Pierce's Disease
Research Updates


What is Pierce's Disease?

Pierce's Disease is a bacterial infection, which is spread by bugs that feed on grapevines, particularly the "glassy winged sharpshooter." Grapevines that become infected with PD can quickly become sick and die.

glassy-winged sharpshooter

First records of Gonatocerus dolichocerus Ashmead, Palaeoneura sp., Anagrus sp (Hymenoptera : Mymaridae), and Centrodora sp (Hymenoptera : Aphelinidae) in French Polynesia, with notes on egg parasitism of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar) (Hemiptera : Cicadellidae)

  • Author(s): Davies, N; Grandgirard, J; Hoddle, MS; Petiti, JN; Roderick, GK; Triapitsyn, SV;
  • Abstract: The glassy-winged sharpshooter, Homalodisca vitripennis (Germar) [= H. coagulata (Say)] (Hemiptera: Cicadellidae: Proconiini), invaded Tahiti in 1999 and at the time of writing this pest was widespread in French Polynesia being extremely abundant in Tahiti and Moorea. Homalodisca vitripennis is a major threat for agriculture and biodiversity. In 2004, a classical biological control program against H. vitripennis was initiated with the goal of introducing and establishing the exotic egg parasitoid Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae) in French Polynesia. As part of the preliminary studies for this program, a survey was conducted of existing natural enemies, in particular egg parasitoids of H. vitripennis. Pan trap surveys and monitoring parasitism of If. vitripennis egg masses was performed in Tahiti. The results of the pan trap surveys provide the first record of the presence of Gonatocerus dolichocerus Ashmead (Hymenoptera: Mymaridae) in French Polynesia, but surveys of H. vitripennis egg masses revealed that it does not attack eggs of this pest. However, H. vitripennis egg masses were found to be parasitized by three parasitoid species: Centrodora sp. (Hymenoptera: Aphelinidae) (on average 30%) as well as Palaeoneura sp. (> 1%,) and an undescribed species of Anagrus Haliday (Hymenoptera: Mymaridae) (> 1%). All three parasitoid species were recorded for the first time in French Polynesia.
  • Publication Date: Sep 2007
  • Journal: Pan-Pacific Entomologist