Biological control of Aulacaspis yasumatsui Ronald D. Cave * lassical biological control of cycad lophanthae is a coccoidopha- A 2.5-year study to look at the popu- C aulacaspis scale (CAS) began in 1998 gous predator native to . This lation dynamics of CAS on a per plant when Dr. Richard Baranowski, of the UF is considered by many to be one basis is drawing to a close. The study Tropical Research & Education Center of the most economically important also examines rates of parasitism by C. at Homestead, imported and released a natural enemies of armored scale in- fulvus in relation to pest density and (Coccobius fulvus) and a pred- sects (Yus 1973, Rosen 1990, Stathas time of year. In general, overall parasit- ator ( nipponicus) from 2001). This beetle has been released all ism is about 30-40%, which is insufficient Thailand against A. yasumatsui (Howard over the world to control a plethora of to provide adequate control of CAS. et al. 1999). Although these natural scale (Honda & Luck 1995). Cooperation from UF extension agents is enemies are established in south Flori- There are many examples of successful allowing us to collect samples to exam- da, they seem not to provide much control of scale using R. lophan- ine geographic variation in parasitism. control (personal observation). The thae especially in the Mediterranean Also being studied, in the laboratory, ladybird beetle region. Then again there have been are the developmental times of the was introduced into 1894 for some very high profile failures as well scale and C. fulvus at different temper- control of other armored scales but such as the inability of R. lophanthae to atures. reportedly provides some control of CAS control the red scale. (Hara et al. undated). Recently, this My research on the biological con- 2. Study of , biology and same beetle was released in Guam. trol of CAS currently focuses on the pesticide susceptibility of the predator following areas: Cybocephalus nipponicus At the time of its introduction by Dr. *Indian River Research & Education Center, 1. Study of population dynamics of CAS Baranowski, the predatory beetle Cyb- University of , 2199 S. Rock Road, Ft. Pierce, FL 34945 and parasitism by Coccobius fulvus ocephalus was being called C. binotatus. The Cycad Newsletter 28(5) December 2005 Page 8 As part of a Ph.D. dissertation, my grad- Vietnam, then the Ryukyu Islands and $50,000 for 2.5 years including M.Sc. uate student Trevor Smith has done a may be alternate areas for student stipend revision of this in exploration. and found that the introduced 3. Exploration to other areas of Asia, by Dr. Baranowski were actually C. nip- Coccobius fulvus not only parasitizes such as Hainan (), Ryukyu Is- ponicus, a species already present in CAS but also attacks the arrowhead lands, Okinawa, , Indonesia, Florida since at least 1990. Trevor has scale, Unaspis yanonensis (Kuwana) and , needs to be con- studied the life history of C. nipponicus (Furuhashi & Nishino 1983), which is a ducted to find all possible biological with CAS as prey and has conducted an pest of in China and . Arrow- control agents. After general obser- experiment to determine the suscepti- head scale is also parasitized by the vation in the field, candidates must bility of C. nipponicus and R. lophanthae Aphytis yanonensis DeBach & Ros- be more thoroughly studied in the to pesticides commonly applied for en. Researchers in Japan report that quarantine laboratory. control of CAS. arrowhead scale is effectively con- $180,000 for 5 years including Ph.D. trolled where C. fulvus and U. yanonen- student stipend 3. Exploration and screening of exotic sis work in tandem. There is no report of CAS being exposed to and parasitized Dr. Hui Ren, an taxonomist by U. yanonensis. However, since C. retired from the Entomologi- fulvus attacks both CAS and arrowhead References cal Institute, where he specializes in scale, it is possible that U. yanonensis the study of minute parasitoid of will do the same, i.e. attack arrowhead Furuhashi, K. and M. Nishino. 