Journal of Chemical Ecology, Vol. 7, No. 1, 1981
JAPANESE BEETLE (COLEOPTERA: SCARABAEIDAE): Response to Synthetic Sex Attractant Plus Phenethyl Propionate: Eugenol 1'2
M.G. KLEIN, 3 J.H. TUMLINSON, 4 T.U LADD, JR., 3 and R.E. DOOLITTLE 4 USDA, SEA, A R 3Japanese Beetle Research Laboratory Ohio Agricultural Research and Development Center Wooster, Ohio 44691 4Insect Attractants, Behavior and Basic Biology Research Laboratory Gainesville, Florida 32604 (Received March 6, 1978; revised February 25, 1980) Abstraet--A combination of the synthetic sex attractant (R,Z)-5-(Idecenyl) dihydro-2(3H)-furanone with a 3:7 mixture of phenethyl propionate (PEP) and eugenol (4-allyl-2-methoxphenol) caught significantly more Popilliajaponica Newman than either the sex attractant or the mixture did alone. Also, the synthetic sex attractant captured significantly more males than the PEP--eugenol did during the period of heavy adult emergence of the beetles. The two lures were not significantly different in their attractancy to males about a week later and thereafter. A combination of PEP-eugenol and virgin females in the same trap late in the season also significantly increased beetle captures. Key Words--Japanese beetle, Popilliajaponica, Coleoptera, Scarabaeidae, sex attractant, survey lure, phenethyl propionate, eugenol, synergism.
INTRODUCTION C h e m i c a l s t i m u l i p l a y a n i m p o r t a n t r o l e in t h e activities o f t h e J a p a n e s e beetle, Popillia j a p o n i c a N e w m a n . T h e beetles a r e v o r a c i o u s f e e d e r s , a n d ~In cooperation with the Ohio Agricultural Research and Development Center, Wooster, Ohio 44691. Approved for publication as Journal Article No. 182-77. 2Mention of a proprietary product does not constitute an endorsement by the USDA. 1
0098-0331 / 81 / OIO0-O001$03.00/0 9 ! 981 Plenum Publishing Corporation
2
KLEIN ET AL.
odors are probably the most important factor in the beetle's selection of a host plant (Fleming, 1972). In addition, mate location is greatly enhanced by the presence of a chemical sex attractant produced by the female (Goonewardene et al., 1970; Ladd, 1970). The beetle is a highly visible pest and is still extending its range in this country. Although effective lures have been developed, there is a continuing need for new attractants and lure combinations for use in programs of survey and pest management. The quest for general lures attracting both males and females began in 1919 (Fleming, 1969) and led to the adoption of the present stardard survey lure, phenethyl propionate (hereafter referred to as PEP) + eugenol (3:7) (Ladd et al., 1976). In addition, Ladd (1970) demonstrated that unmated female beetles emerging from the ground produce a potent, volatile pheromone and could be used to lure large numbers of males to traps. That finding led us to investigations resulting in the elucidation of the natural pheromone and the subsequent development of a powerful synthetic sex attractant, (R, Z)-5(1-decenyl) dihydro-2(3 H)-fnranone (hereafter referred to as R,Z-furanone) (Tumlinson et al., 1977). Unexpectedly, when virgin females were added as lures to traps baited with the former survey lure PEP-eugenol (7:3), the simultaneous release of the two lures resulted in a significant increase in the captures of females, but did not significantlyaffect the captures of males (Klein et al., 1973). Given the availability of two distinct types of synthetic lures and the interaction between virgin females and the former survey lure, our primary objective in this study was to determine the relative attractancy to Japanese beetles of the simultaneous release of the synthetic sex attractant plus the present ratio of PEP-eugenol (3: 7) used as a survey lure. Furthermore, since the effectiveness of virgin females and PEP-eugenol changes during the flight season (Klein et al., 1972), we ran our tests at several different times during the life span of the beetles to get information on lure interactions during an extended trapping season. In addition, since we only had information on the simultaneous exposure of PEP lures early in the season (Klein et al., 1973), we included a test using virgin females and PEP-eugenol late in the beetle season to establish their relative attractancy then. M E T H O D S AND MATERIALS
