Preferential incorporation of choline into the lipids of the nervous system of the housefly Musca domestica

The accumulation into the nervous system of a disproportionate amount of the phosphatidylcholine present in housefly larvae when reared on diets containing very low concentrations of choline is found to occur even when two analogues of choline, N-dimethylethylcholine (DMECh) or β-methylcholine (βMCh), are included in the diet at more than one hundred times the choline concentration. Both analogues are incorporated into phospholipids of the whole larvae and nervous system. The ratio of choline to analogue found in the lipids of the whole insect is 1 : 48 (DMECh) and 1 : 24 (βMCh) and in the nervous system 1 : 22 (DMECh) and 1 : 4 (βMCh). This preferential accumulation into the lipids also occurs during the development of the adult nervous system. The total phospholipid content of the head and thoracic ganglia of the adult is two to three times that of the fused larval ganglion. This results in 40 per cent of the phosphatidylcholine present in the adult fly, obtained from larvae fed on diets containing βMCh, being concentrated in the nervous system.     

家蝇和大头金蝇在麦麸和猪瘦肉上的产卵选择和发育差异

在中国许多地区, 大头金蝇Chrysomya megacephala F.已侵入过去由家蝇Musca domestica L.占绝对优势的垃圾生态位, 逐渐成为城市蝇类的优势种. 为了解单独和混合饲养时食物种类对家蝇和大头金蝇幼虫生长发育的影响, 在室内观察了野外大头金蝇和家蝇F1代在湿麦麸、猪瘦肉以及两者混合物上的产卵选择和生活史. 结果显示: (1)大头金蝇嗜在含有猪瘦肉的基质上产卵, 而家蝇嗜在含有麦麸的基质上产卵;(2)初孵家蝇和大头金蝇幼虫都能在含有瘦肉的食物上发育至成虫. 在麦麸上, 初孵家蝇幼虫能发育至成虫, 而初孵和2龄大头金蝇幼虫在进入下一龄期前全部死亡, 但少数3龄大头金蝇幼虫能发育至成虫;(3)等量初孵家蝇与大头金蝇在含有猪瘦肉的食物上共同生长时, 与家蝇相比, 大头金蝇的发育历期较短、存活率较高. 与家蝇在麦麸上共同生长时, 与在麦麸上独立生长的同龄大头金蝇相比, 大头金蝇的发育历期较短、存活率较高. 这些结果表明, 共生时家蝇可促进大头金蝇对植物质营养的利用, 这也许是大头金蝇能成功侵入家蝇占绝对优势的垃圾生态位的一个重要原因.     

Changes in fatty acid composition of phospholipids and triglycerides of Musca domestica resulting from choline deficiency

The fatty acid composition of the phospholipids and triglycerides extracted from housefly larvae reared on diets containing no added fatty acids but containing differing concentrations of choline has been determined. Reducing the choline content of the diet resulted in a graded reduction of the percentage of phosphatidylcholine present in the phospholipids of the larvae. This was accompanied by changes in the fatty acid composition, choline deficiency causing an increased utilization of 16-C rather than 18-C acids by the phospholipids. Changes in the fatty acid composition of the triglyceride fraction were also observed but these were associated with insects containing very low levels of phosphatidylcholine. Examination of the fatty acids in the different classes of phospholipids showed that the major change resulting from choline deficiency was in the fatty acids of the phosphatidylethanolamine fraction—the phospholipid which increased as the phosphatidylcholine decreased.Although the fatty acid composition of the different classes of phospholipids was not completely fixed, some preferential utilization of certain fatty acids by certain classes was observed, in both larval and adult insects. The fatty acid composition of the phospholipids extracted from larval gut, muscle, fat body, cuticle, trachea, nervous tissue, and haemolymph was determined. Changes resulting from choline deficiency similar to those seen in the whole larva were observed in all tissues except the nervous tissue. The effect of rearing larvae at temperatures between 24 and 35°C resulted in only minor changes in the fatty acid composition of both phospholipid and triglyceride fractions but the difference due to choline deficiency was observed at all temperatures. The possibility that the observed changes in the fatty acids of the phospholipids are compensatory to the changes in the proportion of the choline to the ethanolamine phospholipids is discussed.     

