John F. Anderson The Red Pine Scale in North America LEASE HANDLE WITH CARE University of ronnecticut Libraries GAVLORD RG BULLETIN 765 JULY 1976 A Report to the 1975 Eastern Plant Board THE RED PINE SCALE IN NORTH AMERICA John F. Anderson Chairman Robert P. Ford John D. Kegg John H. Risley siveo UNIVERSITY LIBRARY STAiJ THE CONNECTICUT AGRICULTURAL EXPERIMENT STATION. NEW HAVEN \ Members of the 1974 Eastern Plant Board appointed a four-man committee to make an in- depth evaluation of the present and future status of the red pine scale, Matsiicoccus resinosae B. & G., in North America. Herewith is our report. John F. Anderson, Chalrmarv Department of Entomology The Connecticut Agricultural Experiment Station New Haven 06504 Robert P. Ford USDA Forest Service, Northeastern Area State and Private Forestry Portsmouth, N.H. 03801 John D. Kegg Division of Plant Industry New Jersey Department of Agriculture Trenton 08625 John H. Risley Division of Lands and Forest New York State Department of Environmental Conservation Sherburne 13460 THE RED PINE SCALE IN NORTH AMERICA John F. Anderson, Robert P. Ford, John D. Kegg, and John H. Risley The red pine scale was initially found in 1946 in red pine plantations in western Connecticut (Plumb 1950). The infestation was extensive, indicating that the insect had b^en present for several years prior to its recognition. It was recognized as an undescribed species of Matsucoccus and subsequently described and named Matsucoccus resinosae by Bean and God- wan ( 1955 ) . It now occurs in Connecticut, New York, and New Jersey. This species is presently estabhshed south of the natural range of red pine, but it is mov- ing north and westward and may, in time, infest nat- ural stands. Inasmuch as there are no suitable pro- cedures for coping with this pest, which kills its host, this insect must be considered the most serious pest of red pine. TAXONOMY Red Pine ( Harlow and Harrar 1958, Critchfield and Little 1966 ) . Order • Coniferales Family • Pinaceae Genus • Pinus Subgenus * Pinus Section • Pinus Subsection • Sylvestres Species • resinosa Ait. Red Pine Scale ( Bean and Godwin 1955 ) Order • Homoptera Superfamily « Coccoidea Family • Margarodidae Tribe • Matsucoccini Genus • Matsucoccus Species • resinosae B. & G. BIONOMICS Red Pine The silvics of red pine have been discussed by Powells (1965). It ranges through southern Canada from Newfoundland to southeastern Manitoba and south through the Lake states and northeastern U.S., with outliers in Illinois and West Virginia. The na- tural stands of red pine are generally confined to sandy soils of low fertility, although it is often found in small groups near swamps and on rocky cliffs. Heavy cutting in the early 1800s depleted many nat- ural stands, which did not reproduce because of competition from more aggressive species such as hemlock, white pine, and hardwoods. The largest stands now occur in Quebec, Ontario, New York, Minnesota, Michigan, and Wisconsin (Table 1). Red Pine Scale Life Cycle. The life cycle has been discussed in de- tail by Bean and Godwin (1955) and Duda (1961). The stages include the egg, first stage larva, inter- mediate stage, and adult. (a) Egg. These hatch in 15-20 days in the labora- tory. Adults of the overwintering generation lay eggs from May until the first week of July. Adults of the summer generation lay eggs from about the middle of August until the last of October. Eggs are laid in ovisacs in cracks or crevices in the bark and axils of branches, under loose bark scales, and on needles. (b) First stage larva. This is the overwintering stage. Duration varies from 45-50 days for the sum- mer generation and from 235-260 days for the over- wintering generation. The newly hatched larvae are active and may crawl considerable distances before settling down to feed. Suitable feeding sites are un- der loose bark scales or in cracks and crevices where Connecticut Agricultural Experiment Station Bulletin 765 the crawlers have access to the succulent inner bark. SessCe or motile forms