A modified Berlese funnel system was developed to extract alfalfa weevil larvae (Hypera postica) from quadrats 30.5 cm on a side. Data from this system were comp.wed with simultaneous data from a hand sorting extraction system. In most instances, the modified Berlese system was as efficient as the hand sorting method and the number of man hours required to process samples by hand was far greater than that required by the Berlese system

Armbrust, E. J

Bartell, D. P

Roberts, S. J

English

ValpoScholar

The Great Lakes Entomologist 
Volume 12 
Number 2 - Summer 1979 Number 2 - Summer 
1979 
Article 3 
June 1979 
Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae 
(Coleoptera: Curculionidae) from Alfalfa Samples 
S. J. Roberts 
Illinois Natural History Survey and Illinois Agricultural Experiment Station 
D. P. Bartell 
Texas Tech University 
E. J. Armbrust 
Illinois Natural History Survey and Illinois Agricultural Experiment Station 
Follow this and additional works at: https://scholar.valpo.edu/tgle 
 Part of the Entomology Commons 
Recommended Citation 
Roberts, S. J.; Bartell, D. P.; and Armbrust, E. J. 1979. "Evaluation of Two Systems Used to Extract Alfalfa 
Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples," The Great Lakes Entomologist, vol 12 (2) 
Available at: https://scholar.valpo.edu/tgle/vol12/iss2/3 
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. 
1979 THE GREAT LAKES ENTOMOLOGIST 73 
EVALUATION OF TWO SYSTEMS USED TO EXTRACT 
ALFALFA WEEVIL LARVAE (COLEOPTERA: CURCULIONIDAE) 
FROM ALFALFA SAMPLES1 
S. J. Robertsl, D. P. Bartellz, and E. J. Armbmstl 
ABSTRACT 
A modified Berlese funnel system was developed to extract alfalfa weevil larvae (Hypera 
postica) from quadrats 30.5 cm on a side. Data from this system were comp.wed with 
simultaneous data from a hand sorting extraction system. In most instances, the modified 
Berlese system was as  efficient as the hand sorting method and the number of man hours 
required to process samples by hand was far greater than that required by the Berlese 
system. 
Intensive sampling programs designed to obtain data for constructing life tables, studying 
population dynamics, and supporting modeling efforts associated with the alfalfa weevil, 
Hypera postica (Gyllenhal), generate samples which often contain several hundred larvae 
each. Extraction of larvae from large quantities of plant material by conventional systems, 
such as  the one used by Wilson and Armbrust (1970), is inadequate in terms of time 
involved for processing and efficiency in retrieving larvae. Reported here are results of 
research implemented to  evaluate a modified Berlese funnel system versus hand sorting 
for speed and efficiency in extracting weevil larvae from alfalfa samples. 
MATERIALS AND METHODS 
Figure 1 shows the basic design of the Berlese unit. Upper and lower funnels were 
constructed of galvanized sheet metal and machined as near replicas. Light bulbs (40W) 
provided the drying temperatures in the funnels. Hardware cloth (6 mm) was fitted inside 
the bottom funnel to support the sample. Gaskets (top and bottom) were made by glueing 
split rubber tubing to the funnel rims. Rubber bands were stretched over two sets of bolts 
to secure the top and bottom halves and prevent escape of larvae. Individual units could 
be utilized as  shown in Figure 2 or in a series (Fig. 3). 
Three alfalfa fields were sampled on a degree day basis in Washington County, Illinois 
during the 1974 growing season. Initial samples were taken on 11 April and sampling 
continued until first harvest (24-29 May) for a total of 10 sampling dates in field IL-1, eight 
in IL-3, and nine in IL-6. When fields were sampled, 20 quadrats of alfalfa, 30.5 cm on a 
side, were cut just above the ground for each field sampled. Alfalfa stems and litter were 
placed in paper grocery bags. Soil surface was examined for any larvae remaining in the 
quadrat. After returning the samples to the laboratory, 10 were processed through the 
Berlese units which extracted larvae into alcohol in the attached canning jars. The con- 
tents of the 10 remaining samples (insects, plants, and litter) were placed in a modified 
Carnoy's fixative (Humason, 1%7). These preserved samples were later washed through 
two Bureau of Standards screens (sieve openings of 12.7 mm and 0.177 mm) to recover 