The effect of dietary changes on the phospholipid composition of the haemolymph lipoproteins of larvae of the housefly, Musca domestica

Qualitative and quantitative analyses have been made of the phospholipid composition of haemolymph from larvae of Musca domestica and of the two lipoprotein fractions separated from it by agarose-gel electrophoresis. The effect of rearing the larvae on defined diets containing adequate choline, no added choline, and choline plus 2-aminobutan-1-ol on this composition has been studied.The haemolymph lipoproteins have a phospholipid pattern similar to that of the unfractionated haemolymph. The chief component is phosphatidylethanolamine. Diglycerides and free sterols are the major neutral lipids present in the haemolymph and the separated lipoproteins.The different diets cause changes in the various phospholipids present in the two lipoproteins which are similar to those that occur in other tissues of the larvae. Choline deficiency increased the proportion of the haemolymph phospholipid that is associated with the lipoprotein having the slower electrophoretic mobility. The results are compared with those obtained from other insects and vertebrates and the rôle of the lipoprotein in choline deficiency in the housefly is discussed.     

Dietary cholesterol utilization by the housefly,Musca domestica

The amount of cholesterol and the distribution of its metabolites were studied in various larval tissues of the housefly (Musca domestica), reared on a high cholesterol diet containing the radioactive cholesterol. The sterol content was also examined in adults derived from larvae reared on increasing dietary cholesterol concentration in separate batches. The results suggest that when the dietary sterol concentration was raised from 0.002 to 0.02% wet weight (an optimal concentration required for a maximal growth and development of insect), the sterol content of six-day old larvae was increased approx. 4-fold. However, a further 10-fold increase of dietary cholesterol (to 0.22% of wet weight) was associated with only a 1.5-fold increase in larval sterol content, and no increase in the sterol content of adult insects derived from such larvae was observed. This increase of sterol content of whole larvae was found to be confined to the larval cuticle and composite gut fractions and may be attributed to unabsorbed cholesterol in the gut, and to a solubilizing effect of the cuticle. These findings suggest that when the cholesterol requirement for the maximal growth of the insect has been reached, larvae are able to regulate the intake of ingested cholesterol, and no more is taken up through the gut even when a high gut concentration of cholesterol is present.The adults contained a higher percentage of esterified sterols than the larvae, approx. 25% of the sterol in females and 14% of sterol in males were esterified.     

Influence of canola hulls on gain in weight of larvae of the yellow mealworm, Tenebrio molitor L

Larvae of the yellow mealworm, Tenebrio molitor L., Gembloux strain, race F, were reared on diets in which the protein component was supplied by defatted ground seed, defatted ground dehulled fraction, or defatted ground hulls of Brassica napus L. cv. Tower or Brassica campestris L. cv. Candle, obtained from autoclaved seed. They were also fed casein diets to which defatted ground hulls of Tower or Candle seed were added. Gain in weight was equally good for all diets containing Candle seed fractions and for diets containing Tower ground seed. However, it was lower for diets containing the ground dehulled fraction or the ground hulls of Tower. Addition of Candle hulls or of a mixture of equal proportions (w/w) of Candle and Tower hulls to diets containing dehulled Tower did not improve the gain in weight of larvae, compared with that of larvae fed diets containing the dehulled fraction, alone. Similar additions of Tower hulls or of the mixture to diets containing the dehulled fraction of Candle had no adverse effect on larval gain in weight, compared to that registered by larvae fed the dehulled fraction of Candle. Significant improvement in weight gain in comparison with that recorded for larvae fed the unsupplemented casein diet could not be demonstrated when ground hulls of Tower or Candle were added to this diet. Considered collectively, weight gains of larvae of T. molitor were consistently greater when Candle products were fed than when Tower products provided the protein fraction of the diet.     

Effect of dietary cholesterol deficiency upon its distribution in the larvae of the housefly, Musca domestica

