Morphological Features of the Ovaries During Oogenesis of the Oriental Fruit Fly,Bactrocera dorsalis, in Relation to the Physiological State

Abstract

Determination of physiological state in insects is useful in furthering the understanding of how insect behavior changes with age. Central to this determination is the identification of characters that allow assessment of physiological age. While non-destructive measures produce the most desired outcomes, internal markers may be more diagnostic and reliable. In this study, key morphological characters during previtellogenesis through vitellogenesis and ovulation were assessed as markers to determine physiological states of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). Ovary length and width, ovarian index (length × width), and egg load of laboratory-reared B. dorsalis females recorded daily from eclosion up to 80 days old suggested significant differences in the ovarian index and egg load between females from each oogenesis stage. Parity status determined by the presence of follicular relics was found to provide high-accuracy classifications for B. dorsalis females. The presence of follicular relics with distinct morphological features provides a reliable identification tool to determine the physiological state of wild female oriental fruit fly. The potential applications of this technique to identify the physiological age of female fruit flies to study behavioral attributes in their natural habitat, and also the potential applications in relation to field control, are discussed.

Tudor knockdown disrupts ovary development in Bactrocera dorsalis

“…Its vigorous reproductive capacity leads to extreme levels of destruction. A female adult fruit fly can lay ~1000 eggs during its lifetime under field conditions (Chen et al, 2008;Chou et al, 2012;Wei et al, 2015). Frequent application of various types of insecticides has led to high levels of insecticide resistance (Hsu et al, 2012).…”

Comparative demography ofBactrocera dorsalis(Hendel) andCeratitis capitata(Wiedemann) (Diptera: Tephritidae) on deciduous fruit

“…The egg load for the two species was not determined in these experiments. For B. dorsalis aged between 7 and 80 days with full access to protein, egg load was found to be 20.7 ± 2.7 per female (Chou et al ., 2012). Egg load of 7-day-old C. capitata with access to protein was found to be 20 per female (Prokopy et al ., 1994).…”

Influence of Supplemental Protein on the Life Expectancy and Reproduction of the Chinese Citrus Fruit Fly, Bactrocera minax (Enderlein) (Tetradacus minax) (Diptera: Tephritidae)

“…Finally, 800 females were kept in four separate cages (200 females/cage) where they were provided with four food sources as described above. Twenty insects were dissected every 5 d for a duration of 20 d to assess the ovarian development and egg load ( Chou et al 2012 ).…”

“…Mature Eggs in ovary, before and after the onset of oviposition ( Fig. 1 ) ( Fletcher et al 1978 ; Kendra et al 2006 ; Chou et al 2012 ). To calculate the ratio of different ovary stages the following formula was used: “Ratio of specific ovary stage (%)” = (number of flies with the specific ovary stage)/(total number of flies dissected) * 100.…”