Tests were conducted in 1976 during June in North Carolina and during July and August in Ohio on golf courses infested with Japanese beetles. Yellow Ellisco| Japanese beetle traps (Ellisco Inc., Philadelphia) baited with PEP-eugenol, synthetic sex attractant, and PEP--eugenol plus sex attractant were exposed at the Buccaneer Country Club, Burgaw, North Carolina, June 24-25, and at the Mohican Hills Golf Club, Jeromesville, Ohio, July 9 and 18
3
JAPANESE BEETLE RESPONSE
and August 4. Traps baited with PEP--eugenol, virgin females, and the chemical lure plus females were used at the Echo. Farms Country Club, Wilmington, North Carolina, June 24-25. Periods of heavy beetle emergence were determined by observations of males searching for females over infested turf. The traps were suspended with the upper edges of the funnels ca. 56 cm above ground on steel trap rods placed 15 m apart and were arranged in a randomized complete block with at least 30 m between the five replicates. Trap canisters were emptied at the end of each day of the tests, and the beetles were counted. Also 100 beetles from each trap were chosen at random from each day's capture, and the sex was determined so we could calculate the number of males and females captured. The data from the two days in each of the North Carolina tests were combined for analysis. Twenty milliliter of PEP-eugenol (3 : 7) were placed in glass bottles in the bait well of traps and evaporated from 1.3-cm-diam cotton dental wicks that protruded 2.5 cm above the perforated metal caps. The R,Z-furanone was synthesized and purified (99%) at the Insect Attractants, Behavior and Basic Biology Research Laboratory by the method of Tumlinson et al. (1977). The R,Z-furanone was exposed by placing a stainless-steel planchet (2.5 cm diam) containing 5 #g of the attractant at the bottom of the bait well when used alone, or on top of the bait bottle next to the wick in tests using combinations of the two lures. The virgin females were collected in the field as 3rd-stage larvae and reared individually at the Japanese Beetle Research Laboratory. Recently emerged females were placed in the bait wells (4/trap) in circular wire cages as described by Klein et al. (1973). The data were analyzed statistically, and mean captures were separated at the 5% level of significance by Duncan's multiple range test. RESULTS
AND DISCUSSION
The average captures of beetles by traps baited with PEP-eugenol, R,Zfuranone, and PEP-eugenol/R,Z-furanone for a period during heavy emergence of the beetles are given in Table 1. Although the sex attractant was over 3.5 times as attractive to males as PEP-eugenol, simultaneous release of the two lures captured 1.6 times more beetles than the sex attractant alone. In addition, it resulted in a significantly better lure (1.9X) than the PEP-eugenol for capturing females, even though traps baited only with the R,Z-furanone captured few females. Furthermore, simultaneous release increased captures of males, females, and total beetles over the combined captures by the two lures separately. The average numbers of beetles captured after the heaviest emergence (July 18 in Ohio) and very late in the beetle season (June 24-25 in North Carolina and August 4 in Ohio) by the survey lure, the sex attractant, and both
4
KLEIN ET AL.
TABLE 1. CAPTURES OF JAPANESE BEETLES IN TRAPS BAITED WITH PEP-EUGENOL, SYNTHETIC SEX ATTRACTANT (R,Z-FuRANONE), AND BOTH DURING HEAVY BEETLE EMERGENCE (JULY 9, 1976, IN OHIO, 5 REPLICATES)
Avg. beetle catch/trap a Lure
Males
Females
Total
PEP-eugenol/R,Z-furanone R, Z-furanone PEP-eugenol
1845a 1122b 304c
662a 64b 348c
2507a l 186b 652c
"Means in the same columns followed by the same letter are not significantly different at the 5% level (Duncan's new multiple range test).
