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JOURNAL OF PLANT PROTECTION RESEARCH
Vol. 48, No. 3 (2008)
HARMFUL HEMIPTERA OF LYGUS GENUS (MIRIDAE,
HEMIPTERA) ON ALFALFA (MEDICAGO SATIVA L.)
IN HAMEDAN PROVINCE (WESTERN IRAN)
Majid Mirab-balou1, Mohammad Khanjani2
1 Department of Plant Protection, Faculty of Agriculture, Tehran University, Karaj-Iran
2 Department of Plant Protection, Faculty of Agriculture, Bu-Ali Sina University, Hamedan-Iran
Received: September 2, 2007
Accepted: May 4, 2008
Abstract: The research on the occurrence of herbivorous heteroptera of Lygus genus on alfalfa (Medi-
cago sativa L.) was carried out over 2005–2006 in the Hamedan province (Western Iran). The analysis
of the faunistic material collected from Hemiptera showed the occurrence of 4 species where domi-
nant Heteroptera were represented by: Lygus rugulipennis Poppius, L. pratensis L., L. gemellatus H.-S.
and L. punctatus Z. The maximum abundance of these species coincided with full flowering alfalfa.
Among Lygus species, L. rugulipennis P. was the most highly abundant in alfalfa’s the main species in
these fields.
Key words: Alfalfa, Miridae, Heteroptera, Lygus rugulipennis P., Lygus pratensis L., Lygus gemellatus
H.-S., Lygus punctatus Z., Hamedan, Iran
INTRODUCTION
Alfalfa (Medicago sativa L.) is highly valued legume forage, extensively cultivated
in warm temperate and cool subtropical regions. It has been heralded as having the
highest feeding value of all commonly grown hay crops, producing more protein per
ha than any other crop for livestock (Metcalf and Luckmann 1982). The alfalfa due
to its specific floristic and faunestic status has provided particular microclimate that
because it is the habitat of the insects and arthropods.
Heteroptera, known as true bugs, is a very large and diverse order. They are
found all over the world; there are few habitats without a Heteroptera adapted to
living there. There are 80,000 described species in 37 families (Slater and Baranowski
1987; Borror et al. 1989; Henry and Froeschner 1988). It is attacked in the West of Iran
*Corresponding address:
mirab_m2003@yahoo.com; Khanjani@basu.ac.ir
314 Journal of Plant Protection Research 48 (3), 2008
by the mirid bugs Lygus species, thus establishing novel insect–plant associations.
Although all of these insects have piercing-sucking mouthparts that normally con-
fine their feeding to liquids (plant and animal) (a few Lygaeidae excepted) they are
remarkably diverse in habit and in habitat occupied (Weber 1930; Dolling 1991). The
majority of species are phytophagous, feeding on virtually every type of plant from
mosses (Tingidae: Acalypra) to legumes (Miridae: Lygus) to conifers (Pentatomidae:
Dendrocoris) (Lattin et al. 1992).
Family Miridae is one of the most populated families in Hemiptera order with
more than 10,000 species in 1,400 genera in all over the world (Schuh 1995). The mem-
bers of this family in spite of various morphologic differences specially having cone-
us and 1 or 2 cells on the base of membrane are identifiable from all the close families
(Ross et al. 1982; Wheeler 2001). Members of this family are similar to Anthocoridae
family. In having cuneus, tarsal formula (3-3-3) and number of antennal segments.
However it differs from the later family by the generally head is devoid of simple
eyes (Bei-Beinko et al. 1955; Slater and Baranowski 1978). The species in this family
have extensive range of host, so that some of them are phytophagous and some oth-
ers are predator (Slater and Baranowski 1978; Alford 1984; McGavin 1992).
