白星花金龟室内外繁育技术研究

[目的]根据新疆气候特点和白星花金龟Protaetia brevitarsis Lewis生物学特性,探究在新疆人工繁育白星花金龟的可行性及潜力,以期为白星花金龟在新疆的人工繁殖和转化利用畜禽粪便提供科学依据.[方法]以牛粪为繁育基质,在适宜季节分别在室内外保育白星花金龟的蛹及作为成虫产卵基质,最终统计比较室内外成虫的羽化及产卵情况.[结果]室外露天条件更利于白星花金龟的羽化,老熟幼虫做土室26 d后羽化出成虫,比室内及室外棚下处理提前4d.在化蛹30d后进入羽化高峰期,持续13d,羽化率83％.成虫雌雄比接近1∶1,雌虫羽化时间早于雄虫1-3 d.白星花金龟成虫室内外产卵量差异不显著(P＜0.05),室内单雌产卵量109.80粒,室外105.94粒,成虫羽化后30-35 d进入产卵高峰期,第60天室内外成虫产卵量显著下降(P＜0.05),甚至不产卵.[结论]白星花金龟规模化人工繁育在新疆是可行性的,在室外自然条件和室内控温条件下白星花金龟繁育的效果差异不显著.     

不同农业有机废弃物对白星花金龟生物学特性影响研究

【目的】白星花金龟Protaetia (Liocola) brevitarsis (Lewis)幼虫取食农作物秸秆、畜禽粪便等农业废弃物,在自然界中发挥着净化环境、变废为宝的作用。【方法】本文选用8种农牧业有机废弃物,包括腐熟沼渣、平菇菌糠、猪粪、牛粪、玉米秸秆、25%玉米秸秆+牛粪、50%玉米秸秆+牛粪、75%玉米秸秆+牛粪作为饲料,研究不同农业有机废弃物对白星花金龟生物学特性的影响。【结果】沼渣组和平菇菌糠组单雌产卵量较高,分别为130.17粒和117.00粒,显著高于猪粪、牛粪和玉米秸秆处理;在牛粪与玉米秸秆混配组,各处理单雌产卵量为101.50-108.67粒,不同混合比例间无显著差异。从幼虫孵化率比较,平菇菌糠组和猪粪组幼虫孵化率较高,分别为87.78%和82.22%;玉米秸秆及其与牛粪不同比例混合处理的幼虫孵化率均很低,仅为46.67%-57.78%。从幼虫化蛹率、羽化率比较,玉米秸秆添加不同比例牛粪处理组的化蛹率和羽化率均较高,分别达到90.00%-95.56%和88.89%-91.11%;沼渣、猪粪等单一物质处理的化蛹率和羽化率均较低,分别低于90%和70%。单一物质处理中,沼渣、平菇菌糠、牛粪、玉米秸秆处理组羽化后均为雌虫比例大于雄虫比例。玉米秸秆与牛粪混配组中,仅50%玉米秸秆+牛粪处理组为雌虫比例大于雄虫比例;雌、雄成虫的体长及体宽均在(17-19)mm、(10-11)mm之间,沼渣、猪粪和牛粪处理组体长略小。以不同农业有机废弃物饲喂的白星花金龟全世代发育历期中,牛粪饲喂组白星花金龟历期最短,为(315.29±0.55)d;沼渣饲喂组白星花金龟历期最长,为(330.75±1.76)d。【结论】不同农业有机废弃物均可作为白星花金龟繁育基质,并可为其幼虫转化处理农业有机废弃物提供理论依据。     

白星花金龟为害玉米初步观察

<正> 白星花金龟Potosia(Liocola)brevitarsis Lewis近年来为害玉米较严重,作者于1983-1985年对该虫进行了初步观察。此虫在天津地区每年发生一代,以老熟成虫越冬。各虫态平均历期:卵11天;幼虫一龄9天,二龄13天,三龄280天,共计302天;成虫寿命45天,雌虫产卵前期5天。成虫白天活动,取食、交配,飞翔能力很强,稍受惊立即飞走,雨天停止活动。卵产     