combined are given in Table 2. Throughout the season, PEP-eugenol/R,Zfuranone was a significantly better lure for both males and females than the two lures used independently. The abilities of sex attractant and PEP-eugenol to attract males about a week after the heavy beetle emergence, late in the season, were not significantly different. The decrease in attractiveness of the synthetic sex attractant after the period of heavy emergence confirms our observations over several years that males are most strongly attracted to virgin females and their extracts during the l- to 2-week period of maximum beetle emergence. A stronger response of males to virgin females rather than PEP-eugenol noted in a previous field test (Klein et al., 1972) may have been due to the changes in design (RCB instead of t test) used in these experiments, change of placement of traps, use of small quantities of volatile pheromone instead of females, or use in the present test of a more attractive ratio of PEP-eugenol (3:7 rather than 7:3) (Ladd et al. 1976). However, since survey trapping covers an entire season, it is important to note that the presence of R,Zfuranone in traps with PEP-eugenol significantly increased captures in tests conducted one month apart. The sex ratios of beetles captured at Burgaw, North Carolina, in traps baited with PEP-eugenol dropped from 1.3 : 1 (M: F) on June 24 to 0.75: 1 (M: F) on June 25. This decrease suggests that a very high percentage of males in the area was captured the first day and that few, if any, additional males moved into the area by the second day. This result may have been caused by male trapping elsewhere on the golf course and natural mortality at the end of the beetle season. A combination bait of virgin females plus PEP-eugenol late in the beetle season significantly increased captures of males, females, and the total beeetles over the number captured by either lure alone (Table 3). The ability of the virgin females to attract males late in the season was only about 0.6 times as greast as the ability of PEP-eugenol. The lack of attractancy of the females
1420a 474b 180b
PEP-eugenol/R,Z-furanone 745a 385b 15c
Females 2166a 859b 194b
Total 1799a 732b 665b
Males 896a 400b 26c
Females
July 18c
2695a 1138b 691 b
Total
508a 276b 70b
Males
341a 164b 19c
Females
August 4 b
OMeans in the same c o l u m n s followed by the same letter are not significantly different at the 5% level (Duncan's new multiple range test). b3-4 weeks after heavy beetle emergence. CApproximately I week after heavy beetle emergence.
PEP-eugenol R, Z-furanone
Males
Lure
June 24-25 b
Avg. beetle catch/trap a
TABLE 2. CAPTURES OF JAPANESE BEETLES IN TRAPS BAITED WITH P E P - E u G E N O L , SYNTHETIC SEX ATTRACTANT (R,Z-FuRANONE AND BOTti AFTER PERIOD OF MAXIMUM BEETLE EMERGENCE DURING JUNE IN NORTH CAROLINA AND JULY AND AUGUST IN OHIO (5 REPLICATES)
849a 440b 89c
Total
t~
9
z
>,
6
KLEIN ET AL. TABLE 3. CAPTURES OF JAPANESE BEETLES IN TRAPS BAITED WITH PEP-EuGENOL, VIRGIN FEMALES, AND BOTH ON JUNE 24 AND 25, 1976, IN NORTH CAROLINA (5 REPLICATES)
Avg. beetle catch/trap, Lure
Males
Females
Total
PEP-eugenol/females PEP-eugenol Females
430a 182b 108b
836a 459b 7e
1265a 641 b 115c
"Means in the same columns followed by the same letter are not significantly different at the 5% level (Duncan's new multiple range test).
(natural sex attractant), together with their ability to improve the PEPeugenol as a lure, is consistent with what we found for the R,Z-furanone (synthetic sex attractant). The synergism of R,Z-furanone and PEP-eugenol will have immediate applications in survey programs for Japanese beetles by providing a much more effective lure throughout the trapping season. In addition, the unique combination of lures for both males and females and the availability of a synthetic sex attractant, R,Z-furanone, and an inhibitor, S,Z-furanone (Tumlinson et al. 1977), offers a system for studies on control, disruption, attraction, and other aspects of the chemical ecology of the Japanese beetle. A c k n o w l e d g m e n t s - - W e acknowledge the assistance of Kathleen P. Callahan and Bonnie J. Gold, summer employees, who aided in these studies. We also thank the management and membership of the Buccaneer Country Club, Burgaw, North Carolina; the Echo Farms Country Club, Wilmington, North Carolina; and the Mohican Hills Golf Club, Jeromesville, Ohio, for allowing us to conduct the tests on their property.
