Digestion, growth and reproductive performance of the zoophytophagous rove beetle Philonthus quisquiliarius (Coleoptera: Staphylinidae) fed on animal and plant based diets

Dietary and phylogenetic correlates of digestive trypsin activity in insect pests

“…This is particularly important for generalist phytophagous and omnivorous insects that encounter extreme variation in food quality. For example, only 2 h after switching from a plant to an animal diet the zoophytophagous coleopteran, Philonthus quisquiliarius (Gyllenhal), achieved digestive enzyme activities characteristic for individuals fed on an animal diet for 48 h (García et al., ).…”

“…Understanding regulatory responses to complex diets and the mechanistic basis of evolutionary shifts toward higher or lower flexibility of digestive enzymes represent major challenges to evolutionary physiology. It is well‐documented that feeding on different host plants in phytophages (Chikate et al., ; Chougule et al., ; Erlandson et al., ; Govind et al., ; Saikia et al., ; Sinha et al., ) as well as plant‐ and animal‐based diets in zoophytophages (García et al., ) alter the gene expression and isozyme patterns of digestive proteinases. Despite the possible costs of responses induced by the switching of diets that stem from allocation trade‐offs, the plasticity of enzyme activity could be maintained in populations because insects may benefit (i.e., increase fitness) from consuming different plant species or a mixed feeding habit.…”

“…Switching behavior ensures an appropriate quantity of specific nutrients and water, nutrient balancing, and overcoming periodical exhaustion of specific food sources. As a result, in comparison with insects fed on uniform diets, higher mass gain was recorded in phytophagous insects mixing different host plants (Miura & Ohsaki, ; Unsicker et al., ), zoophagous insects mixing different prey (Zanuncio et al., ; Pascual‐Ruiz et al., ), and insects switching between animal and plant diets (Torres & Boyd, ; García et al., ). The ability to use heterogeneous food sources, achieved by diversification in trypsin structures and regulatory patterns, among other factors, gave rise to extreme ecological success and further evolutionary divergence in generalist phytophagous (Srinivasan et al., ) and omnivorous species (Coll & Guershon, ).…”

“…Evolutionary change in diet observed in a taxonomic group of insects, which presumes adaptive shifts in the activities of digestive enzymes, can be similar to the responses of an individual to switching among diets of different composition. Experiments with omnivores (García et al., ) as well as comparisons between phylogenetically close species with phytozoophagous and zoophytophagous feeding habits reflect the inverse ratio of proteinases and amylase on plant‐ and animal‐based diets. Investigations on representatives of Heteroptera belonging to the same families (Cohen, ; Cohen & Wheeler, ; Agusti & Cohen, ; Zeng & Cohen, ; Zhu et al., ; Swart et al., ; Wright et al., ; Azevedo et al., ; Guedes et al., ; Bigham & Hosseininaveh, ; Zibaee et al., ) have shown that incorporation of animals into a diet led to evolution of the following physiological adaptations: (1) higher protease activity in salivary glands than gut, (2) a decreased amylase‐to‐trypsin ratio, and (3) an increased proportion of trypsin in total protease activity.…”

“…Besides the evolutionary novelties in proteinase classes and structures, food composition may have both short‐ and long‐term influence on the regulation of proteinase activity. It is known that the feeding habit of an insect species determines the relative amount of digestive enzymes (Mochizuki, ; Ortego, ; Terra & Ferreira, ) and this can vary even within species depending on food composition (García et al., ). Ingested food affects trypsin activity by direct interaction between food components and trypsin molecules, through perturbations in the regulation of trypsin synthesis and secretion and by changes in gut pH and redox conditions.…”