Two Michigan peach orchards were sampled for leafhoppers using a fixed-area ground sampling device attached to a D-vac®. Absolute abundance estimates indicated that routine tree insecticide applications greatly depressed leafhopper populations. This, and the fact that no resident, known vectors of the X-disease pathogen were detected, suggests that increasing insecticide applications to check the spread of the disease through vector control would be ineffective

Mowry, Thomas M

Whalon, Mark E

English

ValpoScholar

The Great Lakes Entomologist 
Volume 17 
Number 4 - Winter 1984 Number 4 - Winter 
1984 
Article 4 
December 1984 
Comparison of Leafhopper Species Complexes in the Ground 
Cover of Sprayed and Unsprayed Peach Orchards in Michigan 
(Homoptera: Cicadellldae) 
Thomas M. Mowry 
Michigan State University 
Mark E. Whalon 
Michigan State University 
Follow this and additional works at: https://scholar.valpo.edu/tgle 
 Part of the Entomology Commons 
Recommended Citation 
Mowry, Thomas M. and Whalon, Mark E. 1984. "Comparison of Leafhopper Species Complexes in the 
Ground Cover of Sprayed and Unsprayed Peach Orchards in Michigan (Homoptera: Cicadellldae)," The 
Great Lakes Entomologist, vol 17 (4) 
Available at: https://scholar.valpo.edu/tgle/vol17/iss4/4 
This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. 
It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. 
For more information, please contact a ValpoScholar staff member at scholar@valpo.edu. 
1984 THE GREAT LAKES ENTOMOLOGIST 205 
COMPARISON OF LEAFHOPPER SPECIES COMPLEXES IN THE 

