Housefly as a protein source for shrimp and mice

Item Type text; Thesis-Reproduction (electronic)

Authors Soifer, Norman Lewis

Publisher The University of Arizona.

Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

Download date 01/10/2021 18:55:25

Link to Item http://hdl.handle.net/10150/557707 HOUSEFLY AS A PROTEIN SOURCE

FOR SHRIMP AND MICE

by

Norman Lewis Soifer

A Thesis Submitted to the Faculty of the DEPARTMENT OF ENTOMOLOGY

In Partial Fulfillment of the Requirements For the Degree of

MASTER OF SCIENCE

In the Graduate College THE UNIVERSITY OF ARIZONA

1 9 7 9 STATEMENT BY AUTHOR

This thesis has been submitted in partial fulfillment of re­ quirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library« Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judg­ ment the proposed use of the material is in the interests of scholar­ ship. In all other instances, however, permission must be obtained from the author.

/ SIGNED

APPROVAL BY THESIS DIRECTOR

This thesis has $>een approved on—the date shown below;

^WILLIAM L. NUTTTNl Dat Professor of Entomology ACKNOWLEDGMENTS

My sincere gratitude is extended to Dr. Charles Weber and Dr. Bernard Colvin and their staffs for providing me with laboratory facilities, assistance, and invaluable guidance. Special thanks must go to John Kern who worked with me on the shrimp experiment. I am also indebted to Dr. William Nutting and Dr. Harry Graham for their continued encouragement and advice.

iii TABLE OF CONTENTS

Page LIST OF TABLES ...... v

ABSTRACT . , . . . . ';i » ...... vi

INTRODUCTION ...... 1

MATERIALS AND METHODS ...... 6

Rearing Pupae . . 6 Poultry Excreta 6 Cow Manure . . 6 Processing Pupae . 7 Biological Assay . 7 Mice ..... 7 Shrimp .... 10

RESULTS ...... 13

Rearing Pupae, ...... 13 Chicken Excreta ...... 13 Cow Manure ■...... « ...... 13 Processing Pupae ...... 13 Biological Assay ...... 13 Mice ...... 13 Shrimp ...... 15 DISCUSSION ...... 17 Rearing Pupae ...... 17 Processing Pupae ...... 19 Bioassay ...... 19 Mice ...... 19 Possibilities ^ 20

CONCLUSION ...... * . 21

LITERATURE CITED ...... 22

iv LIST OF TABLES

Table Page 1. Composition of diets used in the mouse feeding study 9

2. Composition of diets employed for evaluating housefly meal as a protein source for shrimp (Penaeus californiensis). . .11 3. Nutritional evaluation of housefly as a sole protein source for weanling mice »o«oeo»eo«eeo«*o«aos 14 4. Effect on growth and survival of substituting housefly meal for fish meal and shrimp meal in the diet of cal T foniiensis 16

5. Maximum yields of housefly larvae and pupae ...... 18

v ABSTRACT

Pupae of the housefly (Musca dpmestlca L«) were grown on cow

and chicken manure. To assay the protein quality of the pupae and

puparial cuticle, feeding studies were carried out on mice (Mus muscuius L.) and shrimp (Penaeus califofaiensis Holmes)»

In the mouse feeding study,- the Net Protein Ratio of pupa meal with the puparia’removed (3«71) was not significantly different from

the whole egg control (4.00), while that of the pupa meal which in­ cluded the puparia was significantly lower (2.80). However, all fly meal diets resulted in significantly lower body weights, feed consump­

tion, and Protein Efficiency Ratios. Cuticle alone gave the poorest

results in all tests.

In the shrimp feeding study, the percent change in biomass with a fly meal diet was not significantly different from the basal diet, and was greater than with a fish meal or shrimp meal diet. How­

ever fly meal combined with fish meal or shrimp meal did not give as

good results as fish meal combined with shrimp meal. INTRODUCTION

The World'is caught in a protein shortage. In the United

. States this is reflected in the high price of protein feed supplements,

while in poorer countries there is malnutrition and even starvation.

The human population could reach up to 8 billion by the. year 2000, near­ ly double the present population. At the same time, the price of fuel and agricultural chemicals is rising, while soils, fisheries, and range­

lands are being depleted. As the gap between supply and demand for

protein grows, additional sources of protein and other nutrients must be

exploited, and present methods of agriculture must be made less wasteful

and more productive.

