Progress 06/01/07 to 09/30/08

Outputs
OUTPUTS: Chromolaena odorata (L.) R. M. King and H. Robinson (Asteraceae) is of Neotropical origin. Since its introduction as an ornamental plant in 1845, it has spread throughout humid tropical Asia, Africa and Micronesia and become a serious invasive weed. It is perennial, forms thickets and grows to a height of three meters. It is a problem mostly in plantations, pastures, vacant lots, disturbed forests, and wildlife reserves, but not in annual-cropping fields. Attempts to control this weed by mechanical, cultural, and chemical means proved either uneconomical or ineffective. Biological control has proven effective and it has been developed and adapted in several countries, where this weed is a problem. The gall fly, Cecidochares connexa (Macquart) (Diptera: Tephritidae) is considered as one of the effective agents, which induces galls both on the terminal- and axillary-vegetative meristems of C. odorata. The gall fly Cecidochares connexa (Macquart) was imported from Indonesia to Guam in 1998. The following are the objectives: 1) Study the biology of the gallfly, 2) Evaluate the reduction in plant growth and seed production due to the galls, 3) Determine the spatial and temporal spread of the gallfly in Guam, 4) Identify the local natural enemies recruited by this fly and to evaluate the possible impact of the natural enemies on the gallfly population, and 5) Evaluate the interaction of the gallfly and P. pseudoinsulata in suppressing C. odorata. PARTICIPANTS: R. Muniappan, Program Director, IPM CRSP, Virginia Tech, Blackburg, VT TARGET AUDIENCES: Guam Department of Agriculture and growers PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
It was field established at one spot in north central port of Guam, and subsequently its spatial and temporal spread in Guam was monitored. Biology of the gall fly is presented. No relationship between the number of larvae in a gall and the dimensions of the gall (length and width) existed. The most frequent number of pupae found in a gall was three, although the range was between one and seven. The sex ratio of the flies emerged from the galls was 1:1 irrespective of number of larvae in a gall. C. connexa-induced galls established a nutrient sink as a result of the formation of a nutritive tissue along the walls of the larval chamber. Younger galls had more mineral nutrients, viz., Ca, Fe, K, Mn, and Zn, and these minerals depleted as the galls matured. Galls developing on the terminal meristems reduced the vegetative growth of C. odorata.

Publications

• Lai,P.Y.,G.V.P.Reddy,and R.Muniappan (2007). Proceedings of the Seventh International Workshop on Biological Control and Management of Chromolaena odorata and Mikania micrantha,119pp.
• Muniappan, R.,K.Englberger, and G.V.P. Reddy (2007). Biological control of Chromolaena odorata in the American Pacific Micronesian Islands. Proceedings of the Seventh International Workshop on Biological Control and Management of Chromolaena odorata and Mikania micrantha,Taiwan,pp.49 to 52.
• Zachariades,C., M. Day,R.Muniappan,and G.V.P.Reddy(2009). Chromolaena odorata (L.) King and Robinson (Asteraceae). Biological Control of Tropical Weeds Using Arthropods.Cambridge University Press,Cambridge,UK,pp.130 to 162.