产卵基质模式和性比对白星花金龟生殖力的影响

[目的]为探究产卵基质模式和雌雄比对白星花金龟生殖力影响,寻求提高白星花金龟繁殖力的技术参数.设计复合产卵基质模式的思想,可为其他产卵于固体基质中的昆虫提高生殖力提供借鉴.[方法]本研究设计了5种产卵基质模式(牛粪、细沙单一基质、粪沙混、粪沙分和粪液沙复合基质)和5个雌雄比(早∶♂=4∶8、5∶7、6∶6、7∶5和8∶4),在室外敞口棚和自然温光条件下,开展对白星花金龟成虫产卵量和死亡率、幼虫孵化率的影响研究.[结果]5种产卵基质下白星花金龟成虫产卵量的顺序为粪沙分＞粪沙混＞牛粪＞粪液沙＞细沙,其中,白星花金龟在粪沙分复合产卵基质40 d的单雌产卵量达129.0粒,是原生产卵基质——牛粪的1.72倍;5个雌雄比处理比较,白星花金龟群体产卵量的顺序为7∶5＞8∶4＞6∶6＞5∶7＞4∶8;单雌产卵量的顺序为4∶ 8＞6∶6＞5∶7＞7∶5＞8∶4,最高达3.60粒/d.2项试验下成虫死亡率和幼虫孵化率在各处理间无显著差异,幼虫孵化率均在90％以上.综合分析和结合群体实际雌雄比可知,雌雄比为1∶1时,对于保障白星花金龟的群体繁殖力效果最佳.[结论]牛粪和细沙两复合体系作为产卵基质和维持雌雄比1∶1,可显著提高白星花金龟的繁殖力.     

白星花金龟幼虫对酵化玉米秸秆取食效果的研究

为探寻玉米秸秆资源化利用新途径、提高玉米秸秆利用效益,本研究利用白星花金龟Protaetia brevitaris Lewis幼虫的腐食性行为,选择其3龄幼虫,用EM菌液发酵玉米秸秆,以每5 d取食量为评价指标,选出幼虫取食的玉米秸秆最佳发酵时间及取食温度;以玉米秸秆发酵饲料为对照,以筛选出牛粪添加量分别为20%、60%的两组发酵饲料为处理,研究了白星花金龟幼虫对发酵饲料的利用率、转化率、消化率以及发酵饲料对白星花金龟幼虫死亡率、生物量增长率的影响。结果表明玉米秸秆发酵时间为25 d,温度为28℃时白星花金龟幼虫取食量最大;白星花金龟幼对玉米秸秆的转化率达到63.82%±30.90%,消化率为22.75%±3.07%,利用率为17.51%±8.50%,显著高于添加的组合;取食玉米秸秆发酵料的白星花金龟幼虫死亡率为5.75%±5.75%,生物量增长率达到11.01%±5.25%,均显著优于牛粪添加的玉米秸秆发酵料;添加牛粪可显著提高白星花金龟幼虫对玉米秸秆发酵饲料的取食量及虫粪产量,可利用白星花金龟3龄幼虫对玉米秸秆进行资源化利用,具有较好的应用前景。     

灰胸突鳃金龟生物学特性研究

灰胸突鳃金龟是沙区的重要地下害虫,以幼虫为害花生等作物的地下部分。室内饲养和田间观察表明:该虫1年多发生1代,以3龄和2龄幼虫越冬。幼虫期326.3天;蛹期24.4天。成虫羽化一般在5月下旬和6月上旬。雄成虫有较强的趋光性,雌成虫趋光性较弱,成虫寿命20天。每头雌虫产卵8～74粒,散产在5～10cm深的松温沙土中。室内饲养:卵历期平均18.45天,田间观察卵孵化盛期在7月上中旬。     