Insects are a rich source of protein as well as fat and other

nutrients. For example, some grasshoppers contain more than 75% protein

(Ueckert, Yang and Albin, 1972) and some termites contain more than 50%

fat (Bodenheimer, 1951, p. 31).

Except in those societies with food habits of modern European

derivation, insects have been a traditional foodstuff all over the world. Entomophagy was noted as far back as the dawn of history by the

ancient Assyrians (Bequaert, 1921) and the ancient Israelites (Leviticus, XI, 22, 21); and if we draw analogies from our relatives

the primates and from many existing pre-industrial cultures, we can as­

sume pre-historic man also consumed insects. Indeed, archeologists

have found insect parts petrified in human coprolites.

1 2

F. S. Bodenheimer (1951) gives the most complete account in his 352- page book Insects as Human Food.

Traditionally, edible insects have been obtained by hunting and gathering, and thus could not provide a constant and reliable food supply. Just as mankind has done with crops and livestock, perhaps the time has come for us to take the step from hunting and gathering to cultivation of insects. The mass culture of insects for food and fibre is not without precedent. Honey and silk have been products of great economic importance for ages.

Among the insects, the housefly has many characteristics that make it. suitable for mass production, Musca domestica is fecund, some females being capable of laying up to 800 eggs (Shipp and Osborn,

1967). Development time is short, as little as 5 days from egg to pupa under optimal conditions. The larvae can be reared on waste materials such as manure. The biology and techniques for rearing are well known. This insect is hardy, resistant to disease, and available practically anywhere in the world.

The American Indians of Mono Lake, southeast of Lake Tahoe in California, used to eat the pupae of Ephydra sp. brine flies which they gathered at the shore of the lake (Bequaert, 1921), The pupae were dried in the sun and the puparium rubbed off by hand. The re- . maining, yellowish kernels were an important item of food called Koo- tsabe or Koo-chah-bee. This suggested that a similar technique could be used with other Diptera having the same type puparium, Musca domestica, for example. 3 Both Ephydra and Musca are cyclorrhaphous Diptera. That is, the true pupa lies within an ovoid, puparium derived from the cuticle of the 3rd instar larva (Fraenkel and Bhaskaran, 1973). At maturity, the vermiform larva contracts into an ovoid shape, and this process is called pupariation. The puparial cuticle then hardens and darkens in a process called sclerotization'or Banning in which chains- of the cuti- cular protein, arthropodin, are cross-linked into the highly stable 3 dimensional matrix of the protein sclerotin. Within the puparium, a delicate, new cuticle forms around the insect, and this process is called pupation. If the pupa, which consists of 70% water, should now be desiccated, it would solidify and shrink away from the wall of the puparium which continues to hold its shape. The dried pupa occupies only a fraction of the space within the puparium, and if the puparium is crushed or torn, the pupa will fall free. The puparial cuticle con­ sists mostly of chitin and sclerotin and has a texture like celluloid.

In this research, the quality of the protein in the cuticle and the advantages of removing it are evaluated. A feeding study was carried out using housefly pupae with and without the puparial cuticle as the sole protein source for weanling mice.

Some authors have advocated direct consumption of insects by humans as a solution to food shortages (Holt, 1885; Taylor, 1975); however, though some insects may be delicious as well as nourishing, it is difficult for people to overcome food habits and taboos. House- flies and maggots in particular would be hard for people to accept, being some of the most disgusting and noxious pests to afflict man­ kind. The pupal stage of M. domestica is less repulsive than the 4

larva or adult, especially since it can be processed after the manner of the Mono Lake Indians. However, a more practical approach, might be

the indirect utilization of housefly as a feed ingredient for domestic animals. •

Barnyard poultry have always supplemented their diet with what­ ever wild insects they could catch. Feldman-Mahsam (1944) proposed

rearing fly larvae in chicken excreta, adding water, and allowing the

chickens to capture the larvae when they migrated out of the wet manure.