The Lygus bugs of Miridae are tremendously scattered and they are of injurious
pests in field crops. Feeding by Lygus bugs damages the apical meristem, with con-
sequent development of secondary stems and leaf tattering. Lygus bugs are small,
oval-shaped insects that feed on a variety of crops and weeds. Several species infest
alfalfa. Adult Lygus bugs are about 3 mm wide and 6 mm long. They vary from pale
green to reddish brown to black and from fairly uniform color to mottled. Lygus bugs
share characteristics with all‚ true bugs, these include the distinctive, triangular or ‘V’-
shaped marking in the upper centre of their backs and membranous wingtips. Adults
are active and fly readily when approached. Immature Lygus bugs (nymphs) are light
green and wingless. Several black spots, usually five, become noticeable on the backs
of nymphs as they mature through five instars (growth stages). Wing buds are evi-
dent in the fourth and fifth instar (Slater and Baranowski 1987; Schuh and Slater 1995;
Dolling 1991; Kelton 1975). In Northern America L. lineolaris (Palisot) and L. hesperus
Knight are the key pests (Kelton 1975) and the other species such as L. borealis (Kelton),
L. elisus (Van Duzee), L. keltoni Schwartz and L. shulli Knight are secondary pests in
some districts. These bugs are main pests in flowering stage of alfalfa and they lead to
seed fall and decline of thousand seed’s weight (Khanjani 2005). Conti and Bin (2001)
L. rugulipennis and L. pratensis have been reported as important pest of kenaf, Hibiscus
cannabinus in Italy. Carvalho (1955) reviewed published a comprehensive content of
the bugs in this family in the world, and therefore he has reviewed the keys of this
family genera Eyles and Carvalho (1975) have reviewed the key of Stenodemini genera
in the world. Schuh and Slater (1995) have also published the Heteroptera classifica-
tion in the world and their life. The literature available offers few reports on Heter-
optera infesting alfalfa. Therefore, the aim of the present research was to define the
species composition of herbivorous Heteroptera of Lygus genus of alfalfa.
MATERIALS AND METHODS
Population samples of the true bugs species were collected from several different
sites in Hamedan province (33 59 N: 47 44 E) including Famenin, Ghahavand, Asad-
Abad, and Kabutarahang, which is located at western Iran. A total sampling, were
Harmful Hemiptera of Lygus genus on Alfalfa… 315
performed in about 30000 ha area in this province, period of 2005–2006. The material
was collected with a standard sweeping net and a hand-held aspirator. The sampling
twice per week and each time there were taken 2 nets in different hours per day and
also the samplings were taken 3 times in each period by the motion in 2 diameters
of the field. The specimens of the net were poured in to the packet and there were
written all the attribution following date, the place and plant phonology and there
were sent to Entomology laboratory in Bu-Ali Sina University to discrimination. The
specimen were discriminated and then detected in lab.
RESULTS AND DISCUSSION
The analysis of the faunistic material collected on alfalfa showed the occurrence
of 4 species of Heteroptera of Lygus genus (Miridae): Lygus rugulipennis Poppius, Ly-
gus pratensis L., Lygus gemellatus H.-S. and Lygus punctatus Z. Among Lygus species,
L. rugulipennis was the most highly abundant in alfalfa which is the main species in
these fields (Fig. 1).
Fig. 1. The comprise of Lygus spp. population in various sampling month (2006) in Hamedan province
The Miridae family infesting alfalfa, besides Lygus genus Heteroptera, was also
represented by other species of the following genera: Adelphocoris and Stenodema,
which was mostly accessory species (except for Adelphocoris lineolatus) (Mirab-balou
2007).