GROUND COVER OF SPRAYED AND UNSPRAYED PEACH 

ORCHARDS IN MICHIGAN (HOMOPTERA: CICADELLlDAE)l 

Thomas M. Mowry and Mark E. Whalon2 
ABSTRACT 
Two ~lichigan peach orchards were sampled for leafhoppers using a fixed-area ground 
sampling de\"ice attached to a D-vac®. Absolute abundance estimates indicated that 
routine tree insecticide applications greatly depressed leafhopper populations. This, and 
the fact that no resident, known vectors of the X-disease pathogen were detected, suggests 
that increasing insecticide applications to check the spread of the disease through vector 
control would be ineffective. 
X-dise3-"C. 
a stone fruit malady 
of probable mycoplasma etiology (Nasu et al. 1970, 
Jones et aI. 1974}. is a major problem in the peach and cherry growing areas of southern 
:-'1ichigan 1Rosenberger and Jones 1977). This is true for many of the major stone fruit 
producing areas in the United States (Gilmer and Blodgett 1976, Purcell and Elkington 
19801. 
Leafboppers are the only known vectors of the X-disease pathogen (Gilmer and 
Blodgett 1976. "Sielson 1968). There is much grower interest in checking the spread of 
X-disease through insecticidal control of the leafhopper vectors. To investigate this poten­
tiaL it is necessary to sample leafhopper populations in such a manner as to allow for 
comparison between treated and untreated sample sites. The major means of sampling 
leatboppers in stone fruit orchards has been yellow sticky-board traps (McClure 1980, 
Purcell and Ellington 1980, Rosenberger and Jones 1978, Taboada et al. 1975). The 
relati\e abundartce estimates obtained through this method preclude interspecific or in­
tersite comparisons because the units of measurement are unknown, making only com­
pari:.ons. 
in space and time possible (Southwood 1978). This paper 
reports the comparison 
of 
the leatbopper species complexes between a sprayed and unsprayed peach orchard 
absolute abundance estimates. 
METHODS AND MATERIALS 
Sample Sites. The sprayed sample site was a commercial peach orchard maintained on 
a regular pesticide spray schedule until harvest (Howitt et al. 1981). Approximately 1165 
trees 
of scyeral varieties were planted on 12-ft (3.7 m) centers in rows spaced 20 ft (6.1 m) 
The ground cover consisted primarily of orchard grass (Dactylis glomerata L.) and 
clm"er iTrifolium pratense L.) with many herbaceous weeds scattered throughout the 
orchard. The trees were marked with spray paint for X-disesase symptoms in 1978. 1979, 
1980 and 1981 with 4.1 Ck, 15.9%, 22.9% and 25.0%, respectively, showing symptoms. 
The unsprayed sample site was a three-row peach block on the canlpus of Michigan 
State ("nlvcrsity i~fSU). Originally, 123 trees were planted on 6-ft 0.8 m) centers in rows 
spaced 12 ft. i 3.7 ml apart. Currently, X-disease has reduced the orchard to 45 trees and, 
'Ii.,hi,'.n AgJriculturaI Experiment Station Journal Article Number 10465. This research was 
by a grant from the Michigan Peach Sponsors. 
C[);:parunent of Entomology, Michigan State University, East Lansing, MI 48824. 
1
Mowry and Whalon: Comparison of Leafhopper Species Complexes in the Ground Cover of
Published by ValpoScholar, 1984
206 THE GREAT LAKES ENTOMOLOGIST Vol. 17, No.4 
of 
these, 11.1 
% showed symptoms of the disease. The ground cover was mainly orchard 
and other grasses which remained unmowed throughout the season. 
Sampling Method. Both sites were sampled every 3-4 days from 9 June to 10 October 
1980, using a D-vac® suction sampler (D-vac Corp., Riverside, CA). A cone 34 cm high 
with upper and lower diameters of 19 and 40 cm, respectively, was constructed from 
I-mm thick, semi-transparent fiberglass. A 5-cm vertical flange of fiberglass was attached 
to 
the upper edge 
of the cone to accommodate a 20-cm ID suction hose. Two 15-cm 
diameter holes were cut, opposite one another, into the side of the cone. These were 
covered with two layers of I .5-mm thick black rubber and a slit was cut into each 
perpendicular to one another to allow for hand entry into the interior of the cone. The 
bottom of the cone encompassed an area of 0.125 m2.
The trap was used by inserting a nylon net into the upper hole of the cone, carefully 
approaching the sample area, and quickly setting the cone into the ground cover before 
any insects could escape. The D-vac® hose was then attached and the vacuum motor 
started. By inserting the hand into the cone, all plant material was uprooted and vacuumed 
into the sample net. The bare ground was raked over with the hands to insure that all 
trapped insects were taken up into the sample (Fig. 1). To prevent any insects from 
escaping, the vacuum hose was disengaged from the cone and the nylon net removed 
before shutting off the motor. The sample was transferred to a plastic bag, returned to the 
lab and frozen for future leafhopper identification and counting. 
Random samplc locations in cach orchard were generated based upon a grid size 
delineated by the tree spacings. The grid sizes were 12 by IO ft (3.7 by 3.0 m) and 6 by 6 
ft 
(1.8 by 1.8 
m) for the sprayed and unsprayed sites, respectively. Each grid ( sample 
unit) was sampled at its center with 20 grids at the sprayed site and four grids at the 
unsprayed site sampled each sampling day for a seasonal total of 508 and 112 samples, 
respectively. 
RESULTS AND DISCUSSION 
Leafbopper Complexes. The leafhopper species complexes and relative number cap­
tured at both sample sites were similar (Table 1). Only one specimen of a known vector of 
Fig. 1. Ground sampling device with attached D-vac® showing method of operation. 
2
The Great Lakes Entomologist, Vol. 17, No. 4 [1984], Art. 4
https://scholar.valpo.edu/tgle/vol17/iss4/4
1984 THE GREAT LAKES ENTOMOLOGIST 207 
Table 1. Leafuopper species and their total numbers captured throughout 1980 in ground 
cover samples at the commercial (COMM) and Michigan State University (MSU) sample 
sites. The total number of samples at the COMM and MSU sites were 508 and 112, 
respecthely. 
Sample Site 
Species 
COMM MSU Total 
StreptanllS confillis <Reuter) 

Aphrodes f1amstrigata (Donovan) 

Athvsanlls ar!(entarills Metcalf 

Draeculacepllaia amica (Walker) 

Psammotetrix jerrafl/s (DeLong & Davidson) 

Doratura sn·lata (8oheman) 

.4phrodes Jilscojaciata (Goeze) 

Dicranellra mali (Provancher) 

Endria inimica (Say) 

Latalus sayi (Fitch) 

Commelllls comma (Van Duzee) 

Maerosteles faseifrons (Stal) 

Aphrodes bicineta (Schrank) 

Parabolocrants riridis (Uhler) 

Tylo::ygus btfldllS (Say) 

Xestoeephalus pulicarius Van Duzee 

Paraphlepsills irroratus (Say) 