Calvert, Martin and Morgan (1969) found that dried, ground housefly

pupae contained 63.1% protein and 15.5% fat. They successfully sub­ stituted the housefly meal for soybean meal in the diet of one day-old

chicks. Teotia and Miller (1973a, 1974) found that housefly meal con­ tained 61.4% protein, 9.3% fat, was a good source of the limiting amino

acids argenine, lysine, and methionine, and that it could replace meat

and bone meal and fish meal in the diet of starting chicks.

Another purpose for mass rearing M« domestics is the biodegrada­

tion of manure. Cattle feed-lots, dairy farms, pig and poultry farms are

faced with a major problem in the disposal of vast amounts of manure. In

the United States, 1.2 billion tons of cow manure are produced each year

(Ettinger and Wade, 1971). The manure causes problems with odors, water

pollution, and wild flies. One day's production of poultry manure con­

tains 28.8 million kg of nitrogen (Calvert, 1974), with one third of the

nitrogen from protein (Blair, 1974). Miller and Shaw (1969), Calvert,

Morgan and Martin (1970), and Miller, Teotia and Thatcher (1974) have

.shown that fly larvae can reduce poultry excreta to a stable, semi-f

dry, crumbly, odorless, granular material suitable as a fertilizer ' ' ' ■ ■ ' . ' 5 and still conditioner. Papp (1975) processed pig manure with housefly larvae9 and Morgan and Eby (1975) have built a mechanized system in which larvae degrade either poultry or cow manure and then are extracted.

Considerable research has also been done in the Soviet Union with house­ fly larvae raised on swine manure (Ignatfev et al., 1975; Koltypin et al., 1975) but translations are not available. A prototype commercial shrimp culture facility is being built on the northern Gulf of California near Puerto.Penasco, Sonora, Mexico, as a cooperative project of the Environmental Research Laboratory (ERL) of The University of Arizona and its counterpart, CICTUS, at the

University of Sonora. Much research has gone into finding the optimum diet for raising shrimp. An animal protein source is required and, so far, the best results have been obtained using a mixture of shrimp meal and fish meal. These ingredients, however, are expensive and sometimes supplies are unreliable, so that there is a need for suit­ able, alternative protein sources. A feeding study was carried out in which dried, ground, housefly pupae were tested in the diet of shrimp as a substitute for fish meal, shrimp meal, and a combination of the two. In some diets, the puparial cuticle was removed to see if this affected the results. MATERIALS AND METHODS

Rearing Pupae

Poultry Excreta . ■ - •* Dry poultry manure (10.4% water) was collected from an unused henhouse at the University of Arizona poultry farm. It was impractical to obtain fresh manure because of the way the droppings collect in heaps under the cages and quickly lose moisture in the dry air. Water was added until the desired consistency was obtained (66-76% water).

As fly eggs appeared in laboratory culture over a period of 4 days, 78 kilos of reconstituted manure were placed in available trays, tubs» . buckets, and trash cans and innoculated at a rate of roughly 3 eggs per g of manure. The containers were covered with cheese cloth held down with elastic bands. The cultures were kept in the open hen house under ambient, July conditions. After pupation $ the manure was im­ mersed in water so that the pupae rose to the Surface while the manure remained at the bottom. The pupae were scooped out of the water with a ten mesh sieve, rinsed, and dried in a vacuum oven for 24 hours at

80°G.

Cow Manure

Enameled metal pans, 29 x 23 x 6 cm, were each filled with 3 kg of cow manure from the University of Arizona dairy farm. Each pan was innoculated with 1.8 ml of fly eggs or about 3 eggs per g of ma­ nure. The pans were held on shelves in a ventilated closet at an ambient temperature of about 23° C with relative humidity varying be­ tween 35 and 45%» The larvae pupated under the dry crust which formed on the surface. The crust was removed and the pupae were scraped off along with the top layer of flaky, dry, spent manure. The pupae were separated by sifting through a screen (4 mesh/inch), and then blowing away the chaff in a seed cleaner such as that described by Bailey

(1970). The pupae were then dried in a vacuum oven at 105° for 14 hours.

Processing Pupae R Dried pupae were put through a Hobart wheat and c o m mill. The working part of the mill consists of two, toothed disks, one spinning, the other stationary, and facing each other at an adjustable distance.