白星花金龟聚集信息素的分离鉴定及引诱效果

[目的]明确白星花金龟Protaetia brevitarsis Lewis聚集信息素的有效成分,为白星花金龟的绿色防控提供支持.[方法]通过动态顶空法收集白星花金龟雌虫、雄虫和雌雄虫混合挥发物,用气相色谱-质谱(Gas chromatography-mass spectrometry,GC-MS)联用技术对收集的挥发物进行分析鉴定,并利用触角电位(Electroantennogram,EAG)仪和Y型嗅觉仪测定白星花金龟对8种化合物的触角电位和行为选择反应.[结果]白星花金龟雌虫、雄虫和雌雄虫混合挥发物中皆鉴定出8类15种化合物,包括6种烷烃类、2种酚类、2种芳香烃类、1种烯类、1种吡啶类、1种胺类、1种醇类和1种酮类.EAG试验结果表明,白星花金龟对8种化合物都有EAG反应,且不同挥发物间、同种挥发物不同浓度间的EAG反应存在差异.白星花金龟对蒎烷胺、3,4-二甲基-6-乙基苯酚、2,3-二甲基苯乙酮和2,6,10,14-四甲基十七烷4种挥发物的EAG反应相对值在1μg/μtL时达到最大,对萘、苯并噻唑、百里酚和正十四烷4种挥发物的EAG反应相对值在10 μtg/μtL时达到最大.行为选择反应表明,白星花金龟雌成虫、雄成虫对2,3-二甲基苯乙酮有明显趋向性,选择反应率大于70％,对2,6,10,14-四甲基十七烷、萘、苯并噻唑、百里酚和正十四烷5种物质均表现出显著或极显著的驱避效果,对3,4-二甲基-6-乙基苯酚和蒎烷胺表现出了性别上的差异,雄虫对3,4-二甲基-6-乙基苯酚表现出显著的趋向性,对蒎烷胺表现出显著的驱避性,而雌虫对这2种挥发物却无明显反应.[结论]2,3-二甲基苯乙酮对白星花金龟雌成虫、雄成虫有明显的引诱效果,2,6,10,14-四甲基十七烷、萘、苯并噻唑、正十四烷和百里酚有较强的驱避作用,推测2,3-二甲基苯乙酮是白星花金龟聚集信息素的有效组分.     

高温对稻褐飞虱发育与生殖的影响

通过高温处理及交配产卵实验,探讨了高温对稻褐飞虱Nilaparvata lugens (Stal)发育与生殖的影响。研究了不同高温条件对褐飞虱若虫发育历期、产卵量、产卵前期、寿命等生物学特性的影响。34℃以上高温导致褐飞虱若虫发育历期延长。高温处理4龄若虫使羽化后的雌成虫产卵量减少。高温处理不同日龄雌成虫也致使其产卵量减少,其中以1日龄短翅型、3日龄长翅型的产卵量影响最大。高温处理后褐飞虱寿命缩短。高温恒温处理,对短翅型雌成虫的产卵前期影响不大,但能延长长翅型雌成虫的产卵前期;而高温变温处理致使短、长翅型雌成虫的产卵前期均延长。高温变温对褐飞虱生殖的影响程度大于高温恒温。高温处理组雌、雄成虫与对照组相应的成虫交配试验表明,高温对雌性的影响大于雄性。实验初步确定34℃为对褐飞虱发育与生殖产生影响的临界温度。     

幼虫期短时高温暴露对二点委夜蛾存活和繁殖的影响

【目的】随着全球气候变暖,夏季短时极端高温发生的频率逐渐增加。本研究旨在探明二点委夜蛾Athetis lepigone幼虫期对高温的适应性。【方法】将二点委夜蛾不同日龄(1,6,12和18日龄)幼虫在不同高温(35,38和41℃)条件下暴露不同时间(0.5,1,2,4和6 h)后转移至适温(26℃)继续饲养,观察短时高温对其存活率、发育历期、化蛹率、羽化率、雌虫寿命、单雌产卵量及次代卵孵化率的影响。【结果】幼虫期短时高温暴露的温度和时间对二点委夜蛾幼虫的存活率和发育历期有显著影响,而对化蛹率、成虫羽化率、雌虫寿命、单雌产卵量以及次代卵孵化率影响不显著。随着温度的升高和处理时间的延长,幼虫存活率逐渐降低,发育历期逐渐延长。其中,18日龄的幼虫最为敏感,38℃和41℃暴露6 h后存活率分别为58.3%和17.7%,显著低于对照,发育历期分别为25.5 d和29.2 d,较对照显著延长。【结论】幼虫期经历短时高温暴露仅对幼虫的存活和发育历期有影响,而对后续蛹和成虫的生长发育及成虫繁殖力没有影响。     