:1mbln;elllls cllrtisii (Fitch) 

Psanimoteni:r: liridellus (Zetterstedt) 

Graminella lligrijrolls (Forbes) 

187 
35 
13 
6 
1 
I 
4 
8 
10 
I 
2 
6 
1 
1 
1 
2 
o 
o 
o 
1 
726 
249 
54 
42 
29 
26 
18 13 5 
9 
5 
o 
5 
5 
I 
o 
1 
I 
1 
o 
913 
284 
67 
48 
30 
27 
22 21 
15 
10 
7 
6 
6 
6 
2 
2 
1 
1 
1 
1 
the X-disease pathogen (Paraphlepsius irroratus (Say» was captured. This was un­
expected because the most important known vectors in Michigan (P. irroratus and 
Scaphnopius aClitus (Say» use herbaceous plants predominantly as hosts for feeding and 
o\·iposition !Rosenberger and Jones 1978, McClure 1980). The lack of this, and any 
other. vector species suggests that the increase in X-disease at the commercial site for 
1980 and 1981 might be attributed to non-resident vector species moving into and out of 
the orchard within a matter of hours or to resident leafuopper species not yet known to 
vector the X-disease pathogen. The most numerous leafuopper captured at both sites, 
Streptanlls confinis (Reuter), has been observed on yellow sticky board traps along with 
P. irrorafl/s at a height of ca. 1.8 m in cherry trees, which may warrant further investiga­
tion into its potential vector status. 
Insecticide Influence. Comparing seasonal population trends for the two most com­
mon 
leafuopper species found in both sites 
(S. confinis and Aphrodes Jlavostrigata (Dono­
van II indicates that tree foliar insecticide applications appears to greatly reduce their 
abundance in the ground cover (Figs. 2 and 3). While azinphosmethyl apparently reduces 
leatbopper numbers. endosulfan, and possibly phosmet. seem to have an even greater 
effect. Following termination of insecticide applications toward the end of July, leafuop­
per populations at the commercial site did tend to increase, but they never approached the 
densities recorded during the same period at the MSU site. 
This indicates that while the ground cover may offer some protection from insecticides. 
tree foliar applications are likely to reduce leafuopper abundance. This calls into question 
the advisability of ground cover applications for vector control as it is unlikely that further 
reduction will be obtained (note the period around 1 August. Fig. 3). Late season, i.e., 
after harvest. insecticide applications may not aid in checking disease spread through 
3
Mowry and Whalon: Comparison of Leafhopper Species Complexes in the Ground Cover of
Published by ValpoScholar, 1984
208 THE GREAT LAKES ENTOMOLOGIST Vol. 17, No.4 
0 
'" 
'" 
0 
0 • • S. confinis 
'" 
0 
ID .t.---__ .... A. fia!IJostrigata
« N 
E 
'­if) 
0::: 0 <:>W 
0.. '" 
0.. 0 ::c 0 
lL. 
i5 ~ 
-l 
<:> 
~ 
<:> 
II) 
<:> JUN JUL RUG SEP OCT NOV 
1980 
Fig. 2. Seasonal population trends for Streptanus confinis and Aphrodes Jlavostrigata at the un­
sprayed Michigan State University sample site. 
.. AA E P ME A
- • • s. confinis11 1j TJ 
....-----. A. fiavostrigata 
'" JUN JUL AUG SEP OCT NOV 
1980 
Fig. 3. Seasonal population trends for Streptanus con finis and AphrodesJlavostrigata at the sprayed 
commercial sample site showing dates of insecticide applications (A azinphosmethyl, E = 