The mill was set to a coarse grind so that the puparium was torn from the pupae while the pupae passed through relatively undamaged. The re­ sulting mixture of dry pupae and cuticle fragments was placed in the seed blower where the two parts were neatly separated, the lighter cuti­ cle being blown out the top of the column, and the heavier pupae remain­ ing near the bottom. The granular pupae were then returned to the wheat mill, now adjusted to a finer grind, and ground to a meal.

Biological AsSay

Mice

Three experimental groups of weanling mice were fed diets con­ taining housefly meal as their only protein source. One group received ground, dried, pupae with the puparia retained; another received pupa meal with the puparia removed; and the third group received puparial cuticle as its only protein source. A fourth group, the control, re­ ceived whole egg with added methionine, a complete protein, as its protein.source (Table 1).

Twenty mice in 10 cages were used for each treatment. Mice, weighing approximately 8 g each, were housed, 2 per cage (1 male and 1 female), in stainless steel, wire-bottomed cages with distilled water supplied ad libitum. The food, in powdered form and covered with wire mesh screens to prevent wastage, was provided in stainless steel feeder cups. Temperature was maintained at 27° C with the lights on 12 hours/ day. The feed was weighed twice weekly and the mice once weekly for three weeks. Feces and uneaten feed were collected twice weekly. The Micro-Kjeldahl method was used to determine the crude protein content of feed, feces, and protein feed ingredients. . Chromium oxide (C^Og) was mixed into the rations (0.2%) as an inert marker. The level of

Cr^Og in both feed and feces was subsequently determined on a Coleman

Spectrophotometer after being digested in HNO^ and HCIO^ according to the procedure of Weber and Reid (1969).

Using formulae from Henry (1965), the Protein Efficiency Ratio

(PER) and Net Protein Ratio (NPR) were calculated:

PER = L^X i(.e^gM.jainiXgI protein intake (g)

body weight gain with test plus loss in body weight with N free diet ™ " ------?rote& K'tSS"® ------The % Apparent Digestion of protein was calculated with a formula from

Weber and Reid (1969): Table 1. Composition of diets used in the mouse feeding study.

% of Diet Diet 1 Diet 2 Diet 3 Diet 4 Whole Egg Pupae with Pupae without Puparia Ingredients (% protein) Control Puparia Puparia Alone

Whole Egg (43.8) 18.27 -- w . Pupae With Puparia (62.0) 12,90 Pupae Without Puparia (64.4) - — 12.42 - Puparia (53.0) - -— 15.07 Corn Oil 3.00 3.00 3,00 3.00 Cerelose . 58.75 71.83 72.41 70.51 Bentonite 12.03 4.27 4.27 3.53 Cellulose 3.00 3.00 3.00 3.00 AIN Vitamin Mix 1.00 1.00 1.00 1.00 AIN Trace Mineral Mix 3.50 3.50 3.50 3,50 Cr2°3 0.20 0.20 0.20 0.20 Choline Chloride 0.20 0.20 0,20 0.20 DL-Methionine 0.05 -

Total 100 100 100 100

% Protein =8.00 Assumed Metabolizable Energy Values (kcal./lb) Metabolizable Energy (kcal./lb) = 1400 Pupae with Puparia 1500 % Calcium =0.80 Pupae without Puparia 1500 % Available Phosphorus = 0.50 Puparia 1500 10

% Apparent Digestion = 100,- E ^ r2 ° 3 ^ e4- x %Pro5gin;feces) x 100] (% C^Og;feces % protein:feed)

Shrimp

Eight shrimp diets (Table 2) were prepared using four different animal protein sources, but having approximately equal crude protein content as verified by Micro-Kjedahl analysis. The diets were based on formulae developed by Colvin and Brand (1977). Diet 1, the control, contained fish meal together with shrimp meal. Diet 2 contained fish meal as the only source of animal protein, and diet 3 contained shrimp meal alone. Diet 4 contained fish meal and pupa meal with the puparial cuticle retained. Diet 5 contained fish meal and pupa meal with the puparial cuticle removed. Diet 6 contained shrimp meal and pupa meal with.puparia, and diet 7 had shrimp meal and pupa meal without puparia.

Diet 8 contained a mixture of the 2 fly meals: pupa meal with and with­ out puparia. Both of the fly meals were made from pupae grown in cow manure.