lfllinois Natural History Survey and Illinois Agricultural Experiment Station, Urbana, IL 61801. 
2~epartment of Entomology, Agricultural Sciences Building, Texas Tech University, Lubbock, TX 
79409. 
1
Roberts et al.: Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (
Published by ValpoScholar, 1979
THE GREAT LAKES ENTOMOLOGIST 
LIPPER FUNNEL 
Vol. 12, No. 2 
S E C U R I N G  
B O L T  
RUBBER GASKET 
R O L L E D  
, EDGE 
BOTTOM FUNNEL 
-30.5 cm - ROLLED 
RUBBER GASKET 
J A R  R I N G  
SOLDERED I N  P L A C E  
C A N N I N G  J A R  
Fig. 1.  Berlese unit design depicting the upper and lower funnels, respectively 
2
The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 3
https://scholar.valpo.edu/tgle/vol12/iss2/3
1979 THE GREAT LAKES ENTOMOLOGIST 75 
3
Roberts et al.: Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (
Published by ValpoScholar, 1979
76 THE GREAT LAKES ENTOMOLOGIST Vol. 12, No. 2 
4
The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 3
https://scholar.valpo.edu/tgle/vol12/iss2/3
1979 THE GREAT LAKES ENTOMOLOGIST 77 
larvae that were free in the sample. The plants were then dissected to extract 1st and 2nd 
instars lodged in the terminals and leaf axils. The preserve-wash system was considered a 
measure of absolute density, in that great care was taken to search every plant for all 
larvae present. Larvae from each extraction system were categorized to instar with a head 
capsule caliper (Bartell and Roberts, 1974). Although the total extraction time for samples 
in the Berlese units varied from 36-72 hr, the time involved for hand labor to load and 
remove 10 samples was % hr. In contrast, hand labor for the preserve-wash required 2-3 
hr for processing 10 samples. The time required for classifying larvae to instar and count- 
ing was independent of both systems. 
These sampling and processing procedures yielded 27 data sets x four instars equaling 108 
paired means (540 individual sample observations) which represented three different 
fields, differences in numbers of individuals per life stage during the season, a wide range 
of sampling conditions (wet, dry, etc.), and different sample sizes (by volume of plant 
matter) as the crop matured. Data for the four instars recovered by the two systems were 
compared by using a 2 x 4 factorial design and analysis for each date. The two factors 
were methods (2 levels) and instars (4 levels) thus making a 2 x 4 factorial. 
RESULTS AND DISCUSSION 
The F tests of the 108 paired means are essentially LSD comparisons, but were made only 
in those instances after the significant interactions of extraction systems used, and 
number of instars recovered showed evidence of real differences attributable to the four 
instars extracted and evidence of the nature of these differences. These differences were 
included in a separate and combined analysis of the data from the three fields. From the 
108 comparisons, there were 22 and 3 in the separate and combined analysis respectively, 
with significant differences between the method used and the four instars extracted. 
Conversely, for 80% of the separate and 97% of the combined analysis there were no 
significant differences. Table 1 shows by field, date, and instar the 25 paired means that 
were significantly different. Twelve of these differences were attributed to higher numbers 
in the funnels, while 13 resulted from higher numbers in the preserve-wash system. 
Peak density in the three fields was indicated by both extraction systems between 19 and 
24 April. All fields had insecticide applications for larvae after 19 April but before 24 
April. In field IL-6, 28 April, and 24 April of the combined field data, the preserve-wash 
Table 1. Significant paired means for instars by field and date for Berlese (B) and preserve- 
wash (PW) extraction systems representing only those fields and dates where there was a 
significant F value for the interaction of instars recovered and extraction method used in the 
factorial analysis. 
INSTARS 
Field Data B PW B PW B PW B PW 
IL-I 2415 - - 0.1 1.4* 0.1 1.6** 
IL-3 1114 - 71.7* 52.1 61.8** 28.9 35.3** 7.2 
2814 - 113.0** 47.8 57.7** 13.3 17.9** 4.0 
515 10.2 20.2** 64.9* 60.3 - 45.1** 17.9 
2015 4.7** 0.5 8.6* 1.8 - 18.6 40.2** 
IL-6 2414 - 49.0 108.2** - 6.0 18.5** 
2814 0.5 13.5** 0.4 14.3** 0.5 5.6** 0.2 1.7** 