endosulfan, P phosmet). 
4
The Great Lakes Entomologist, Vol. 17, No. 4 [1984], Art. 4
https://scholar.valpo.edu/tgle/vol17/iss4/4
1984 THE GREAT LAKES ENTOMOLOGIST 209 
vector control as the leatbopper populations did not seem to reach high levels following 
the pre-harvest treatments. 
CONCLUSIONS 
Fixed-area ground 
CO\'er sampling for absolute abundance estimates is an effective 
means of interspecific or intersite comparison but does not reveal leatbopper activity. 
Insects moving into and out of the orchard within short periods of time can only be
detected v.ith relatiye sampling methods, e.g., yellow sticky board traps. The sampling 
method used here may be used to assess the effectiveness of insecticidal control of 
leafhoppers. The incidence of X-disease increased in both 1980 and 1981 in the com­
mercial orchard. This increase occurred in the absence of a resident known vector popula­
tion and v.ith greatly reduced leafhopper abundance in general. It would scem unreason­
able. therefore. to increase insecticide applications in the orchard to check the spread of 
X-disease through "cctor control. 
ACKNOWLEDGMENT 
We 
would like to 
thank Mr. Robert D. McCall for technical assistance in the field and 
laboratory 
LITERATURE CITED 
Gilmer. R. ~L and E. C. Blodgett. 1976. X-disease. p. 145-155 in Virus diseases and 
n~~-inf~tious 
disorders 
of stone fruits in North America. USDA Agric. Handbook 
4.J1'. 4.:>.:> p. 
Howin.. -\. 1.. J. Hull. and A. L. Jones. 1981. Fruit pesticide handbook. CES Michigan 
State Cui\,. BulL E-154. 96 p. 
Jones.. -\. L.. G. R. Hooper, and D. A. Rosenberger. 1974. Association of mycoplasma­
like bodies v.ith linle peach and X-disease. Phytopathology 64:755-756. 
McClure. ~L S. 1980. Role of wild host plants in the feeding, oviposition, and dispcrsal 
of Scaphytopius acutus (Homoptera: Cicadellidae), a vector of peach X-disease. En­
viron. Entomol. 9:265--274. 
Nasu. S.. D. D. Jensen, and J. Richardson. 1970. Electron microscopy of mycoplasma­
like bodies associated with insect and plant hosts of peach western X-disease. Virology 
41:583--595. 
Nielson. ~t W. 1968. The leatbopper vectors of phytopathogenic viruses (Homoptera: 
Cicadellidael: Taxonomy, biology and virus transmission. USDA Tech. BulL 1382. 
386 p. 
PurcelL A. H. and J. S. Elkington. 1980. A comparison of sampling methods for leatbop­
per yectors of X-disease in California cherry orchards. J. Econ. Entomol. 73:854--860. 
Rosenberger. D. A. and A. L. Jones. 1977. Spread of X-disease in Michigan peach 
orchards. Plant Dis. Rep. 61:830-834. 
___
1978. Leafhopper vectors 
of the peach X-disease pathogen and its seasonal 
transmission from chokecherry. Phytopathology 68:782-790. 
Southwood. T. R. E. 1978. Ecological methods with particular reference to the study of 
insect populations. Chapman and Hall, London. 524 p. 
Taboada. 0 .. D. A. Rosenberger, and A. L Jones. 1975. Leatbopper fauna of X-diseased 
peach and cherry orchards in southwest Michigan. 1. Econ. EntomoL 68:255-257. 
5
Mowry and Whalon: Comparison of Leafhopper Species Complexes in the Ground Cover of
Published by ValpoScholar, 1984


