Investigation of Relationships Between Temperature and Developmental Rates of TickIxodes scapularis(Acari: Ixodidae) in the Laboratory and Field

Abstract

Relationships between temperature and preoviposition, preeclosion, and premolt developmental periods for the tick Ixodes scapularis Say were investigated by holding field-collected ticks in the laboratory at temperatures of 0 to 32 degrees C at constant daylength. The duration of these developmental periods decreased significantly with increasing temperature. Host of origin, prior storage at 4 degrees C, and season of collection of the ticks were also significantly associated with variations in the duration of the preoviposition period. For each developmental stage, the effect of temperature on development rate was best described as a power relationship. Laboratory-derived relationships were used to predict dates for molting, oviposition, and eclosion of engorged larvae and nymphs, engorged adult females and egg masses, respectively, placed in the field during 1989-1992. Predicted dates for oviposition by adult females, eclosion of eggs, and molting of engorged larvae were within 2 wk of the observed dates, and field-observed seasonal activity of questing larvae and nymphs also was predicted well by laboratory data. Molting of engorged nymphs and seasonal activity of questing adult ticks were, however, poorly predicted. Our findings suggest that duration of development in the field, of larvae from engorged adult females, and of nymphs from engorged larvae, may be explained largely by temperature effects alone, whereas emergence of adult I. scapularis from engorged nymphs may depend on temperature-independent diapause phenomena. The significance of these findings for understanding current and future distributions of I. scapularis, and of the pathogens it transmits, is discussed.

Meteorological Influences on the Seasonality of Lyme Disease in the United States

“…44 The host-seeking behavior of the nymphal stage is most relevant for the transmission of B. burgdorferi to humans because nymphs are believed to be responsible for most human infections. Interstadial development rates in ixodid ticks typically increase with increasing temperature, [6][7][8]46,47 and the timing of nymphal host seeking is correlated with ambient temperatures. 6,43,[48][49][50] The negative relationship between cumulative GDD through Week 20 and the week of the year when the Lyme disease season begins, indicating that higher cumulative GDD at Week 20 are associated with an earlier start to the season (or the positive relationship between the number of weeks to reach 300 GDD and the week when the Lyme disease season begins), is likely due in part to this positive effect of temperature on the activity of newly emerged nymphs in the spring.…”

“…5 The timing of peak nymphal activity depends on both temperature and moisture. Ixodid tick development rates increase with temperature, [6][7][8][9] and temperature also influences nymphal questing activity. [10][11][12] Nymphal questing activity may also be reduced when relative humidity is low or saturation deficit is high, [11][12][13] or when precipitation is heavy.…”

Comparison of efficiency and reproductive aptitude indexes between a reference and field strains of the cattle tick Rhipicephalus (Boophilus) microplus, in Sinaloa, Mexico

“…The success or failure in egg viability has important biological ramifications, for example, in models that calculate reproductive success of females located at the edges of the distribution range for the species (PRICE, 1977) where not only egg-laying values are considered, but also hatchability and final larvae production. Reproductive capacity of the studied strains provides reference values that should be considered for different uses, as the information generated in the laboratory can be useful to predict behavior in the field (DE LA VEGA; DIAZ, 1996;DE LA VEGA, 2000;OGDEN et al, 2004).…”

The Biological Survey of Canada: A Personal History

“…Dispersal by fed females following disengagement is minimal though they do seek protected microhabitats in which to lay eggs (Stafford 1992). Temperature influences, in a non-linear fashion, the duration of the pre-oviposition and oviposition period in I. scapularis (Ogden et al 2004). In field studies on Long Point, Ontario, regardless of whether females fed in the fall or subsequent spring, eggs were laid during late April and early May (Lindsay et al 1998).…”

“…Engorged larvae (and nymphs) tend to detach from their hosts during the day; the resulting nymphs accumulate in the nest of the host, where they have a higher probability of encountering a host and obtaining a second blood meal (Mather and Spielman 1986). Timing of the larval moult to nymphs is dependent primarily on temperature; larvae that feed later in the year (late July onward), delay moulting until the following year (Ogden et al 2004). However, fewer larvae successfully moult if they overwinter than those that moult before overwintering.…”