The free sterol, total phospholipids and protein content of the various tissues and haemolymph lipoproteins obtained from the larvae of Musca domestica, reared on the diets containing 0.56 μmole cholesterol/g wet weight of diet (normal) and 0.05 μmole cholesterol/g wet weight of diet (deficient) have been determined. The cholesterol in the diet was found to be taken up by the larvae and distributed between all the tissues examined. About 60% of the free sterol in the larvae was recovered from the composite gut fraction and muscle. Cholesterol deficiency reduced both the growth of larvae and the free sterol content of the various tissues and haemolymph when compared to that of normal larvae. Cholesterol deficiency resulted in a slightly higher proportion of sterol and protein of the larval haemolymph being associated with the lipoproteins having slower electrophoretic mobility. Most of the different tissues from the cholesterol deficient larvae contained a much smaller proportion of their normal free sterol content than of their phospholipid or protein; the brain tissue however contained a higher percentage of free sterol and the haemolymph a much lower percentage than would be expected from the lowering of phospholipid and protein content as a result of the deficiency. When the sterol content was expressed relative to the protein, the ratio was higher in the brain tissue of both the normal and deficient larvae than the ratio present in the remaining tissues, apart from the composite gut fraction of the normal larvae. The results suggest that a disproportionate amount of available cholesterol was being concentrated into the nervous system of the cholesterol deficient insect.A rather higher proportion of the total sterol fraction recovered from the various tissues and haemolymph lipoproteins of cholesterol deficient larvae behaved as ‘polar metabolites’ of cholesterol when compared with that of normal larvae.     

Larval diet influence on oviposition behaviour inSpodoptera littoralis

Females ofSpodoptera littoralis Boisd. (Lepidoptera: Noctuidae) with different feeding experiences during their larval development were tested for their ovipositional response to methanol extracts of larval frass and semisynthetic diets. The effect of the following frass, diet and diet component extracts was tested: (a) frass fromS. littoralis orAgrotis segetum larvae fed on a potato-based diet; (b) frass fromS. littoralis larvae fed on a wheat germ-based diet; (c) potato and wheat germ-based diets; and (d) potatoes and wheat germ. Ovipositing females without prior experience of the potato diet were deterred by extracts of: (1) larval frass from either species fed on potato diet; (2) the potato-based diet; (3) potato. Also females with experience of the potato diet during only a part of their larval development were deterred from oviposition by frass of larvae reared on the potato diet and by the diet itself. However, for females reared on the potato diet for their entire larval development, oviposition was no longer deterred by either of the three extracts listed above. Extracts of: (1) frass from larvae of either species reared on wheat germ diet: (2) the wheat germ diet; or (3) wheat germ did not significantly affect oviposition. Females with ablated antennae were still deterred by frass extracts from larvae fed on potato diet, when they had been reared on the wheat germ diet. In feeding experiments, larvae of larval stage one and of larval stage three-four reared on either of the two diets preferred to feed on the wheat germ diet. However, the preference was significantly stronger for larvae with no prior contact with the potato diet. The effect of larval experience on the loss of oviposition-deterring activity by extracts of larval frass, diets and diet components is discussed in view of induction and selection.     

雷公藤总生物碱对粘虫幼虫神经系统酶活性及神经递质含量的影响

【目的】明确雷公藤Tripterygium wilfordii Hook. f.生物碱对粘虫Mythimna separata (Walker)神经系统的影响,为阐明其杀虫作用机制提供依据。【方法】采用载毒叶片法测定粘虫5龄幼虫经雷公藤总生物碱处理后体内乙酰胆碱酯酶（AChE）、Na⁺, K⁺-ATPase、Ca²⁺, Mg²⁺-ATPase、谷丙转氨酶（GPT）和谷氨酸脱羧酶（GAD）等重要神经系统酶活性及乙酰胆碱（ACh）、谷氨酸（Glu）和γ-氨基丁酸（GABA）等神经递质的含量。【结果】雷公藤总生物碱处理对粘虫5龄幼虫AChE无明显影响,麻醉期处理粘虫幼虫体内ACh相对含量与同期对照无显著差异。处理粘虫幼虫在轻度麻醉期、深度麻醉期和复苏期体内GABA和Glu含量显著升高,GABA含量分别升高了89.86%, 49.28%和20.29%,Glu含量分别升高了24.55%, 23.33%和8.13%。处理粘虫幼虫GPT活性明显受到抑制,而GAD活性无明显变化。处理明显抑制粘虫幼虫头部Na⁺, K⁺-ATPase和Ca²⁺, Mg²⁺-ATPase活性,但对中肠两种ATPase活性影响不大。【结论】研究结果有助于了解雷公藤生物碱对昆虫神经系统的影响,也为进一步阐明其作用靶标奠定了基础。     

SUBCELLULAR LOCALIZATION AND PROPERTIES OF A CHOLINERGIC RECEPTOR ISOLATED FROM HOUSEFLY HEADS

—Protein(s) possessing the ligand-binding properties expected of the insect cholinergic receptor were demonstrated in both aqueous and chloroform-methanol extracts of an 80,000 g supernatant obtained from frozen housefly heads. There is reasonable correlation in both the properties and concentration of the housefly head cholinergic receptor in these radically different extracts. Binding constants for decamethonium, acetylcholine, nicotine and atropine have been determined with aqueous housefly head extracts using an ultrafiltration assay. These observations are taken as further evidence that the cholinergic receptor in the insect central nervous system differs in specificity to the more widely studied nicotinic and muscarinic cholinergic receptors from vertebrates.     