Lygus rugulipennis Poppius
Alfalfa tarnished plant bug; Lygus rugulipennis attacks a wide variety of economi-
cally important herbaceous plants, vegetable crops, commercial flower plants, fruit
trees, and nursery stock (Kelton 1975; Wheeler 2001; Khanjani 2005; Conti and Bin
2001). This polyphagous bug is reported to attack more than 400 species of plants and
is a dangerous pest to numerous vegetables (Khanjani 2007). This species is one of the
most important pests in alfalfa fields in most parts of Iran. This bug had a key role
316 Journal of Plant Protection Research 48 (3), 2008
in flower shattering, drying green terminal buds, and shrinkage and weight loss of
seeds in alfalfa seeds production (Khanjani 2005, 2007). In this species, hemelytra ap-
pearing more or less dull because of the dense and long silvery pubescence. Genitalia
as in figure 2. Base or right paramere with markedly projecting tubercle. Specula not
thickened apically, 1.5 times as long as small lobe of aedeagus. Grayish green, brown
or blakish, pattern of scutellum forming a bifid stripe or W-shaped (Bei-Bienko and
Baghdanov 1955). Length of male 4.5–6.1 mm, width 2–2.5 mm (Fig. 3) and female
length 6–6.7 mm, width 2.2–2.7 mm. The maximum abundance of L. rugulipennis was
recorded in the second and third decade of June, namely at full flowering (Fig. 1). The
highest number of plant bugs was collected in 2006 at Famenin. The lowest number of
those phytophagous insects was recorded in 2006 at Bahar (Fig. 4).
Fig. 2. L. rugulipennis: 1–2. lobe of aedeagus, 3. spicula, 4–5. right and left paramere
Fig. 3. Adult male of L. rugulipennis Popp.
Harmful Hemiptera of Lygus genus on Alfalfa… 317
Fig. 4. The distribution L. rugulipennis Popp. in alfalfa fields of Hamedan Province
Lygus pratensis Linnaeus, 1758
Genitalia as in figure 5. Spicula of aedeagus apically thickened, twice as long as
small lobe; small lobe of aedeagus with only isolated denticles. Black spot at base of
scutellum not bifid or only slightly notched apically. Color varying, often with red-
dish spots. Length of male 4.35–5.36 (Fig. 6) and female 4.55–5.38 mm. The greatest
number of representatives of this species was caught in 2006 at Famenin (Fig. 7).
Fig. 5. L. pratensis: 1–2. 1–2. lobe of aedeagus, 3. spicula, 4–5. right and left paramere
318 Journal of Plant Protection Research 48 (3), 2008
Fig. 6. Adult male of L. pratensis
Fig. 7. The distribution L. pratensis in alfalfa fields of Hamedan Province
Lygus punctatus Zetterstedt
Genitalia as in figure 8. In this species color with more or less distinct reddish,
tinge, often orange-red or brownish red. Middle of corium less densely and less
coarsely punctate than other parts of hemelytra. The greatest number of representa-
tives of this species was caught in 2006 at Hamedan (Fig. 9).
Harmful Hemiptera of Lygus genus on Alfalfa… 319
Fig. 8. L. punctatus: 1–2. lobe of aedeagus, 3. spicula, 4–5. right and left paramere
Fig. 9. The distribution L. punctatus in alfalfa fields of Hamedan Province
Lygus gemellatus Herrich-Schaffer
Genitalia as in figure 10. Spicula tapering apically, very small, not longer than
small lobe; small lobe with numerous denticles. Black spot on scutellum usually bifid
apically. Pale grayish green, rarely with brownish or reddish tinge. The greatest num-
ber of representatives of this species was caught in 2006 at Hamedan (Fig. 11).