of this stage may be found throughout the year. (c) Intermediate stage. This is a sessile feeding stage. It remains in the same location selected by the first stage larva. Intermediate stages of the overwin- tering generation occur in the latter part of April into early July. Those of the summer generation occur from mid July into October. (d) Adult. The male forms that emerge from the cast skins of the intermediate stages are not true adults but pre-adults. Almost immediately after emer- gence, these pre-adult males spin a loose, fluffy, spindleshaped cocoon of wa.xy threads whereupon transformation to the true-adult stage occurs. Females, which do not pupate, are wingless and resemble the pre-adult males but are much larger. They crawl over the bark in search of suitable oviposition sites. Males are winged and locate females via a pheromone (Doane 1966). Females lay an average of 262 eggs. (e) Generations. There are two generations per year and sometimes there is a partial third generation (Bean, personal communication). Dispersal. Dispersal mechanisms are not thoroughly understood. Females are wingless, accounting in part Table 1. Red Pine Round wood Resource in North America million cubic foot volume Location Acres of Plantations' (all stands)' USA Connecticut 9,900 58.7 Maine 15,700 42.5 Massachusetts 7,400 23.3 Minnesota 199,000 199.5 Michigan 723,500 289.6 Ohio 33,900 16.3 Pennsylvania 32,200 NA* Rhode Island 600 11.8 New Hampshire 16,000 49.1 New Jersey 9,500" NSV= New York 95,900 327.3 Vermont 15,200 32.9 Wisconsin 239,400 241.1 West Virginia 200 NSV Indiana 1,300 NSV Iowa 1,800 NSV Canada' New Brunswick 45.0 Nova Scotia 26.0 Ontario 750.0 Quebec 222.0 TOTAL 2335.1 'Data obtained from Kingsley and Mayer ( 1972). 'Data obtained from the most recent forest survey by the U.S. Forest Service. 'Data obtained from Horton and Bedell ( 1960). 'NA — Not available. ''NSV — No significant volume. "Data from John D. Kegg. for the slow spread of this insect (Doane 1959a). Also, red pine is sparsely scattered throughout much of the infested area (Mclntyre 1956). Presumably, natural dispersal occurs only during the motile stages; i.e. first stage larva and female. First stage larvae may become air-borne and have been recorded to travel a c^uarter of a mile (Bean and Godwin 1955). Birds and mammals may also transport the motile stages (Duda 1961). Motor vehicles are also known to trans- port these insects, and this means of transport may account, in part, for infestations occurring initially along roadsides (Duda 1961). All stages may be carried on nursery stock and timber and other red pine products that are transported out of infested areas. Wind, however, is probably the natural and most important means of dispersal. Natural mortality factors. Life table studies suggest that the primary mortality factor is the degeneration of phloem cells following repeated attacks on trees (Duda 1961). This effect on the host prevents the establishment of first stage larvae. Predators are also considered important, but obviously, these biological agents are not sufficient to protect plantations from being heavily infested. Predators include Xenotra- cheliella inimica Drake and Harris (Hemiptera: An- thocoridae), a cecidomyid that preyed upon eggs, Chrysopa sp. nr. cornea, Hemerobius stigmatus Fitch, Mulsantina picta (Rand), Crematogaster cerasi Fitch, and mites belonging to die genus Amjstis, along with several species of spiders and nuthatches (Duda 1961, Bean and Godwin 1955, Plumb 1950). No insect pathogens or parasitoids have been reported. Hartzell ( 1957 ) reported that first stage larvae were highly susceptible to temperatures of — 10°F. Few survived two exposures of —10° for four hours. This susceptibility may, in part, explain the slow north- ward spread of this insect. Hosts. Aside from red pine, M. resinosae has been reported infesting three species of exotic pines in North America. Infestations have been reported on Chinese pine (P. tabulaeformis Carr. ), Japanese red pine (P. densiflora