The objective of this work was to determine the biological and morphological parameters of Dysdercus maurus fed with cotton (Gossypium hirsutum) seeds with a high or low oil content, as well as to identify genotypes to be used in breeding programs as sources of resistance to this stink bug. The development, survival, and reproduction of the cotton stainer bug were determined in a completely randomized experimental design. The treatments consisted of the insect nymphs being feed with cotton seeds of the CNPA 2001-5581 (high oil content) or CNPA 2001-5087 (low content) genetic line. Survival, weight, and morphological parameters of the bug were determined. The survival of second- and third-instar nymphs and of the total nymph stage of D. maurus was lower with cotton seeds with a low oil content. The body length and head width of D. maurus adults were greater, but pronotum length and width were smaller and the females heavier with cotton seeds with a high oil content. Low-oil cotton genotypes can reduce populations of the stainer bug.

Anthonomus grandis Boheman (Coleoptera: Curculionidae) survives on alternative diets; however, this induces reproductive diapause. The objective was to evaluate the morphology and morphometry of the reproductive tract of this weevil after feeding on alternative diets. The experimental design was completely randomized with 160 replications and treatments arranged in a factorial design 3 × 3, represented by A. grandis adults fed on 3 food types (fragments of banana (T1) or orange (T2) endocarp, or with cotton squares of cultivar BRS 286 (T3, control)) and three evaluation periods (30, 60, and 90 days) and after each of these periods they were fed with cotton squares for 10 days. The reproductive tract of 100% of A. grandis females fed banana endocarp, orange endocarp, and cotton squares for 30 and 60 days and then cotton squares were morphologically adequate for reproduction, and after 90 days, only 50% of those fed cotton squares were in this condition. The length of the ovarioles and the width of the mature oocyte were greater for A. grandis fed on cotton squares and smaller in those with banana and orange endocarps. Histological sections reveal that male testes even with strong degenerative signals are already producing spermatozoa. On the other hand, females displayed ovaries with nurse cells in the tropharium and some maturing oocytes in the vitellarium. The body length was longer and the testis area and diameter smaller in males fed on cotton squares than in those with banana and orange endocarp. Anthonomus grandis females fed for ≥90 days with alternative food sources do not recover the functionality of their reproductive tract, even after consuming, for 10 days, a diet that favors reproduction. On the other hand, the males remain with their reproductive organs functional with this condition.

Alabama argillacea é uma importante praga desfolhadora da cultura do algodoeiro no Brasil e em países produtores como Austrália, Burkina, China, Índia entre outros. Ela acarreta destruição da área foliar, comprometendo taxas fotossintéticas e a produtividade da pluma e do caroço. Objetivou-se estudar a atratividade e preferência alimentar de A. argillacea a genótipos de algodoeiro. Avaliou-se a atratividade e preferencia alimentar de lagartas do curuquerê em teste de chance de escolha nos genótipos TB 87, TB 85, TB 91 e Grandless. O delineamento experimental foi blocos ao acaso, com quatro tratamentos, 10 repetições e quatro horários de avaliação (15 minutos, 45 minutos, 1 e 2 horas). O genótipo de algodoeiro menos preferido e atrativo para alimentação é o Grandless enquanto que as cultivares TB 87, TB 85, e TB 91 são mais atacadas pelas lagartas. Dentre os genótipos avaliados, a Grandless apresenta menos susceptibilidade em mesmas condições de ataque.