The experiment was carried out at the Environmental Research

Laboratory Experiment Station at Puerto Penasco. Twenty-five postlarval shrimp weighing an average of 0.31 g were randomly distributed in each of 48 fiberglass, flow-through tanks. Each of the eight diets was fed . to the shrimp in 6 replicates in a randomized design. The shrimp were fed twice a day for 28 days. For the first 14 days, they were fed 13% of their body weight per day, and 17%/day.for the second 14 days. The biomass was determined for each tank before and after the. experimental period and the animals were counted. The percent change in biomass, the average final weight per shrimp, the average weight gain per week. Table 2, Composition of diets employed for evaluating housefly meal as a protein source for shrimp (Penaeus califomiensis)»

Diets 1 2 3 4 5 6 7 8 Ingredients % ■ % % % % % % %

Pupa meal with puparia 12.0 - 15.0 - 12.0

Pupa meal without puparia . — -— - 15.0 15.0 Shrimp meal (sundried) 15.0 - 15.0 - ■ - 15.0 15.0

Fish meal (menhaden) 15.0 15.0 — 15.0 15.0 -- . - Wheat, whole, ground 50.8 48.1 49.8 49.8 47.8 47.8 50.8 Soybean oil meal 13.5 28.0 13.5 13.5 13.5 13.5 13.5

Oyster shell 2.2 1.0 1 .0 • — 1 ,0 Dicalcium phosphate - 1.0 3.0 3.0 3.0 3.0 2.0 Premia^ 5.7 5.7 5.7 5.7 5,7 5.7 - 5.7 5.7

Total 100.0 100,0 100.0 100,0 100.0 100.0 100,0 100.0

Crude protein 37.2 38.1 35.3 37.2 38.0 36.5 37.7 37.5

■^Premix = dried fish solubles — 35,00%, cod liver oil — 17.50%, vitamins — 8.75%, binders 35.00%, choline Cl^ — 3.50%aethoxyquin — 0.25%. 12 the percent change in average weight, the food conversion ratio (g food/ g gain)s and the percent survival were calculated. RESULTS

Rearing Pupae

Chicken,Excreta

A total yield of 229 g of dried pupae or 2.9 g per kg of wet manure was obtained.

Cow Manure Ah average of 19.7 g of dried fly pupae were produced from each panj yielding 6 .6 g per kg of fresh cow manure. The maximum yield from any one pan was 27.9 g or 9.3 g dried puparia per kilogram fresh manure, or 42.3 g per kg of dry manure.

Processing Pupae The pupal biomass was separated into 2 fractions, approxi­ mately 29% puparia and 71% pupae. The dried pupae themselves are yellow to brown in color and granular in texture.

Biological Assay

Mice

Table 3 shows that the mice fed on fly meal, with or without puparia, gained about 70% as much as the control, while those on the cuticle protein gained only 46%, However, these groups consumed less feed than the control. The groups receiving pupae with or without

13 Table 3. Nutritional evaluation of housefly as a sole protein source for weanling mice,,

1 2 Protein source Mean body (g) Feed Net protein Protein % Apparent or weight (g) consumed ratio (NPR) efficiency digestion treatment 3rd week 3rd week 1st week ratio (PER) of protein

1. Whole egg, control 26,7a 36.1* 4.00a 2.50* 76.2

2. Pupae with puparia 18.3b 31.4b 2.80b 1.55* 65.1

3. Pupae without puparia 18.2b 30. lb 3.71* 1.73b 74.7

4. Puparia alone 12.1C 21.5C 1.48* 0.60d 35.7

1NPR values were adjusted to 4600 2 PER values were adjusted to 2.50

3Means having different superscripts are significantly different at the .05 level of probability 15

puparia ate about 83% as much as the control, and the puparia group only

about 58% as much.

The Net Protein Ratio of the pupal protein alone was not signif­ icantly different from that of the control, as determined by a Duncan's Multiple Range Test, while the pupae with puparia had a significantly

lower NPR, and the puparia protein was lower still. . The PER was significantly better for pupae without puparia than with puparia$ but the difference was small when compared to whole egg . or puparia^alone.