Sieb. and Zucc. ) and Japanese black pine (P. thunbergiana Franco) (Hartzell 1957, Duda 1962, 1964b). Red pine scale was reported not to attack any of the following eighteen species of pine (Hartzell 1957): Pinus ari.'itata Engelm. P. armandi Franch. P. ayacahuite Ehrenb. (P. hamata Roezl.) P. hungeana Zucc. P. cembra L. var. sibirica Loud. P. flexilis James P. griff ithii McClelland (P. exceha Wall.) The Red Pine Scale in North America P. heldreichii Christ, var. leucodermis (Ant.) Markgraf ex Fitschen. P. koraiensis Sieb. & Zucc. P. lamhertiana Dougl. P. monticola Dougl. P. mugo Turra var. rostrata Hoopes (P. montana Mill., P. uncinata Ramond.) P. nigra poiretiana (Ant.) Aschers. & Graebn. (P. laricio Poir. var. calahrica Loud. ) P. parviflora Sieb. & Zucc. (P. pentaphylla Mayr.) P. pence Griseb. P. ponderosa Dougl. P. rigida MUl. P. sylvestris L. var. rigensis Loud. Survival in cut logs. Infested trees have been and are continuing to be salvaged and are often shipped outside of infested areas. These salvage operations are often carried out during the wanter, and the ques- tion arises as to whether the first stage larvae can survive to adulthood the following spring on cut logs. Data by Duda (1964a) suggest that survival does oc- cur and that logs could carry this species unless they are debarked or otherwise utilized in such a fashion that would destroy the overwintering larvae. Geographical distribution. Red pine scale occurs in Connecticut, New York, and New Jersey. The in- fested areas within these states are shown in Figure 1. In Connecticut, infestations have been moving north and eastward at a rate of about 1 or 2 miles per year, though in recent years the spread may be more rapid. This scale presently occurs throughout much of Fair- field and New Haven Counties, southern Litchfield County, southern portions of Hartford County, a western portion of Middlesex County, and one loca- tion in New London County. The initial infestation in New Jersey was found near the Wanaque Reservoir in Passaic County. All infestations to date have occurred within 10 miles of the initial infestation. Infestations also occur in Ber- gen County. In New York, red pine scale was initially found in 1950 in East Norwich, Long Island, and in lower Westchester County. Spread has been at 1 to 5 miles per year. The scale now occurs in all but the north- western part of Westchester County, on most of Long Island, in southeastern Putnam County, the extreme southeastern tip of Orange County and the extreme southwestern tip of Rockland County. RELATED SPECIES AND THEIR GEOGRAPHICAL DISTRIBUTION Red Pine The following species all belong to the subsection Sylvestres and are closely related to P. resinosae (Critchfield and Little 1966) : P. tropicalis Morelet, Tropical pine. Isle of Pines and western Cuba. P. nigra Arnold, Austrian pine. Ranges widely through south- em Europe from Spain to Austria and throughout much of the Balkan Peninsula east to southern Russia and south to Turkey, on the islands of Cyprus, Sicily, and Corsica, with outliers in Algeria and Morocco. P. heldreichii Krist, Heldreich pine. Balkan Peninsula and southern Italy. P. mugo Turra, Swiss mountain pine. Central and southern Europe, ranging east to the USSR, south to Rumania, Bulgaria and central Italy, north to Germany and Poland, and west to eastern Spain. P. pinaster Ait., Maritime pine. Ranges from the Iberian Peninsula to southern France, to the west coast of Italy, in northern Africa from Morocco to Tunisia, and to the islands of Corsica and Sardinia. P. halepensis Mill., Aleppo pine. Widely distributed in the Mediterranean region. P. hrutia Ten. The eastern Aegean region, Turkey, the Levant, on the Mediterranean islands of Crete and Cyprus, and in the Black Sea region. P. sijlvestiis L., Scotch pine. This is the most widely dis- tributed species of pine and grows throughout northern Eurasia, from Scotland, southern Spain, northern Greece and northern Turkey to northern Manchuria, and the Sea of Okhotsk. P. densiflora