Additions to the Knowledge of Taxonomy and Biology of Arge simlaensis (Cameron) (Argidae: Hymenoptera) in Rain Fed Conditions of Punjab (Pakistan).
Arge simlaensis has appeared as major pest of rose in recent years. The biology, taxonomy, mode of damage, larval stage, cocoons and host plant data are presented in this article.
Key Words: Arge simlaensis. Hymenoptera, Argidae, Saw flies.
The Argidae (Hymenoptera) is a large family of sawflies containing nearly 800 species worldwide, mostly in tropical regions. The larvae are phytophagous, commonly feeding (and often pupating) in groups and very few sometimes attain pest status. The member of this can easily be distinguished from all other Symphyta by the reduction of antennae in to a single elongated flagellomere, which is often like a turning fork in males. http://en.wikipedia.org/wiki/Argidae.
Medium sized adults of the genus Arge frequently visit flowers and broad leathery leaves of various plants to feed on nectar, pollen grain and leaf juices (Saini and Thind, 1995). The larvae feed like caterpillars on foliage of many plants (Goulet and Huber, 1993) and sometimes become abundant to cause significant loss.
This species Arge simlaensis was briefly described by Cameron (1877) as Hylotoma simlaensis, from Simla (India). Later, Rohwer (1921) recorded this species from Murree (Pakistan) with the name Arge annulitarsis (a synonym of Arge simlaensis). Saini and Thind (1995) gave detailed description taxonomic characters of this species.
Only the adults of this species were known. The biology, mode of damage, eggs, larval stage, cocoons and host plant data are presented in this article.
Materials and methods
Adult specimens were collected using hand net and also collected by hand from the host plants, killed using methyl acetate, pinned and dry preserved. The specimens were identified to species level by using key and description of Saini and Thind (1995) and were deposited in insect repository of Pakistan Museum of Natural History, Islamabad, Pakistan.
The specimens were collected from Barani Agricultural Research, Chakwal (31o55'96?N, 72o43'37?E, and 1725 feet altitude) and Pakistan Museum of Natural History, Islamabad (33o41'17?N, 73o04'61?E, and 1716 feet altitude). Preserved specimens were studied under Wild Heerbrugg stereomicroscope model M5A. Terminology of Snodgrass (1936) and Ross (1937) was followed.
The male and female abdomen were detached and placed in 10% KOH overnight for softening. After dissection the slides of male and female genetalia were prepared using the techniques of Ross (1937). Rest of abdomen was preserved in glass micro-vial with a drop glycerol and pinned with the specimen.
The shoots containing the eggs were placed in a cage (1x1x1 feet) at room temperature. The larvae were fed on fresh rose leaves on daily basis, till pupation. The larvae were preserved in absolute alcohol. Photographs were taken with help of Camera Sony DSC-H2 and microscope Olympus BH2.
Hylotoma simlaensis Cameron, 1877:91.
Arge simlaensis: Saini and Thind, 1995:83.
Arge annulitarsis Rohwer, 1921:89
Eggs are shining white, oval and 4-6 deposited into the soft rose shoot one at a time Larva: Larva of Arge simlaensis feed on rose especially Desi Ghulab Rosa indica Linn. This insect could be called the rose sawfly as rose is the most frequently preferred host plant. The larvae are pale green with light brown colored head and tiny black-colored spines on each body segment (Fig. 1c). They are slightly gregarious up to three larvae feeding on one leaf (Fig. 1d).
Cocoon: The mature larvae spin a tough silken cocoon on the base of the plant or nearby. From the cocoons emerge new adults to mate and lay eggs (Fig. 1e).
Adult: Body not punctured and covered with golden brown pubescence (Fig. 1f). Brownish yellow with black antennae, head, deflexed portions of mesonotum lateral to scutellum, mesoscutellum, metanotum, metascutellum, mesosternum, anterior margin of propodium, terminal 1/4 of ovipositor sheath, apices of all tibiae and tarsi. Wings sub-hyaline and infumated, more blackish in intercostal area and under stigma; costa, stigma and venation light brown to black. Fore wing with vein 3r-m slightly excurved, 3rd cubital cell as long as on top as on bottom. Mesoscutellum squarish, sub-convex with blunt posterior tip.
Male: Body length 7.8-9.36 mm. Head narrowing behind eyes. Antennae 2.5 X head width and of uniform thickness, flagellum longer than in female. Gonostipes sickle-shape (Fig. 1g). The adult description of this species exactly tallied with that of Saini and Thind, (1995).
Female: Body length 7.02-8.27mm. Head widened behind eyes. Antennae 1.5 X head width, flagellum somewhat compressed club shaped with its maximum almost double the apical thickness of scape. Eyes converging below. Lancet 2 mm long with 14 serrulae (Fig. 1h).
The females after emerging from over wintering pupae, mated and start oviposition in early February on different cultivars of rose especially Rosa indica. The eggs were laid singly (in the batches of 4-6) in slits. The slits were made by cutting the tender shoots with the sharp ovipositor of female. Egg slit changed colour gradually and turns into black (Fig. 1b). The shoot above that point dried and died.
The egg hatched and larvae appeared feeding on nearby leaves. Early larval instars appear gregariously on the host plant. As the dark green larvae grow older, they feed individually. Due to intensity of pest attack, they ate all the leaves of apical shoots and branches and caused a considerable damage to flower bearing branches. The larval development was completed in three weeks by feeding on the leaves. The mature larvae spined two inner and outer tough silk cocoons and turn into pre-pupa at first and then to pupa.
The adults again appeared in September same year indicating that this species was multi-voltine. This species appeared in 2003 and has become an important pest of all varieties of rose especially Desi Ghulab Rosa indica. This insect is not particularly resistant to pesticides. Dust formulations of insecticide give adequate control. Spray of insecticide is not recommended on open blossoms to avoid killing pollinators.
BARI, Chakwal, 9? and 1?, 25.ii.2004, 3? and 2?, 26.ii.2004, 1?, 27.ii.2004, Islamabad, 1?, 10.xi.2006, 1?, 30.xi.2006, 3?, 18.vii.2005, 2?, 21.vii.2005, 1?, 16.viii.2005.
We are grateful to David Smith (National Museum of Natural History, Washington, USA) for his help in identification and sending the concerned literature. We acknowledge Dr. Muhammad Rafique and Ubaidullah Azeem for their encouragement and moral support in this study. We are also thankful to Maqsood, for his help in photography.
Cameron, P., 1887. Trans. R. entomol. Soc. London. 35: 87-92.
Goulet, H. and Huber, J.T., 1993. Hymenoptera of the world: An identification guide to families. Centre for Land and Biological Resource Research, Ottawa, Canada. pp. 107-108.
Rohwer, A.S., 1921. Proc. U.S. Nat. Mus., 59: 83-109.
Ross, H.H., 1936. Annl. Entomol. Soc. Am., 29:99-111.
Ross, H.H., 1937. III Biol. Monogr., 15:1-173.
Saini, M.S. and Thind, A.S., 1995. Deut. Ent. Z., 42:71-111.
Snodgrass, R.E., 1935. Principles of insect morphology. McGraw-Hill International Book Company, Singapore. pp. 1-667 Website: http://en.wikipedia.org/wiki/Argidae
Khalid Mahmood and Mishkat Ullah Zoological Sciences Division, Pakistan Museum of Natural History, Islamabad Corresponding author: email@example.com
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|Publication:||Pakistan Journal of Zoology|
|Date:||Aug 31, 2011|
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