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Abstract

In recent years, various studies have investigated the growth of the larval stage of the black soldier fly (BSF). Nevertheless, the biology and reproductive behaviors of the adult is still largely unknown. Expanding the understanding of this area of research will assist the optimization of breeding-systems of BSF. In this present study, the mating behavior of BSF adults under summer sunlight conditions was evaluated. The number of couplings were evaluated based on a variety of environmental parameters that may have affected the copula: temperature (°C), humidity (RH) and light intensity (lux). 1000 g of pupae were put inside a cage to obtain one hundred adults to put in each three experimental units. Each specimen was then marked with an individual code in the dorsal portion of the thorax using fine-tipped acrylic markers and for each fly the body length parameters were taken. Individuals of interest were subsequently marked; in the first experiment only females, in the second only male, and in the third both sexes. During the trials observations were carried out from 9.30 am to 5.30 pm. During this time the key behaviors evaluated are as follows: mating, mating failure, struggles, deposition, failure to lay eggs, and multiple mating. The rate recorded in the Male and Female trials was 16.5%, but the peak of copulas changed with the trials. Mating events demonstrated strong positive correlation between light intensity (0.73) and humidity (0.64), whereas a negative correlation was seen between temperature and matings (−0.59). A weakly negative correlation was seen between deposition number and light intensity (−0.34) and humidity (−0.41), while positively correlated with the temperature (0.47). Multiple mating events were seen 2 times for females and up to 4 times for male.

In: Journal of Insects as Food and Feed

Abstract

The main challenge in establishing and maintaining shallow, extensive (non-irrigated) green roofs in semi-arid climate is plant selection. The chosen species should cover the roof and remain green all-year round and at the same time to survive the long, hot and dry summer in this harsh microhabitat. Three perennial species were selected for the present study conducted on a green roof at Haifa University, Israel: Sedum sediforme, Carpobrotus edulis and Portulacaria afra. These succulents were planted in non-irrigated plots, in a 17 cm deep substrate that consisted a mixture of 90% perlite and 10% compost. All three species have survived two consecutive summers and manifested notable spreading ability. Their groundcover area has increased between 3-5 times during the 18 months monitoring period of this study. These results suggest that they are suitable for the design of extensive green roofs in the semi-arid areas of Israel. Two additional species Aptenia cardifolia and Malephora crocea showed varying results, but nevertheless should be regarded as reasonable candidates. In contrast, ten other perennial plant species that were tested in the same conditions did not survive the dry summer. The results suggest, that a main factor of extensive green roofs design in semi-arid areas is species selection, namely identifying, choosing and monitoring of the fittest plant species for this harsh microhabitat.

In: Israel Journal of Ecology and Evolution

Abstract

Insects are part of the natural diet of fish and poultry species and to a lesser extent of pigs, dogs and cats. In traditional farming, poultry gather their food in a free roaming manner, and insects are part of the diet. Similarly, a large fraction of the diet of freshwater fish consists of aquatic insects. These features are exploited by farmers all over the world, as feed costs are high. For example, farmers lure termites to baskets filled with organic matter, and the insects are then fed to chickens. They also employ light sources above fishponds to attract insects for their fish. More sophisticated methods are, for example, attracting naturally occurring houseflies to containers filled with organic waste, e.g. manure. The captured maggots or pupae are then fed to poultry. We discuss the following insect groups as feeds for poultry, pigs, fish, dogs and cats: bees, caterpillars, cockroaches, flies, grasshoppers and termites. Feed for poultry can also consist of insect pests, which are then controlled at the same time, for example ducks to control rice pests. Moreover, leftovers from the silk industry can be used to feed chickens, pigs and fish. Insects are also commonly used as bait for fishing. The interest in a more industrial production of insects such as the black soldier fly and housefly as animal feed started in the 1970s. In the last 15 years, large-scale rearing of insects for animal feed has taken off, with the industry receiving more than 1.5 billion dollars in investment. The market is expanding, the legislation is becoming more conducive, while academic interest is increasing exponentially. The environmental, nutritional and functional benefits of insects as feed are becoming more and more recognized. Insects are poised to play an increasingly prominent role in shaping the future of animal feed production.