Sieb. & Zucc, Japanese red pine. Japan, Korea, to eastern Manchuria and adjacent USSR, and the Shantung Peninsula of China. Its distribution on the mainland of Asia is uncertain. P. thunbergiana Franco, Japanese black pine. Japan and southern Korea. P. massoniana Lamb., Masson pine. Widely distributed in China. P. taiwanensis Hayata, Taiwan red pine. Taiwan. P. hichuensis Mayr, Luchu pine. Ryukyu Islands between Japan and Taiwan. P. htvangshanensis Hsia, Hwangshan pine. Central China. P. tahulaeformis Carr., Chinese pine. Occupies a broad dis- continuous belt in China. P. tjunnanensis Franch., Yunnan pine. Confined to Yunnan, southern Szechuan, and the western parts of Kwangsi and Kweichow. P. insidaris Endl., Khasi pine. Southeast Asia. P. merkusii Jungh and deVriese, Merkus pine. Ranges from eastern Burma, northern Laos, northern Viet Nam and the island of Hainan, south to Cambodia, southern Viet Nam and the island of Sumatra, and east to the Philippine Islands. Red Pine Scale The following species also belong to the genus Matsucoccus (Bean and Godwin 1955, Duda 1961): Species of Matsucoccus Host Nearctic Distribution acalyptus Herbert Pinus edulis California, Arizona, Engelm. New Mexico, Utah, P. monophylla Colorado, and Idaho T. & F. P. balfouriana G. & B. P. aristata Engelm. alahamae Morr. Pinus sp. Alabama bisetosus Morr. P. ponderosa California, Oregon, Laws. and Arizona P. jeffreyi G. &B. Connecticut Agricultural Experiment Station Bulletin 765 Species of Matsucoccus Host Nearctic (cont.) P. sabiniana Dougl. P. radiata D. Don. P. contorta Dougl, Distribution californicus Morr. P. ponderosa P. jeffreyi California and Arizona degeneratus Morr. P. ponderosa Arizona eduli Morr. P. edulis Arizona fasciulensis Herbert P. ponderosa California and P. jeffreyi Oregon P. sabiniana gallicolus Morr. P. rigida New England west Mill. to Ohio and P. echinata Mis.souri and south Mill. to Florida and P. ponderosa Georgia P. taeda L. P. virginiana Mill. P. glabra Walt. P. serotina Michx. monophyllae McK. P. monophylla P. edulis California paucicicatrices P. lamhertiana California, Oregon, Morr. Doug. Montana, and P. monticola Wyoming Doug. P. flexilis James secretus Morr. P. ponderosa California, Nevada, Arizona. New Mexico, and Colorado subdegeneratus P. occidentalis Dominican Republic Morr. (cubensis) Griseb. vexillorum Morr. P. ponderosa California, Nevada, Arizona, New Mexico, and Colorado macrocicatnces P. strobus L. Ontario, Quebec, Richards New Brunswick, Nova Scotia, and New Hampshire Palearctic & Oriental M. boratynskii Pinus sp. Russia Borkhsenius M. feytaudi P. maritima France Ducasse Mill. M. josephi P. halepensis Israel Bodenheimer & Mill. Harpaz M. pini (Green) P. sylvestris L. England M. matsumurae P. thunbergiana Japan ( Kuwana ) Franco M. sinensis Chen P. yunnanensis Franch. China M. yunnanensis Ferris P. yunnanensis Franch. China ORIGIN OF RED PINE SCALE The origin is unknown. The suggestion was made that it was brought into this country on pines planted on the grounds of the World Fair in 1937 and then carried to Connecticut (Doane 1959b). Although its origin is unknown, the evidence sug- gests tliat it is indeed an imported pest from Eurasia. Red Pine is the only species of the typically Eurasian group of pines in the subsection Sylvestres that is na- tive to North America (Critchfield and Little 1966). The host range of M. resinosae is unknown, but aside from red pine, it does attack three species of pine, P. densiflora, thunbergiana, and tahulaeformis that are native to Asia. It is not known to infest species of pine that occur naturally in Europe. These data suggest that red pine scale may have originated on a species of pine native to Asia. EFFECT ON HOST Infested red pine, including mature trees, eventual- ly die from the feeding of the scale (Bean and God- win 1955, Duda 1961, Doane 1959b). Trees often die quickly with little stunting or change in form (Duda 1961). The progressive morphological and histological effects on the tree have been described (Bean and Godwin 