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Few insecticides have proven effective in control of this scale, however, the difficulty of application of insecticides in the forest areas where C. micronesica is abundant, proved this method impractical. Classical biological method is the only option available to suppress this exotic invasive pest. It is one of the major components in the management of CAS and it has been actively pursued Richard Baranowski of the Tropical Research and Education Center at Homestead, Florida, imported the parasitoid, Coccobius fulvus Compere and Annecke (Hymenoptera; Aphelinidae) and the predatory beetle, Cybocephalus nipponicus Endrody-Younga (Coleoptera: Cybocephalidae) from Thailand and released them in 2002. A ladybird, Rhyzobius lophanthae Blaisdell (Coleoptera: Coccinellidae) was imported from Hawaii and released it Guam in 2005 (Moore, A. University of Guam, pers. comm.). Coccobius fulvus from Florida has been introduced to Pureto Rico, U.S. Virgin Islands (D. Meyerdirk, APHIS, USDA. pers. comm.). A strain of C. fulvus from China was received from Dr. Ru Nguyen, Florida Department of Agriculture and Consumer Services and released in August-September 2005 in Guam. In Taiwan, the predatory beetle, C. nipponicus received from Thailand has been released at Taitung on October 15, 2005 and at Taichung and Pingtung on November 15, 2005 (Po-Yung Lai, pers. comm.). The introduced parasitoids C. fulvus and the predatory beetle, C. nipponicus are not able to suppress the population of CAS below the economic level in Florida. Hence further attempts are being made for introduction of additional natural enemies (Cave, 2005). The parasitoids, Arrhenophagus chionaspidis Aurivillius (Hymenoptera: Encyrtidae), Pteroptrix chinensis (Howard) (Hymenoptera: Aphelinidae), Aphytis lepidosaphes Compere (Hymenoptera: Aphelinidae), and Thomsonisca sankarani Subba Rao (Hymenoptera: Encyrtidae) were received in quarantine in Gainesville, Florida by Dr. Ru Nguyen but attempts at rearing and further study are being directed towards A. chionaspidis only (Cave, 2005). Dr. Nguyen has also observed Aprostocetus sp. possibly purpureus Girault (Hymenoptera: Eulophidae) and Encarsia sp. (Hymenoptera: Aphelinidae) parasitizing CAS in Vietnam (Cave, 2005). Within a relatively short period of its introduction, CAS has threatened with extinction of the endemic species, Cyacs micornesica in Guam and Cycas taitungensis in Taiwan. Currently the options available to tackle the menace of this pest are chemical and biological control methods. Chemical control is feasible only in the urban areas and it is difficult to adopt in the habitats of the native and endemic cycads. Further it is cost and labor intensive and risk interference with insect pollinators (IUCN/SSC Cycad Specialist Group-Subgroup on Invasive pests, 2005). Biological control is the most cost and labor-effective method for controlling CAS and it is the standard approach for long-term control of introduced exotic scale pests. PARTICIPANTS: Z.T. Cruz, Reserch Assistant-II and Ray Gumataotao, Field Technician has been carrying out monthly surveys and also responsible for analyzing the data. They are also involved in maintain the cultures of Coccobius fulvus in the laboratory. Dr. Ru Nguyen, Florida Department of Agriculture and Consumer Services, has been supplying the cultures of Coccobius fulvus (Thailand strain) and Arrhenophagus chionaspidis to Guam. Additionally he will assist us in rearing these parasitoids. TARGET AUDIENCES: Scientific communities: The final results will be disseminated to the scientific community by publishing in journals and technical reports. Farming community: Farmers are being informed of the benefit of project through demonstration and outreach activities. General public are being informed through news media, brochures and publishing in local newspapers. PROJECT MODIFICATIONS: We are trying to introduce another parasitoid, Arrhenophagus chionaspidis which parasitizes male of CAS in April.

Impacts
Cycad aulacaspis scale (CAS), Aulacaspis yasumatsui is a native of Southeast Asia in the region between the countries, Thailand and southern China. Its accidental introduction in to Florida was first observed 1995. Since then, it got introduced to Alabama, California, Hawaii, Georgia, Louisiana, South Carolina, Texas, Guam, Puerto Rico, Virgin Islands and Taiwan through the legal trade of cycad plants especially the species, Cycas revoluta. CAS has been recorded over 22 species of cycads in Florida. It has killed several thousands of cycads in the introduced states, countries and territories. In Guam and Taiwan, CAS has been threatening with extinction of the endemic cycads, Cycas micronesica and Cycas taitungensis, respectively. A ladybird, Rhyzobius lophanthae introduced from Hawaii in early 2005 has established but it does not provide adequate control of CAS. A parasitoid Coccobius fulvus (China strain) from Florida was released at the Marbo area in the north central part of Guam in later part of 2005. We will also be introducing the parasitoid, C. fulvus (Thailand strain) from Florida at Talofofo, a place in south central part of Guam. The out come from the project will greatly help in managing the population of A. yasumatsui not only in Guam but also the techniques can be used for other islands.

Publications

• No publications reported this period