|Keywords (Extracted from title, table of contents and
abstract of thesis)|
Behavioral Responses, Adult Fruit
Flies, Food, Sex Lures, Relation, Management, Bait, mango, Biology
Fruit flies (Diptera:
Tephritidae) has been recognized as a cosmopolitan pest of fruits
and vegetables. In Pakistan, it is a serious pest of mango, melons,
citrus and guava and a major threat to export of these commodities.
The pesticides used for this pest leave residues, which are not
acceptable for many buyers under WTO agreement. Studies were
undertaken to get more precise information on behavioral aspects of
fruit flies and to devise management techniques with integrated
Field studies on population fluctuation of Bactrocera zonata (Diptera:
Tephritidae) were monitored in mango (Mangifera indica) orchards,
located at 2 different ecological zones; Dera Ismail Khan and
Paniala for three consecutive years, using methyl euginol baited
traps. Abiotic weather factors were correlated with population
fluctuation. The population density data at both locations showed
two prominent peaks with some variations, first in late spring and
second and larger one in late summer or early fall. The population
builds up of flies in the early spring were found associated with
off-host fruits [Ber (Ziziphus jujuba) and Guava (Psidium guajava)]
shifted to mango. The second and larger peak was associated with mid
and late mango varieties like Chounsa, Fajri. Overall, a positive
correlation of population fluctuation in relation to abiotic factors
exists. However, inverse relation was found significant in relative
In a series of experiments, comprised of lures (food and sex), and
neem extracts was tested in comparison with untreated check to
devise the IPM model for fruit fly management in mango orchards. The
IPM model reduced the infestation to 0.4 and 0.8% in dropped and
harvested fruits respectively in comparison with that of farmers’
practice where it was 7% in dropped fruits and 10.5% in harvested
fruits. The experiments to evaluate the management techniques
revealed bait (Protein hydrolysate) application technique (BAT) and
crop hygiene (CH) equally effective to that of synthetic insecticide
(Diptrex 80SP). In other experiments, BAT + CH and neem oil
reduced 87.27 and 75.11% infestation of fruit fly, as compared to
Diptrex 80SP (2.42%). Turmeric oil was less effective than neem oil.
The integration of crop hygiene (removal of weed flora and burying
of damaged fruits) with intermittent spray of bait and one neem
application on and around the field significantly reduced the fruit
fly infestation. The farmers’ practice fields had 25.3% fruit fly
infestation whereas it was 3.6% where IPM model was applied.
In a series of experiments, infective capabilities of
entomopathogenic nematodes (EPN) were evaluated against fruit flies
under lab conditions. Results indicated Hetrerorhabditis
bacteriophora and S. feltiae with 97.6 and 85.10% infection and were
leading EPN among the tested nematodes. In addition, the fly
emergence was better option for EPN evaluation than dissection of
insect. EPN showed comparatively less infectiveness towards fruit
fly pupae and only 60% infection was caused due to S. feltiae
followed by 58% due to H. indica.
The progeny development experiment with three nematode species viz.
S. carpocapsie, S. feltiae and H. bacterophora, in the lab, showed
J3 started emerging in all nematode after day 11. The J3 production
increased until day 13 for S. feltaie and ends on day 23. H.
bacterophora produced 697 progeny in 16 days. Progeny production as
unit body weight, S. carocapsae produced 784 J3/mg followed by H.
bacterophora and S. feltiae with 580 and 221/mg body weight of fruit
fly. In another experiment, LC50 for S. feltiase was 516 J3/ml and
H. bacterophora was 600 J3.
Fruit fly Bactrocera zonata pupation habitat preference was
evaluated in two lab experiments. In first experiment, three soil
types were tested for preferred pupation depth by late instar fruit
fly larvae. Results revealed more than 57% of the pupae preferred
2.54 - 5.02 cm depth for pupation comparing with 20% in the top 2.53
cm, 17.7% in the 5.03 - 7.67 cm and only 2.1% in the 7.67 - 10.23
cm. The experiment regarding soil particle sizes was evaluated for
pupation depth preference. Results indicated 2.53 - 5.03 cm is the
preferred depth for all particles sized except for the 13 - 25
particle size where pupae preferred top 2.54 cm to other two depths
tested. In another experiment with neem as additive adult diet,
showed adult feeding on ground neem seed kernel with sugar and yeast
hydrolysate arrested the egg laying capacity significantly.