1955, Duda 1961). Plumb (1950) suggested that death may, in part, be caused by a toxin pro- duced by the scale. Japanese red pine has succumbed to scale attack in New York. CHEMICAL CONTROL No methods are available to protect plantations from succumbing to scale attack. Ornamental pines may be protected by spraying repeatedly with a 2% oil emulsion (Bean and Godwin 1955). Weekly ap- plications of Cygon and malathion against motile first stage larvae are also effective, though neither of these two insecticides is registered for this use (Duda, per- sonal communication). POTENTIAL IMPACT OF RED PINE SCALE M. resinosae is attacking trees outside the natural range of red pine. Should the scale extend into the natural range of its host, red pine would become a rare, rather than an uncommon species. It is suspected that the red pine in stands would be killed, but some, if not many, isolated trees might survive. Reproduc- tion of natural stands would be unlikely because of unsatisfactory seedbed and sunlight. Red pine is a relatively unimportant species in terms of the total forest of North America. It supplies a very small fraction of the timber harvested when compared to white pine, southern pines, Douglas fir, and Ponderosa pine. The chief value of red pine Hes The Red Pine Scale in North America in its adaptability to reforest on dry sites, its aesthetic aspects, and its use as pulp, posts and poles. The popularity of red pine for reforestation is evident by the many plantations ( Table 1 ) ( Kingsley and Mayer 1972). Potential losses of red pine are in the millions of cubic feet of both natural and planted stock. The total red pine round wood that is threatened is shown in Table 1. Damage to red pine cannot be measured in saw timber or pulpwood values alone. The impact on aesthetic values is illustrated in New Jersey where in a single year 156 ornamental red pines were cut and burned because they were infested (Kegg 1974). If these trees were replaced, the cost would average $150 per tree. PRESENT STATE POLICIES Connecticut guidelines are as follows: (1) Shippers of red pine timber are encouraged to move their products during the cold months. (2) Movement of red pine at any time within Connecticut from one uninfested location to another is permissible. (3) Movement of red pine at any time during the year from one location to another within the infested area is permissible. (4) Nurserymen within infested areas are en- couraged to destroy their plantings. The New Jersey State Board of Agriculture declared the red pine scale a "dangerously injurious insect" in 1961, and efforts were initiated to remove and destroy all known infestations. This policy continues to the present. The purpose of destroying infested trees is to reduce spreading the insect to pines in other areas of the state. To date, 331.5 acres of plantation and over 1,000 ornamental red pines have been cut and des- troyed. New York has no quarantine on the red pine scale. Some eradication was attempted to 1969, but this pohcy has been discontinued. CONCLUSIONS (1) Biological control. Scale insects have been the targets of numerous successful biological control at- tempts (DeBach et al. 1971). In fact, the proportion of success has been higher in the coccoideae than in any other group of pests. M. resinosae may be found in Eurasia. Biologi- cal control agents could then be shipped to the United States for colonization. Efforts could also be expended to colonize on M. resinosae natural enemies isolated from other Matsucoccus species in North America and Eurasia. Several successful biological controls, using enemies of allied species, have been reported (Pimentel 1963). This latter ap- proach would of necessity require a thorough study of the bionomics of the genus Matsucoccus. (2) Regulatory measures. Regulations that could be used to limit the spread of this insect need ex- amination. A quarantine was rejected by the Eastern Plant Board in 1965 because the scale had already spread considerably. Nevertheless, the State of New