Guava [Psidium guajava L., (Family: Myrtaceae)]
is the only cultivated species among 70 odd Psidium species
(Landrum et al, 1995).  Though other species of Psidium
are non-edible and wild in nature, some of them possess a
few desirable traits, which could be exploited either as
rootstocks or as parents for incorporating the pest and
disease résistance. (Vasugi and Dinesh, 2007). Mango fruit
fly, Bactrocera dorsalis (Hendel) and tea mosquito bug,
Helopeltis antonii (Sign.) are serious and economically
important pests of guava (Butani, 1975) and finding a source
of resistance against them would be useful in evolving
resistant varieties. Varietal differences of guava in their
reaction to fruit fly and tea mosquito bug are reported (Arora
et al, 2000; Reddy and Vasugi, 2004) but information is
lacking on the reaction of wild Psidium species. In the
present study, five wild species of Psidium were field
evaluated for their resistance to B. dorsalis and H. antonii.
As endogenous metabolites were reported to play a
significant role in fruit fly resistance (Kaur et al, 1994),
the per cent fruit fly and tea mosquito bug infestation were
correlated with TSS, total sugars, vitamin C and acidity.

Field studies were carried out during 2002-2004
at the Indian Institute of Horticultural Research, Bangalore

Short communication

Resistance to fruit fly, Bactrocera dorsalis (Hendel) and tea mosquito bug, Helopeltis
antonii (Sign.) in certain wild Psidium species

P. Venkata Rami Reddy and C. Vasugi
Division of Plant Genetic Resources

 Indian Institute of Horticultural Research
Hessaraghatta Lake Post, Bangalore-560089, India

E-mail: pvreddy@iihr.ernet.in

ABSTRACT

Five wild species of Psidium viz., Psidium cattleianum lucidum, P. chinensis, P. friedrichsthalianum, P. molle
and P. quadrangularis were evaluated  for resistance to fruit fly [Bactrocera dorsalis (Hendel)] and  tea mosquito
bug (TMB) [Helopeltis antonii (Sign.)], during 2002-04. Significant variations were recorded among species in
their reaction to pests. Two species viz., P. chinensis and P. quadrangularis were resistant to fruit fly (<10% fruit
damage) while P. quadrangularis was immune. Psidium. molle and P. cattleianum were resistant to tea mosquito
bug. Pest incidence was correlated with fruit biochemical components viz., total soluble solids (TSS), total sugars,
vitamin C and acidity. The TSS and total sugars were positively correlated with fruit fly infestation while
acidity was negatively correlated. The TMB incidence did not exhibit significant correlation with any of these
parameters.

Key Words: Guava, Psidium species, resistance, fruit fly, tea mosquito bug

using 8-10 years old wild Psidium species viz., P.
cattleianum var. lucidum, P. chinensis, P.
friedrichsthalianum, P. molle and P. quadrangularis.
‘Lucknow-49’, a popular cultivar of P. guajava, was used
as standard check. One hundred and fifty randomly selected,
mature fruits were harvested from each species (comprising
four trees) and brought to the laboratory to record fruit fly
incidence during the months of August – September. On
attaining the fully ripened stage, fruits were cut open and
observed for the maggots. Tea mosquito bug incidence was
recorded based on the visual symptoms of damage such as
corky appearance on the fruit surface. Three replications
were maintained with fifty fruits per replication. Data were
subjected to the analysis of variance (ANOVA) to compare
the significance of mean differences. Species were classified
as immune (0% fruit damage), resistant (1-10%),
moderately resistant (11-25%), susceptible (26-50%) and
highly susceptible (>50%) based on the pooled means of
both the years following a partially modified varietal
classification suggested by Reddy and Vasugi (2002). The
titrable acidity (%), vitamin C (mg/100g) and total sugars
(g/100g) were estimated following Ranganna (2000) and
total soluble solids (TSS) was determined as 0Brix using a
hand refractometer.

J. Hortl. Sci.
Vol. 3 (1): 79-81, 2008

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80

Data on the variable reaction of Psidium species
to fruit fly and tea mosquito bug are presented in table 1.
There were significant differences in the extent of fruit
damage due to both the pests. The resistance trends of
species were consistent in both the years of study. None of
the Psidium species was completely free from fruit fly
infestation. Psidium quadrangularis recorded the lowest
fruit fly damage (4.66%) followed by P. chinensis (7.33%)
during 2002-03 and they sustained the resistance in the
subsequent year also with 3.33 and 6.00 % damage,
respectively. Two species viz., P. cattleianum var. lucidum
and    P. molle suffered high incidence (38.66 and 39.33%,
respectively) and were on par with ‘Lucknow-49’ (35.00%)
during 2002-03 and recorded a similar trend in the following
year. The extent of fruit damage due to H. antonii ranged
from 0.00 to 29.33 % and 0.00 to 32.00 % during 2002-03
and 2003-04 respectively. Psidium quadrangularis
remained free from tea mosquito bug damage in both the
years while P. friedrichsthalianum had the highest fruit
damage and at a par with check variety.