515 - 25.2** 8.8 - 2.1** 0.0 
IL-I, 3 & 6 2414 56.2 77.2** 38.0 72.7** - 5.0 9.4** 
(combined data) 
5
Roberts et al.: Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (
Published by ValpoScholar, 1979
78 THE GREAT LAKES ENTOMOLOGIST Vol. 12. No. 2 
system was significantly higher than the funnel system for all instars except 3rd in the 
combined data. These samples were taken on successive dates following insecticide spray 
applications. Since the preserve-wash system did not differentiate between live and dead 
larvae (all larvae within the sampling quadrat were preserved), those larvae killed by the 
insecticide could be extracted. The funnels essentially extracted only live larvae. 
In fields IL-6, 3 and 1, on 24 April, 20 and 24 May, respectively, there were significantly 
higher numbers of the 4th instars recovered by the preserve-wash system. Prepupae 
which had already spun cocoons, could have been dislodged in the preserve-wash pro- 
cedures and counted as 4th instars. This would not be as likely to happen with the Berlese 
extractions. Another possibility is that some of the 4th instars may have pupated in the 
funnels during extraction, and consequently lowered those counts. 
The preserve-wash again was higher for 2nd instars in field IL-6 on 24 April, and 1st 
instars in field IL-3 on 5 May. On several sampling dates, the alfalfa was wet because of 
rain or a heavy dew. Some 1st and 2nd instars may have stuck to the bottom funnels and 
could have been overlooked. Excess moisture from the sample was usually absorbed by 
the paper grocery bag while in transit. The preserve-wash system is not affected by wet 
sampling conditions. 
The number of processing steps for the preserve-wash system probably subjects this 
system to more human error. Larvae could have been lost in transfemng the samples to 
the fixative jars, or from the fixative jars to the washing sieves. Larvae may have splashed 
out of the top sieve during the washing process. First and possibly 2nd instars may have 
been overlooked in the bottom sieve. Even though the plants were dissected to extract the 
smaller instars, some larvae could have escaped detection. Any of these conditions could 
have been responsible for the instances where the Berlese counts were higher than the 
preserve-wash. 
Although 1st and 2nd instars are lodged in the plant terminals and leaf a i l s ,  the Berlese 
system extracted all instars as well as the preserve-wash system for 80% of the individual 
field and 97% of the combined sample comparisons. Wet sampling conditions and pupa- 
tion of 4th instars during extraction may cause an underestimated larval density when 
samples are processed by the Berlese system. Absolute density samples (processed by the 
preserve-wash system) most likely overestimated larval densities after insecticide applica- 
tions until dead larvae were no longer present in the samples. Considering time for proces- 
sing and no significant differences for at least 80% of the comparisons of the two systems, 
the Berlese funnel system is an acceptable method for approximating densities of alfalfa 
weevil larvae from the sample units. This Berlese extraction system can be adapted to a 
variety of insect-plant situations by changing bulb and hardware cloth size. The merits of 
this extraction system for population estimates of another insect species should be deter- 
mined by similar data comparisons with absolute density samples of that insect. 
ACKNOWLEDGMENTS 
We thank Kathleen Wood and Robert Barney for technical assistance, Tai-San Yip for 
help in preparing the factorial analysis of the data, and Dr. Robert Pausch for critique of 
the manuscript. All personnel are staff members at the Illinois Natural History survey 
except Kathleen Wood who is currently a research assistant at Louisiana State Uni- 
versity. 
LITERATURE CITED 
Bartell, D. P., and S. J. Roberts. 1974. A head capsule caliper: New tool for determining 
instars of the alfalfa weevil. J. Econ. Entomol. 67:801-803. 
Humason, G. L. 1967. Animal tissue techniques. W. H. Freeman and Co. San Francisco. 
2nd Ed. 
Wilson, M. C., and E. J. Annbrust. 1970. Approach to integrated control of the alfalfa 
weevil. J. Econ. Entomol. 63554-557. 
6
The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 3
https://scholar.valpo.edu/tgle/vol12/iss2/3


Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples

Valparaiso University

The Great Lakes Entomologist Volume 12 Number 2 - Summer 1979 Number 2 - Summer 1979 Article 3 June 1979 Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples S. J. Roberts Illinois Natural History Survey and Illinois Agricultural Experiment Station D. P. Bartell Texas Tech University E. J. Armbrust Illinois Natural History Survey and Illinois Agricultural Experiment Station Follow this and additional works at: https://scholar.valpo.edu/tgle  Part of the Entomology Commons Recommended Citation Roberts, S. J.; Bartell, D. P.; and Armbrust, E. J. 1979. "Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples," The Great Lakes Entomologist, vol 12 (2) Available at: https://scholar.valpo.edu/tgle/vol12/iss2/3 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. 1979 THE GREAT LAKES ENTOMOLOGIST 73 EVALUATION OF TWO SYSTEMS USED TO EXTRACT ALFALFA WEEVIL LARVAE (COLEOPTERA: CURCULIONIDAE) FROM ALFALFA SAMPLES1 S. J. Robertsl, D. P. Bartellz, and E. J. Armbmstl ABSTRACT A modified Berlese funnel system was developed to extract alfalfa weevil larvae (Hypera postica) from quadrats 30.5 cm on a side. Data from this system were comp.wed with simultaneous data from a hand sorting extraction system. In most instances, the modified Berlese system was as  efficient as the hand sorting method and the number of man hours required to process samples by hand was far greater than that required by the Berlese system. Intensive sampling programs designed to obtain data for constructing life tables, studying population dynamics, and supporting modeling efforts associated with the alfalfa weevil, Hypera postica (Gyllenhal), generate samples which often contain several hundred larvae each. Extraction of larvae from large quantities of plant material by conventional systems, such as  the one used by Wilson and Armbrust (1970), is inadequate in terms of time involved for processing and efficiency in retrieving larvae. Reported here are results of research implemented to  evaluate a modified Berlese funnel system versus hand sorting for speed and efficiency in extracting weevil larvae from alfalfa samples. MATERIALS AND METHODS Figure 1 shows the basic design of the Berlese unit. Upper and lower funnels were constructed of galvanized sheet metal and machined as near replicas. Light bulbs (40W) provided the drying temperatures in the funnels. Hardware cloth (6 mm) was fitted inside the bottom funnel to support the sample. Gaskets (top and bottom) were made by glueing split rubber tubing to the funnel rims. Rubber bands were stretched over two sets of bolts to secure the top and bottom halves and prevent escape of larvae. Individual units could be utilized as  shown in Figure 2 or in a series (Fig. 3). Three alfalfa fields were sampled on a degree day basis in Washington County, Illinois during the 1974 growing season. Initial samples were taken on 11 April and sampling continued until first harvest (24-29 May) for a total of 10 sampling dates in field IL-1, eight in IL-3, and nine in IL-6. When fields were sampled, 20 quadrats of alfalfa, 30.5 cm on a side, were cut just above the ground for each field sampled. Alfalfa stems and litter were placed in paper grocery bags. Soil surface was examined for any larvae remaining in the quadrat. After returning the samples to the laboratory, 10 were processed through the Berlese units which extracted larvae into alcohol in the attached canning jars. The con- tents of the 10 remaining samples (insects, plants, and litter) were placed in a modified Carnoy's fixative (Humason, 1%7). These preserved samples were later washed through two Bureau of Standards screens (sieve openings of 12.7 mm and 0.177 mm) to recover lfllinois Natural History Survey and Illinois Agricultural Experiment Station, Urbana, IL 61801. 2~epartment of Entomology, Agricultural Sciences Building, Texas Tech University, Lubbock, TX 79409. 1Roberts et al.: Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Published by ValpoScholar, 1979THE GREAT LAKES ENTOMOLOGIST LIPPER FUNNEL Vol. 12, No. 2 S E C U R I N G  B O L T  RUBBER GASKET R O L L E D  , EDGE BOTTOM FUNNEL -30.5 cm - ROLLED RUBBER GASKET J A R  R I N G  SOLDERED I N  P L A C E  C A N N I N G  J A R  Fig. 1.  