Jersey does quarantine and it would seem that some regulatory measures might impede the progress of this insect at least until satisfactory methods of coping with it have been developed. Two suggestions follow: a. Determine the feasibility of removing major scale infestations around parking lots, picnic and recreational areas and along major highways. b. Determine the feasibility of establishing a barrier zone with the assistance of federal funds. (3) Dispersal. Intensive experiments on disper- sal mechanisms of the red pine scale seem worth- while. (4) Weather. The role of low winter tempera- tures in limiting the spread of this species into the natural red pine growing areas of North America needs re-examination. (5) Host. The mechanisms by which the scale ultimately kills the tree need investigation. (6) Chemical control. Methods of controlling scales on ornamental trees with chemicals need to be re-examined and thoroughly studied. (7) Early detection. Methods of early detection of infestations need to be developed. ACKNOWLEDGMENTS We express our appreciation to the following individuals who contributed to the report: Charles C. Doane, George R. Stephens, and George W. Schuessler, The Connecticut Agricultural Experiment Station. Jim Bean and Neal Kingsley, U.S. Forest Service Edward J. Duda, University of Connecticut E. G. TerriU, New York State Department of Environmental Conservation Douglas R. Miller, U.S. Department of Agriculture Connecticut Agricultural Experiment Station Bulletin 765 REFERENCES CITED Bean, J. L. and P. A. Godwin. 1955. Description and bionomics of a new red pine scale, Matsvcoccus resinosae. For. Sci. 1: 164-176. Critchfield, W. B. and E. L. Little, Jr. 1966. Geographic dis- tribution of the pines of the world. USDA For. Ser. Misc. Publ. 991: 97 p. DeBach, P., D. Bosen and C. E. Kennett. 1971. Biological con- trol of coccids by introduced natural enemies. In Biological Control, C. B. Huffaker (ed.). pp. 165-194. Doane, C. C. 1959a. The red pine scale, Matsucoccus resinosae. Conn. Woodlands 24( 1 ) : 8-9. . 1959b. The red pine scale. Conn. Agric. Expt. Sta. Circ. 207: 1-7. . 1966. Evidence for a se.\ attractant in females of the red pine scale. J. Econ. Entomol. 59: 1539-40. Duda, E. J. 1961. Some aspects of the biology and ecology of the red pine scale, Matsucoccus resinosae B. & G. (Homoptera: Margarodidae). Univ. Mass. Ph.D. Thesis. 168 p. . 1962. The genus Matsucoccus with special reference to M. resinosae B. & G. Scientific Tree Topics 2: 1-10. . 1964a. Survival of the red pine scale on cut logs. Ibid. 2(10): 3,4. .1964b. An infestation of Matsucoccus resinosae B. & G. on Pinus thunbergii Pari, Ibid. 2( 10) : 9. Fowells, H, A. (ed.). 1965. Silvics of forest trees of the United States. USDA-FS Agricultural Handbook 271 : 762 p. Harlow, W. M. and E. S. Harrar, 1958. Te.\tbook of Den- drology. McGraw-Hill, New York. 561 p. Hartzell, A. 1957. Bed pine scale with special reference to its host plants and coldhardiness. Contrib. Boyce Thompson Inst. 18: 421-28. Horton, K. W. and G.H.D. Bedell. 1960. White and red pine. Can. Dept. North. Affairs & Nat. Res. Forestry Branch Bull. 124. Kegg, J. D. 1974. Red pine scale status. Unpubhshed report. N.J. Dept. Agr., Trenton, N.J. 1 p. King.sley, N. P. and C. E. Mayer. 1972. The e.xtent, com- position, and general condition of Northern conifer plan- tations in the Northeast region. Unpublished paper presented at the Conference on the Utilization of Planta- tion-grown Northern Softwoods, Syracuse, New York. Mclntyre, T. 1956. Matsucoccus resinosae B. & G. on red pine in Connecticut. lOth Intern. Congr. Entomol. Proc. (Montreal) 4:. 369-371. Pimentel, D. 1963. Introducing parasites and predators to con- trol native pests. Canadian Entomol. 95: 785-92. Plumb, G. H. 1950. A new and serious insect pest of red pine. Conn. Agric. E.xpt. Sta. Special Circ. 4 p. Figure I. Shaded areas show infested areas of red pine scale In Connecticut, New York, New Jersey and Long Island. University of Connecticut Libraries 39153G28S7325G