Calcium Accumulation and Loss and Vitamin D3 Content of Feeder Black Field Crickets (Gryllus bimaculatus) Fed on a High Calcium Diet with and without UVB Irradiation

Calcium metabolism in insectivores may be perturbed by insufficient calcium or vitamin D3. Insects may be gut loaded to increase calcium content, and recent research shows that exposure to UVB radiation can increase the vitamin D3 content of some invertebrates. Typical gut loading protocols result in peak calcium content after 24–48 h, while existing evidence with UVB irradiation involves exposure periods of tens of days. We UVB-irradiated fasted black field crickets (Gryllus bimaculatus) while feeding them on high calcium diets for 48 h, then fasted them for a further 24 h, and measured the vitamin D3, calcium, and phosphorus content compared with non-irradiated controls. UVB irradiation had no effect on vitamin D3 (crickets had no detectable levels of vitamin D3 at any point), or on calcium accumulation rates, which approximated existing research. Crickets significantly increased their calcium:phosphorus ratio from 0.17 to approximately 0.4 over 24 h and this did not increase over a further 24 h of feeding. Removal of the food source resulted in loss of all accumulated calcium within 24 h. Our results have implications for managing food sources for captive insectivores and highlight the importance of good feeder preparation and rapid consumption to ensure optimal calcium delivery to predators.

Edible wild field cricket (Brachytrupes portentosus) trading in Bangladesh

A cross-sectional survey was conducted to evaluate the market channels, relationship between market intermediates and their functions along with the marketing cost and profit margin of edible wild field cricket Brachytrupes portentosus in Bangladesh. Male respondents were dominantly involved in the insect collection procedure and female were widely engaged in the market. The field cricket trading totally depends on its availability from nature. Generally, this insect becomes available in the winter season (November to February). It was found that insect collectors, wholesaler cum retailers, and local trader cum retailers are the key market intermediates of the four different marketing channels of wild field cricket in Bandarban district of Bangladesh. Among the four observed marketing channels, the channel from insect collectors to the consumer held the big share in the local market. Approximately 43% of the total collection of the wild field crickets occurred through this channel. Both local trader cum retailers and wholesaler cum retailers processed and graded the B. portentosus on the basis of size and sex with the demand of consumers. The net marketing margin was the highest in insect collectors followed by wholesaler cum retailers and local trader cum retailers. The returns on operating capital of insect collectors, wholesaler cum retailers, and local trader cum retailers were 283.7, 48.7 and 42.9%, respectively. The major constraint of edible insect marketing was poor transportation and processing.

Studies on Neotropical crickets: New species and notes on the classification of Field Crickets genera Anurogryllus and Gryllus (Orthoptera: Gryllidae: Gryllinae)

In this contribution to the American Field and Short-tail crickets, two new species from the continental and insular area of Colombia are described. Anurogryllus (Urogryllus) edithsantosum n. sp. from the Meta department, is more related to some Caribbean species, and its genital structure fits the morphological current definition of the subgenus Urogryllus, although it has pseudepiphallic median lophi covered with hairs, as it happens in the species of the subgenus Pilosogryllus. The same way, Gryllus (Gryllus) providiensis n. sp. from Providencia Island, San Andres Archipelago is described, this new species has thick hairs on the pronotum as Gryllus (Gryllus) assimilis (widely distributed in America), as well as the color pattern of the cephalic capsule; but the new species is smaller in size, and has a particular organization in the harp veins of the tegmina, which only resembles Gryllus (Gryllus) marchena from the Galapagos Archipelago (Ecuador), from which it differs markedly in its morphology. Finally, the status of the Gryllus species, distributed in Latin America and the Caribbean, is reviewed, and it is recorded which species have acoustic records, and from here we start with the review of this peculiar genus in Latin America.

Physiological demands and nutrient intake modulate a trade-off between dispersal and reproduction based on age and sex of field crickets

ABSTRACT Animals adjust resource acquisition throughout life to meet changing physiological demands of growth, reproduction, activity and somatic maintenance. Wing-polymorphic crickets invest in either dispersal or reproduction during early adulthood, providing a system in which to determine how variation in physiological demands, determined by sex and life history strategy, impact nutritional targets, plus the consequences of nutritionally imbalanced diets across life stages. We hypothesized that high demands of biosynthesis (especially oogenesis in females) drive elevated resource acquisition requirements and confer vulnerability to imbalanced diets. Nutrient targets and allocation into key tissues associated with life history investments were determined for juvenile and adult male and female field crickets (Gryllus lineaticeps) when given a choice between two calorically equivalent but nutritionally imbalanced (protein- or carbohydrate-biased) artificial diets, or when restricted to one imbalanced diet. Flight muscle synthesis drove elevated general caloric requirements for juveniles investing in dispersal, but flight muscle quality was robust to imbalanced diets. Testes synthesis was not costly, and life history investments by males were insensitive to diet composition. In contrast, costs of ovarian synthesis drove elevated caloric and protein requirements for adult females. When constrained to a carbohydrate-biased diet, ovary synthesis was reduced in reproductive morph females, eliminating their advantage in early life fecundity over the dispersal morph. Our findings demonstrate that nutrient acquisition modulates dispersal–reproduction trade-offs in an age- and sex-specific manner. Declines in food quality will thus disproportionately affect specific cohorts, potentially driving demographic shifts and altering patterns of life history evolution.