Berlese unit design depicting the upper and lower funnels, respectively 2The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 3https://scholar.valpo.edu/tgle/vol12/iss2/31979 THE GREAT LAKES ENTOMOLOGIST 75 3Roberts et al.: Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Published by ValpoScholar, 197976 THE GREAT LAKES ENTOMOLOGIST Vol. 12, No. 2 4The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 3https://scholar.valpo.edu/tgle/vol12/iss2/31979 THE GREAT LAKES ENTOMOLOGIST 77 larvae that were free in the sample. The plants were then dissected to extract 1st and 2nd instars lodged in the terminals and leaf axils. The preserve-wash system was considered a measure of absolute density, in that great care was taken to search every plant for all larvae present. Larvae from each extraction system were categorized to instar with a head capsule caliper (Bartell and Roberts, 1974). Although the total extraction time for samples in the Berlese units varied from 36-72 hr, the time involved for hand labor to load and remove 10 samples was % hr. In contrast, hand labor for the preserve-wash required 2-3 hr for processing 10 samples. The time required for classifying larvae to instar and count- ing was independent of both systems. These sampling and processing procedures yielded 27 data sets x four instars equaling 108 paired means (540 individual sample observations) which represented three different fields, differences in numbers of individuals per life stage during the season, a wide range of sampling conditions (wet, dry, etc.), and different sample sizes (by volume of plant matter) as the crop matured. Data for the four instars recovered by the two systems were compared by using a 2 x 4 factorial design and analysis for each date. The two factors were methods (2 levels) and instars (4 levels) thus making a 2 x 4 factorial. RESULTS AND DISCUSSION The F tests of the 108 paired means are essentially LSD comparisons, but were made only in those instances after the significant interactions of extraction systems used, and number of instars recovered showed evidence of real differences attributable to the four instars extracted and evidence of the nature of these differences. These differences were included in a separate and combined analysis of the data from the three fields. From the 108 comparisons, there were 22 and 3 in the separate and combined analysis respectively, with significant differences between the method used and the four instars extracted. Conversely, for 80% of the separate and 97% of the combined analysis there were no significant differences. Table 1 shows by field, date, and instar the 25 paired means that were significantly different. Twelve of these differences were attributed to higher numbers in the funnels, while 13 resulted from higher numbers in the preserve-wash system. Peak density in the three fields was indicated by both extraction systems between 19 and 24 April. All fields had insecticide applications for larvae after 19 April but before 24 April. In field IL-6, 28 April, and 24 April of the combined field data, the preserve-wash Table 1. Significant paired means for instars by field and date for Berlese (B) and preserve- wash (PW) extraction systems representing only those fields and dates where there was a significant F value for the interaction of instars recovered and extraction method used in the factorial analysis. INSTARS Field Data B PW B PW B PW B PW IL-I 2415 - - 0.1 1.4* 0.1 1.6** IL-3 1114 - 71.7* 52.1 61.8** 28.9 35.3** 7.2 2814 - 113.0** 47.8 57.7** 13.3 17.9** 4.0 515 10.2 20.2** 64.9* 60.3 - 45.1** 17.9 2015 4.7** 0.5 8.6* 1.8 - 18.6 40.2** IL-6 2414 - 49.0 108.2** - 6.0 18.5** 2814 0.5 13.5** 0.4 14.3** 0.5 5.6** 0.2 1.7** 515 - 25.2** 8.8 - 2.1** 0.0 IL-I, 3 & 6 2414 56.2 77.2** 38.0 72.7** - 5.0 9.4** (combined data) 5Roberts et al.: Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Published by ValpoScholar, 197978 THE GREAT LAKES ENTOMOLOGIST Vol. 12. No. 2 system was significantly higher than the