The crude protein of fly pupae with no puparia is almost as

digestible as whole egg. With the puparia retained, digestibility was

lowered, and with puparia alone only about 1/3 of the crude protein was

digested.

Shrimp

As indicated in Table 4, significant, differences were detected

only in the percent change in biomass and the food conversion ratios.

The percent change in biomass with a diet containing fly meal alone was

not significantly different from the control. It was, on the other

hand, significantly better than a diet with fish meal or shrimp meal

alone.

Among the food conversion ratios, the diet containing fly meal

alone was not significantly different from the control, while it was

significantly better than the diet containing fish meal alone. Table 4. Effect on growth and survival of substituting housefly meal for fish meal and shrimp meal in the diet of P. californiensis»1

Biomass Average weight % 2 Animal protein source Final (g) % Change Final (g) Gain (g)/wk % Change F,C.R. Survival lo Fish meal and shrimp meal 20.52 310 1.08 .20 411 2.21 76

2. Fish meal 16.82 222° 1.06 .19 347 3.65C 64

3, Shrimp meal 18.77 22 7C 1.10 .19 327 3.48bc 70 4. Fish meal and pupa meal (P) 19.00 237bc 1.18 .22 366 3.47bc 65

5. Fish meal and pupa meal (NP) 20.48 229c 1.25 .22 363 3.40bc 65

'6. Shrimp meal and pupa meal (P) 18.75 241bG 1.10 .20 354 3.16abc 68

7. Shrimp meal and pupa meal (NP) 18.13 232bc 1.11 .20 353 3.31bc 65

8. Pupa meal (P) and pupa meal (NP) 20.39 282ab 1.16 .22 400 2.51ab 71

Values in a column with the same superscript are statistically similar according to a Duncan*s Multiple Range Test (p <_ 0.05), 2 (P) = with puparia (NP) = without puparia. DISCUSSION

Rearing Pupae

The yield of pupae depends on the interaction of a number of

factors: quality, depth, and moisture content of the medium, ambient

relative humidity, population density, and temperature. Small changes

in environmental conditions result in large changes in size and yield of pupae. When conditions are less than optimum, yield will be greatly re­

duced. For example, when population density is too high, scramble com­ petition results in reduced biomass production. Excessive dryness of the medium limits the available food supply and also increases competi­ tion. If the manure is too wet or deep, anaerobic conditions make the lower levels of the medium inaccessible and reduce the carrying capac­ ity of the habitat. Relative humidity affects the rate of drying of the manure and temperature regulates both manure drying and rate of larval growth. Thus, for optimum yield, all conditions must be prop­ erly balanced and controlled. Teotia and Miller (1973b) got their maximum yield with a combination of 3 g fly eggs/4 kg of fresh poultry manure at 27° C and 41% relative humidity.

Yields of pupae produced for this study were low compared to those of some researchers (Table 5), This was probably due to poorly

controlled rearing conditions. Facilities for large scale rearing are described by Patterson (1978) and Wilkes et al. (1948). Basden (1947) describes 8 ways to separate pupae from rearing media.

' ■ ' 17 18

Table 5. Maximum yields, of housefly larvae and pupae.

Yield, g dry . . % Yield, g dry housefly/kg housefly/100 g Researcher . Manure wet manure dry manure

Miller et al., 1974 poultry 19 : „ Morgan and Eby» 1975 poultry 8.0

Soifer, (this study) cow 9.3 4.2 Ettinger and Wade, 1971 cow 18 9.0 Morgan and Eby, 1975. cow 10.5

Rapp, 1975 swine «=■= 8.0 ' , 19 Processing Pupae Removing the puparia makes the pupae more appealing for human

consumption; however,this is not a realistic idea at this time in this country. Removal of the puparial cuticle improved the digestibility

and quality of the fly protein for mice, but growth was not improved in

either mice or shrimp. Since 29% of the material was lost in process­

ing , removing the puparia is not justified.

The larval stage may be a better source of housefly meal be-?

cause, during the pre-pupal stage (from maturation of the larva to pupariation), the insect does not eat and 20% of the body weight is lost, mostly as a result of fat oxidation (Papp, 1975). Also, the high population densities necessary to yield the greatest biomass and com­ pletely utilize the medium create a competitive situation that prevents

full growth and pupation of all larvae (Calvert, Morgan and Martin, 1970).