REFERENCES FLEMING, W.E. 1969. Attractants for the Japanese Beetle. USDA Tech. Bull. 1399. 87 pp. FLEMING, W.E. 1972. Biology of the Japanese Beetle. USDA Tech. Bull. 1449. 129 pp. GOONEWARDENE,H.F., ZEPP, D.B., and GROSVENOR,A.E. 1970. Virgin female Japanese beetles as lures in field traps. J. Econ. Entomol. 63: 1001-1003. KLEIN, M.G., LADD, T.L., and LAWRENCE,K.O. 1972. A field comparison of lures for Japanese beetles: Unmated females vs. phenethyl propionate + eugenol (7:3). Environ. Entomol. 1: 397-399. KLEIN, M.G., LADD, T.L., and LAWRENCE, K.O. 1973. Simultaneous exposure of phenethyl propionate-eugenol (7 : 3) and virgin female Japanese beetles as a lure. J. Econ. EntomoL 66: 373-374. LADI), T.L. 1970. Sex attraction in the Japanese beetle. J. Econ. Entornol. 63:905-908. LADD, T.L., McGOVERN,T.P., BURIFF,C.R., and KLEIN, M.G. 1976. Japanese beetles: Attrac-
JAPANESE BEETLE RESPONSE
7
tancy of phenethyl propionate + eugenol (3 : 7) and synthetic eugenol. J. Econ. Entomol. 69 : 468-470. TUMLINSON, J.H., KLEIN, M.G., DOOLITTLE, R.E., LADD, T.L., and PROVEAUX, A.T. 1977. Identification of the female Japanese beetle sex pheromone: Inhibition of male response by an enantiomer. Science 197:789-792.
JAPANESE BEETLE (COLEOPTERA: SCARABAEIDAE): Response to Synthetic Sex Attractant Plus Phenethyl Propionate: Eugenol 1'2
M.G. KLEIN, 3 J.H. TUMLINSON, 4 T.U LADD, JR., 3 and R.E. DOOLITTLE 4 USDA, SEA, A R 3Japanese Beetle Research Laboratory Ohio Agricultural Research and Development Center Wooster, Ohio 44691 4Insect Attractants, Behavior and Basic Biology Research Laboratory Gainesville, Florida 32604 (Received March 6, 1978; revised February 25, 1980) Abstraet--A combination of the synthetic sex attractant (R,Z)-5-(Idecenyl) dihydro-2(3H)-furanone with a 3:7 mixture of phenethyl propionate (PEP) and eugenol (4-allyl-2-methoxphenol) caught significantly more Popilliajaponica Newman than either the sex attractant or the mixture did alone. Also, the synthetic sex attractant captured significantly more males than the PEP--eugenol did during the period of heavy adult emergence of the beetles. The two lures were not significantly different in their attractancy to males about a week later and thereafter. A combination of PEP-eugenol and virgin females in the same trap late in the season also significantly increased beetle captures. Key Words--Japanese beetle, Popilliajaponica, Coleoptera, Scarabaeidae, sex attractant, survey lure, phenethyl propionate, eugenol, synergism.