Open Access
In: Journal of Insects as Food and Feed

Summary

The genus Oscheius includes species with different habits and some of them have been shown to kill some insect pests. The occurrence of Oscheius in hay meadow soils from the area recently invaded by the Japanese beetle Popillia japonica in Lombardy, Italy, has been surveyed. Oscheius myriophilus was detected at five out of 18 sites resulting positive to entomopathogenic nematodes (EPN), either alone or together with other genera of EPN, indicating a widespread occurrence. The morphological analysis of the strains retrieved showed that they are morphologically in agreement with those of the type population and with other populations recently described. The phylogenetic analysis supported the sub-grouping of all sequences of O. myriophilus from Lombardy with those present in the databases and a close relationship with O. safricana was observed. The capacity to kill the laboratory host Galleria mellonella was similar to that observed in a previous study related to isolates from P. japonica, although O. myriophilus did not cause significant mortality in laboratory trials with the invasive beetles. The isolates of O. myriophilus from Lombardy were characterised in relation to their infectivity to G. mellonella and response to environmental stress, such as heat tolerance and desiccation. Overall, O. myriophilus appears to be an important component of the EPN community of hay meadow soil in Lombardy and might play a role in the containment of the invasive P. japonica.

In: Nematology

Abstract

Primate males normally protect reproductive females, genetic offspring, and other relatives from external threats. Nevertheless, male protection of group members other than the above individuals is widely reported. Here, we show qualitative data on a silverback’s charging behaviors toward human observers (predator surrogates) to protect group members having various age-sex and kinship traits in a group of wild western gorillas containing one reproductive male. We observed 106 and 33 charging behaviors by the leading silverback in two separate study periods. Two natal infants were often involved in his protective charging. Further, the silverback provided protection services to reproductive females. Surprisingly, immigrant individuals (i.e., unrelated to the silverback), including a wide range of age-sex classes, were also protected multiple times. His protection services for natal infants and adult females can be interpreted as a form of parenting effort and mating effort, respectively. Further, those for some immigrant immatures accompanied by their mothers can be considered part of mating effort, advertising his quality as a mate to the mothers. Finally, his charging behaviors to protect immigrant young males, who could be reproductive threats to him, may be due to group augmentation benefits. That is, the recruitment of additional males in exchange for protection services would improve the ability of group defense. Protection services of the leading silverback in the one-male group of western gorillas, in which members of various age-sex classes and kinship traits coexist, could be interpreted by some existing functional explanations.

In: Folia Primatologica

Abstract

The use of insects as’ food and feed’ is rapidly increasing due to global population growth and rising food demands. Over the past few decades, this immediate popularity of edible insects has led to a substantial upsurge in research publications on edible insects. The present study aimed to bibliographically analyze the status of work done on edible insects throughout India and provide its comprehensive review. Articles published from 1945 to December 2023 were retrieved from Scopus and non-Scopus databases using web search engines like Google Scholar and PubMed using keywords such as ‘entomophagy,’ ‘food insects,’ and ‘edible insects.’ These were then analyzed based on publication category, leading authors and publishers, active states, and journals. Between 1945 and 2023, 219 articles on entomophagy in India were published by Indian authors. This analysis highlights the historical inclusion of insects in Indian diets, particularly among ethnic communities in the North-East Region (NER), and identifies key researchers advancing this field. The findings indicate that India has the potential to become a hub for insect supplement manufacturing. Current research shows a unidirectional focus, emphasizing the need for greater collaboration among Indian researchers to drive further progress. This study serves as a pioneering effort in performing a bibliographic analysis of publications on edible insects in India and assessing the progress this practice has made in terms of consumer acceptance and its future development as a promising food resource.

