Scientific Notes 435

MELANAPHIS SACCHARI (HOMOPTERA: ), A SUGARCANE PEST NEW TO LOUISIANA

W. H. WHITE1, T. E. REAGAN2 AND D. G. HALL3 1USDA, ARS, Sugarcane Research Unit, P. O. Box 470, Houma, LA 70361-0470

2Department of Entomology, 402 Life Sciences Bldg., Louisiana State University, Baton Rouge, LA 70803

3Research Department, United States Sugar Corp., P. O. Drawer 1207, Clewiston, FL 33440

While inspecting sugarcane (interspecific hy- can be associated with other sugarcane homopter- brids of spp.) varietal trials on the ans (principally the West Indian canefly, Saccha- USDA-ARS Ardoyne Research Farm near Houma, rosydne saccharivora Westwood), sooty mold alone LA on 9 September 1999, we noticed an infesta- could not be used as a means of verifying the oc- tion of an unfamiliar in Louisiana sugar- currence of the aphid in our sample fields. cane. Specimens were collected and sent to the Sugarcane were found in eight of the 21 USDA-ARS Systematic Entomology Laboratory, parishes surveyed (38%) (Fig. 1). We did not find Beltsville, MD for identification. Gary L. Miller aphids at all four sample sites in any given par- identified the specimens as the sugarcane aphid, ish. Generally, where sugarcane aphids were de- sacchari (Zehntner). The collection of tected their infestation densities were low. this species represents a new distribution record Overall, the survey indicated the aphid has al- for the continental United States and holdings of ready spread throughout much of the sugarcane the National Aphidoidea Collection, which until growing areas in Louisiana. The low population now included specimens from Florida and Hawaii. levels of the aphid observed at each site during The sugarcane aphid is a widely distributed in- our survey may have been related to the time of sect being reported from 24 countries (Mead 1978). year our survey was conducted. Pemberton (1948) reported the sugarcane aphid in Large outbreaks of M. sacchari in Florida sug- Hawaii as early as 1896. The aphid was first re- arcane occur most commonly during the summer. ported in the continental United States during 1977 The aphid is subjected to biological control in sug- on sugarcane in Florida (Mead 1978). Hall and Ben- arcane in Florida by pathogens (Verticillium leca- nett (1994) presented a general review of M. sac- nii), predators including Diomus terminatus Say chari as a pest of Florida sugarcane. The aphid is (Coleoptera: ) and Allograpta exotica known to attack grasses including species in the fol- (Wiedemann) (Diptera: Syrphidae), and one para- lowing genera: Saccharum, , Oryza, Echi- sitoid species ( (Cresson) nochloa, Panicum, and Pennisetum (Denmark (: ) (Hall 1987). The fol- 1988). Its status as an economic pest of sugarcane lowing predators are also thought to attack the remains unclear. Yield reductions associated with sugarcane aphid in Florida: Chrysoperla externa sooty mold that accompanies severe infestations of (Hagan) (Neuroptera: Chrysopidae), Micromus the aphid in sugarcane and the possibility that the subanticus (Walker) (Neuroptera: Hemerobiidae), aphid might vector sugarcane mosaic virus and Coleomegilla maculata fuscilabris (Mulsant), Cy- other diseases are of principal concerns with the in- cloneda sanguinea (L.), Hippodamia convergens vasion of the into Louisiana. Guerin, and Ola v-nigrum Mulsant (Coleoptera: Following identification of the aphid, a survey Coccinellidae) (Hall 1988). Environmental factors of the Louisiana sugarcane producing area was may often be largely responsible for the initial de- initiated on 25 October 1999 to assess the geo- cline in aphid levels following a summer outbreak graphical range of the infestation. Four sites in (Hall 1987). Although an assessment of biological each of the parishes growing sugarcane were sur- control of the aphid in Louisiana has not been veyed, except in St. Charles Parish where only two conducted, we noted during our survey that the sites were chosen because it has comparatively aphid was attacked by D. terminatus (specimens less acres of sugarcane in cultivation. Similarly, identified by M. Thomas, Florida Department of Calcasieu and Cameron Parishes were combined Agriculture & Consumer Services, Division of into a single survey unit because they are contig- Plant Industry, Florida State Collection of Ar- uous to one another and both having only a few thropods, Gainesville), by an unidentified syrphid scattered acres of sugarcane in cultivation. Survey fly larvae, and by at least one unidentified species sites were cane fields chosen at random and were of an internal parasitoid. No information is avail- selected to be a minimum of 9 km distant from able on varietal resistance to the aphid. each other. The sample scheme was patterned af- Thanks are extended to Dr. Chris Carlton and ter that of White et al. (1995) such that two sets of research associates Fred Posey and Vickey ten separate stools of cane in perpendicular direc- Mosely, Louisiana State University Agricultural tions were examined for the presence of sooty Center, Baton Rouge, LA for technical support. mold and colonizing aphids. Because sooty mold Voucher specimens of the aphid are located in the

436 Florida Entomologist 84(3) September 2001

Fig. 1. The distribution of the sugarcane aphid throughout the Louisiana sugarcane growing area during the 1999 growing season. Groupings in legends are based on the total of fields sampled within a parish and those found to be infested by the sugarcane aphid.

Louisiana State University Museum HALL, D. G. 1987. The sugarcane aphid, Melanaphis in Baton Rouge, LA and the USDA-ARS System- sacchari, in Florida sugarcane. J. Amer. Soc. Sugar atic Entomology Laboratory, Beltsville, MD. Cane Techn. 7:26-29. HALL, D. G. 1988. and mites associated with sugarcane in Florida. Florida Entomol. 71(2): 138- SUMMARY 150. The sugarcane aphid, HALL, D. G., AND F. D. BENNETT. 1994. Biological con- (Zehntner) was found in Louisiana on 9 Septem- trol and IPM of sugarcane pests in Florida. In Pest ber 1999 and documented as a new record and po- Management in the Subtropics, Biological Control – tential pest for the state. The aphid was found in a Florida Perspective. eds. D. Rosen, F. D. Bennett, and J. L. Capinera. Intercept Ltd, Andover, Hamp- 8 of 21 sugarcane growing Parishes that were sur- shire. 737 pp. veyed in Louisiana, indicating the pest is already MEAD, F. W. 1978. Sugarcane aphid, Melanaphis sac- widely distributed across Louisiana. The coccinel- chari (Zehntner)—Florida—New Continental lid Diomus terminatus Say was identified as one United States Record. Cooperative Plant Pest Re- of several biological control organisms attacking port 3(34): 475. the aphid in Louisiana. PEMBERTON, C. E. 1948. History of the Entomology De- partment Experiment Station, H.S.P.A. 1904-1945. REFERENCES CITED Hawaii. Planters’ Rec. 52: 53-90. WHITE, W. H., T. E. REAGAN, AND O. SOSA, JR. 1995. The DENMARK, H. A. 1988. Sugarcane aphids in Florida. Fla. sugarcane Delphacid (Homoptera: Delphacidae) ex- Dept. Agric. & Consumer Serv., Div. Plant Industry. tends its North American range into Louisiana. Flor- Entomol. Circ. 302. 2 pp. ida Entomol. 78: 617-619.