Bioassay

Mice

The differences in body weight appear to be highly influenced by the amount of feed consumed (Table 3). The PER*s of 1.73 for pupae with puparia and 1.55 for pupae without puparia would indicate that either the balance of amino acids is not as good as that of whole egg

(PER = 2.5), or that the protein is less available. However, the PER value of a protein is higher when a greater amount of the protein is

consumed, while the NPR measures the quality of a protein independent of the amount consumed (Bender and Doell, 1957)« Since the NPR and 20 digestibility of fly pupae without puparia are not significantly differ­ ent from that of whole egg, the higher PER for whole egg is probably attributable to greater cbnsumptlon. Pupae with puparia have a lower

PER and NPR than pupae without puparia, while the feed consumption is not significantly different. These results probably can be attributed to the lower digestibility of pupae with puparia (65% vs. 75%).

The poor quality of protein evidenced.in the puparia diet might be attributed to a distorted determination of protein quantity: Chitin is composed of n-acetyl glucosamine units which contain non-protein nitrogen, and Kjeldahl analysis interprets this nitrogen as though it came from protein, thus giving an incorrectly high crude protein con­ tent. Also, sclerotin, which truly is a protein might be indigestible.

Possibilities

Other insects might prove more useful as dietary protein sup­ plements than Musca domestica. For example, G. L. Newton (1977) found soldier fly meal (Hermetla illucens) to be a good feed supplement for swine, Dashefsky et al. (1976) showed face fly pupae (Musca autumnalis) to be a good source of phosphorus.

Besides livestock feed, housefly meal might be useful as pet food, for example, as a feed ingredient for tropical fish, turtles, caged birds, or even cats and dogs. CONCLUSION

Effective mass production of fly pupae requires, delicate control of rearing conditions,

The removal of the puparial cuticle gives a small improvement in protein digestibility and quality. . ..However, the process is not jus­ tified because it requires two steps and results in a considerable loss of material.

In the mouse feeding study, the NPR of pupa meal without puparia was not significantly different from the whole egg control, while that of the pupa meal with puparia was significantly lower. However, all fly meal diets resulted in significantly lower feed consumption and con­ sequently lower body weights and PER*s. Cuticle alone gave the poorest results in all tests.

The % change in biomass of shrimp fed with fly meal alone was not significantly different from the control, and was greater than that of shrimp fed with fish meal or shrimp meal alone. Therefore it ap­ pears that housefly meal is suitable for use as a protein source for

Penaeus californiensis.

21 LITERATURE CITED

Basden, E. B. 1947. Breeding the house-fly in the laboratory. Bull. Entomol, Research. 37; 381-7. Bender, A. E. and B. H. Doell. 1957. Biological evaluations of pro­ teins; A new aspect. Brit. J. Nutr. 11; 140-8=

Bequaert, J. 1921, Insects as food.Natur. Hist. 21; 191^-200.

Bailey, D. L. 1970. Forced air for separating pupaeof house flies from rearing medium. J. Econ. Entom. 63(1); 331-3. . Blair, R. 1974. Evaluation of dehydrated poultry waste as a feed in­ gredient for poultry. Federation Proceedings 33(8); 1934-6.

Bodenheimer, F. S. 1951. Insects as human food. Dr, W. Junk, Publishers, The Hague. 352 pp.

Calvert, C. C. 1974. Animal wastes as substrates for protein produc­ tion. Federation Proceedings 33(8); 1938-9.

Calvert, C. C., R. D. Martin and N. 0,Morgan. 1969. House fly pupae as food for poultry. J. Econ, Entomol. 62; 938-9.

Calvert, C. C«, N. 0. Morgan and R. D.Martin. 1970, House fly larvae; Biodegradation of hen excreta to useful products. Poultry Sci. 49; 588—9,

Colvin, B. and C. Brand. 1977. The protein requirement of penaeid shrimp at various life-cycle stages in controlled environment systems. Proc. 8th Ann. Meet. World Mariculture Soc. p. 821-40. Dashefsky, H. S., D. L. Anderson, E, N. Tobin and T, M. Peters. 1976. Face fly pupae; A potential feed supplement for poultry. Environ. Entomol. 5(4); 680-2.