氯虫苯甲酰胺对非靶标害虫褐飞虱实验种群的亚致死效应

在稻田中,氯虫苯甲酰胺是以鳞翅目幼虫为主要防治对象的新型杀虫剂,而褐飞虱 是该药剂的重要非靶标害虫.本文采用稻茎浸渍法测定氯虫苯甲酰胺对其非靶标害虫褐飞虱3龄若虫和成虫的毒力.结果表明:氯虫苯甲酰胺对褐飞虱3龄若虫和成虫的LC50分别为26.85和35.53 mg·L-1;以氯虫苯甲酰胺亚致死浓度LC10和LC25分别处理褐飞虱3龄若虫后,对当代褐飞虱雌虫寿命无显著影响,但LC25剂量处理后,当代褐飞虱雌虫产卵量显著降低45.6粒.亚致死剂量处理褐飞虱3龄若虫后,显著影响F1代褐飞虱的产卵量和雌虫寿命,雌虫产卵量分别减少43.5和72.9粒,雌虫寿命分别缩短1.35和2.87 d;两个剂量处理后F1代的各虫态发育历期均有所延长;施药后各项种群参数也发生了变化,种群内禀增长率rm分别降低12.8％和23.5％,净增殖率R0分别降低37.4％和68.7％,而世代平均历期T和种群加倍时间t均延长.表明氯虫苯甲酰胺亚致死剂量对褐飞虱种群增长具有一定的抑制作用.     

Cotesia plutellae parasitizing Plutella xylostella: Host-age dependent parasitism and its effect on host development and food consumption

The braconid Cotesia plutellae(Kurdjumov) (Hymenoptera: Braconidae) is amajor solitary, larval endoparasitoid of thediamondback moth, Plutella xylostella(L.) (Lepidoptera: Plutellidae). Parasitism oflarvae of different host instars and fourdevelopmental ages of the 4th instar ofthe pest was examined. The effects of hostinstar at initial parasitization on thedevelopment, survival, size and fecundity ofthe parasitoid were determined in thelaboratory at 25 °C. The effects ofparasitism on host development and foodconsumption were investigated at 28 °C.Cotesia plutellae could parasitize larvaeof all four instars of P. xylostella, butpreferred 2nd and 3rd instars. In achoice test, the relative parasitism indicesfor 2nd, 3rd and 4th instarswere 0.37, 0.39 and 0.24, respectively.Parasitism decreased sharply with increasinghost age in the 4th instar and approachedzero in host larvae that had gone beyond 37%of 4th stadium. The development time andthe final adult size of the parasitoid variedwith the host instar at initial parasitization.Parasitoids with initial parasitism in the4th instar hosts had the shortestdevelopment time, followed by those in the3rd instar, and then by those in the2nd instar. Parasitoids startingparasitism in 2nd instar hosts weresmaller in body size than those starting in the3rd or 4th instar. However, resultantfemales starting parasitism in 3rd instarhosts had the highest fecundity. Parasitizedlarvae exhibited longer development time andincreased food consumption compared withunparasitized ones. This study presents thefirst record that a solitary parasitoidregulates host behavior leading to an increasein food consumption by the host.     

饥饿对东亚飞蝗生长和取食的影响

研究了不同龄期东亚飞蝗Locusta migratoria manilensis(Meyen)的耐饥饿能力和3龄后的东亚飞蝗在不同饥饿程度下的取食量和取食速度。结果表明,东亚飞蝗的耐饥饿能力基本随龄期的增加而增强,平均耐饥饿时间为46～116h;同一龄期的东亚飞蝗,饥饿12h后的取食量和取食速度均大于正常情况,饥饿24h后的取食量和取食速度与正常情况下差异不显著,饥饿36、48h后的取食量和取食速度均明显小于正常情况;饥饿程度越大,取食量就越小,取食速度越慢。     

Rearing <Emphasis Type="Italic">Chrysoperla externa</Emphasis> Larvae on Artificial Diets

We tested three artificial diets for rearing larvae of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), aiming at reducing the production costs of this predator. Two of the diets come from studies with other species of lacewings, and the third is a modification described in this paper. All diets were based on animal protein and were supplied to 2nd and 3rd instar larvae, whereas 1st instar larvae received eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae). We evaluated the preimaginal duration and survival, adult size, longevity and fecundity, egg hatchability, and predatory capacity of larvae produced. The performance of the diets was followed for seven generations. The diet we describe showed to be the best among the artificial diets tested. Our results show that C. externa can be successfully reared on artificial diets during second and third instars, reducing in 90% the dependency on eggs of A. kuehniella.     

