Delcourt and Guyenot 1910 [8] explained that in their efforts to study the heredity of Drosophila over successive generations, a requisite for accurate determination of virtually all genetic questions was the development of controlled conditions in the rearing process. They explained that the inconsistencies of the foods used to rear the flies, where the qualities and differences in fermentation progress of raisins, bananas, and apples caused variability that was too great to allow interpretation of the genetic results that they were testing. These inconsistencies and difficulties demanded a control of the rearing system―mainly through control of diets. It was also obvious that there was a microbial involvement in Drosophila rearing as was addressed by Delcourt and Guyenot 1910 [8] , Guyenot 1913a, b, and c [9] , [10] , and [11] , and Guyenot 1914a and b [12] and [13], Baumberger 1917a and b ( [18] , [19] , and [20] ), Baumberger and Glasser 1917 [17] , Loeb and Northrup 1917 [15] , and by Morgan et al. 1913 [28] (as explained further by Bridges and Darby 1933 [26] ). The sequence of development of artificial diets for Drosophila was: fermented fruit (generally bananas)àmashed over-ripe bananas with yeast addedàbanana puree extract with yeast and agaràvarious fruit (raisins, apples, etc.) purees with yeast and agar. Two of the major advancements that were profoundly influential to not only Drosophila rearing but to rearing countless other insect species were the addition of yeast (live or dead) and agar to provide a gelled diet.

For the period of 1910 through 1933, one of the liveliest subjects of inquiry was the relationship between insects and microbes in terms of dietary issues. There was a preoccupation with establishing the role and extent of microbial involvement in the feeding biology of Drosophila and other insects, especially other Diptera. A major portion of this progression was explained in elegant detail by Baumberger [20] who reviewed his own and other researchers’ experiments with yeasts vs. bacteria as food sources (as external or internal symbionts vs. nutrients) and live vs. heat-killed microbes. An important and illuminating part of these studies was the series of experiments that sought to tease apart the nutritional requirements that were part of the foods prior to microbial action vs. the foods post-fermentation (meant here as microbial action on media or raw materials) vs. the microbes themselves (Baumberger 1919 and Michelbacher et al. [16] ). After extensive review of the literature on the roles of microbes in feeding success on natural and artificial diets, it remains difficult to conclude how much of a diet’s success in meeting target insects’ needs is from direct effects of microbes (changing the nutritional quality of raw materials or media components), the contribution of the original raw materials, or the nutritional value of the microbes themselves [1] . Cohen [1] concluded that these complex questions about microbe/media/microbe-media interactions must be determined on a per species basis across all insects being reared. In summation, the many diets for Drosophila that are currently being used were evolved through a series of refinements of a fruit base with yeast added along with other nutritional and functional components such as corn meal, agar, and antifungal agents. Despite considerable effort to develop completely defined (holidic) diets for Drosophila to help establish the basic nutritional requirements for this insect, and in this context, all practical diets for this insect are based on complete foods in conjunction with yeast―mainly baker’s or brewer’s yeast Saccharomyces cerevisiae.

Rearing systems are treated in this review in separate sections on temperature and humidity, containers, and miscellaneous environmental factors (such as light, radiation, etc.). Section 5 “Environmental Factors in Rearing Systems” is a general review of rearing systems for various species, divided into the major environmental topics.

A search of “Insect rearing” and “temperature” in the Web of Science revealed 927 references. The earliest one was Smith 1931 [30] , but careful scrutiny of a body of other papers where rearing conditions are treated reveal that temperature and humidity had been recognized for decades prior to the Smith [30] paper was published. For example, Bridges 1933 [27] provides an in-depth history of the treatment of temperature in the “Fly Room” at T. H. Morgan’s Drosophila facilities at Columbia University had been a subject of intense effort to regulate temperature of fly rearing containers. Bridges 1933 [27] wrote:

“DURING the early work on the genetics of Drosophila melanogaster the cultures were reared on laboratory tables or on open wall shelving. This method gave irregular results. The cold nights of the winter season made a considerable proportion of the cultures fail to start properly, and also lengthened the generation interval.” “In 1913 I built above my laboratory table a large wooden incubator which held all my experimental cultures. This incubator was heated by carbon electric lamps placed in the lowest shelf space. The thermostat was of the ‘ether-wafer’ type. The expansion of the ether forced apart contacts in the heating circuit. A six inch electric fan continuously circulated air down a gap behind the shelving with return through a similar gap between the shelves and the doors.”

