Effects of Photoperiod on Nymphal Diapause in Amblyomma americanum (Acari: Ixodidae)

Jm, Pound; Je, George

doi:10.1093/jmedent/25.6.479

Cited by 9 publications

(17 citation statements)

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“…This tick began ovipositing between 12 and 26 April and the resulting eggs, similar in appearance to those observed for Argas reflexus (Dautel and KnOlle, 1998), were viable until 12 May. This ovipositional delay is characteristic of developmental diapause as described by Belozerov (1982), and in A. americanum (Pound and George, 1988), A. marmoreum (Fielden et al, 1992), A. triguttatum triguttatum (Guglielmone and Moorhouse, 1986) and D. andersoni (Pound and George, 1991). However, the ticks in this study that were fed outside or inside and returned to the laboratory showed no delay.…”

Section: Resultssupporting

confidence: 70%

Winter-exposedAmblyomma americanumandDermacentor variabilisadults (Acari: Ixodidae) do not exhibit behavioral diapause

Stewart

Tammariello

Fielden

et al. 1998

International Journal of Acarology

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Behavioral diapause was evaluated for overwintering Amblyomma americanum (L.) and Dermacentor variabilis (Say) laboratory strains. Ticks were placed in outdoor arenas on 30 Oct. 1996. On 9 Jan. 1997 specimens were removed for infestation on New Zealand white rabbits exposed to outside conditions or in a temperature and photoperiod controlled vivarium. Upon repletion, females were placed in tick rearing chambers indoors or retnmed to natural conditions. Both tick species readily attached when placed outside or in controlled conditions. Significantly more D. variabilis (63%) were attached than A. americanum (47%) three days post infestation. All females of both species failed to oviposit and perished when returned to natural winter conditions, while all successfully laid viable eggs under standard laboratory conditions. Based on the criteria of ability to attach, feed and oviposit, behavioral diapause was not in evidence during January for lone star and American dog tick females.

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Section: Resultssupporting

confidence: 70%

Winter-exposedAmblyomma americanumandDermacentor variabilisadults (Acari: Ixodidae) do not exhibit behavioral diapause

Stewart

Tammariello

Fielden

et al. 1998

International Journal of Acarology

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“…Survival of fed larvae to the nymphal stage was highest in the 10:14 group (100%), but no signiÞcant differences in survival to the nymphal stage were observed between the photoperiod groups. In comparison, Pound and George (1988) previously found that fed A. americanum larvae molted to nymphs in a shorter time under regimes that had decreased hours of light (0:24 and 10:14) and that ticks exposed to regimes with increased hours of light had decreased survival to the nymphal stage. For A. maculatum, differences in larval mean molting times or mortality could not be attributed to effects of the various photoperiodic regimes.…”

Section: Discussionmentioning

confidence: 76%

“…Previous photoperiodic studies conducted on A. americanum found that by day 25 after detachment all ticks that had been held under 14:10 during both developmental periods had either molted or were in postapolysial stages of molting (Pound and George 1988). Therefore, for this study, ticks under all of the photoperiod regimes were categorized as either diapausing or nondiapausing on day 25 after detachment.…”

Section: Methodsmentioning

confidence: 96%

“…Therefore, for this study, ticks under all of the photoperiod regimes were categorized as either diapausing or nondiapausing on day 25 after detachment. Ticks were scored as being in a state of developmental diapause on day 25 after detachment if there was no evidence of preapolysial posturing (Pound and George 1988). Mortality was determined by a blackening of the idiosoma and shrinkage and dehydration evidenced by a medial dorso-ventral compression.…”