The nature of the nutritional importance of serum albumin to Glossina morsitans

The nutritional significance of albumin protein and its constituent amino acids or associated impurities to Glossina morsitans was evaluated. Flies fed serum-free or albumin-free diets or diets containing delipidated serum or delipidated albumin failed to reproduce. The sizes of offspring produced by flies fed on diets containing different commercial albumins varied in proportion to the amount of bound lipid present in the albumin. FLies fed on albumin-containing diets supplemented with serum lipoproteins produced heavier offspring than flies fed on unsupplemented diets or on diets supplemented by other serum proteins. Delipidation of serum lipoproteins abolished this supplementary effect suggesting a possible similarity between lipoprotein-associated and albumin-bound lipid in terms of their importance to the nutrition and reproduction of tsetse. It is concluded that the observed nutritional importance of albumin to tsetse flies may derive from albumin-associated substances rather than albumin per se.     

Amino acids in nectar enhance longevity of female Culex quinquefasciatus mosquitoes

Culex mosquitoes feed on a wide range of nectars consisting of mostly carbohydrates and amino acids, however, little is known about the utilization and effects of these different carbohydrates and their accompanying amino acids on longevity. Culex quinquefasciatus larvae were reared on low- and high-quantity food diets to produce adults that were nutritionally representative of wild-caught and laboratory-reared mosquitoes. Emerging adults reared on low- or high-quantity food diets as larvae were then provided Lantana camara nectar mimics containing mixtures of carbohydrates and amino acids to evaluate effects of nectar amino acids on longevity. Carbohydrates (with or without amino acids) were a critical component of the adult diet, and in their absence, adult mosquitoes died within 3-5 days. The nectar mimic that contained both carbohydrates and amino acids did not increase adult longevity of males originating from either poorly or well-fed larvae. However, females receiving adult diets containing both carbohydrates and amino acids lived 5% longer than females fed adult diets with only sugar.     

Recycling of urea associated with the host plant urease in the silkworm larvae,Bombyx mori

Urea concentration and urease activity in the midgut content were compared between larvae of the silkworm, Bombyx mori fed an artificial diet and those fed fresh mulberry leaves. A considerable amount of urea was found in the midgut content of the both larvae, however it was significantly lower in the larvae fed fresh mulberry leaves than in the larvae fed the artificial diet; average urea concentrations in the midgut content of the larvae fed fresh mulberry leaves and the artificial diet were 2.9 and 4.6 &mgr;mol/g, respectively. Urea in the midgut content seems to be secreted from the insect itself since the amount of urea in both diets were negligibly small. Urease activity was detected only in the midgut content of the larvae fed fresh mulberry leaves but not in other tissues of the larvae. On the other hand, no urease activity was detected in the midgut content of the larvae fed the artificial diet. Subsequently, to elucidate the role of mulberry leaf urease in the midgut lumen, larvae that had been reared on the artificial diet were switched to fresh mulberry leaves. The diet switch caused a rapid decrease in urea concentration in the midgut content and an increase in ammonia concentration in the midgut content, suggesting that secreted urea could be hydrolyzed to ammonia by mulberry leaf urease in the midgut lumen. Furthermore, to investigate the physiological significance of mulberry leaf urease on urea metabolism of the silkworm, (15)N-urea was injected into the hemocoel, and after 12 h the larvae were dissected for (15)N analysis. A considerable amount of (15)N was found to be incorporated into the silk-protein of the larvae fed fresh mulberry leaves, but there was little incorporation of (15)N into the silk-protein of the larvae fed the artificial diet. These data indicate that urea is converted into ammonia by the action of mulberry leaf urease in the midgut lumen and used as a nitrogen source in larvae fed mulberry leaves.     

