Submitted to: Florida Entomologist
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/1/2004
Publication Date: 6/1/2005
Citation: Virla, E., Logarzo, G., Jones, W.A., Triapitsyn, S. 2005. Biology of gonatocerus tuberculifemur (hymenoptera: mymaridae) an egg parasitoid of the sharpshooter tapajosa rubromarginata (hemiptera: cicadellidae). Florida Entomologist. 88:67-71 Interpretive Summary: Pierce's disease (PD) of grape is caused by the bacterium which threatens California wine, table, and raisin grape-dependent industry valued at $33 billion, and almond leaf scorch threatens the $730 million almond industry. The introduction of the glassy-winged sharpshooter (GWSS) into southern California in the 1990's has resulted in epidemics of disease in grape inTemecula, in Riverside County and in the lower San Joaquin Valley un Kern County. Currently, there are no effective treatments for Pierce's disease of grapevines and almond leaf scorch disease. So far, native natural enemies cannot control population of GWSS, so, a classical biological control program was started as part of the management control strategy of this pest. Since November of 2000, the ARS has performed a survey of egg parasitoids in South America. In this study, the biological traits of the mymarid wasp native to Argentina are reported. This egg parasitoid is a prospective candidate for biological control of the GWSS in the United States. Aspects of the parasitoid biology (egg-laying behavior, egg viability, duration of developmental stages, sex ratio, longevity) were studied as an initial step to utilize this parasitoid in control strategies against GWSS.
Technical Abstract: Biological traits of a prospective candidate for biological control of the glassy-winged sharpshooter (GWSS), Homalodisca coagulata (Say) (Hemiptera: Cicadellidae), in the United States, are herein reported. The mymarid wasp, Gonatocerus tuberculifemur (Ogloblin), is an egg-parasitoid native to Argentina and its first known host is Tapajosa rubromarginata (Signoret), a species related to GWSS. Laboratoty studies were made in Tucumán and buenos Aires Provinces, Argentina. Seven generations were maintained in the laboratory, and only one adult emerged per host egg. The average parasitism rate was 71.6 % per total eggs. Although eggs of all ages (4 to 190 h old) were parasitized, wasps did not emerge from eggs over 96 h old. The percentage of wasp emergence was 64.1 % (from eggs between 4 and 190 hrs old). Over the seven generations that G. tuberculifemur was reared, the parasitism rate ranged between 55-84%. This percentage of emergence increased as the parasitoid generations progressed. The duration of development from oviposition to adult emergence of G. tuberculifemur was 12.6 plus or minus 1.8 days (range 11.4-13.0) at 22.5-27.5 degrees C and 70-80% RH. The duration of development was significantly affected by sex and temperature. Males developed faster than females (12.2 vs. 12.8 respectively).The sex ratio was not significantly different. Average adult longevity was 6.73 plus or minus 3.93 days fed on honey. Male and female longevity was not significantly different. Oviposition and mating behavior are described.