1983. Biological the families Aphelinidae and , scale and CAS. This needs to be tested control of arrowhead scale, Unaspis has collaborated with University of Flori- in the laboratory. yanonensis, by parasitic wasps intro- da (UF) and DPI scientists the past two duced from the People’s Republic of China. Entomophaga 28(3): 277-286. years to find parasitoids with potential 4. Entomopathogenic nematodes for Hara, A.H, R.Y. Niino-DuPonte, W.T. Naga- for release into Florida. During 2003- control of CAS mine, R.A. Heu and N.M. Nagata. Undat- 2005, Dr. Ren collected and sent the Aulacaspis yasumatsui not only in- ed. What’s killing my sago plam? Cycad following parasitoid species to Dr. Ru fests the leaves of cycads, but also scale Aulacaspis yasumatsui. University Nguyen of the DPI quarantine in Gaines- penetrates minute sites on the trunk of Hawaii Extension Bulletin. ville: and roots of the plant. Scales in these Honda, J. Y., and R. F. Luck. 1995. Scale Arrhenophagus chionaspidis Aurivil- microhabitats are inaccessible to parasi- morphology effects on feeding behavior lius Pteroptrix chinensis (Howard) toids and predators. Recent research in and biological control potential of Rhyzo- bius lophanthae (Coleoptera: Coccinel- Aphytis lepidosaphes Compere Thom- Ft. Pierce has examined the capability lidae). Ann. Entomol. Soc. America 88: sonisca sankarani Subba Rao of tiny entomopathogenic nematodes to 441-450. Additionally, Dr. Nguyen recently infect nymphal and female scales on the Howard, F. W., A. Hamon, M. McLaughlin, T. observed the following species parasitiz- trunk and roots of cycads. Preliminary Weissling, and Si-Lin Yang. 1999. Aula- ing CAS in Vietnam: observations showed that nematodes in caspis yasumatsui (: Sternor- Aprostocetus sp. possibly purpureus the genera Steinernema and Heterorhab- rhyncha: ), a Girault ditis will attack and kill second instar pest of cycads recently introduced into Encarsia sp. and adult female CAS. Laboratory and Florida. Fla. Entomol. 82: 14-27. Rosen, D. 1990. Armored scale insects their All these parasitoids are general field experiments are being carried out biology, natural enemies and control. armor scale parasitoids, but the most in 2005 to determine the best nematode Vol. B. Elsevier, New York, USA, 688 pp. promising is A. chionaspidis because it species and efficacy in the field. Stathas, G. J. 2001. Ecological data on pred- causes high levels of parasitism of male ators of Parlatoria pergandii on sour scales in China. Current research with Additional research orange trees in southern . Phyto- this insect is on-going in the quarantine parasitica 29: 207-214. facilities in Gainesville and Ft. Pierce. Further research needs to be con- Yus, R. 1973. On the presence in the Iberian The species of Aprostocetus from Viet- tinued on the following projects: Peninsula of Rhyzobius lophanthae (Blais- dell, 1892) (Col. ). Graellsia nam also looks interesting because it 29: 111-115. appears to cause significant mortality in 1. Nematode research: More laboratory that area. The taxonomy and biology of studies and field trials need to be these parasitic wasps need thorough conducted. study before a release permit can be $15,000 for 2 years solicited from USDA PPQ. 2. Studies on Rhyzobius lophanthae Funds were recently received from behavior and feeding: This predator USDA APHIS to conduct exploration in is reported to be a voracious con- Asia and screen any new natural ene- sumer of CAS in Hawaii, and we have mies discovered. Plans are for R. Cave seen it destroy populations of CAS and R. Nguyen to travel to China and on laboratory plants. In Florida, it Vietnam in spring 2006 (exploration in has only been seen in the Tampa fall 2005 could not be arranged). Cycas area. We do not understand why it revoluta and C. rumphii are favored has not dispersed throughout south hosts for the CAS. The native homes for Florida. Feeding studies need to be these plants are the Ryukyu Islands and conducted and predator release Indonesia, respectively. If suitable natu- technologies should be developed. ral enemies are not found in China and

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