Elsewhere in this paper and in several other places, Bridges [27] emphasized the importance of temperature regulation in rearing circumstances―that it was not only crucial for optimization and uniformity, but also to help control the very genetic factors that Drosophila researchers were trying to explore. For example, he pointed out that linkage/crossover studies are skewed by deviations in temperature. Bridges [27] wrote, “Plough’s work on the effect of temperature extremes on crossing-over showed that it was necessary to maintain the temperature constant for genetic reasons as well as to improve culture conditions.” Unfortunately, the recognition of the far-reaching effects of temperature and many other facets of rearing conditions is lost to the community of scholars in terms of the consequences of deviations or lack of control of rearing conditions.

A series of papers that were influential in the role of temperature in rearing systems were Smith [30] , Butler [31] , Stinner et al. 1974 [32] , and Butler et al. 1983 [33] . These papers followed the classic line of inquiry where constant temperatures were the independent variable and the biological outcomes were observed such as rates of development, survival, and sometimes body weight or reproductive success. Visscher et al. 1979 [34] added the variable of host plant growth temperatures as well as rearing temperatures, showing that temperature, and probably other plant history factors, were influential on rearing outcomes. The more natural condition for insects under field conditions includes variable temperature, humidity, light conditions, and other parameters; however, most insect rearing has been done at a single, constant temperature. But there is a body of literature (51 references identified under the search words, “insect rearing” and “variable temperature). The earliest papers in this search were from the 1990s such as Manel and Debouzie 1997 [35] where a field-based model is reported, and more recently, Sprugeon and Brent 2016 [36] reported the value of using variable temperature. Manel and Debouzie 1997 [35] used field temperatures to model development. The use of “room temperatures” or slightly above has such extensive use that the original use of these temperatures is no longer cited. However, it remains an interesting and important fact that Bridges 1933 [27] provided a chronicle of the use of temperatures kept constant and slightly above room temperature, and he further explained the importance of the maintenance of stable, well-regulated temperatures in the synchronization of development and in the prevention of genetic or chromosomal alterations of the test insects.

The term “light conditions” includes photo period, light intensity, and light quality―meaning the wavelengths provided in the rearing system [1] . Although nearly every paper that includes rearing information provides information as an incidental component in rearing conditions, only 49 papers were found with the key words, “light” and “rearing” in a Web of Science search. The range of papers under this category is broad, with papers on different qualities of light through unique papers such as the effects of light conditions on diapause in gypsy moths rearing in a spaceship [37] . The Hayes et al. 1991 paper [37] also includes other useful rearing biology information such as responses of the gypsy moth eggs and larvae to microgravity, cosmic radiation, sub-freezing temperatures and unusual vibrations (please see Figure 2). One of the most interesting results of this unusual study is that space travel conditions led to a decrease in diapause from 3 - 4 months to six days. In fact, the topic of diapause and the environmental factors that induce or influences it is a dominant topic in insect biology. The key words, “insect rearing” and “diapause” elicited 289 papers in Web of Science. When the term “rearing” is removed from the key words (=“insect” and “diapause”), the search reveals 2075 papers. The oldest of these papers was a 1930 paper that

describes the evolutionary background of what Roubaud [38] calls, “obligatory larval hibernation” in mosquitoes (Culex pipiens L.). The author also mentions the word “diapause” in this paper, so this topic dates back nearly 100 years. Lees [39] was a pioneer in arthropod diapause factor analysis where in 1953 he recognized the importance of light and dark phases in controlling diapause. During that same time frame, C. M. Williams discovered that the induction of diapause involved direct light stimulation to the insect brain [40] , and Harris et al. [41] demonstrated that in the boll weevil, the quality of light (the narrow wavelengths) were key factors in controlling or contributing to induction of diapause. The Harris et al. group [41] also demonstrated that infrared radiation is also an important influence on diapause in boll weevils.