All species of Lygus are mainly plant feeders and thrive on a very wide range
of host plants including many commercially-grown flowers, fruit trees, garden, for-
age, and field crops, small fruits, forest tree nurseries, and weeds. Lygus bugs have
a particular preference for young developing tissue and as such, their damage in al-
falfa is often manifested by development of multiple shoots and distortion of flowers
and shedding of floral buds. Genus of Lygus are the main pests of the seed alfalfa
320 Journal of Plant Protection Research 48 (3), 2008
Fig. 10. L. gemellatus: 1–2. lobe of aedeagus, 3. spicula, 4–5. right and left paramere
Fig. 11. The distribution L. gemellatus in alfalfa fields of Hamedan Province
that with the nutrition of the flower stage led to the most damage on the second and
the third cuts on the seed alfalfa. Alfalfa tarnished plant bug, Lygus rugulipennis Pop-
pius is one of the most important pest in alfalfa fields in most parts of Iran. This bug
had a key role in flower shattering, drying green terminal buds, and shrinkage and
weight loss of seeds in alfalfa seeds production. This insect is highly polyphagous,
and its preferred host under Hamedan conditions is alfalfa in flower stage and its
main damage is flower shattering. It overwinters in dead plant material or under tree
bark as adults. Over wintered adults leave the shelters as temperature rises in spring
and the female deposits eggs inside the plant stems. The first generation appears in
June. It usually migrates after the first harvesting of alfalfa to unharvested fields or
Harmful Hemiptera of Lygus genus on Alfalfa… 321
alfalfa seed farms. The second generation appears on the second and third cut and the
adults appear in September and have an incomplete generation. This insect has two
complete generations every year in this area (Khanjani 2005). Among Lygus species, L.
rugulipennis was the most highly abundant in alfalfa which is the main species in this
field (Mirab-balou 2007). Also, L. rugulipennis was one of native and important pest in
Kenaf, Hibiscus cannabinus fields in Italy (Conti & Bin 2001). Lygus bug damage may
occur in all major apple districts and sometimes is severe. Lygus attack is more frequent
in orchards that have a permanent cover crop and in orchards adjacent to crops or veg-
etation that host Lygus. Lygus bugs may feed on developing flower buds early in spring,
causing the buds to exude gum and shrivel up. Usually this damage is not serious
unless a very heavy infestation is present. Lygus cause their most serious damage by
feeding directly on fruit (Anonymous 2007). Damage caused by Lygus bugs in cucum-
bers could include destruction of the growing point of young seedlings and ragging of
leaves which appear crinkled and may have several holes (Ferguson 2005).
ACKNOWLEDGEMENTS
We would like to thank Mrs. Parisa Heidari and Mr. Qobad Suri in the field sam-
pling and laboratory works. This project was supported by the Research Division of
the Tehran University, Iran, which is greatly appreciated.
REFERENCES
Anonymous. 2007. Apple Lygus bug. UC Pest Management Guidelines. Available in:
http://www.ipm.ucdavis.edu/PMG/r4300411.html
Alford D.V. 1984. A Colour Atlas of Fruit Pests, (their recognition, biology and control). Printed by
Bblantyre Printing & Binding Co. Ltd, Glasgow, Scotland, 320 pp.
Bei-Beinko G.Ya. And Bagdanov K. 1955. Agricultural Entomology. Agricultural litterature, Gove-
ment Publisher, Moscow, 616 pp. (In Russian).
Borror D.J., Triplehorn C.A., Johnson N.F. 1989. An Introduction to the Study of Insects. Saunders
College Publishing, 875 pp.
Carvalho J.C.M. 1955. Keys to the genera of Miridae of the world (Hemiptera). Bol. Museu paracnse
Emilio Goeldi, 11: 1–51.
Conti E., Bin F. 2001. Native Lygus spp. (Heteroptera: Miridae) damaging introduced Hibiscus can-
nabinus in Italy. J. Econ. Entomol. 94: 648–657.
Dolling W.R. 1991. The Hemiptera. Natural History Museum, 274 pp.
Eyles C., Carvalho J.C. M. 1975. Revision of the genus Dolichomris with a revised key to the genera of
Stenodemini (Het., Miridae). J. Nat. History 9: 257–269.
Ferguson G. 2005. The Lygus Bug – A Problem for Greenhouse Pepper and Cucumber Growers.Avail-
able in: http://www.omafra.gov.on.ca/english/crops/facts/lygusbug.htm
Henry T.J., Froeschner R.C. 1988. Catalog of the Heteroptera, or True Bugs, of Canada and the Conti-
nental United States. E.J. Brill, Leiden, 958 pp.