Ettinger, M, B. and L. L. Wade. 1971. Conversion of cattle manure into high quality protein. Proceedings 26th Industrial Waste Conference Purdue University Engineering Bulletin. Engineering Extension Series no. 140 part 1, p. 266.

Feldman-Mahsam, B. 1944. A note on the conditions of pupation of Musca domestica vicina (Diptera) in Palestine, and its applications Proc. Royal Entomol, Soc. London (A). 19; 139-40.

22 Fraenkel, G. and G- Bhuskaran. 1973. Pupariation and pupation in cyelorrhaphous flies (Diptera); Terminology and interpretation. Annals Entomol. Soc. Am. 66: 237-48.

Henry, K. M. 1965. A comparison of biological methods with rats for determining the nutritive value of proteins. Brit. J. Nutrition 19: 125-35.

Holt, V. M. 1885. Why not eat insects. E. W. Classey Ltd., Hampton Middlesex, England. 99p.

Ignat’ev, A. D., I. U. A. Koltypin, E. V. Fomicheva, E. V. Vasal’eva, G. N. Serkova and V. P. Alenin. 1975. Biologic value of non­ specific feeds obtained from house fly (Musca domestica) larvae. Biulleten nauchnykh rabot. VsesOiuzhyi nauchnoissledovatel’skii institut zhivotnovodstva.

Koltypin, I. D. A., L. K. Ernst, M. N. Sukhova, T. V. Erofeeva, E. I. Kapanadze, T. V. Mitiukhina, I. U. I. Raetskaia and A. A. Cherepanov. 1975. Rearing the house fly (Musca domestica) (for swine feed) in semiproduction conditions for the utilization of swine manure. Biulleten nauchnykh rabot. Vsesoiuznyi nauchno­ issledovatel’skii institut zhivotnovodstva. 44: 32-9.

Miller, B. F. and J. H. Shaw. 1969. Digestion of poultry manure by Diptera. Poultry Sci. 48: 1844. Miller, B. F., J. S. Teotia and T. 0. Thatcher. 1974. Digestion of poultry manure by Musca domestica. Brit. Poultry Sci. 15: 231-4

Morgan, N. 0. and H. J. Eby. 1975. Fly protein production from mechanically mixed animal wastes. Israel J. Entomol. 10: 73-8.

Newton, G. L. 1977= Dried Hermetia illucens larvae meal as a sup­ plement for swine. J. Anim. Sci. 44(3): 395-400.

Papp, L. 1975. House fly larvae as protein source from pig manure. Folia Entomol. Hung. 28(1): 127-36.

Patterson, R. S. 1978. Room for rearing house flies and stable flies. In Facilities for insect research and production, eds. Leppla, N. C. and Ashley, T. R., U.S.D.A., Science and Education Admin. Tech. Bull. 1576.

Shipp, E. and A. W. Osborn. 1967. The effect of protein sources and of the frequency of egg collection on egg production by the housefly (Musca domestica). Bull. World Health Organ. 37: 331-5.

Taylor, R. L. 1975. Butterflies in my stomach. Woodbridge Press. Santa Barbara, Calif. 224p. 24

Teotia, J. S. and B. F . Miller. 1973a. Fly pupae as a dietary ingred- for starting chicks. Poultry Sci. 52: 1830-5.

Teotia, J . S. and B. F. Miller. 1973b. Environmental conditions ef­ fecting development of house fly larvae in poultry manure. Environ. Entomol. 2: 329-33.

Teotia, J. S. and B. F. Miller. 1974. Nutritive content of house fly pupae and manure residue. Brit. Poultry Sci. 15: 177-82.

Ueckert, D. N., S. P. Yang and R. C. Albin. 1972. Biological value of rangeland grasshoppers as a protein concentrate. Jour. Econ. Entom. 65(5): 1286-8.

Weber, C. W. and B. L . Reid. 1969. Effect of dietary cadmium on mice. Toxicology and Applied Pharmacology. 14: 420-5.

Wilkes, A., G. E. Bucher, J. W. Cameron and A. S. West. 1948. Studies on the housefly (Musca domestica) I. The biology and large scale production of laboratory populations. Can. J. Res. 26 D: 8-25.