Interestingly, the concept of photoperiod and its influence on biological systems seems to have been developed in the early 20^th Century in relationship to plants and is first described in the literature in 1927 in the context of growth and fruitfulness of apple trees [42] . In relating photophase to insects, several papers treat various aspects of this subject including the concept of lunar phase [43] , relationship between photoperiod and body size and flight capacity [44] , a biochemical/nutritional basis of response to photoperiod [45] , and relationship between maternal photoperiod on diapause [46] [47] . The topic of ultraviolet effects on insects has been treated in a few studies such as by McCloud and Berenbaum 1994 [48] . The importance of color and light environment as well as hatching rhythm were treated by Connor 2006 [49] , Collins et al. 2008 [50] , and Tao et al. 2017 [51] , respectively. Light intensity has been recognized as a key factor in many aspects of insect biology [52] , and this recognition took place in the earliest studies of rearing Drosophila [27] . Several laboratories use continuous light, rather than light/dark photoperiods [53] [54] [55] . However, too often rearing facilities use light conditions that are based on conditions that have not been properly documented or vetted on the basis of their target insect’s biology. When rearing personnel are trying to develop a rearing system for an insect that is new to them, they simply depend upon conditions that were successful in other laboratories―often this information is passed on by word of mouth [1] .

While the literature on gas exchange, metabolic dynamics, and energetics is vast, few papers deal directly with these parameters in rearing systems. Reverting to the axiom that the rearing system is our domesticated insects’ ecosystem, we are reminded that all the insects’ needs must be met, including gas exchange and their related aspects: metabolism and energetics. This means that for terrestrial insects, the containers must meet the O₂ and CO₂ requirements while diets and insects are protected from desiccation due to excessive water loss. This also includes the cases where insects tunnel into diets or are otherwise positioned where insufficient oxygen supplies render the target insects into anoxic states or where excessive carbon dioxide prevents normal metabolic functions, including pH regulation of internal fluids. The intimate relationship between nutrient utilization and gas exchange also underlies the rearing system, leading to a relationship between respiratory quotient (RQ) and the insect’s nutritional profile. In this context, it is important to recognize that the nutrient profiles of artificial diets can affect the insects’ oxygen requirements, where the insects’ inherent nature as a “lipid specialist” vs. a “carbohydrate specialist” can drive the insect to increase its oxygen demand, if there is excessive and unavoidable lipid (especially fats) in the diet [55] and [56] . It is also crucial to recognize that other factors in the rearing environment such as temperature have profound influence on oxygen demands and carbon dioxide dynamics [55] and [56] . An excellent explanation of the relationships between metabolic rate variation in tsetse flies is found in Klok et al. [57] , Terblanche and Klok 2004 [58] , and Harak et al. 1998 [59] provide a compelling overview of stress in mealworms and the resulting changes in caloric differences in stress vs. non-stress conditions. It is worth noting that a series of interesting papers has been produced by the Terblanche group over the past two decades, and many of these papers on thermal tolerance, metabolic rates, and related topics are of interest to researchers in the rearing community in the context of food utilization, stress, and evolutionary perspectives of metabolic responses to rearing/environmental conditions. Schilman et al. 2011 [60] and Frazier et al. 2001 [61] treat the important relationship between temperature and oxygen demands and anoxia as related to temperature.

Using the key words, “Insect Rearing” and “containers”: 76 papers were found. What may seemingly be a minor part of insect rearing systems―containers― must be recognized as one of the most consequential parts of the rearing system/ecology concept. A good container must serve the target insect’s needs, including thermal features, humidity accommodation, gas exchange, being hospitable to developmental and reproductive needs, and any other microhabitat factors inherent in the insect’s biology. The container must also serve the needs of the rearing personnel, including availability of the containers at a reasonable cost, storage accommodation, ease in access to the insects, and cleaning requirements. The comments of one of the earliest papers on rearing (Burgess 1908 [70] ) these comments were made:

One of the serious problems which it was necessary to solve in order to successfully rear the parasitic and predaceous insects which were being shipped from Europe to prey on the gypsy and brown-tail moths was to secure apparatus by means of which these insects, as well as their hosts, could be successfully reared in large numbers. All of the old style equipment in general use by entomologists for rearing work was tested, but in many cases it was found that radical improvements were necessary in order to accomplish the results desired. It was of primary importance to place the insects under as nearly as possible natural conditions and at the same time to keep them in confinement where they could be studied and observed and not allowed to escape from captivity.

In the last paragraph of the paper, Burgess [70] elegantly stated the concept that the rearing conditions must simulate nature―but with conditions that meet the convenience of the investigator (or the rearing system personnel):

It is perfectly true that breeding devices must be used which are especially adapted to the habits and character of the insects to be studied, and it may be desirable to modify these cages in such a way as to suit the special needs of the investigator.

