Macronutrient composition of spermatophores of Cryptolaemus montrouzieri varies depending on male feeding? Andréa Karla Lemos da Silva Sena, Maria Flora Menezes Tomás, Marciel Teixeira de Oliveira, Franklin Magliano da Cunha, Wendel José Teles Pontes Physiological Entomology, 2025 Many insect species produce nutritive ejaculates, which represent the male's contribution to female reproductive fitness. Studies on the quantification of male contribution are assessed via indirect observations and direct assessment through the post‐copulation effect on female reproductive performance, such as longevity and fecundity. Few studies directly address the nutritive content transferred by males via spermatophores. In species with multiple copulations, males produce ejaculates whose proportion of allocated substances varies according to the adult diet. We hypothesized that the spermatophores of C. montrouzieri show significant variations in nutrient composition when dietary modifications occur and whether this affects female fecundity and fertility. To test this hypothesis, we analysed the macronutrients proteins, lipids, sugars and glycogen using colorimetric methods. We tested for quantitative changes in these macronutrients in adult males well fed with Planococcus citri mealybugs, under limited amounts of P. citri (food scarcity), and with honey. The macronutrient profile of a spermatophore from a well‐fed C. montrouzieri is composed of approximately 49.62 μg/mL lipids, 5.18 μg/mL glycogen, 3.25 μg/mL sugar and 0.27 μg/mL proteins. When compared with the spermatophores produced by males subjected to food scarcity or honey, no significant difference was found in the macronutrients. Fecundity was not affected, but there was a significant reduction in fertility in females that mated with males fed with honey.
More eggs are not more sires: long-term monogamy reduces fertility in a predatory ladybird Gabriela Streppel Steindorff, W. J. T. Pontes Bulletin of Entomological Research, 2025 Multiple mating is a behaviour observed across various polyandrous insect species. It is suggested that, in ladybirds, this strategy of multiple copulations is used to enhance fecundity and fertility through sperm replenishment. Studies on sperm depletion need to correlate fertility with the presence of spermatozoa in the spermatheca. This study investigates the role of sperm replenishment in the ladybird Cryptolaemus montrouzieri. We hypothesised that females of this species exhibit fecundity and fertility rates proportional to the number of sperm replenishment opportunities (constant, periodic or absent). We observed oviposition behaviour and hatching rates over 30 days, and simultaneously tested for sperm depletion in females that copulated once. We dissected the spermathecae at four post-copulation moments to count spermatozoa under a microscope. Our results indicate that a single copulation suffices to maintain fertility for at least 30 days. Females with constant replenishment opportunities exhibited higher fecundity but lower fertility and increased mortality, suggesting a reproductive cost associated with frequent mating. Females with no replenishment during the experiment, exhibited the highest hatchability rate and lowest oviposition. Periodic copulation resulted in optimal female mating rate, with average fertility and fecundity. A plausible hypothesis would be that paired females choose to fertilise fewer eggs from a single male but are unable to control the effects of the oviposition stimulus induced by the male's presence. These findings have implications for the management and rearing of C. montrouzieri in biological control programmes, optimizing mating strategies for mass production.
Comparison of desiccation resistance in the litter-dwelling scorpion Tityus pusillus Pocock, 1893 (Scorpiones: Buthidae) from dry and wet tropical forests Thayna R. Brito-Almeida, Renato P. Salomão, Wendel J. Teles-Pontes, André F. A. Lira Journal of Arachnology, 2023 Water conservation is one of the major challenges encountered by terrestrial arthropods; species inhabiting dry forests are hypothesized to have adapted to dry conditions. Tityus pusillus Pocock,1893 is one of the most abundant scorpion species in northeastern Brazil, occurring in dry and tropical rainforests. Considering the wide distribution of T. pusillus, we aimed to investigate differences in desiccation resistance between populations originating from the Atlantic rainforest and the Caatinga dry forest. In this study, 40 individuals of T. pusillus from each of the two ecosystems were used. The two groups were separated into control and treatment groups (individuals without a water supply). Scorpions from the Atlantic rainforest had a shorter lifespan than those from the Caatinga dry forest, both in the control and treatment groups. However, the weight loss rate was higher in scorpions from the Caatinga dry forest than those from the Atlantic rainforest. In addition, Atlantic rainforest scorpions presented a lower resistance to desiccation, exhibiting a higher mortality rate than the Caatinga dry forest individuals. These results suggest that T. pusillus can exhibit, via phenotypic plasticity or local adaptation, a broad range of tolerances that allow it to persist in different habitats. Furthermore, our findings suggest that T. pusillus individuals from the Caatinga dry forest have physiological attributes that allow them to resist prolonged desiccation, which may be related to adaptations that are intrinsic to the population from the dry forest.
Acaricidal activity of the essential oils of leaves and fruits of Xylopia sericea St. Hill. on the two spotted spide mite (Tetranychus urticae Koch) Quimica Nova, 2007
