koch were released in an observation arena covered with garden soil. The arena was evenly split into wet and dry sides, each containing 5 different types of structures (totaling 10). Upon release, observations at particular time points were made over 2 days as to speed, distance, actual paths traveled, and ultimate site selection, presumably for oviposition. In addition, time-lapse videography was utilized to record the track of each individual tick. This scenario was replicated 3 times with different cohorts of ticks (n = 5 per replicate). Of the total 15 ticks released in the arena, all attained a final site selection by 24 h. These final sites were 7/15 (47%) edge of arena; 2/15 (13%) under bark; 2/15 (13%) open soil; 2/15 (13%) at or near release point; 1/15 (7%) tunnel with animal fur; and 1/15 (7%) tunnel with chicken feathers. At final site selection, 11/15 (73%) subsequently burrowed into the soil, 3 of which were completely buried. Time-lapse videography revealed that most ticks (80%) explored the arena in a “looping back” fashion. Overall, engorged Gulf Coast ticks moved at an average speed of 0.09 mm/s, and the total distance traversed by the ticks averaged 2.37 m.

The larva of the ixodid tick Dermacentor parumapertus Neumann, chiefly a parasite of hares and rabbits, is redescribed using scanning electron micrographs of seven specimens derived from two engorged females collected from two black-tailed jackrabbits, Lepus californicus, at the Black Gap Wildlife Management Area, Brewster County, southwestern Texas. The use of chaetotaxy for separating the genera of Ixodidae is discussed, and a morphological key is provided for separating the larvae of D. parumapertus from those of five other Dermacentor species with partly sympatric geographic ranges.

The blacklegged tick, Ixodes scapularis Say, is one of the most important vectors of tick-borne disease agents in North America. Accordingly, it is crucial to know this species local composition, abundance, and seasonality (phenology) to help prevent tick-borne illnesses. The phenology of adult I. scapularis is reported in the scientific literature from October through May. Data from previous research in Mississippi have all supported this time frame for adult blacklegged tick activity. However, in this study, we report a collection of 13 I. scapularis from 9 widely separated areas in Mississippi during the summer and early fall of 2022 (June, July, and September). These findings are remarkable, even enigmatic, and should prompt further investigation.

Bed bugs (Hemiptera: Cimicidae) are common, hematophagous ectoparasites of humans and other animals and are experiencing an international resurgence. Cimicids have been suspected in the transmission of many disease agents, including Bartonella species; however, disease transmission of any kind has not yet been confirmed in natural disease cycles. Bartonella spp. are transmitted by a variety of arthropods, including fleas, lice, and sand flies, but the potential role of bed bugs in transmission remains unknown. In this study, we used an artificial membrane to feed rabbit blood, either infected or uninfected with Bartonella henselae Regnery et al. (Alphaproteobacteria: Bartonellaceae) to two groups of adult Cimex lectularius L. After 2 wks, the presence of B. henselae in the gut and salivary glands of bugs was assessed via PCR and transmission electron microscopy (TEM), respectively. Although 4 of 10 bed bug guts showed evidence of B. henselae, we were unable to visually detect B. henselae in any of the salivary gland TEM images.

Background: Imported fire ants aggressively sting humans, leading to a variety of local and systemic effects. Fire ants display a behavioral adaptation to survive flooding called "rafting" bringing humans into even more contact with fire ants. Methods: To assess frequency of encounters with fire ant rafts, duck hunters on the website "Duck Hunter's Forum" were asked about their experiences with the ants while wading or boating in flooded areas. All members of the group received a brief explanation and asked to respond directly if they had had such an encounter. They were then asked to fill out a short six-question survey. Results: There were 2,021 views of the thread about fire ant raft encounters with 35 (1.7%) responses. Twenty-four (68.6%) said they had experienced encounters with fire ant rafts. Six responders described purposely or inadvertently physically touching the rafts with their body parts, boat, or a paddle, causing the ants to enter their boat or to climb directly onto the hunter(s). Five respondents were stung (number of stings from "a few" to 50), describing reactions to stings as "small pustules," "whelps," and "pimple-like, puss-filled whelps." Conclusions: These results confirm fire ant rafts formed during flooding present a potential hazard to persons walking, wading, or boating in those areas. We suggest these rafts are an under-appreciated health hazard. It is reasonable to assume that people in flooded areas occasionally contact these floating rafts and are stung multiple times. We provide preliminary prevention/protection recommendations for health professionals to be shared with their patients and the general public.

Black flies (Diptera: Simuliidae) are reemerging as biting and nuisance pests in many southern states, presumably from improving water quality in creeks and rivers. Since 2009, entomologists at Mississippi State University and the Mississippi Department of Health have conducted surveys to ascertain what black fly species are present in the state as well as their geographic distribution and seasonality. These surveys revealed what appears to be a recurring, significant emergence of black flies every year around 25 December at one site in southern Mississippi. In this study, adult black flies were collected from 1 January 2018 to 31 December 2021 by hand netting in the exact same way each time at Okatoma Creek, Seminary, MS. Forty-eight collecting trips to the site over the 4-yr period yielded a total of 176 black flies, all morphologically identified as Simulium jenningsi Group Malloch. Molecular identification was successfully performed on 17 specimens collected during the December outbreaks. Of the 17 specimens analyzed, 10 and 7 specimens grouped with 100% bootstrap confidence inside clades comprising S. jenningsi or S. podostemi, respectively.

Hard ticks (Acari: Ixodidae) use their mouthparts to cut through the epidermis and insert a barbed hypostome, leading to deep inflammation of local tissues. Herein, we describe cutaneous lesion development resulting from a tick bite at seven time points over a 30-day period. This case highlights the fact that ticks may produce lasting cutaneous lesions, which may persist for at least 30 days, even without any obvious pathology or complications.

A variety of potential triggers of atrial fibrillation (AF) have been reported, including alcohol consumption, caffeine, exercise, and stress. Vagal AF triggers include gastrointestinal factors such as the amount of food consumed, types of foods, and gas and bloating. In this case report, detailed data of seven dietary and behavioral factors (many vagal) believed to be possible atrial tachycardia (AT) or AF triggers in a single patient with paroxysmal AT/AF were recorded. Episodes of AT and AF were recorded in the patient using a Medtronic loop recorder and analyzed by a cardiac electrophysiologist. To evaluate these potential triggers of AT/AF events, a general linear model with binomial family error distribution was used to fit the data. Then, a stepAIC function from the MASS package in R was used to perform a stepwise model selection using AIC (Akaike information criterion). The analysis only identified the amount of salt intake and the use of polyethylene glycol 3350 as predictors of AT/AF, and high salt intake was the only factor significantly associated with the onset of AT/AF (P < 0.05). Thus, salt intake may trigger AT/AF in ways other than via hypertension.