From these earliest treatments of containers (or rearing devices) throughout the history of insect rearing, a variety of container-types is remarkable. As is the case for many rearing innovations, the rearing system for Drosophila spp. was often the earliest model. For example Bridges (1933) [27] wrote about the early rearing system in the laboratory of T. H. Morgan (a famous facility that came to be known as “The Fly Room.”)

In the early work on the heredity of Drosophila the cultures were raised in quart fruit jars, in quart milk bottles, and in a very miscellaneous collection of museum jars and other laboratory glassware. The great difficulty was in getting the flies out of these cultures for etherization and examination. By 1913 pint and half-pint milk bottles had become standard, largely on account of their uniformity of mouths, their heavy, strong glass and the ease with which they could be procured.

Bridges [27] went on to explain in elaborate detail the other advantages of half pint milk bottles and the rationale behind the refinements, including the importance of being able to clean and even sterilize the milk bottles to prevent carryover of insects from a previous generation as well as for sanitation. For example, he describes the modification of the standard round milk bottle to a more convenient and efficient square shape:

In 1916 I made experiments to determine the optimum area of culture surface, and concluded that the pint milk bottle was best for the flies, but the half-pint, which was not far inferior in that respect, was greatly superior in ease of handling, etc. Accordingly in 1917 I drew designs and made a wooden model of a special bottle, having the floor area of the pint bottle and the height (135 mm) and other good features of the half-pint bottle.

Bridges (1933) [27] went into further detail about the optimization of container design, including his developing an agreement with a bottle manufacturing company to produce a special, custom-made square version of the half-pint bottle. Many laboratories continued to use the glass milk bottles until the later 20^th Century when the convenience and low expense of plastic containers overtook glass bottles in popularity.

After Bridges’ (1933) [27] paper, there are very few papers that treat containers as a specific, central topic. However, as is the case with many aspects of rearing systems publications, there is a wealth of information about rearing containers that can be found in publications if they are scrutinized. Several papers that treated container specifications and that were influential or that presented novel containment systems among the larger body of rearing papers are Shorey 1963 [71] , Shorey and Hale (1965) [72] , Tillman et al. 1997 [73] , Ignoffo and Boening 1970 [74] , Cothran and Gyrisco 1966 [63] , and Singh and Surrey 1980 [75] . The Ignoffo and Boening 1970 [74] paper introduced the multiple cell rearing tray which became a tremendous improvement in mass-rearing containment systems, including the innovation of using the food industry’s form-fill-seal technology to make various plastic trays such as the 32-cell tray and the 8-cell tray, which greatly reduce handling of individual cups. Several laboratories invested in the purchase of tray-making form-fill apparatus to ultimately reduce costs of tray purchases (Tillman et al. 1997 [73] , Cohen and Staten 1996) [76] . As Tillman et al. (1997) [73] describe, the multiple-cell trays [73] required specially-adapted lidding materials that consisted of a plastic material with a glue adhesive that was either a self-sticking glue or a heat-activated glue. Such lidding was designed to include pre-perforated zones fitted to each rearing unit, allowing adequate gas exchange while reducing the loss of water from the diet and insects. Of course, these gas exchange demands must be met and balanced with protection from excessive water loss through evaporation from the diets and the insects, and for this appropriate containers must be designed such as those described by Tillman et al. [73] .

