Biodiversity and distribution of edible saturniidae (Lepidoptera) and their potential for mass rearing in Kenya

Edible insects including saturniid caterpillars are traditionally consumed in sub-Saharan Africa. Saturniids are utilized both as food and a source of income for rural communities. This study includes a review of available information on edible saturniids in Africa. They feed on specific host plants and could either be univoltine or bivoltine depending on the location. For instance, <em>Cirina forda</em> (Westwood) feeds exclusively on <em>Vittelaria paradoxa</em> C.F. Gaertn (Sapotaceae) in West Africa while it prefers <em>Crossopteryx febrifuga</em> (Afzel.) Benth. (Rubiaceae) in Congo. They are attacked by parasitoids at different life stages. Local communities who consume them have vernacular names for different saturniid species signifying their cultural importance. Edible saturniid caterpillars are harvested in the wild which is unsustainable. Overharvesting and destruction of natural habitats point to the need to establish mass rearing protocols to ensure constant supply and reduce pressure on natural habitats. Communities process the harvested insects before consuming or selling within and outside their communities. Edible saturniids have an average protein content of > 50% and all the essential amino acids and an average fat content of >10%. Poor handling when processing can cause contamination of insects. Bacteria such as <em>Escherichia coli</em> and fungi such as <em>Aspergillus</em> spp. have been found in processed saturniid caterpillars hence the need for hygienic handling and proper post-harvest storage. Perceptions and practices among communities known to consume edible insects were additionally studied with particular emphasis on edible saturniids in Kenya. Popularity of the most and least preferred edible insects among the interviewees ranged from 88% for termites to 1.5% for lake flies respectively. Saturniid consumption is restricted to the coastal region among the Giriama community. Insect consumption varied by age, gender and occupation but was not influenced by the level of education nor region. Children and women were mainly involved in the collection and sale of edible insects. More than 98% of the respondents were familiar with saturniids, while only 67% were willing consumers. It is therefore necessary to create awareness on the nutritional benefits of edible saturniids and to process them into more palatable forms to alleviate malnutrition in the region. Seven edible saturniid species were identified including <em>Gonimbrasia zambesina</em> (Walker), <em>Go. krucki</em> (Hering), <em>Bunaea alcinoe</em> (Stoll), <em>Go. cocaulti</em> (Darge & Terral), <em>Go. belina</em> (Westwood), <em>Gynanisa nigra</em> (Klug) and <em>Cirina forda</em> (Westwood). They feed on 11 different host plants, and they all occur twice a year except for <em>Go. cocaulti</em> which occurs only once. Two colour morphotypes were recorded for <em>Go. zambesina</em> and <em>B. alcinoe</em>. Predictive models revealed that tropical and subtropical regions were potentially suitable for <em>B. alcinoe</em> and <em>C. forda</em>. Climate change may affect their populations negatively by the year 2055. Parasitoids observed in this study belong to the orders <em>Diptera</em> and <em>Hymenoptera</em>. Larval pupal dipteran parasitoids included Tachinids like <em>Senometopia sp</em>. (cf. evolans Wiedemann) that emerged from <em>Go. zambesina</em>, <em>Go. krucki</em> and <em>Go. gueinzii</em>; a new <em>Ceromyia sp</em>. (Robineau-Desvoidy) from <em>B. alcinoe</em>, <em>Go. belina</em> and <em>Gy. maja</em>; a <em>Tachinidae sp</em>. from <em>C. forda</em> and a <em>Sarcophaga sp</em>. from <em>B. alcinoe</em>. The large Ichneumonid parasitoid, <em>Euryophion pisinnus</em> (Gauld & Mitchell) was also frequently encountered as a parasitoid of <em>B. alcinoe</em>. Braconid larval parasitoids constituted a <em>Cotesia sp</em>. from <em>Go. zambesina</em>, <em>Go. belina</em> and <em>B. alcinoe</em>; <em>Aleiodes trifasciatus</em> (Enderlein) from <em>Go. zambesina</em>; <em>Glyptapanteles maculitarsis</em> from <em>B. alcinoe</em> and a <em>Microgastrinae sp</em>. from <em>C. forda</em> were also recorded. Egg parasitoids included a parasitoid belonging to sub-family Entedoninae of Eulophidae and <em>Eupelmus sp</em>. (Eupelmidae) observed on <em>B. alcinoe</em> and <em>Go. krucki</em>, respectively. Thirteen bacteria species were isolated among which nine were potential entomopathogens. They include <em>Enterococcus mundtii</em> (Collins et al.), <em>Bacillus cereus</em> (Frankland & Frankland), <em>Staphylococcus sciuri</em> (Kloos et al.), <em>Staphylococcus gallinarum</em> (Devriese et al.), <em>Pseudomonas putida</em> (Trevisan), <em>Enterobacter hormaechei</em> (O’hara et al), <em>Enterococcus faecalis</em> (Andrewes & Horder), <em>Alcaligenes faecalis</em> (Castellani & Chalmers) and <em>Stenotrophomonas maltophilia</em> (Palleroni & Bradbury). Eight potential fungal entomopathogens were identified. Life cycles of <em>Go. zambesina</em> and <em>C. forda</em> were recorded. This study improves our understanding of edible Saturniids in East Africa and provides a baseline for the future development of mass rearing technics.