Life history and host-plant resistance of Blissus pulchellus (Hemiptera: Blissidae) on key Urochloa forages

Insect pest attacks on pasture areas adversely impact Brazilian livestock. At present, livestock farmers encounter challenges in managing pests, notably chinch bugs of the genus Blissus (Hemiptera: Blissidae), which have emerged as a substantial threat to pastures in Brazil. A notable gap exists in research on this insect group. This study examines the life history of Blissus pulchellus across various economically relevant forage crops in Brazil. We investigated the life history of B. pulchellus in four forage species: Urochloa humidicola cv. Humidicola; Urochloa ruziziensis cv. Ruziziensis; Urochloa humidicola cv. Llanero, and Urochloa brizantha cv. Marandu. The plants were infested in vivo with newly emerged pairs (up to 48 h). Pairs were isolated in clip cages, and specific parameters, such as fecundity and fertility, were assessed daily until the females died. Newly hatched nymphs were placed individually on in vivo plants to evaluate the development time, and the sex ratio was analyzed following the emergence of adults. Fecundity (number of eggs per female) was significantly influenced by the forage species. The number of eggs laid per female was significantly higher on U. humidicola cv. Humidicola and U. ruziziensis cv. Ruziziensis, whereas the nymph development time was significantly shorter on U. humidicola cv. Humidicola and U. ruzizizensis cv. Ruziziensis. Our study showed that the life history parameters of B. pulchellus were significantly affected by forage species. Assessing the influence of this insect on prospective hosts is anticipated to enhance future forage breeding initiatives.