Biologia de Dermanyssus gallinae (De Geer, 1778) (Acari, Dermanyssidae) em condições de laboratorio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The purpose of this work was to study the biological cycle of D. gallinae in the laboratory at temperatures of 15, 20, 25, 30 and 35ºC, to determine the fecundity, the fertility and the influence of fasting on fertility, as well as the thermal requirements for D. gallinae. The mean cycle duration of the different phases (in hours), at different temperatures was: Pre-oviposition: 86,7h at 15 °C; 24h at 20 °C; 24,21h at 25 °C; 24,24h at 30 °C and 24,05h at 35 °C. Egg: 214,30h at 15 °C; 67,7h at 20 °C; 42,11h at 25 °C; 38,70h at 30 °C and 51,77h at 35 °C. Larva: 163,44h at 15 °C; 34,73h at 20 °C; 29,44h at 25 °C; 24,85h at 30 °C and 32,23h at 35 °C. Protonymph: 81,25h at 15 °C; 73,06h at 20 °C; 30,35h at 25 °C; 25,66h at 30 °C and 26,4h at 35 °C. Deutonymph: 145,02h at 15 °C); 63,63h at 20 °C; 38,37h at 25 °C; 27,24h at 30 °Ca and 37,6h at 35 °C. Total cycle lenght: 690,75h (28 days) at 15 °C, 263,12h (11 days) at sob 20 °C, 164,63h (7 days) at 25 °C, 140,69h (6 days) at 30 °C and 172,04h (7 days) at 35 °C. The development of D. gallinae was higher at temperature of 30 °C, exhibiting the highest viability in the different phases and the shorter development time. The cycle time of D.gallinae decreased with the increase of temperature, from 690,75 at 15 °C to 140,69 at 30 °C. At 35 °C there was an increase in the cycle length and a drop in viability in all phases, suggesting that in warmer seasons D. gallinae population may decrease or even disappear for a period of time. No variations were found in pre-oviposition time at temperatures of 20 °C, 25 °C, 30 °C and 35 °C. In the experiment where female samples were kept from 1 to 12 days of fasting, oviposition occurred up to the 11th day, with the highest rate up to the 3rd day, decreasing from the 4th day. We recommend that the interval of three days between feedings is the most adequate to maintain D. gallinae in the laboratory. Four or more days of interval between feedings are not recommended due to the low fecundity, less than 67,1%, found during those periods of time. The results on fecundity showed that the females began to lay eggs just after the first blood meal and continued to lay eggs up to the seventh day after the meal. The highest percentage of females (58%) laid eggs after the first meal. After the second meal this pencentage began to decrease until the eighth meal, when only one female was present, but it died before it was able to lay eggs. Dermanyssus gallinae females had a total of 7 oviposition cycles totaling 25 eggs. The thermal requirements for D. gallinae were determined, for basal temperature (Tb), thermal constant (k), determination coefficient (R2) and regression equations for preoviposition, egg, larva, protonymph and deutonymph phases. Different values for thermal requirements were found for each developmental phase of D. gallinae. Based on isothermal maps the incidence of D. gallinae in São Paulo State was estimated, verifying that it can develop continuously in São Paulo State, with a decrease in its population numbers during the winter, varying from 15 to 42 generations per year

ASSUNTO(S)

fecundity development thermal requirements fecundidade acaros hematofagos haematophagous mites graus-dia galinha hens

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