INTRODUCTION C h e m i c a l s t i m u l i p l a y a n i m p o r t a n t r o l e in t h e activities o f t h e J a p a n e s e beetle, Popillia j a p o n i c a N e w m a n . T h e beetles a r e v o r a c i o u s f e e d e r s , a n d ~In cooperation with the Ohio Agricultural Research and Development Center, Wooster, Ohio 44691. Approved for publication as Journal Article No. 182-77. 2Mention of a proprietary product does not constitute an endorsement by the USDA. 1
0098-0331 / 81 / OIO0-O001$03.00/0 9 ! 981 Plenum Publishing Corporation
2
KLEIN ET AL.
odors are probably the most important factor in the beetle's selection of a host plant (Fleming, 1972). In addition, mate location is greatly enhanced by the presence of a chemical sex attractant produced by the female (Goonewardene et al., 1970; Ladd, 1970). The beetle is a highly visible pest and is still extending its range in this country. Although effective lures have been developed, there is a continuing need for new attractants and lure combinations for use in programs of survey and pest management. The quest for general lures attracting both males and females began in 1919 (Fleming, 1969) and led to the adoption of the present stardard survey lure, phenethyl propionate (hereafter referred to as PEP) + eugenol (3:7) (Ladd et al., 1976). In addition, Ladd (1970) demonstrated that unmated female beetles emerging from the ground produce a potent, volatile pheromone and could be used to lure large numbers of males to traps. That finding led us to investigations resulting in the elucidation of the natural pheromone and the subsequent development of a powerful synthetic sex attractant, (R, Z)-5(1-decenyl) dihydro-2(3 H)-fnranone (hereafter referred to as R,Z-furanone) (Tumlinson et al., 1977). Unexpectedly, when virgin females were added as lures to traps baited with the former survey lure PEP-eugenol (7:3), the simultaneous release of the two lures resulted in a significant increase in the captures of females, but did not significantlyaffect the captures of males (Klein et al., 1973). Given the availability of two distinct types of synthetic lures and the interaction between virgin females and the former survey lure, our primary objective in this study was to determine the relative attractancy to Japanese beetles of the simultaneous release of the synthetic sex attractant plus the present ratio of PEP-eugenol (3: 7) used as a survey lure. Furthermore, since the effectiveness of virgin females and PEP-eugenol changes during the flight season (Klein et al., 1972), we ran our tests at several different times during the life span of the beetles to get information on lure interactions during an extended trapping season. In addition, since we only had information on the simultaneous exposure of PEP lures early in the season (Klein et al., 1973), we included a test using virgin females and PEP-eugenol late in the beetle season to establish their relative attractancy then. M E T H O D S AND MATERIALS
Tests were conducted in 1976 during June in North Carolina and during July and August in Ohio on golf courses infested with Japanese beetles. Yellow Ellisco| Japanese beetle traps (Ellisco Inc., Philadelphia) baited with PEP-eugenol, synthetic sex attractant, and PEP--eugenol plus sex attractant were exposed at the Buccaneer Country Club, Burgaw, North Carolina, June 24-25, and at the Mohican Hills Golf Club, Jeromesville, Ohio, July 9 and 18
3
JAPANESE BEETLE RESPONSE
and August 4. Traps baited with PEP--eugenol, virgin females, and the chemical lure plus females were used at the Echo. Farms Country Club, Wilmington, North Carolina, June 24-25. Periods of heavy beetle emergence were determined by observations of males searching for females over infested turf. The traps were suspended with the upper edges of the funnels ca. 56 cm above ground on steel trap rods placed 15 m apart and were arranged in a randomized complete block with at least 30 m between the five replicates. Trap canisters were emptied at the end of each day of the tests, and the beetles were counted. Also 100 beetles from each trap were chosen at random from each day's capture, and the sex was determined so we could calculate the number of males and females captured. The data from the two days in each of the North Carolina tests were combined for analysis. Twenty milliliter of PEP-eugenol (3 : 7) were placed in glass bottles in the bait well of traps and evaporated from 1.3-cm-diam cotton dental wicks that protruded 2.5 cm above the perforated metal caps. The R,Z-furanone was synthesized and purified (99%) at the Insect Attractants, Behavior and Basic Biology Research Laboratory by the method of Tumlinson et al. (1977). The R,Z-furanone was exposed by placing a stainless-steel planchet (2.5 cm diam) containing 5 #g of the attractant at the bottom of the bait well when used alone, or on top of the bait bottle next to the wick in tests using combinations of the two lures. The virgin females were collected in the field as 3rd-stage larvae and reared individually at the Japanese Beetle Research Laboratory. Recently emerged females were placed in the bait wells (4/trap) in circular wire cages as described by Klein et al. (1973). The data were analyzed statistically, and mean captures were separated at the 5% level of significance by Duncan's multiple range test. RESULTS
AND DISCUSSION
The average captures of beetles by traps baited with PEP-eugenol, R,Zfuranone, and PEP-eugenol/R,Z-furanone for a period during heavy emergence of the beetles are given in Table 1. Although the sex attractant was over 3.5 times as attractive to males as PEP-eugenol, simultaneous release of the two lures captured 1.6 times more beetles than the sex attractant alone. In addition, it resulted in a significantly better lure (1.9X) than the PEP-eugenol for capturing females, even though traps baited only with the R,Z-furanone captured few females. Furthermore, simultaneous release increased captures of males, females, and total beetles over the combined captures by the two lures separately. The average numbers of beetles captured after the heaviest emergence (July 18 in Ohio) and very late in the beetle season (June 24-25 in North Carolina and August 4 in Ohio) by the survey lure, the sex attractant, and both
4
KLEIN ET AL.