Comparison of Leafhopper Species Complexes in the Ground Cover of Sprayed and Unsprayed Peach Orchards in Michigan (Homoptera: Cicadellldae)

Valparaiso University

The Great Lakes Entomologist Volume 17 Number 4 - Winter 1984 Number 4 - Winter 1984 Article 4 December 1984 Comparison of Leafhopper Species Complexes in the Ground Cover of Sprayed and Unsprayed Peach Orchards in Michigan (Homoptera: Cicadellldae) Thomas M. Mowry Michigan State University Mark E. Whalon Michigan State University Follow this and additional works at: https://scholar.valpo.edu/tgle  Part of the Entomology Commons Recommended Citation Mowry, Thomas M. and Whalon, Mark E. 1984. "Comparison of Leafhopper Species Complexes in the Ground Cover of Sprayed and Unsprayed Peach Orchards in Michigan (Homoptera: Cicadellldae)," The Great Lakes Entomologist, vol 17 (4) Available at: https://scholar.valpo.edu/tgle/vol17/iss4/4 This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. For more information, please contact a ValpoScholar staff member at scholar@valpo.edu. 1984 THE GREAT LAKES ENTOMOLOGIST 205 COMPARISON OF LEAFHOPPER SPECIES COMPLEXES IN THE GROUND COVER OF SPRAYED AND UNSPRAYED PEACH ORCHARDS IN MICHIGAN (HOMOPTERA: CICADELLlDAE)l Thomas M. Mowry and Mark E. Whalon2 ABSTRACT Two ~lichigan peach orchards were sampled for leafhoppers using a fixed-area ground sampling de\"ice attached to a D-vac®. Absolute abundance estimates indicated that routine tree insecticide applications greatly depressed leafhopper populations. This, and the fact that no resident, known vectors of the X-disease pathogen were detected, suggests that increasing insecticide applications to check the spread of the disease through vector control would be ineffective. X-dise3-"C. a stone fruit malady of probable mycoplasma etiology (Nasu et al. 1970, Jones et aI. 1974}. is a major problem in the peach and cherry growing areas of southern :-'1ichigan 1Rosenberger and Jones 1977). This is true for many of the major stone fruit producing areas in the United States (Gilmer and Blodgett 1976, Purcell and Elkington 19801. Leafboppers are the only known vectors of the X-disease pathogen (Gilmer and Blodgett 1976. "Sielson 1968). There is much grower interest in checking the spread of X-disease through insecticidal control of the leafhopper vectors. To investigate this poten­tiaL it is necessary to sample leafhopper populations in such a manner as to allow for comparison between treated and untreated sample sites. The major means of sampling leatboppers in stone fruit orchards has been yellow sticky-board traps (McClure 1980, Purcell and Ellington 1980, Rosenberger and Jones 1978, Taboada et al. 1975). The relati\e abundartce estimates obtained through this method preclude interspecific or in­tersite comparisons because the units of measurement are unknown, making only com­pari:.ons. in space and time possible (Southwood 1978). This paper reports the comparison of the leatbopper species complexes between a sprayed and unsprayed peach orchard absolute abundance estimates. METHODS AND MATERIALS Sample Sites. The sprayed sample site was a commercial peach orchard maintained on a regular pesticide spray schedule until harvest (Howitt et al. 1981). Approximately 1165 trees of scyeral varieties were planted on 12-ft (3.7 m) centers in rows spaced 20 ft (6.1 m) The ground cover consisted primarily of orchard grass (Dactylis glomerata L.) and clm"er iTrifolium pratense L.) with many herbaceous weeds scattered throughout the orchard. The trees were marked with spray paint for X-disesase symptoms in 1978. 1979, 1980 and 1981 with 4.1 Ck, 15.9%, 22.9% and 25.0%, respectively, showing symptoms. The unsprayed sample site was a three-row peach block on the canlpus of Michigan State ("nlvcrsity i~fSU). Originally, 123 trees were planted on 6-ft 0.8 m) centers in rows spaced 12 ft. i 3.7 ml apart. Currently, X-disease has reduced the orchard to 45 trees and, 'Ii.,hi,'.n AgJriculturaI Experiment Station Journal Article Number 10465. This research was by a grant from the Michigan Peach Sponsors. C[);:parunent of Entomology, Michigan State University, East Lansing, MI 48824. 