Kelton L.A. 1975. The Lygus bugs (genus Lygus Hahn) of North America (Het., Miridae). Mem. Ento-
mol. Soc. Canada. 95: 1–101.
Khanjani M. 2005. Field Crop Pests in Iran. 3rd ed. Bu-Ali Sina University Publication, 732 pp.
Khanjani M. 2007. Vegetables Pests in Iran. 3rd ed. Bu-Ali Sina University Publication, 467 pp.
322 Journal of Plant Protection Research 48 (3), 2008
Lattin J.D., Henry T.J, Schwartz M.D. 1992. Lygus desenus Knight, 1944, a newly recognized synonym
of Lygus eZisus Van Duzee, 1914 (Heteroptera: Miridae). Proceedings of the Entomological So-
ciety of Washington 94: 12–25.
McGavin G.C. 1992. Insects of the Northern Hemispher. Illustrated by Richard Lewington. Dragon’s
World Ltd Published, 192 pp.
Metcalf D.S., Luckmann W.H. 1982. Introduction to insect pest management Wiley Interscience Pub-
lication, London, UK: 469–486.
Mirab-balou M. 2007. Study on taxonomy of phytophagous bugs of the family Miridae and introduc-
ing insects’ natural enemies of alfalfa tarnished plant bug in Hamedan alfalfa farms. MSc thesis,
College of Agriculture, Tehran University, 126 pp.
Ross H.H., Ross C.A., Ross J.R.P. 1982. A textbook of Entomology. 4th ed. Printed in the United States
of America, 666 pp.
Schuh R.T. 1995. Plant Bugs of the World (Insecta: Heteroptera: Miridae): Systematic Catalog, Distri-
butions, Host List, and Bibliography. New York Entomological Society, New York, 1329 pp.
Schuh R.T., Slater J.A. 1995. True Bugs of the World (Hemiptera: Heteroptera) Classification and Nat-
ural History. Cornell Unive. Press. Ithaca, NY and London, 336 pp.
Slater J.A., Baranowski R.M. 1978. How to Know the True Bugs. W.M.C. Brown Company Publishers,
Dubuque, Lowa, 256 pp.
Weber H. 1930. Biologie der Hemipteren:eine Naturgeschichte der Schnabekerfe. Verlag von Julius
Springer, Berlin, 543 pp.
Wheeler A.G., Jr. 2001. Biology of the Plant Bugs (Hemiptera: Miridae). Pests, Predators, Opportun-
ists. Cornell University Press, Ithaca and London, 507 pp.
POLISH SUMMARY
SZKODLIWE PLUSKWIAKI RÓŻNOSKRZYDŁE (HETEROPTERA)
Z RODZAJU LYGUS (MIRIDAE, HEMIPTERA) WYSTĘPUJĄCE NA
ROŚLINACH LUCERNY SIEWNEJ (MEDICAGO SATIVA L.) W PROWINCJI
HAMADAN (ZACHODNI IRAN)
W prowincji Hamadan (zachodni Iran), w latach 2005 i 2006 przeprowadzono ba-
dania nad występowaniem roślinożernych pluskwiaków różnoskrzydłych z rodzaju
Lygus na lucernie siewnej (Medicago sativa L.). Analiza zebranego materiału fauni-
stycznego należącego do rządu Hemiptera wykazała występowanie czterech gatun-
ków. Dominującymi pluskwiakami były: Lygus rugulipennis Poppius, L. pratensis L.,
L. gamellatus H.-S. i L. punctatus Z. Największa obfitość tych gatunków była zbieżna
z pełnym kwitnięciem lucerny. Lygus rugulipennis był najliczniejszy spośród gatun-
ków z rodzaju Lygus na lucernie, głównym gatunku na tych polach.