TABLE 1. CAPTURES OF JAPANESE BEETLES IN TRAPS BAITED WITH PEP-EUGENOL, SYNTHETIC SEX ATTRACTANT (R,Z-FuRANONE), AND BOTH DURING HEAVY BEETLE EMERGENCE (JULY 9, 1976, IN OHIO, 5 REPLICATES)
Avg. beetle catch/trap a Lure
Males
Females
Total
PEP-eugenol/R,Z-furanone R, Z-furanone PEP-eugenol
1845a 1122b 304c
662a 64b 348c
2507a l 186b 652c
"Means in the same columns followed by the same letter are not significantly different at the 5% level (Duncan's new multiple range test).
combined are given in Table 2. Throughout the season, PEP-eugenol/R,Zfuranone was a significantly better lure for both males and females than the two lures used independently. The abilities of sex attractant and PEP-eugenol to attract males about a week after the heavy beetle emergence, late in the season, were not significantly different. The decrease in attractiveness of the synthetic sex attractant after the period of heavy emergence confirms our observations over several years that males are most strongly attracted to virgin females and their extracts during the l- to 2-week period of maximum beetle emergence. A stronger response of males to virgin females rather than PEP-eugenol noted in a previous field test (Klein et al., 1972) may have been due to the changes in design (RCB instead of t test) used in these experiments, change of placement of traps, use of small quantities of volatile pheromone instead of females, or use in the present test of a more attractive ratio of PEP-eugenol (3:7 rather than 7:3) (Ladd et al. 1976). However, since survey trapping covers an entire season, it is important to note that the presence of R,Zfuranone in traps with PEP-eugenol significantly increased captures in tests conducted one month apart. The sex ratios of beetles captured at Burgaw, North Carolina, in traps baited with PEP-eugenol dropped from 1.3 : 1 (M: F) on June 24 to 0.75: 1 (M: F) on June 25. This decrease suggests that a very high percentage of males in the area was captured the first day and that few, if any, additional males moved into the area by the second day. This result may have been caused by male trapping elsewhere on the golf course and natural mortality at the end of the beetle season. A combination bait of virgin females plus PEP-eugenol late in the beetle season significantly increased captures of males, females, and the total beeetles over the number captured by either lure alone (Table 3). The ability of the virgin females to attract males late in the season was only about 0.6 times as greast as the ability of PEP-eugenol. The lack of attractancy of the females
1420a 474b 180b
PEP-eugenol/R,Z-furanone 745a 385b 15c
Females 2166a 859b 194b
Total 1799a 732b 665b
Males 896a 400b 26c
Females
July 18c
2695a 1138b 691 b
Total
508a 276b 70b
Males
341a 164b 19c
Females
August 4 b
OMeans in the same c o l u m n s followed by the same letter are not significantly different at the 5% level (Duncan's new multiple range test). b3-4 weeks after heavy beetle emergence. CApproximately I week after heavy beetle emergence.
