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Sexual maturation of Sunn Pest adults in Syria

M. El Bouhssini International Center for Agricultural  Research in the Dry Areas (ICARDA)  Aleppo, Syria

M. Abdul Hay Agricultural Research Center, ARC Aleppo, Syria

Sunn Pest adults spend about nine months in overwintering sites where they go through the summer and winter. They migrate back to cereal fields in the spring around mid-March. In wheat or barley fields they mate and start laying eggs. We conducted a three-year study at ICARDA to determine when Sunn Pest adults could mate and lay eggs if environmental conditions are favorable. The insects were collected from the overwintering sites in September, October, November and December and were put (5 ? and five ?) on wheat pots in a rearing room set at 20 °C and 16 H (L:D) photoperiod. Daily observations were made on their feeding, mating, and oviposition.  The insects collected over the whole period were feeding normally, but mating and oviposition started only beginning of December.  The eggs laid were fertile and most of them hatched and gave live nymphs.  These results are very useful as Sunn Pest workers could use this period of about three months, from the time adults reached sexual maturation early December to when they migrate to cereal fields around mid-March, to rear the insect under controlled conditions for different purposes, pheromone work, screening for resistance, parasitoids etc..

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An Investigation for Identifying and Efficiency of Parasitoid Flies
of Cereal Sunn Pest (Eurygaster integriceps Puton) in Karaj, Iran.

Masood Amir-Maafi
Tehran University, College of Agriculture,
Department of Plant Protection

From 1988 to 1990 four species of phasiine flies: Heliozeta helluo F., Phasia subcoleopterata L., Ecotophasia crassipennis F. and Elomyia lateralis Meg. were the most  important parasitoids of adult Eurygaster integriceps Put. on in Karaj, Iran and vicinity. The biology and morphology of different stages of these flies were studied.  The 4 species, each having one generation per year (on the sunn pest), overwinter as 3rd instar in the body cavity of the host. Shortly after migration to the field the larvae, which are full grown, leave Sunn Pest and pupate in the soil where they remain until adult eclosion.  The immature stages lasts 26-33 days for H. helluo, 38-46 days for P. subcoleopterata, 33-42 days for E. crassipennis and 33-38 days for E. lateralis. In Karaj H. helluo was the dominant species.

Parasitism of overwintering adult Sunn Pest was 5.12, 7.56% in Fashand and Dorvan in 1988 and 11.56, 10.25% in 1989, respectively.  In both years parasitism was higher in the spring after migration of Sunn Pest to the field.  Parasitism of adults in the field was 52.89% (Saeid-Abad), 66.92% (Fashand) in 1989, and 64.72% (Saeid-Abad), 62.59% (Fashnad) in 1990.

In 1989 and 1990 flight from the overwintering sites occurred from late March to early May.  In 1989, population density of E. integriceps was 3.4 and 2.1/m² in the fields at Fashnad and Saeid-Abad, respectively.  In 1990, it was 3.6 and 2.3/m² at Fashand and Saeid-Abad, respectively.  Maximum density does not occur simultaneously in these two areas.  In Fashand where the fields are located on a mountainside it occurs 9-15 days later than at Saeid-Abad where the fields are on the plains. The new generation of Sunn Pest appear in early June and migrate to overwintering sites about two weeks later.

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Biological Control of Sunn Pest with Entomopathogenic Fungi
Bruce Parker and Margaret Skinner
University of Vermont Entomology Research Laboratory
661 Spear Street, Burlington, Vermont   05401-0105

The Sunn Pest (Eurygaster integriceps Puton) is a major insect pest of wheat and barley in West and Central Asia.  Feeding by this pest significantly reduced crop yield and quality.  In some regions chemical insecticides are heavily used, which disrupts native parasite and predator populations.  A decrease in insecticide efficacy has been reported in recent years, and is suspected to be a sign of resistance.