Based on two year means, two species viz., P.
quadrangularis and P. chinensis were resistant (< 10%

damage) to fruit fly while P. cattleianum was moderately
resistant. The other two species viz., P. friedrichsthalianum
and P. molle with >30% damage were classified as
susceptible and were on par with the check ‘Lucknow-49’.
The species, P. quadrangularis was free from tea mosquito
bug (immune) and the factors contributing to immunity need
to be further examined. However, considering an earlier
report of Reddy and Vasugi (2004), rough fruit surface can
be one of the contributing factors. Among the rest of species,
P. cattleianum (4.33%) and P. molle (5.33%) were resistant,
P. chinensis (18.67%) was moderately resistant and P.
friedrichsthalianum was susceptible.

 The TSS in Psidium species ranged from 7.4% in
P. cattleianum to 11.6% in P. molle (Table 2).  Similarly
total sugars varied from 5.85 to 9.62g, vitamin C from 16.78
to 81.33 mg/100g and total acidity from 0.61 to 2.70%.
Correlation analysis (Table 3) showed that the extent of
fruit fly incidence was significantly correlated with three
characters viz., TSS, total acidity and sugars.  There was a
positive correlation between the fruit fly infestation levels
in different species and their TSS and total sugar contents.
The correlation coefficient values were 0.576 and 0.674
pertaining to TSS and total sugars, respectively. However,
fruit acidity was negatively correlated with the fruit fly
incidence (r = - 0.614) and thus considered to have a role
in imparting resistance, while correlation with vitamin C
was non-significant. Arora et al (2000) reported a similar
trend of correlation between fruit fly incidence and TSS of
guava fruits. They also observed that total phenols were
negatively correlated while vitamin C had non significant
correlation. Our findings are in agreement with these
observations. On the other hand, none of these parameters
showed significant correlations with the tea mosquito bug
infestation. The non significant effect of biochemical
components on tea mosquito bug infestation could be
because of the fact that, the infestation starts at early stages
of fruit formation and also confines to the fruit surface
unlike fruit fly, where maggots develop inside the fruit and

Table 1. Extent of fruit fly and tea mosquito damage in Psidium species

Species Fruit fly damage (%) Tea mosquito bug damage (%)
2002-03 2003-04 Mean 2002-03 2003-04 Mean

P. cattleianum var. lucidum 38.66 26.00 32.33 5.33 3.00 4.17
P. chinensis 7.33 6.00 6.67 21.00 16.33 18.67
P. friedrichsthalianum 16.00 12.00 14.00 29.33 32.00 30.67
P. molle 39.33 34.00 36.67 6.33 4.33 5.33
P. quadrangularis 4.66 3.33 4.00 0.00 0.00 0.00
P. guajava (Lucknow-49) 35.00 30.33 32.62 30.66 25.66 28.16
CV (%) 15.59 11.14 15.37 14.85
CD (P=0.05) 4.31 4.67 4.19 4.02

Table 2. Biochemical composition of Psidium species

Species TSS Total Vitamin C Acidity
(%) sugars (g) (mg/100g) (%)

P. cattleianum var. lucidum 7.40 5.85 16.78 1.31
P. chinensis 8.30 9.34 22.15 0.70
P. friedrichsthalianum 3.20 9.62 19.75 1.13
P. molle 11.60 8.12 80.65 2.70
P. quadrangularis 9.10 5.89 81.33 1.10
P. guajava (Lucknow-49) 11.50 8.80 19.50 0.61
CD (P=0.05) 1.14 1.85 4.02 0.78

Table 3. Correlation coefficient (r) values of per cent fruit infestation
with biochemical parameters of Psidium species

Pest TSS Total Vitamin C Acidity
sugars

Fruit fly 0.586* 0.674* NS -0.614*
Tea mosquito bug NS NS NS NS
* Significant at p= 0.05; NS = Non-significant

J. Hortl. Sci.
Vol. 3 (1): 79-81, 2008

Venkata Rami Reddy and Vasugi



81

are thus vulnerable to fruit biochemical composition
variations.

High TSS and total sugars are generally desirable
traits in fruits and hence it is appropriate to locate a
resistance source rich in these quality parameters. Our
results show that P. quadrangularis, which was immune to
fruit fly and resistant to tea mosquito bug, holds promise in
this direction. Psidium cattleianum and P. chinensis, which
exhibited resistance to one pest and moderate resistance to
another may also be useful. Though P. molle was resistant
to tea mosquito bug, it was highly susceptible to fruit fly
and thus its potential is limited. As majority of species tested
showed high degree of resistance compared to the check, it
is worthwhile to screen as many wild species as possible to
find resistance.

ACKNOWLEDGEMENTS

Authors are grateful to the Director, IIHR for
facilities and acknowledge the assistance of Sri. Dasappa,
Field Technician, in the field gene bank maintenance. We
thank Dr. N. K. Krishna Kumar, Head, Division of
Entomology, IIHR for critical evaluation of the manuscript.

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J. Hortl. Sci.
Vol. 3 (1): 79-81, 2008

Resistance to fruit fly and tea mosquito bug