It is clearly a crucial responsibility of rearing system personnel to provide suitable conditions to allow their target insects to perform the reproductive functions that allow them to sustain continuous generations of offspring. These conditions include mating accommodations, suitable oviposition circumstances, and appropriate hatching and developmental requirements. A search of the key words, “insect rearing” and “reproduction” yielded 539 publications (from 1979-2017) with a large range of topics, many including diet quality/nutritional relationships, microbial interactions, or environmental conditions such as lighting and temperature. However, the focus of this topic in the current review is more confined to conditions that affect mating success and oviposition factors. So, for example, the adult cage configuration that was conducive to mating and supply of liquid diet (sugar or honey solution) was presented by Yamamoto 1969 [77] and by Bell and Joachim 1976 [78] for rearing two lepidopteran species (Manduca sexta Sphingidae: Lepidoptera and Pectinophora gossypiella Gelechiidae: Lepidoptera). These papers ( [77] and [78] ) as well as Patana 1977 [79] also provide suggestions for oviposition substrates such as waxed paper or paper toweling that lend themselves to convenient substrates for collecting and processing the eggs laid by the various moth species. Similar requirements are met by use of ice-cream cartons with organdy lidding material for lacewing rearing as described by a number of authors, starting with Ridgway et al. 1970 [80] . A unique and highly efficient ovipositional accommodation was designed by Patana (1982) [81] who reported using packets made from Parafilm™ covering filled with a carrageenan gel. The packets were laid on top of wire or organdy mesh cage tops, allowing the plant bugs (Lygus hesperus Knight, Miridae: Hemiptera) to oviposit into the packets where the eggs could absorb moisture as they would under conditions where the insects ordinarily would oviposit into plant tissues. This system allows the insect rearing staff to harvest packets without opening the cages or otherwise disturbing the insects, and the packets were reported to contain more than a thousand eggs per 100 cm² surface area. The insect rearing literature contains hundreds of specialized reproduction/oviposition accommodations, too numerous to describe here but all clearly part of the need to meet on a per case basis various insects’ needs.

As in nature, pathogens can have a huge influence on insect populations in rearing systems, and the close proximity of insects in captivity and conditions dislocated from natural epidemic control renders rearing systems into a status of ripe target of obligate and facultative pathogens (Inglis and Sikorowski 2009) [83] . Inglis and Sikorowski [84] explain several mechanisms of pathogen transfer in rearing system, with examples from viral, bacterial, protozoan, and fungal microbes. The Web of Science search of “rearing” and “pathogens” revealed 1403 papers over the past 60 years. A search of “insect” and “pathogens” revealed more than 8000 papers, many of which included insects held in rearing conditions.

The importance of symbionts in successful rearing programs cannot be overemphasized in terms of fitness or even the survival of colonized insects (Cohen 2015) [1] . Depending on the taxa of the target insect species, symbionts may be internal or external. Internal symbionts may be part of the insect’s gut microbiome (Dillon and Dillon) [82] , or they may be held by specialized structures in the insect’s hemocoel in mycetocytes or mycetomes (Douglas 1998, [85] ) Douglas and Prosser 1992 [86] , Sandstrom et al. 2001 [87] ; Nishide et al. 2017 [88] , for a more recent review of this topic. External symbionts are found in wood-consuming beetles such as ambrosia beetles (discussed by Klepzig and Six 2004, [89] , Six 2012 [90] , Biedermann, and Rohlfs, 2017 [91] ) where fungus-bearing external structures known as mycangia are adapted to inoculation of fungi into wood galleries.

Because of the essential nature of rearing systems where highly nutritional diets are kept for extended periods under environmental conditions that are optimal for microbial growth, contamination becomes one of the most prominent challenges to rearing personnel. These conditions are further made problematic by the density of insects in most rearing systems and the proximity of fecal materials (frass) to the insects. The issue of contamination, therefore, has received attention since the earliest years of rearing efforts. For example, Bridges and Darby 1933 [26] discussed the extensive efforts to manage mold in diets used for Drosophila rearing in the Fly Lab of T. H. Morgan, dating back to 1913. The control of contamination has included modification of the media (diets) to make them less susceptible to microbial contaminants by using sanitation (Sikorowski and Lawrence 1994 [92] , Inglis and Sikorowski 2009a [83] and 2009b [84] , Sikorowski and Lawrence [92] , Inglis and Cohen 2004 [93] ), pH (Funke 1983 [94] , Cohen 2015 [1] ), water activity or use of humectants (Ludemann et al. 1979 [95] , Cohen 2015 [1] ), or antimicrobial chemicals (Singh and House 1970 [96] , Zha and Cohen 2014 [97] Funke 1983 [94] , Vail et al. 1968 [98] , Ludemann et al. 1979 [95] , Alverson and Cohen 2002 [99] , Inglis and Cohen 2004 [94] , Zha and Cohen 2014 [97] , and Cohen 2015 [1] ).