麻疯树蛀梢斑螟生物学特性观察及其防治药剂筛选

本文对攀西地区麻疯树(Jatropha curcasL.)人工林中的麻疯树蛀梢斑螟Oncocera faecella Zeller进行了生物学特性观察及其防治药剂筛选的研究。结果表明:该虫在攀西地区1年发生5代,每雌产卵量为(29±17.05)个,卵期(7±1)d,孵化率93.23%;幼虫共4龄,1、2龄取食量小,占整个幼虫生长阶段的10.6%,3、4龄幼虫取食量大,占整个幼虫生长阶段的89.4%;蛹期(13.11±1.05)d,雌雄比为1.04(F)∶1(M),羽化率88.96%。成虫寿命为6～8d。初孵幼虫仅取食叶肉,后缀嫩叶为害梢头,老熟幼虫在叶片上或枯枝落叶中织茧化蛹;以老熟幼虫越冬。对2龄和3龄幼虫进行防治药剂筛选,表明4.5%高效氯氰菊酯1.0×103mg·L-1和0.5×103mg·L-1、30%乙酰甲胺磷乳油0.5×103mg·L-1和0.25×103mg·L-1有很好的防治效果。     

温度对东亚飞蝗取食影响及其食物利用效率研究

本文采用对比称重法研究温度对东亚飞蝗Locusta migratoria manilensis(Meyen)取食及食物利用率的影响。结果表明:3～5龄蝗蝻在18、21、24、27、30℃5个温度梯度下发育历期为56.9、34.0、21.3、17.2、15.0d,总取食量为0.85、0.88、0.82、0.99、0.99g。在21、24、27、30℃4个温度梯度下,雄成虫寿命为90.3、62.8、47.0、38.7d,总取食量为3.62、4.67、4.25、4.26g;雌成虫寿命为95.8、63.0、46.3、40.8d,总取食量为6.97、10.48、10.41、11.90g。随温度升高3～5龄蝗蝻近似消化力减小,食物利用率增加;成虫期在18、30℃条件下近似消化力有显著差异(P<0.05),但不同温度下食物利用率差异不显著(P>0.05)。     

Reproductive biology of the microtype tachinid fly Zenillia dolosa (Meigen) (Diptera: Tachinidae)

Reproductive biology including mating, adult longevity, fecundity and development of the tachinid fly Zenillia dolosa was investigated for optimizing rearing procedures using Mythimna separata as a host in the laboratory. Females lay microtype eggs containing a first instar larva on food plants of the host and then the eggs must be ingested by the host for parasitization. Mating success was 58.5% with mating duration of 80.7 min. Mating was most successful when day 0–1 females were kept with day 2–4 male flies. Female body size was positively correlated with its fecundity but not with longevity. However, females that survived longer produced more eggs during their lifetime. Parasitoids successfully developed in 4th to 6th instar host larvae. Host instars at the time of parasitoid egg ingestion significantly influenced development time of the immature parasitoid, but did not affect body size of the emerging parasitoid. We suggest that pairing newly emerged females with day 2–4 males should result in higher mating success and using the last instar hosts for parasitization should minimize development time of the parasitoid for rearing.     

Laboratory studies of the biology and food requirements ofMacrorhaphis acuta [Hemiptera: Pentatomidae)

Macrorhaphis acuta were bred in the laboratory (25°C) and fed on larvae ofAscotis selenaria reciprocaria. The incubation period was 8.4 days and the mean hatch was 94.4%. There were 5 nymphal instars which occupied 3.3, 5.0, 5.6, 6.6 and 12.0 days, respectively, from the lst to the 5th. Each nymph consumed an average of 22.8 host larvae to complete development. Adults had a mean longevity of 74.9 days and each consumed an average of 67.5 host larvae. Significant reduction was noted in pupation of 5th instar host larvae sucked by adult predators for periods ranging from 4 to 10 mn. The food requirements of 3rd, 4th, and 5th instar nymphs fed on 3rd instar host larvae were also investigated. The conversion ratio varied with the weight of food consumed during the instar and later instars were more efficient than earlier ones. Predatory value did not vary significantly with successive instars.     