Mycelia and spent fermentation broth of Beauveria bassiana incorporated into synthetic diets affect mortality,growth and development of larval Helicoverpa zea (Lepidoptera: Noctuidae)

Beauveria bassiana endophytically colonises corn (Zea mays) reducing tunneling from European corn borer (Ostrinia nubilalis). Endophytic colonisation of other plants by B. bassiana has been reported, and potentially, may reduce insect feeding on these plants. We evaluated the effects on larval growth and development, and mortality of different rates of dried, ground mycelia and water-soluble metabolites from fermentation broth culture of different isolates of B. bassiana incorporated into a synthetic diet and fed to neonate bollworm, Helicoverpa zea larvae. Development was delayed, weights of larvae were lower, and mortality was high for larvae fed the highest rates (1.0 and 5.0%, w/v) of mycelia incorporated diet compared to control. Insects fed diets containing mycelia of B. bassiana isolate 11-98 had the greatest mortality. Mortality was 100% for larvae fed 5% (w/v) mycelia incorporated diet of isolate 11-98, and 61% for isolate 3-00. For insects fed low rates (0.1 to 0.5%, w/v) of mycelia incorporated diet, mortality was lower, approximately 5% for isolate 11-98, and 5 to 14% for isolate 3-00. At the 0.1% (w/v) rate of mycelia incorporated diet, development occurred at an accelerated rate, compared to fungus-free controls, indicating increased nutrition in the lowest rate fungal diet. Mortality was low for all larvae fed diets containing spent fermentation broth of B. bassiana; however, development was delayed. Insects fed the highest rate (0.5%, v/v) of spent fermentation broth-amended diet had lower pupal weights, and a greater number of days to pupation than insects fed the lowest (0.1%, v/v) rate. Insects fed the 5% (v/v) rate of spent fermentation broth of isolates 11-98 and 3-00 had the longest days to pupation.     

SYNTHESIS AND RELEASE OF [14C]ACETYLCH0LINE IN SYNAPTOSOMES

Abstract— Synaptosomes took up [¹⁴C]choline, about half or more of which was converted to [^I4C]acetylcholine when incubated in an appropriate medium containing 1 to 5 μ M-[¹⁴C] choline and neostigmine. The amount of [¹⁴C]acetylcholine synthesized in synaptosomes increased in parallel with the increase of Na⁺ concentration in the incubation medium. The effect of Na⁺ on the uptake of [^I4C]choline into synaptosomes was dependent on the concentration of choline in the incubation medium.
About 25 per cent of [¹⁴C]acetylcholine synthesized in synaptosomes was released rapidly into the medium by increasing the K⁺ concentration in the medium from 5 m m to 35 m m . The change of Na⁺ concentration hardly affected the release of [¹⁴C]acetylcholine. The effect of K⁺ on the release of [¹⁴C]choline was rather small compared to that on [¹⁴C] acetylcholine. Ouabain promoted the release of [¹⁴C]acetylcholine.     

Effects of two artificial diets on the development and reproduction of Tirathaba rufivena (Walker) (Lepidoptera: Pyralidae)

Growth, survival, fecundity, and nutrition of Tirathaba rufivena (Walker) fed on two artificial and one natural diet were studied at 29±1°C and 75±5% relative humidity. Larvae reared on the two artificial diets showed faster growth and development, higher pupal survival and weight, and higher adult fecundity than those reared on a natural diet of young coconuts, Cocos nucifera L. The relative growth rate, efficiency of ingested food conversion, and efficiency of digested food conversion in larvae fed on artificial diets were significantly higher than those of larvae fed on young coconuts. The relative consumption rate of larvae fed on artificial diets was significantly lower than that of larvae fed on young coconuts. T. rufivena showed no significant degradation in ability to propagate after being reared on the artificial diet for five successive generations. These results indicated that two artificial diets are suitable for mass rearing of T. rufivena.     