PEP-eugenol R, Z-furanone
Males
Lure
June 24-25 b
Avg. beetle catch/trap a
TABLE 2. CAPTURES OF JAPANESE BEETLES IN TRAPS BAITED WITH P E P - E u G E N O L , SYNTHETIC SEX ATTRACTANT (R,Z-FuRANONE AND BOTti AFTER PERIOD OF MAXIMUM BEETLE EMERGENCE DURING JUNE IN NORTH CAROLINA AND JULY AND AUGUST IN OHIO (5 REPLICATES)
849a 440b 89c
Total
t~
9
z
>,
6
KLEIN ET AL. TABLE 3. CAPTURES OF JAPANESE BEETLES IN TRAPS BAITED WITH PEP-EuGENOL, VIRGIN FEMALES, AND BOTH ON JUNE 24 AND 25, 1976, IN NORTH CAROLINA (5 REPLICATES)
Avg. beetle catch/trap, Lure
Males
Females
Total
PEP-eugenol/females PEP-eugenol Females
430a 182b 108b
836a 459b 7e
1265a 641 b 115c
"Means in the same columns followed by the same letter are not significantly different at the 5% level (Duncan's new multiple range test).
(natural sex attractant), together with their ability to improve the PEPeugenol as a lure, is consistent with what we found for the R,Z-furanone (synthetic sex attractant). The synergism of R,Z-furanone and PEP-eugenol will have immediate applications in survey programs for Japanese beetles by providing a much more effective lure throughout the trapping season. In addition, the unique combination of lures for both males and females and the availability of a synthetic sex attractant, R,Z-furanone, and an inhibitor, S,Z-furanone (Tumlinson et al. 1977), offers a system for studies on control, disruption, attraction, and other aspects of the chemical ecology of the Japanese beetle. A c k n o w l e d g m e n t s - - W e acknowledge the assistance of Kathleen P. Callahan and Bonnie J. Gold, summer employees, who aided in these studies. We also thank the management and membership of the Buccaneer Country Club, Burgaw, North Carolina; the Echo Farms Country Club, Wilmington, North Carolina; and the Mohican Hills Golf Club, Jeromesville, Ohio, for allowing us to conduct the tests on their property.
REFERENCES FLEMING, W.E. 1969. Attractants for the Japanese Beetle. USDA Tech. Bull. 1399. 87 pp. FLEMING, W.E. 1972. Biology of the Japanese Beetle. USDA Tech. Bull. 1449. 129 pp. GOONEWARDENE,H.F., ZEPP, D.B., and GROSVENOR,A.E. 1970. Virgin female Japanese beetles as lures in field traps. J. Econ. Entomol. 63: 1001-1003. KLEIN, M.G., LADD, T.L., and LAWRENCE,K.O. 1972. A field comparison of lures for Japanese beetles: Unmated females vs. phenethyl propionate + eugenol (7:3). Environ. Entomol. 1: 397-399. KLEIN, M.G., LADD, T.L., and LAWRENCE, K.O. 1973. Simultaneous exposure of phenethyl propionate-eugenol (7 : 3) and virgin female Japanese beetles as a lure. J. Econ. EntomoL 66: 373-374. LADI), T.L. 1970. Sex attraction in the Japanese beetle. J. Econ. Entornol. 63:905-908. LADD, T.L., McGOVERN,T.P., BURIFF,C.R., and KLEIN, M.G. 1976. Japanese beetles: Attrac-
JAPANESE BEETLE RESPONSE
7
tancy of phenethyl propionate + eugenol (3 : 7) and synthetic eugenol. J. Econ. Entomol. 69 : 468-470. TUMLINSON, J.H., KLEIN, M.G., DOOLITTLE, R.E., LADD, T.L., and PROVEAUX, A.T. 1977. Identification of the female Japanese beetle sex pheromone: Inhibition of male response by an enantiomer. Science 197:789-792.