A special case of microbial influences on insects in rearing systems is the complex interactions of the bacterium Wolbachia spp. with their insect hosts. The search of key words, “Wolbachia” and “insect rearing” revealed 151 papers, the earliest ones dating back to the mid-1990s (Sinkins et al. 1995) [100] . The comprehensive review by Werren 1996 [101] still serves as an excellent base of information about the various biological effects of Wolbachia such as cytoplasmic incompatibility, influences on sex ratios, feminization of males, induction of parthenogenesis, and various other fitness parameters related to both field and laboratory interactions. The scope of Wolbachia as a “manipulator of invertebrate biology” is further explained by Werren et al. 2008 [102] . The older review by Werren (1996) [101] is updated by Rani et al. 2009 [103] , Goettel and Inglis 2006 [104] , and most recently by Lindsey and Stouthamer 2017 [105] . Also, because Wolbachia presents such a mixed case of a beneficial effects vs. potential harmful effects of Wolbachia, it is valuable to have information about possible management strategies for this bacterium such as the study by Kyei-Poku et al. 2003 [106] dealing with heat treatment or antibiotic therapy to eliminate Wolbachia.

The most celebrated and oldest system of sterile insect technique (SIT) is the one associated with the mass production of sterile screwworm flies, Cochliomyia hominivorax (Coquerel) (Brown 1984 [112] ; Babilonia and Maki Website [111] ; Parker 2005 [116] ). In fact, the demonstration that SIT is feasible is unquestionably thanks to the various successes of the screwworm program. This success starts with the concepts advanced by E. F. Knipling (1955) [117] and became one of the most successful and well-recognized insect control strategies, largely due to the remarkable success in mass-rearing technology developed between 1936 and the 1960s. Babilonia and Maki [111] discuss the eradication of this pest in the US, Mexico, and now throughout most of Central America, and these authors also describe the responses of the screwworm program to outbreaks of this pest in Africa. Parker’s chapter [116] on the development of screwworm rearing updates many of the changes adopted in screwworm rearing programs, including the treatment of the evolution of the mass-rearing system described by Brown 1984 [112] . The Parker chapter, along with the other contents of the Dyck et al. 2005 book, offers a most valuable resource in summarizing the dynamics of changes in the mass-rearing techniques, including the process control and quality control applications to the highly successful mass-rearing systems for screwworms, and other insect species that are produced for SIT programs. The Parker chapter presents valuable economic data in the context of total program effectiveness and in terms of the great leverage of seemingly incremental changes in rearing procedures that effect significant cost savings that help make the SIT programs financially feasible.

Parker [116] includes wide-ranging information as well as granular details in matters of insectary design, management of genetic diversity, process- and quality control, as well as details of automation of sexing, diet-production (including diet development issues), insectary environmental issues, treatment of risks of escape of fertile individuals, and well-being of personnel who spend nearly a third of their working lives in the mass-rearing facility.

The earliest diets for screwworms, as described by Melvin and Bushland [118] [119] , consisted of water, ground beef, citrated beef blood, and formalin which supported 88 consecutive generations over four years with a yield of about 4,000 pupae per week. Melvin and Bushland 1940 [119] also reported smaller scale rearing of screwworms with a sterile diet of egg yolk and whole milk in a soft agar kept sterile with formalin. The early diet’s yield of 4,000 individuals per week was amplified to more than a half billion per week, thanks to the many improvements in diet, automation, and other features of rearing advancements (Brown 1984 [112] ). Although the modifications in diet and the evolutionary progress, which was often seemingly incremental, are too many to cover adequately here, many of the changes in rearing media include substitution of other ingredients for the meat, changes in the semi-solid diet to a liquid form, using whole egg and calf milk supplements, and media for stabilizing the liquid diet, such as cellulose, cellulose acetate, shredded paper, cotton, bagasse, corn cob grits, or other locally available materials. Gingrich [120] presents a useful comprehensive review of earlier diet improvements. Several improvements in the liquid-stabilizing domain of diet components were discussed by Chaudhury and Alvarez 1999 [113] and Chaudhury et al. 2011 [114] . These works document the importance of texture and physical matching of the insects’ feeding requirements, beyond simply meeting nutritional needs. Besides the mass-rearing science and technology in the screwworm SIT system, scores of research studies on the physiology and genetics of mass-reared insects have been stimulated by the impetus of the huge, economically-important rearing programs. There are reciprocal benefits of such studies as Bush et al. 1976 [121] and the technological advancements of the large-scale systems where insects have become highly, though inadvertently, domesticated.

It should be noted that the screwworm mass-rearing system faced many problems that needed to be addressed as the scope, economic and biological feasibility of the program could be satisfied. Some of these improvements or breakthroughs were described in seemingly incremental reports in the peer-reviewed literature (most often in the Journal of Economic Entomology).