The morphology of the reproductive tract of Podisus nigrispinus (Dallas) females fed with Alabama argillacea (Hübner) larvae, artificial diet, Tenebrio molitor L. larvae or Musca domestica L. larvae were studied. The reproductive tract of females of this species presented yellow coloration and independent of the diet, each ovary had seven ovarioles joined through terminal filaments and forming a bunch shape structure. The histological data revealed that the ovary of P. nigrispinus was of meroistic telotrophic type, with each individual ovariole divided in a terminal filament, a tropharium (trophic chamber), a vitellarium, and a pedicel. The prey type affected the development and morphometry of these structures. Females of P. nigrispinus fed with 3rd or 5th instar larvae of cotton leafworm (A. argillacea) presented developed ovaries with ovarioles showing a great number of oocytes in advanced stages of development. Females fed with artificial diet presented atrophic ovaries and ovarioles practically without oocytes. Females fed with T. molitor or M. domestica showed ovaries in intermediary stage of development. The central ovariole was longer in females fed with 5th instar larvae of cotton leafworm and shorter in those fed with artificial diet. Most developed oocytes were observed in ovaries of females fed with 5th or 3rd instar larvae of cotton leafworm, and the majority of atrophic oocytes were found in females fed with artificial diet.
Biological control; morphology; ovaries; predator; reproduction