1Mowry and Whalon: Comparison of Leafhopper Species Complexes in the Ground Cover ofPublished by ValpoScholar, 1984206 THE GREAT LAKES ENTOMOLOGIST Vol. 17, No.4 of these, 11.1 % showed symptoms of the disease. The ground cover was mainly orchard and other grasses which remained unmowed throughout the season. Sampling Method. Both sites were sampled every 3-4 days from 9 June to 10 October 1980, using a D-vac® suction sampler (D-vac Corp., Riverside, CA). A cone 34 cm high with upper and lower diameters of 19 and 40 cm, respectively, was constructed from I-mm thick, semi-transparent fiberglass. A 5-cm vertical flange of fiberglass was attached to the upper edge of the cone to accommodate a 20-cm ID suction hose. Two 15-cm diameter holes were cut, opposite one another, into the side of the cone. These were covered with two layers of I .5-mm thick black rubber and a slit was cut into each perpendicular to one another to allow for hand entry into the interior of the cone. The bottom of the cone encompassed an area of 0.125 m2.The trap was used by inserting a nylon net into the upper hole of the cone, carefully approaching the sample area, and quickly setting the cone into the ground cover before any insects could escape. The D-vac® hose was then attached and the vacuum motor started. By inserting the hand into the cone, all plant material was uprooted and vacuumed into the sample net. The bare ground was raked over with the hands to insure that all trapped insects were taken up into the sample (Fig. 1). To prevent any insects from escaping, the vacuum hose was disengaged from the cone and the nylon net removed before shutting off the motor. The sample was transferred to a plastic bag, returned to the lab and frozen for future leafhopper identification and counting. Random samplc locations in cach orchard were generated based upon a grid size delineated by the tree spacings. The grid sizes were 12 by IO ft (3.7 by 3.0 m) and 6 by 6 ft (1.8 by 1.8 m) for the sprayed and unsprayed sites, respectively. Each grid ( sample unit) was sampled at its center with 20 grids at the sprayed site and four grids at the unsprayed site sampled each sampling day for a seasonal total of 508 and 112 samples, respectively. RESULTS AND DISCUSSION Leafbopper Complexes. The leafhopper species complexes and relative number cap­tured at both sample sites were similar (Table 1). Only one specimen of a known vector of Fig. 1. Ground sampling device with attached D-vac® showing method of operation. 2The Great Lakes Entomologist, Vol. 17, No. 4 [1984], Art. 4https://scholar.valpo.edu/tgle/vol17/iss4/41984 THE GREAT LAKES ENTOMOLOGIST 207 Table 1. Leafuopper species and their total numbers captured throughout 1980 in ground cover samples at the commercial (COMM) and Michigan State University (MSU) sample sites. The total number of samples at the COMM and MSU sites were 508 and 112, respecthely. Sample Site Species COMM MSU Total StreptanllS confillis <Reuter) Aphrodes f1amstrigata (Donovan) Athvsanlls ar!(entarills Metcalf Draeculacepllaia amica (Walker) Psammotetrix jerrafl/s (DeLong & Davidson) Doratura sn·lata (8oheman) .4phrodes Jilscojaciata (Goeze) Dicranellra mali (Provancher) Endria inimica (Say) Latalus sayi (Fitch) Commelllls comma (Van Duzee) Maerosteles faseifrons (Stal) Aphrodes bicineta (Schrank) Parabolocrants riridis (Uhler) Tylo::ygus btfldllS (Say) Xestoeephalus pulicarius Van Duzee Paraphlepsills irroratus (Say) :1mbln;elllls cllrtisii (Fitch) Psanimoteni:r: liridellus (Zetterstedt) Graminella lligrijrolls (Forbes) 187 35 13 6 1 I 4 8 10 I 2 6 1 1 1 2 o o o 1 726 249 54 42 29 26 18 13 5 9 5 o 5 5 I o 1 I 1 o 913 284 67 48 30 27 22 21 15 10 7 6 6 6 2 2 1 1 1 1 the X-disease pathogen (Paraphlepsius irroratus (Say» was captured. This was un­expected because the most important known vectors in Michigan (P. irroratus and Scaphnopius aClitus (Say» use herbaceous plants predominantly as hosts for feeding and o\·iposition !Rosenberger and Jones 1978, McClure 1980). The lack of this, and any other. vector species suggests that the increase in X-disease at the commercial site for 1980 and 1981 might be attributed to non-resident vector species moving into and out of the orchard within a matter of hours or to resident leafuopper species not yet known to vector the X-disease pathogen. The most numerous leafuopper captured at both sites, Streptanlls confinis (Reuter), has been observed on yellow sticky board traps along with P. irrorafl/s at a height of ca. 1.8 m in cherry trees, which may warrant further investiga­tion into its potential vector status. Insecticide Influence. Comparing seasonal population trends for the two most com­mon leafuopper species found in both sites (S. confinis and Aphrodes Jlavostrigata (Dono­van II indicates that tree foliar insecticide applications appears to greatly reduce their abundance in the ground cover (Figs. 2 and 3). While azinphosmethyl apparently reduces leatbopper numbers. endosulfan, and possibly phosmet. seem to have an even greater effect. Following termination of insecticide applications toward the end of July, leafuop­per populations at the commercial site did tend to increase, but they never