Developmental changes in dopamine levels in larvae of the fly Chymomyza costata: comparison between wild-type and mutant-nondiapause strains

Dopamine and two related catecholamines, L-3,4-dihydroxyphenylalanine (DOPA) and N-acetyl dopamine (NADA), were analyzed in whole body and tissue samples taken throughout late larval development of the drosophilid fly Chymomyza costata, which enters facultative diapause as a mature 3rd instar larva in response to short photophase. Wild-type (W) and mutant-nondiapause (M) strains reared under diapause inducing (d) and preventing (nd) photophases were compared. Developmental changes in the whole body of dopamine levels showed some general features irrespective of fly strain and rearing conditions: sharp major peaks during moult from second to third instar larva and during pupariation; lower minor peaks around the middle of both 2nd and 3rd instars. Significant differences between the strains and conditions were also found: dopamine levels were lower throughout the 2nd instar and during the 2nd to 3rd instar moult of mutant strain larvae (M/d) as compared to wild-type larvae (W/nd and W/d); while the late 2nd and late 3rd instar larvae destined to diapause (W/d) maintained relatively high dopamine concentrations, their counterparts destined to continuous development (W/nd and M/d) significantly decreased dopamine levels prior to the 2nd to 3rd instar moult or pupariation. Possible relationship between the dopamine levels and diapause induction/onset in C. costata larvae is discussed. Integument contained more than 90% of the dopamine found in the whole body. The gut and central nervous tissues showed relatively low pools of dopamine, only trace amounts were detected in haemolymph and no dopamine was found in fat body. DOPA levels were low and stable throughout larval development of both W and M strains and under both conditions. NADA levels peaked during second halves of 2nd and 3rd instars of both strains, then dropped to trace levels and were elevated again during 2nd to 3rd instar moult as well as in tanned prepupae. No elevation of NADA levels was recorded in 3rd instar W/d larvae which entered diapause.     

不同食料植物对美国白蛾生长发育和繁殖的影响

2010年6月至7月,在室内研究了美国白蛾Hyphantria cunea(Drury)第1代幼虫对洋白蜡、欧美107号杨、法桐和白榆的取食量及不同的食料种类对美国白蛾生长发育和繁殖的影响。结果表明,美国白蛾对受试的各树种的取食量以洋白蜡为最多,完成一代平均每头可以取食2.21 g,其次为欧美107号杨1.95 g,再次为法桐和白榆,分别为1.85 g/头和1.68 g/头。3龄后幼虫对不同的寄主呈现出一定的偏好性,特别是5龄和6龄幼虫对不同的寄主的取食量表现出显著差异。不同的食料植物对美国白蛾幼虫和蛹的发育历期、存活率、蛹重、成虫寿命、产卵量等有显著影响。取食法桐对其生长发育和繁殖表现出明显的不利性,主要表现为幼虫期延长、蛹重减轻、单雌产卵量降低。     

Growth and development of Encarsia formosa (Hymenoptera: Aphelinidae) in the greenhouse whitefly, Trialeurodes vaporariorum (Homoptera: Aleyrodidae): effect of host age

The tiny parasitoid wasp, Encarsia formosa, has been used successfully to control greenhouse whiteflies (GHWFs) in greenhouses in many countries throughout the world. Therefore, there has been considerable interest in developing methods for artificially rearing this wasp. However, little information is available concerning the regulation of its development including the host-parasitoid interactions that are required for the parasitoid to complete its life cycle. Here we confirm that parasitoid developmental rates differ significantly based upon the host instar parasitized. Development was faster when 3rd and 4th instar GHWFs were offered for parasitization than when 1st or 2nd instars were used. Our results show that it is primarily the embryo and the first two parasitoid instars that exhibit prolonged developmental times when 1st and 2nd instar whiteflies are parasitized. Although percent emergence was not affected by host age at the time of parasitization, adult longevity as well as adult emergence pattern varied greatly depending upon the instar parasitized. When 3rd and 4th instar GHWFs were selected for oviposition, adult wasps lived significantly longer than when 1st or 2nd instars were used; also, there was a sharp emergence peak on the 2nd day after emergence was first observed (reduced or absent when 1st or 2nd instar GHWFs were parasitized) and the emergence period was reduced from between 8 and 11 days to 5 days. In general, the younger the host instar parasitized, the less synchronous was parasitoid development. Previous reports that E. formosa will not molt to the 2nd instar until the host has reached its 4th instar were not confirmed. When 1st instar host nymphs were parasitized, 2nd instar parasitoids were detected in 3rd instar hosts. Importantly, however, no matter which instar was parasitized, the parasitoid never molted to its last instar until the host had reached Stage 5 of its last instar, a stage in which host pharate adult formation has been initiated. It appears, then, that a condition(s) associated with host pharate adult formation is required for the parasitoid's final larval molt. Results reported here should facilitate the development of in vitro rearing systems for E. formosa.