Short Communication
Damage of Sunn Pest Eurygaster integriceps Put. on to Wheat Quality in Israel
Aviv Rapaport, Elazar Quinn, Avihai Harush, Moshe Kostyukovsky*, and David J. Bonfil
Department of Food Quality and Safety, Agricultural Research Organization, Israel
*Corresponding author: Moshe Kostyukovsky, Department of Food
Quality and Safety, Agricultural Research Organization, Israel, Email:
inspect@volcani.agri.gov.il
Submitted: 29 January 2019; Accepted: 17 April 2019; Published: 19 April 2019
Cite this article: Rapaport A, Quinn E, Harush A, Kostyukovsky M, Bonfil DJ
(2019) Damage of Sunn Pest Eurygaster integriceps Put. on to Wheat Quality in Israel. JSM Plant Biol Res 3: 3.
Sunn pest Eurygaster integriceps Put. on is one of the most serious factors affected the gluten quality of wheat grain in Israel. The
object of this study was to evaluate the damage of sunn pest to wheat quality of some cultivars of spring wheat. Field experiments were
conducted in three cultivars with a different phenology: Zahir - early ripening, Bar-Nir - medium, Ruta - later ripening. The isolated by net
plots were infested by unsexed wintering adults of sunn pest. The isolated uninfested plots serve as a control. The sunn pest’s effects
on quantitative parameters of wheat quality, such as thousand kernels weight, test weight, and the effects on gluten quality and quantity,
such as gluten index, IDK test, wet gluten content, were examined. In addition, samples at varying degrees of the bug-damaged kernels
were constructed in order to examine the quality and quantity of gluten. A high level of bug-damaged kernels of 15-20% did not affect the
thousand kernel weight and test weight of the three tested cultivars. At a very high level of bug-damaged kernels of 40-60%, the sunn
pest caused a significant reduction in thousand kernels weight in Zahir and Ruta cultivars. Test weight decreased significantly in all three
cultivars. A damage of up to 4% of the kernels has significantly affected gluten quality but not gluten content. The results of this study
indicate that the cultivar of wheat is of high importance for the level of the gluten quality and the degree of sunn pest’s damages
Keywords: Eurygaster integriceps; Gluten quality; Wheat grain quality
ARO: Agricultural Research Organization; GI: Gluten Index;
IDK: The Device for Identification of Deformation of “Kleikovina”
(Gluten in Russian)
Sunn pest Eurygaster integriceps Put. on (Heteroptera:
Scutelleridae) is well known as a serious limiting factor for
production of wheat grain with strong gluten in the wide area of
the Near and Middle East, Eastern and South Europe and North
Africa. The bug attacks about 150 million hectares of fields each
year [1]. Bug damaged wheat contains enzymes, which degrade
gluten proteins, causes rapid relaxation of dough and results
in the production of bread with poor volume and texture with
financial losses of millions of dollars [2-6].
In Israel, in the years of the bug outbreak, the numbers of new
generation were very high; reaching on some fields 58nymphs
per 1 square meter [7]. A significant part of the grain yield was
characterized by low gluten quality. One of the most serious
factors affected the gluten quality is sunn pest. Different cultivars
of wheat present a large diversity in their response to the sunn pest [2,8-12].
In the case of low numbers of bug population and low level
of damaged kernel, role of genetic, agro-technical and ecological
factors, which affect the gluten quality, is increased.
The object of this study was to evaluate the damage of sunn
pest to wheat quality in Israel.
The level of damage caused by sunn pest is significantly
dependent on the characteristics of the wheat cultivars,
particularly the quality of the wheat. In order to examine the
effect of the sunn pest’s damage on the quality of some cultivars of
spring wheat (Triticum aestivum L.) in Israel, a field experiments
were conducted in the Gilat research center of ARO for three
years. Sunn pest’s wintering adults were collected from wheat
fields at the stage of the wheat flowering and plots of 2 square
meters were infested at a level of 10 unsexed bugs per 1 square
meter. A net of 50 mesh isolated the infested and uninfested
plots. The uninfested isolated plots served as a control. The
experiments were conducted in three spring wheat cultivars
with a different phenology: Zahir- early ripening, Bar-Nirmedium,
Ruta- later ripening, in three replicates. Zahir and Bar-
Nir are considered as strong gluten cultivars, Rutaas moderate
[13]. Before harvesting, the nets were replaced; the sunn pest
adults of the new generation were counted. All the infested and
uninfested plots were harvested separately. The sunn pest’s
effects on quantitative parameters of wheat quality, such as
thousand kernels weight, test weight, and the effects on gluten
quality and quantity, such as GI, IDK test (the common method for
gluten quality evaluation in the former Soviet Union), wet gluten
content, were examined. In addition, samples at varying degrees
of the bug-damaged kernels (from 0 to 8%) were constructed in
order to examine the quality and quantity of gluten.
The current study showed the influence of the spring wheat
cultivars growth in Israel on the level of gluten quality and on the
degree of sunn pest’s damages.
In 2016 and 2017, a very high level of the bug population
and percent of damaged wheat kernels was reached in infested
plots. It was found that a kernels’ damage of 15-20% did not
affect the thousand kernel weight and test weight of the three
tested cultivars, and did not cause quantitative damage to wheat.
However, at a very high level of bug-damaged kernels of 40-
60%, the sunn pest caused a significant reduction in thousand
kernels weight in Zahir and Ruta cultivars. Test weight decreased
significantly in all three cultivars. At low level of bug damage, the
quantitative parameters were not affected (Table 1).
A damage of up to 4% of the kernels has affected gluten
quality but not gluten content (Table 2). Even at 8% bug-damaged
kernels the gluten content did not changed significantly (the data
not shown).
The gluten quality parameters, such as GI and IDK test, were
much lower in the kernels affected by the sunn pest compared
to the healthy kernels, while the Ruta cultivar was characterized
by low gluten quality, and the sunn pest’s damages were more
severe in this cultivar compared to Zahir and Bar-Nir cultivars.
The significant decrease in the gluten quality by GI and IDK
test in comparison to undamaged kernels, took place in most
of the cases at 4% damaged kernels. While in cultivar Zahir the
significant decrease of gluten quality measured by GI and IDK
was recorded at 2-4% damaged kernels, in cultivar Bar-Nir at 4%
(sometimes did non decreased at this level), in Ruta at 3-4%.
The results of this study indicate that the cultivar of wheat
is of high importance for the level of the gluten quality and the
degree of sunn pest’s damages.
A difference in the tolerance of cultivars with different
phenology to the sunn pest’s damage was established; emphasize
the importance of using strong gluten quality cultivars, especially
in years with a high sunn pest population, and the importance of
wheat phenology in terms of quality of wheat.
This study was supported in part by grant from the Chief
Scientist of the Israeli Ministry of Agriculture (grant # 20-10-0066).
Table 1:Bug-damaged kernels (%), test weight and thousand kernels weight in infected and uninfected plots in three wheat cultivars. 