funnel system for all instars except 3rd in the combined data. These samples were taken on successive dates following insecticide spray applications. Since the preserve-wash system did not differentiate between live and dead larvae (all larvae within the sampling quadrat were preserved), those larvae killed by the insecticide could be extracted. The funnels essentially extracted only live larvae. In fields IL-6, 3 and 1, on 24 April, 20 and 24 May, respectively, there were significantly higher numbers of the 4th instars recovered by the preserve-wash system. Prepupae which had already spun cocoons, could have been dislodged in the preserve-wash pro- cedures and counted as 4th instars. This would not be as likely to happen with the Berlese extractions. Another possibility is that some of the 4th instars may have pupated in the funnels during extraction, and consequently lowered those counts. The preserve-wash again was higher for 2nd instars in field IL-6 on 24 April, and 1st instars in field IL-3 on 5 May. On several sampling dates, the alfalfa was wet because of rain or a heavy dew. Some 1st and 2nd instars may have stuck to the bottom funnels and could have been overlooked. Excess moisture from the sample was usually absorbed by the paper grocery bag while in transit. The preserve-wash system is not affected by wet sampling conditions. The number of processing steps for the preserve-wash system probably subjects this system to more human error. Larvae could have been lost in transfemng the samples to the fixative jars, or from the fixative jars to the washing sieves. Larvae may have splashed out of the top sieve during the washing process. First and possibly 2nd instars may have been overlooked in the bottom sieve. Even though the plants were dissected to extract the smaller instars, some larvae could have escaped detection. Any of these conditions could have been responsible for the instances where the Berlese counts were higher than the preserve-wash. Although 1st and 2nd instars are lodged in the plant terminals and leaf a i l s ,  the Berlese system extracted all instars as well as the preserve-wash system for 80% of the individual field and 97% of the combined sample comparisons. Wet sampling conditions and pupa- tion of 4th instars during extraction may cause an underestimated larval density when samples are processed by the Berlese system. Absolute density samples (processed by the preserve-wash system) most likely overestimated larval densities after insecticide applica- tions until dead larvae were no longer present in the samples. Considering time for proces- sing and no significant differences for at least 80% of the comparisons of the two systems, the Berlese funnel system is an acceptable method for approximating densities of alfalfa weevil larvae from the sample units. This Berlese extraction system can be adapted to a variety of insect-plant situations by changing bulb and hardware cloth size. The merits of this extraction system for population estimates of another insect species should be deter- mined by similar data comparisons with absolute density samples of that insect. ACKNOWLEDGMENTS We thank Kathleen Wood and Robert Barney for technical assistance, Tai-San Yip for help in preparing the factorial analysis of the data, and Dr. Robert Pausch for critique of the manuscript. All personnel are staff members at the Illinois Natural History survey except Kathleen Wood who is currently a research assistant at Louisiana State Uni- versity. LITERATURE CITED Bartell, D. P., and S. J. Roberts. 1974. A head capsule caliper: New tool for determining instars of the alfalfa weevil. J. Econ. Entomol. 67:801-803. Humason, G. L. 1967. Animal tissue techniques. W. H. Freeman and Co. San Francisco. 2nd Ed. Wilson, M. C., and E. J. Annbrust. 1970. Approach to integrated control of the alfalfa weevil. J. Econ. Entomol. 63554-557. 6The Great Lakes Entomologist, Vol. 12, No. 2 [1979], Art. 3https://scholar.valpo.edu/tgle/vol12/iss2/3

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Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples

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