Section: Methodsmentioning

confidence: 99%

“…A. t. triguttatum also has a varied range and can be found in more temperate areas of Australia as well as semidesert conditions (Roberts 1962(Roberts , 1970Guglielmone 1992). The previous research by Pound and George (1988) and Guglielmone and Moorhouse (1986) demonstrating the effects of photoperiod on two Amblyomma species that are able to adapt and survive over such a broad distribution and climate ranges led us to investigate the effect of photoperiod on a predominantly tropical Amblyomma species, the Gulf Coast tick, Amblyomma maculatum Koch (Acari: Ixodidae).…”

mentioning

confidence: 96%

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Effects of Photoperiod on Reproduction, Nymphal Developmental Timing, and Diapause inAmblyomma maculatum(Acari: Ixodidae)

2009

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Female engorgement weight, oviposition, and molting times of larvae and nymphs of Amblyomma maculatum Koch (Acari: Ixodidae) were studied at various photoperiods under constant humidity and temperature in the laboratory. Ticks were held at photoperiods of 0:24, 10:14, 12:12, or 14:10 (L:D) h from egg through unfed nymphal stage and then at either the same or a different regime from fed nymphs to adults. No significant effects were observed on oviposition, female engorgement weights, survival, or molting time to unfed nymphs. Nymphal molting times were significantly shorter at the short-day regime (10:14) during the larval stage and 12:12 during the nymphal stage compared with those held at either 14:10 during both life periods or at 0:24 during both life periods. Longer molting times also were observed in ticks held at 12:12 during the larval phase and either 10:14, 12:12, or 0:24 during the nymphal phase compared with 14:10 during both life periods or 0:24 during both life periods. Ticks held at 10:14 during the larval phase and at 0:24 or 10:14 had longer molting times compared with those at 14:10 or 0:24 during both life periods. No differences in survival to either nymphal or adult stages were observed at any regime, and at day 25 no individuals were observed to be in developmental diapause. This study demonstrates that developmental diapause does not seem to be photoperiodically induced in fed nymphal A. maculatum in the laboratory.

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Predicting the potential distribution of Amblyomma americanum (Acari: Ixodidae) infestation in New Zealand, using maximum entropy-based ecological niche modelling

et al. 2020

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Although currently exotic to New Zealand, the potential geographic distribution of Amblyomma americanum (L.), the lone star tick, was modelled using maximum entropy (Max-Ent). The MaxEnt model was calibrated across the native range of A. americanum in North America using present-day climatic conditions and occurrence data from museum collections. The resulting model was then projected onto New Zealand using both present-day and future climates modelled under two greenhouse gas emission scenarios, representative concentration pathways (RCP) 4.5 (low) and RCP 8.5 (high). Three sets of WorldClim bioclimatic variables were chosen using the jackknife method and tested in MaxEnt using different combinations of model feature class functions and regularization multiplier values. The preferred model was selected based on partial receiver operating characteristic tests, the omission rate and the lowest Akaike information criterion. The final model had four bioclimatic variables, Annual Mean Temperature (BIO 1), Annual Precipitation (BIO 12), Precipitation Seasonality (BIO 15) and Precipitation of Driest Quarter (BIO 17), and the projected New Zealand distribution was broadly similar to that of Haemaphysalis longicornis Neumann, New Zealand's only livestock tick, but with a more extensive predicted suitability. The climate change predictions for the year 2050 under both low and high RCP scenarios projected only moderate increases in habitat suitability along the mountain valleys in the South Island. In conclusion, this analysis shows that given the opportunity and license A. americanum could and would successfully establish in New Zealand and could provide another vector for theileriosis organisms.

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Effects of Photoperiod on Nymphal Diapause in Amblyomma americanum (Acari: Ixodidae)

Cited by 9 publications

References 0 publications

Winter-exposedAmblyomma americanumandDermacentor variabilisadults (Acari: Ixodidae) do not exhibit behavioral diapause

Winter-exposedAmblyomma americanumandDermacentor variabilisadults (Acari: Ixodidae) do not exhibit behavioral diapause

Effects of Photoperiod on Reproduction, Nymphal Developmental Timing, and Diapause inAmblyomma maculatum(Acari: Ixodidae)

Predicting the potential distribution of Amblyomma americanum (Acari: Ixodidae) infestation in New Zealand, using maximum entropy-based ecological niche modelling

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