Sand flies Lutzomyia (Psathyromyia) shannoni (Dyar) and Lu. (Helcocyrtomyia) vexator (Coquillet) were collected for the first time in southwest Missouri and southeast Kansas, expanding the known range of these species in North America. Altogether, 680 sand flies (356 males and 324 females) were collected during trapping from May through October 2011 and identified using morphological characters. Of the total sand flies collected 315 were identified as Lu. shannoni, with 181 individuals (or 26.6% of all sand flies) trapped in Missouri and 134 individuals (or 19.7%) trapped in Kansas. Whereas 358 Lu. vexator were identified from SW MO, only a single specimen was trapped in SE KS. One male Lu. vexator with asymmetric gonostyli was trapped in Missouri. We also developed a PCR protocol to consistently and accurately distinguish Lu. shannoni from Lu. vexator based on presence or absence of a 416bp fragment from the cytochrome oxidase I gene.
Tick-borne diseases (TBDs) pose a significant risk to humans and represent one of the major factors influencing readiness within the United States’ military worldwide. Additionally, ticks and TBDs constitute major animal health problems leading to economic losses at multiple levels affecting low- and middle-income countries the hardest. Tick control is frequently hampered by issues ranging from acaricide resistance to lack of data on tick distribution and infection rates. We conducted a cross-sectional study to assess tick species distribution, host use, and rickettsial pathogen infection rate of ticks in different areas of the Uganda Cattle Corridor. We identified 4,425 hard ticks (Ixodida: Ixodidae) comprised of seven species by morphological characters with 3,315 ticks collected from four locations during the dry season and 1,110 ticks from one location during the wet season. Rickettsial pathogen prevalence was assessed in ticks collected from two districts to determine the minimum infection rate compared across seasons, village location, and tick species. We found statistically significant differences in the abundance and distribution of tick species among districts in the dry season, host animal species, and the proportion of rickettsial positive pools between villages. Seasonality, village location, and tick species do not affect the minimum infection rate of rickettsial pathogens of ticks in Uganda, but village location affects the proportion of positive tick pools. These results indicate geographical and seasonal differences among pathogen-harboring ticks contributing to our understanding of the current distribution of ticks and TBDs in Uganda.
Theridion evexum constructs webs in the understory of wet middle-elevation forests in Costa Rica. The spiders construct retreats by curling a leaf and produce a mesh in front of the opening. Long, more or less vertical viscid lines extend from the mesh, and are attached to other leaves. The spiders feed on a large variety of prey (e.g. flies, beetles, earwigs, centipedes), indicating that both flying and walking arthropods are trapped in their webs. The wrapping threads have large viscid globules that rapidly disperse on the prey's surface, forming a thin film. Adult males guard subadult females in their retreats, possibly waiting for them to moult and copulate. As part of courtship, the male places his pedipalps several times on the female's mouthparts, then one pedipalp on her mouthparts and the other on her epigynum before insertion. Eggs were parasitised by Baeus (Scelionidae) and juveniles and subadults by Zatypota petronae (Ichneumonidae). Eggs were eaten by Argyrodes sp. (Theridiidae), and Solenopsis ants stole prey accumulated in the retreats and attacked spiderlings and older juveniles.
During metamorphosis, holometabolous insects undergo significant remodeling of their midgut and become able to cope with changes in dietary requirements between larval and adult stages. At this stage, insects must be able to manage and recycle available food resources in order to develop fully into adults, especially when no nutrients are acquired from the environment. Autophagy has been previously suggested to play a crucial role during metamorphosis of the mosquito. Here, we investigate the overall morphological changes of the midgut of the sand fly during metamorphosis and assess the expression profiles of the autophagy-related genes ATG1, ATG6, and ATG8, which are associated with various steps of the autophagic process. Morphological changes in the midgut start during the fourth larval instar, with epithelial degeneration followed by remodeling via the differentiation of regenerative cells in pre-pupal and pupal stages. The changes in the midgut epithelium are paired with the up-regulation of ATG1, ATG6 and ATG8 during the larva-adult transition. Vein, a putative epidermal growth factor involved in regulating epithelial midgut regeneration, is also up-regulated. Autophagy has further been confirmed in sand flies via the presence of autophagosomes residing within the cytoplasmic compartment of the pupal stages. An understanding of the underlying mechanisms of this process should aid the future management of this neglected tropical vector.
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