A cooperative program between the University of Vermont Entomology Research Laboratory and the International Center for Agricultural Research in the Dry Areas (ICARDA), in Aleppo, Syria was initiated in 1997.  Several strains of entomopathogenic fungi have been isolated from insects in their over wintering sites in Turkey, Syria, Kazakhstan, Kyrgystan, Uzbekistan and Russia.  In laboratory bioassays, they were tested against Sunn Pest, tarnished plant bug and western flower thrips.  Several were highly pathogenic to all of these insects, and selected for further evaluation.

The next step in the development of these biological agents is to determine at what stage in the pests' life cycle fungi could best be used.

Two possibilities are 1) as they migrate to the fields in the early spring or 2) in their over wintering sites among the foothills surrounding the fields.  Six of the most promising isolates were tested in on-plant and in-litter bioassays in January 2000.  Several of the tested isolates provided 80-100% mortality within 10 days.  Though Sunn Pest mortality occurred more rapidly among the in-litter assays, by Day 15 Sunn Pest mortality was equally high in the on-plant assays.  These results demonstrate the great potential of fungi for Sunn Pest IPM.  It may be possible to used them both in over wintering sites and on plants in the field.  Plans are underway to conduct small scale pilot tests to further evaluate their efficacy under field conditions.  The compatibility of fungi with non target organisms and chemical pesticides are also planned for the future.

This work has been done in close cooperation with Dr. Mustapha El Bouhssini, Head of the Entomology Department at ICARDA.  He is currently conducting research to evaluate the impact of egg parasitoids on Sunn Pest field populations.

This work has been supported by the Conservation, Food & Health Foundation and US Agency of International Development.

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Host Plant Resistance as an IPM Component for Management of Sunn Pest
M. El Bouhssini
International Center for Agricultural Research in Dry Areas (ICARDA)
Aleppo, Syria

There has been very little progress towards the use of host plant resistance against Sunn Pest worldwide. Besides the narrow genetic base in cultivated wheat for resistance to this pest, there are great difficulties in screening in hot spots in the field because of aerial insecticide sprays.  Also, there was no reliable screening technique under artificial infestation. For the last three years ICARDA, in collaboration with its NARS partners in Syria, has placed special effort on the development of a screening technique under artificial infestation. The method consists of using mesh screen cages  (6 x 9 x 3 m) constructed directly in the field. The test is done in two stages, preliminary and advanced evaluation.  In the preliminary screening wheat entries are planted in hill plots at the usual planting time in the fall. Plants are infested at the time insects migrate to wheat fields using six adults/m2. The parameters used in the evaluation for resistance are to rank shoot, leaf and spike damage. In the advanced screening, the selected wheat lines from the preliminary test are planted in rows 1-m long, and one cage with uninfested plants is used as a control. The method of infestation and evaluation is similar to that described in the preliminary test, except that two parameters were added: 1000 kernel weight and quality tests. Of the hundreds of lines tested in 2001 using this new screening technique, several promising lines of wheat and its wild relatives have been identified.  Germplasm with confirmed resistance to Sunn pest will be used in the breeding programs to develop wheat resistance varieties for West and Central Asia.

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Investigations on the effectiveness of the tachinid flies (Diptera: Tachinidae) on fecundity of the sunn pest (Eurygaster integricips Put.) (Het; Scutelleridae) in wheat fields of Gaziantep and Kilis provinces

Mahmut Islamaglu  Graduate Student Plant Protection Institute PK 01321 Adana, Turkey

Serpil Kornosor Faculty of Agriculture University of Cukurova Department of Plant Protection 01330  Adana, Turkey

There are many factors suppressing Sunn Pest populations in nature.  The efficiency of the tachinid fly populations is very low on Sunn Pest in the over-wintering areas.  However, deformations occur on the genital organs of the Sunn Pest that are parasitized by tachinid flies, which reduce the fecundity and longevity of Sunn Pest.
This indirect effect of parasitism will be researched.  In Gaziantep and Kilis provinces over 2001-2002, the diversity and abundance of different tachinid fly species will be determined as well as differences in parasitism rates of over-wintered male and female Sunn Pest.  The following specific objectives will be addressed:

1. Influences of the tachinid adult parasitoids on Sunn Pest's fecundity
2. Determination of parasitization rates in Sunn Pest over-wintering areas in  Gaziantep and Kilis provinces
3. Determination of Sunn Pest's adult parasitoid species in Gaziantep and Kilis provinces
4. Influence of insecticides used for controlling Sunn Pest on adult parasitoids
5. Determination of parasitization rates in the male and female Sunn Pest (parasitism in 100 female and male Sunn Pest adults)

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Some Biological Properties of the Sunn Pest Egg Parasitoid (Trissolcus semistriatus Nees Hymenoptera: Scelionidae) and its Effectiveness at Different Release Densities

Sener Tarla Graduate Student

Serpil Kornosor Faculty of Agriculture

University of Cukurova
Department of Plant Protection
01330 Adana, Turkey

Several biological aspects of the Sunn Pest egg parasitoid (Trissolcus semistriatus Nees Hymenoptera: Scelionidae) will be assessed in laboratory studies and field studies will be conducted to evaluate its efficacy at different release rates. Studies will be done to determine the suitability of mass rearing T. semistriatus on the following alternative pentatomid hosts: Eurydema ornatum L., Carpocoris mediteraneus Tam. and Dolycoruc baccarum L. In addition, the influence of different temperatures (18, 22, 26, 30, 34°C) on the developmental rate of T. semistriatus when reared on Sunn Pest eggs will be tested under standard conditions of 65 ±10% relative humidity and 16:8 h L:D. The effect of temperature on the life span and fecundity of T. semistriatus will also be evaluated at 22, 26 and 34°C. In wheat fields, the effectiveness of four different population rates will be tested and methods to improve determination of parasitism rates of egg parasitoids will be considered.

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Sunn Pest Egg Parasitism in Northern Syria

A. Babi College of Agriculture University of Appelo Aleppo, Syria

M. El Bouhssini International Center for  Agricultural Research in Dry Areas (ICARDA) Aleppo, Syria

M. Abdul Hai Directorate of Agricultural Scientific Research Center Aleppo, Syria

Sunn Pest, Eurygaster integreceps Put., is a major pest of wheat in West and Central Asia and North Africa.  The Objective of this study was to assess the role of egg parasitoids in regulating Sunn Pest populations.  The study was conducted at Azaz region in the north of Syria during two seasons, 1998/99 and 1999/2000.  The region studied is rich of parasitoids belonging to the family Scelionidae.  In 1998/99 three Sunn Pest egg parasitoids (Trissolcus spp) were found; the level of parasitism by the end of the season reached 100%.  Preliminary results of the 1999/2000 season are also showing high levels of egg parasitism, similar to that of the last season.  The level of Sunn Pest egg parasitism should be taken into consideration when determining the economic threshold of Sunn Pest populations in the field.

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Temporal Distribution and Abundance of Insects Attacking Barley in Semiarid Environment at Two Locations in Southwest Syria

G. Saour

H. Makee

I. Ghanem

I. Arabi

Department of Biotechnology
Syrian Atomic Energy Commission
Damascus, Syria

A survey was carried out to find the temporal distribution of insect species attacking barley crop in semiarid environment at two locations in the southwestern part of Syria.  Synchronization was found between the sensitive stages of barley crops and the presence of insect pests that feed aggressively on barley plants.  An important damage caused by the ear thrips (Haplothrips tritici Kurd) and the sunn bug (Eurygaster integriceps Puton) was noticed.  A negative relationship was observed between population density of the corn leaf aphid (Rhopalosiphum maidis Fitch) and the population of seven-spotted ladybird beetle, (Coccinella septempunctata L.).  The factorial correspondence analysis (FCA) was employed to obtain an overall interpretation of the results.

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