Cool-textured diets for use in baculovirus production

The incorporation of baculovirus into semi-synthetic diets has been used for the inoculation of large batches of insect larvae reared under gregarious conditions. The preparation of most artificial diets involves heating to dissolve the agar gelling agent followed by cooling to ～55–60°C whereupon virus occlusion bodies (OBs) are incorporated into the diet. To avoid exposure of thermolabile OBs to high temperatures, a cool-textured diet using soy fiber was evaluated as a simple method to inoculate batches of larvae with the baculovirus OBs. Spodoptera exigua larvae that fed on a diet with 120, 140 or 160?g/l of soy fiber, as a substitute for agar, had a similar weight gain over a 24?h period than larvae that consumed a standard agar diet. The larval weight gain with cool-textured diets with 140?g/l of soy fiber was not improved by the addition of chlorophyll, green food dye colour, or by the removal of ascorbic acid, sodium benzoate and potassium sorbate. Preliminary tests performed to determine the optimal OBs concentration needed for the inoculation of groups of four instar larvae in agar and soy fiber diets revealed no virus inactivation in heated diets with a similar optimal concentration of 36?OBs?mg^?1 for both diets. Moreover, no significant differences were observed in OB production when each type of diet was used to inoculate groups of 250 larvae reared gregariously in plastic containers. Cool-textured diets could be of interest for the production of baculoviruses that require a diet that can be prepared quickly and easily.     

土壤和植物对冬虫夏草寄主昆虫规模化饲养的影响

冬虫夏草大量人工培植的关键之一是寄主昆虫的规模化饲养,本文对西藏林芝地区冬虫夏草生境中不同土壤基质在室内对蝙蝠蛾幼虫生长的影响以及寄主幼虫对5种植物的取食行为、嗅觉反应进行了系统研究。结果表明蝙蝠蛾幼虫偏好土质疏松、渗透性好的土壤,土壤因子中湿度和有机质含量与蝙蝠蛾幼虫存活率成正相关。蝙蝠蛾3龄幼虫对适生地植物的取食选择性与嗅觉反应趋性顺序为鹅绒委陵菜>珠芽蓼>小大黄>圆穗蓼>羊角天麻;进一步Spearman相关分析显示,幼虫对各植物的选择系数与可溶性糖（R=0.850,P<0.05）和粗蛋白（R=0.898,P<0.05）都存在显著的正相关关系,而与粗纤维（R=-0.952,P<0.05）有着显著的负相关关系,与粗灰分（R=-0.391,P=0.516）之间没有显著的相关关系;取食鹅绒委陵菜、珠芽蓼后的幼虫单头虫重显著大于取食其他植物的幼虫。这一研究结果为冬虫夏草寄主昆虫规模化饲养提供了理论依据。     

四种昆虫饵料对穴蚁蛉幼虫生长发育及消化利用的影响

选择4种可规模化饲养的昆虫——米蛾Corcyra cephalonica、家蝇Musca domestica、斜纹夜蛾Spodoptera litura、甜菜夜蛾Spodoptera exigu幼虫来饲养穴蚁蛉Myrmeleon sagax(Walker)幼虫(俗称蚁狮),研究这4种饵料对蚁狮生长发育及消化利用的影响。结果显示,用家蝇幼虫饲养的蚁狮,其体重增长、相对生长率、化蛹率、蛹重均显著高于用斜纹夜蛾和甜菜夜蛾幼虫饲养的蚁狮,而幼虫历期则比斜纹夜蛾和甜菜夜蛾幼虫饲养的短;用米蛾幼虫饲养,虽然蚁狮体重增长、化蛹率和蛹重与用家蝇幼虫饲养的差异不显著,但其相对生长率却显著低于用家蝇幼虫饲养的蚁狮,幼虫历期也比用家蝇幼虫饲养的明显延长。同时食物消化利用的结果显示,用4种饵料饲养蚁狮,它们的近似消化率差异不显著,但食物利用率和食物转化率均以家蝇幼虫饲养的蚁狮最高。经分析比较,在4种饵料昆虫中,以用家蝇幼虫每4d喂蚁狮1次的饲养效果最佳。     

二化螟人工饲料研究初报

在温度为(29±1)℃,相对湿度为80%~90%的条件下,分别以3种人工饲料和天然饲料(新鲜水稻茎杆)对二化螟Chilo suppressalisWalker进行连续继代饲养。结果表明,3种人工饲料饲养的二化螟幼虫的生长历期、化蛹率、蛹重、蛹期及羽化率等均与天然饲料的基本接近,而且这3种人工饲料配制简便、成本较低,也不易霉变,是3种较为理想的人工饲料。通过第2代和第3代的继代繁殖表明,3种人工饲料和天然饲料饲养的二化螟的发育情况都稍有下降,但3种人工饲料与天然饲料间不存在显著差异。