Desiccation and egg viability of the ragwort flea beetle,Longitarsus flavicornis (Coleoptera: Chrysomelidae) |
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| Authors: | K.J.B. Potter J.E. Ireson G.R. Allen |
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| Affiliation: | 1. CSIRO Sustainable Ecosystems and Cooperative Research Centre for Forestry , Private bag 12, Hobart, Tasmania, 7001, Australia;2. Tasmanian Institute of Agricultural Research , University of Tasmania , 13 St. John's Avenue New Town, Tasmania, 7008, Australia;3. School of Agricultural Science/Tasmanian Institute of Agricultural Research , University of Tasmania , Private Bag 54, Hobart, Tasmania, 7001, Australia |
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| Abstract: | A study was conducted to investigate the effect of desiccation on the survival of eggs of Longitarsus flavicornis. Eclosion of L. flavicornis eggs in laboratory trials decreased with increasing desiccation time between 0 days (93% hatching) and 42 days (no egg hatching) at 50±2% relative humidity and 23±2°C. Probit analysis indicated that 25, 50 and 99% mortality of L. flavicornis eggs occurred after 5.7, 9.3 and 50.4 days desiccation, respectively. Egg development varied between a minimum of 8 days at 7 days desiccation to a maximum of 15 days at 28 days desiccation. Hatching span did not differ between treatments with all eggs hatching within 12 days of each other. A relative humidity of 88–100% was measured under ragwort rosettes in non-drought field conditions. This would be expected to facilitate successful egg eclosion. However, the occurrence of summer drought could be detrimental to egg survival. |
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| Keywords: | desiccation egg viability biological control Longitarsus flavicornis |
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