Acute Exposure to Low-Dose Radiation Disrupts Reproduction and Shortens Survival of Wasmannia auropunctata (Hymenoptera: Formicidae) Queens

LUIS A. CALCATERRA, CAROLINA COULIN, JUAN A. BRIANO, AND PETER A. FOLLETT

JOURNAL OF ECONOMIC ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Lugar: Lanham; Año: 2012 vol. 105 p. 817 - 822

0022-0493

Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products exported from Hawaii. The radiotolerance of the invasive little Þre ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae: Myrmicinae), was studied to determine a dose sufÞcient for its control. Queens from each of five laboratory microcolonies started from Þve geographic locations in Argentina were irradiated at 20, 50, 70, or 100Gy or left untreated as controls and then followed for 13 wk to observe colony growth. In general, queen survivorship, and the number of eggs, larvae, and pupae observed in the microcolonies decreased with increasing irradiation dose. In the 50-, 70-, and 100-Gy treatments, the number of eggs observed was reduced by 68, 66, and 76%, respectively, compared with untreated control microcolonies. The number of larvae in the 50-, 70-, and, 100-Gy treatments was reduced by 99.6%, and only one pupa was observed in the 50-Gy treatment and none in the 70- and 100-Gy treatments during the 13-wk experiment. Queens in the 100-Gy treatment had signiÞcantly reduced longevity compared with queens in the other treatments. Radiation doses
70 Gy stopped reproduction in W. auropunctata queens and should be sufÞcient as a phytosanitary treatment. Information from additional invasive ants in Myrmicinae and other subfamilies is needed before recommending a generic irradiation treatment for ants.