approached the densities recorded during the same period at the MSU site. This indicates that while the ground cover may offer some protection from insecticides. tree foliar applications are likely to reduce leafuopper abundance. This calls into question the advisability of ground cover applications for vector control as it is unlikely that further reduction will be obtained (note the period around 1 August. Fig. 3). Late season, i.e., after harvest. insecticide applications may not aid in checking disease spread through 3Mowry and Whalon: Comparison of Leafhopper Species Complexes in the Ground Cover ofPublished by ValpoScholar, 1984208 THE GREAT LAKES ENTOMOLOGIST Vol. 17, No.4 0 '" '" 0 0 • • S. confinis '" 0 ID .t.---__ .... A. fia!IJostrigata« N E '­if) 0::: 0 <:>W 0.. '" 0.. 0 ::c 0 lL. i5 ~ -l <:> ~ <:> II) <:> JUN JUL RUG SEP OCT NOV 1980 Fig. 2. Seasonal population trends for Streptanus confinis and Aphrodes Jlavostrigata at the un­sprayed Michigan State University sample site. .. AA E P ME A- • • s. confinis11 1j TJ ....-----. A. fiavostrigata '" JUN JUL AUG SEP OCT NOV 1980 Fig. 3. Seasonal population trends for Streptanus con finis and AphrodesJlavostrigata at the sprayed commercial sample site showing dates of insecticide applications (A azinphosmethyl, E = endosulfan, P phosmet). 4The Great Lakes Entomologist, Vol. 17, No. 4 [1984], Art. 4https://scholar.valpo.edu/tgle/vol17/iss4/41984 THE GREAT LAKES ENTOMOLOGIST 209 vector control as the leatbopper populations did not seem to reach high levels following the pre-harvest treatments. CONCLUSIONS Fixed-area ground CO\'er sampling for absolute abundance estimates is an effective means of interspecific or intersite comparison but does not reveal leatbopper activity. Insects moving into and out of the orchard within short periods of time can only bedetected v.ith relatiye sampling methods, e.g., yellow sticky board traps. The sampling method used here may be used to assess the effectiveness of insecticidal control of leafhoppers. The incidence of X-disease increased in both 1980 and 1981 in the com­mercial orchard. This increase occurred in the absence of a resident known vector popula­tion and v.ith greatly reduced leafhopper abundance in general. It would scem unreason­able. therefore. to increase insecticide applications in the orchard to check the spread of X-disease through "cctor control. ACKNOWLEDGMENT We would like to thank Mr. Robert D. McCall for technical assistance in the field and laboratory LITERATURE CITED Gilmer. R. ~L and E. C. Blodgett. 1976. X-disease. p. 145-155 in Virus diseases and n~~-inf~tious disorders of stone fruits in North America. USDA Agric. Handbook 4.J1'. 4.:>.:> p. Howin.. -\. 1.. J. Hull. and A. L. Jones. 1981. Fruit pesticide handbook. CES Michigan State Cui\,. BulL E-154. 96 p. Jones.. -\. L.. G. R. Hooper, and D. A. Rosenberger. 1974. Association of mycoplasma­like bodies v.ith linle peach and X-disease. Phytopathology 64:755-756. McClure. ~L S. 1980. Role of wild host plants in the feeding, oviposition, and dispcrsal of Scaphytopius acutus (Homoptera: Cicadellidae), a vector of peach X-disease. En­viron. Entomol. 9:265--274. Nasu. S.. D. D. Jensen, and J. Richardson. 1970. Electron microscopy of mycoplasma­like bodies associated with insect and plant hosts of peach western X-disease. Virology 41:583--595. Nielson. ~t W. 1968. The leatbopper vectors of phytopathogenic viruses (Homoptera: Cicadellidael: Taxonomy, biology and virus transmission. USDA Tech. BulL 1382. 386 p. PurcelL A. H. and J. S. Elkington. 1980. A comparison of sampling methods for leatbop­per yectors of X-disease in California cherry orchards. J. Econ. Entomol. 73:854--860. Rosenberger. D. A. and A. L. Jones. 1977. Spread of X-disease in Michigan peach orchards. Plant Dis. Rep. 61:830-834. ___1978. Leafhopper vectors of the peach X-disease pathogen and its seasonal transmission from chokecherry. Phytopathology 68:782-790. Southwood. T. R. E. 1978. Ecological methods with particular reference to the study of insect populations. Chapman and Hall, London. 524 p. Taboada. 0 .. D. A. Rosenberger, and A. L Jones. 1975. Leatbopper fauna of X-diseased peach and cherry orchards in southwest Michigan. 1. Econ. EntomoL 68:255-257. 5Mowry and Whalon: Comparison of Leafhopper Species Complexes in the Ground Cover ofPublished by ValpoScholar, 1984

https://scholar.valpo.edu/cgi/viewcontent.cgi?article=1521&amp;context=tgle

Comparison of Leafhopper Species Complexes in the Ground Cover of Sprayed and Unsprayed Peach Orchards in Michigan (Homoptera: Cicadellldae)

Abstract

Similar works

Full text

Available Versions

ValpoScholar

Valparaiso University