In: Journal of Insects as Food and Feed

Abstract

Feed costs represent up to 60-70% of the total cost of poultry production, with protein sources being the most expensive feed component. Black soldier fly larvae meal (BSFLM) shows promise as a sustainable protein source for use in animal diets. This research was conducted to determine the effects of including up to 13% defatted BSFLM and a supplementary protease-based enzyme (Concentrase-P; CBS Bio Platforms, Inc., Calgary AB, Canada) on laying hen performance and egg quality. To test this objective, 180 Lohmann Brown-Lite hens (52 weeks of age) were fed experimental diets containing 0%, 6.5%, or 13% BSFLM, with or without Concentrase-P (3 × 2 factorial arrangement of treatments). The treatments were fed over 20 weeks. Results indicated reduced feed intake and body weight in laying hens fed a 13% dietary inclusion level of BSFLM ( P < 0.05 ), while other performance traits (egg production and FCR) were similar among treatments ( P > 0.05 ) and met industry performance standards. Shell weight and egg breaking strength did not significantly change with the dietary inclusion level of BSFLM or enzyme inclusion ( P > 0.05 ), although a significant decrease in egg weight and albumen height was noted ( P < 0.05 ), as well as a significant decrease in albumen height for the Concentrase-P treatments ( P < 0.05 ). Yolk colours were significantly lighter and redder in birds fed diets containing high levels of BSFLM ( P < 0.05 ). Results support the use of BSFLM at dietary inclusion levels up to 13% in laying hen diets. Concentrase-P does not appear to be required in combination with BSFLM in terms of growth and laying performance, although potential benefits to other physiological factors are worth consideration.

In: Journal of Insects as Food and Feed

Abstract

The effect of substituting Hermetia illucens (HI) meal for fish meal (FM) on the growth performance, survival rate, feed utilization, digestive enzyme activity, immunological function, and flesh quality of Clarias magur (average weight = 3.3 ± 0.05 g) is investigated in this work. Four iso-nitrogenous diets with 35% crude protein were formulated, each with varying levels of HI substitution: HI25%, HI50%, HI75%, and HI100%, then compared to a control diet (HI0%). Following a 90-day experiment, it was observed that the growth performance and feed efficiency were significantly improved at the 50% level ( P < 0.05 ). However, the control group exhibited greater levels of digestive enzymes, specifically protease and lipase activity. The fish’s health status remained unaffected by the substitution of fishmeal, while the 50% HI group showed significant improvements. The high levels of the antioxidant enzymes SOD and CAT, as well as the metabolic product MDA, suggested enhanced antioxidant activity in the groups that received HI inclusion. However, as the substitution level reached 100%, the quality of the flesh decreased, as indicated by increased lipid and adhesiveness, as well as decreased L* and WI ( P < 0.05 ). The findings of the study suggest that HI larvae can replace FM in diet of C. magur. Overall, at 50% level of HI larvae meal inclusion in diet, better growth and immune function was evident, but it does lead to a decrease in flesh quality. This study enhances the existing knowledge on substituting fish meal with insect meal in catfish that are of regional importance. Additionally, it emphasizes the necessity for additional investigation to examine the underlying mechanisms employing biotechnological approaches.

In: Journal of Insects as Food and Feed
Author:

Abstract

Two morphologically and genetically distinct salamander species (the crested newt, Triturus cristatus and the marbled newt, T. marmoratus) engage over a large area in the west of France where they hybridize at ca. 4%. The species interaction is characterized by ecological differentiation and limited gene flow beyond the F1 hybrid generation. Incompletely isolated species like these allow to investigate the genetic mechanisms and evolutionary forces that maintain their identity in the face of ongoing gene flow, to which a large mosaic hybrid zone provides excellent opportunities. A reanalysis of published morphological data supports the partial breakdown of the species barrier whereas extensive genetic data show that introgression is low yet asymmetric, in line with the dynamics of species replacement inferred earlier. The current work, with seven diagnostic nuclear markers studied for a large sample, revises the estimates of introgression in both T. cristatus (to 0.24%) and T. marmoratus (to 0.11%). Difficulties remain in the recognition of potential triploid hybrids versus backcross hybrids. Haldane’s rule is partially supported, but deeper analyses require the use of a molecular marker for sex that is not yet available.

Open Access
In: Contributions to Zoology