Growth and survival of reared Cambodian field crickets (Teleogryllus testaceus) fed weeds, agricultural and food industry by-products

Abstract

This study evaluated survival and growth of Cambodian field crickets (Teleogryllus testaceus) during captivity when fed a set of local weed species, agricultural and food industry by-products. Wild individuals were caught at two locations in Cambodia, kept in pens and fed commercial chicken feed until the second generation off-spring hatched. First larval stage nymphs from this generation were collected and used in a 70-day feeding trial with one control treatment (chicken feed) and 12 experimental treatments (rice bran, cassava plant tops, water spinach, spent grain, residue from mungbean sprout production, and Alternanthera sessilis, Amaranthus spinosus, Commelina benghalensis, Cleome rutidosperma, Cleome viscosa, Boerhavia diffusa and Synedrela nodiflora). The crickets were kept in plastic cages and feed intake, weight and survival of crickets were recorded weekly. Overall survival did not differ between chicken feed and the experimental treatments with the exception of crickets fed B. diffusa, which had lower survival. From day 35 to day 49, survival on A. sessilis was also lower (P<0.05) than on chicken feed. There was no difference in weight between crickets fed chicken feed, cassava tops and C. rutidosperma. However, crickets fed A. sessilis, A. spinosus and B. diffusa weighed less than those fed chicken feed already at day 21. The feed conversion rate ranged from 1.6 to 3.9 and was ≤1.9 in crickets fed chicken feed, cassava plant tops and C. rutidosperma. Thus this study shows that it is possible, using simple means, to rear Cambodian field crickets. Cassava plant tops and C. rutidosperma both have great potential as cricket feed and the other weeds, with the exception of A. sessilis, A. spinosus and B. diffusa, agricultural and food industry by-products tested, also showed potential.

The environmental sustainability of insects as food and feed. A review

“…Miech et al (2016) found that this species performs well on cassava plant tops, but also on several weeds, in particular Cleome rutidosperma.…”

Approaching Ecological Sustainability in the Emerging Insects-as-Food Industry

“…For example, the FCR for larval stage Tenebrio molitor and nymphal stage Acheta domesticus ranges from 2.2 to 5.3 and from 1.6 to 4.5, respectively, depending on the diet and life stage. It is also clear from individual studies [27] and life cycle assessments (LCAs) [28,29] that the feed used for insect rearing plays a large role in the efficiency of them converting this into protein.…”

Food Wastes as a Potential New Source for Edible Insect Mass Production for Food and Feed: A review

“…Most studies with encouraging results regarding artificial diets based on food wastes or mixtures of wastes have been carried out using edible mealworm (Tenebrio molitor L., Coleoptera: Tenebrionidae), black soldier fly (Hermetia illucens, Diptera: Stratiomyidae), housefly (Musca domestica, Diptera: Muscidae), and Cambodian cricket (Teleogryllus testaceus, Orthoptera: Gryllidae) and have used raw food material as the insect feed [28,31,60,62,[64][65][66][67].…”

“…Farmed edible insects that utilize food materials and wastes during rearing are summarized in Table 2. Rice bran, cassava plant tops, water spinach, spent grain, residues from mungbean sprout production [67] In general, the major macronutrients required for insect mass production are (a) carbohydrates, which serve as an energy pool but are also required for configuration of chitin (exoskeleton of arthropods) [60], (b) lipids (mainly polyunsaturated fatty acids such as linoleic and linolenic), which are the main structural components of the cell membrane, and also store and supply metabolic energy during periods of sustained demands and help conserve water in the arthropod cuticle [29,59,69], and (c) the amino acids leucine, isoleucine, valine, threonine, lysine, arginine, methionine, histidine, phenylalanine, and tryptophan, which insects cannot synthesize [70], and tyrosine, proline, serine, cysteine, glycine, aspartic acid, and glutamic acid, which insects can synthesize, but in insufficient quantities at high energy consumption [61,70]. The essential micronutrients in insect rearing are (a) sterols, which insects cannot synthesize, (b) vitamins, and (c) minerals [30].…”

“…The use of food wastes in rearing edible insects is a quite new and promising approach [7,11]. For this purpose, various artificial food waste-based diets covering the nutritional needs of farmed insects have been proposed, without pre-treatment of the biomaterial [28,31,67] (see also Table 2).…”