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Fruit flies are responsible for causing significant yield losses, dropping the values and creating hindrances in the exports of agricultural produces (Sarwar, 2015). Fruit flies are transported across borders with international trade of fruits and vegetables and hence are regarded as major quarantine pests (Permalloo, 1998; Peck and McQuate, 2004). The damages inflicted by the fruit flies lead to reduced farm produce and hence to limited exports Abstract | The tephritid fruit flies are the major pests of horticultural crops across the globe. In Pakistan, two fruit fly species, Bactrocera zonata (Saunders) and B. dorsalis (Hendel) cause severe qualitative and quantitative damages to various fruits. The present study was executed to record the population dynamics of these fruit fly species in guava and mango orchards with respect to meteorological factors using methyl eugenol-baited traps. The results revealed that population of both the species highly fluctuated round the year. B. zonata appeared to be the most abundant species both in mango and guava orchards as compared to B. dorsalis. The highest mean number of B. zonata (3690.57 flies/trap) was captured in August 2018 in guava orchard. From October, 2018 onward up to February 2019, population of B. zonata tended to decline with the lowest catches (122.5 and 152.8 flies/trap, respectively) in January and February, 2019. In mango orchard, peak population of B. zonata (4062.8 flies/trap) was recorded in May, 2019. Abundance of B. dorsalis in guava orchard reached to its peak (394.625 flies/trap) in August, 2018. However, in mango orchard, an increasing trend in population was observed from April onward with the highest catches of 521.4 flies/trap in June. The correlation matrix revealed a significantly positive relation among the incidence of B. zonata and minimum and maximum temperatures and sunshine hours whereas relative humidity (R.H.) and rainfall were found to have a negative correlation with B. zonata abundance. Correlation analysis of B. dorsalis catches with respect to meteorological data revealed a significantly positive correlation of monthly captured flies with all the climatic factors such as maximum temperature, minimum temperature, R.H. and sunshine duration except the mean monthly rainfall.

Abstract.Results of studies on prey suitability for generalist predators are important for efficient mass rearing and implementing Integrated Pest Management Programmes (IPM). The green lacewing, Chrysoperla sinica (Tjeder), is a polyphagous natural enemy attacking several pests on various crops in China. We investigated the effect of feeding it different species of prey on its preimaginal development, survival, adult longevity and fecundity under laboratory conditions. The prey species tested were nymphs of Aphis glycines Matsumura, cotton aphid Aphis gossypii Glover, peach aphid Myzus persicae Sulzer, corn aphid Rhopalosiphum maidis Fitch and cowpea aphid Aphis craccivora Koch, and eggs of the rice grain moth, Corcyra cephalonica Stainin. None of these species of prey affected the pre-imaginal survival or percentage survival of the eggs of the predator. However, eggs of C. cephalonica and nymphs of M. persicae and A. glycines were the best of the prey species tested, in that when fed on these species the preimaginal developmental period of C. sinica was shorter and its adult longevity, fecundity and percentage survival greater than when fed the other species of prey. In contrast, when fed nymphs of A. craccivora the pre-imaginal development period was longer, adult longevity shorter and fecundity lower. These findings could be helpful in defining more optimum conditions for the mass rearing of C. sinica for use in integrated pest management (IPM) programmes for various crops.

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