Notes on the taxonomy and nomenclature ofAphidius species [Hym.: aphidiidae] parasitic on the pea aphid in North America

A brief discussion is given on the taxonomy, nomenclature, distribution, and hosts of severalAphidius species attacking the pea aphid,Acyrthosiphon pisum (Harris), in North America.Aphidius pisivorus Smith,A. smithi S. & S. R., andA. ervi Hal. are considered distinct species attacking the pea aphid;A. nigripes Ashm. is shown not to be a parasite of the pea aphid;A. pulcher Baker is placed in synonymy withA. nigripes. Distinguishing characters for each species are illustrated.     

Geographical distribution ofAphidiidae [Hym.] imported to California for biological control ofAcyrthosiphon kondoi andAcyrthosiphon pisum [Hom.: Aphididae]

A survey forAcyrthosiphon kondoi Shinji and its insect enemies was conducted in 1976–1977 in Afghanistan, Belgium, Czechoslovakia, Greece, Iran, Israel and Maroc. The search was concentrated in areas having cultivated species ofMedicago. A. kondoi was found only in Afghanistan, and in Iran. It was not found inMedicago-growing areas west from Iran, but it has been reported from India and Japan. Aphidius ervi Haliday,Aphidius urticae group,Praon barbatum Mackauer andAphidius smithi Sharma & Rao, were reared fromA. kondoi constituting new parasite records. New parasite and locality records were also found forA. urticae group,A. smithi andP. barbatum onAcyrthosiphum pisum (Harris). In laboratory trials, all cultures of parasitesA. ervi andP. barbatum readily parasitized and reproduced onA. kondoi onLens esculenta Moench. Cultures ofA. urticae group andA. smithi oviposited on, but did not complete development of immatures in,A. kondoi onL. esculenta. Hyperparasites identified as species includedAsaphes suspensus (Nees),Asaphes vulgaris Walker,Aphidencyrtus aphidivorus (Mayr),Dendrocerus breadalbimensis (Kieffer),Dendrocerus carpenteri (Curtis), andPachyneuron aphidis (Bouche). Available data suggest the origin of distribution ofA. kondoi may be Central Asia, and that populations ofA. ervi may be most suitable for colonization programs againstA. kondoi.     

Influence of temperature on the oviposition rate and longevity ofOpius concolor siculus [Hymenoptera: Braconidae]

The author has studied the influence of different temperatures (22°, 24°, 26°, 28°C) on oviposition and longevity ofOpius concolor siculus Mon., studying separately 13 couples at 22°, 15 at 24°, 100 at 26° and 11 at 28°C. The optimum temperature has been found to be 26°C. Differences have been observed betweenO. concolor Szepl. «African» andO. concolor siculus Mon. «Sicilian».     

Comparative biological studies on two species of predatory beetles of the genusCybocephalus [Col.: Cybocephalidae]

The development, reproduction and longevity ofCybocephalus micans Reitter andC. nigriceps nigriceps (Sahlberg) were studied under controlled laboratory conditions. The data obtained explain the distribution of the 2 predators in different climatic regions of Israel. Under constant temperatures ranging between 16° and 36° C, the duration of development of the egg. larva and pupa of the 2 species became shorter as the temperature increased. For each developmental stage, at each temperature tested, the mean duration of development ofC. n. nigriceps was higher than that ofC. micans. The average time needed for completion of a generation at 28° C was about 39 days forC. micans, as compared with 56 days forC. n. nigriceps. Progeny production of both cybocephalid species was higher and adult longevity was longer at 28° C than at 32° C.     

Biology ofclausicella suturata [Dipt.: Tachinidae] a parasite ofEctomyelois ceratoniae [Lep.: Phycitidae]

The tachinid flyClausicella suturata Rondani is a solitary parasite ofEctomyelois ceratoniae (Zeller). It was grown under laboratory conditions (26±0.5°C, 55±5% R.H.) and the host-parasite relationships were studied. The different stages of the parasite were briefly described. The eggs are deposited on the carob (Ceratonia siliqua L.,Caesalpiniaceae) pods, near the openings of the host's tunnels and hatch immediately. The Ist instar maggot is directed by the web fibers of the host towards the caterpillar which is hidden in the carob pod. The parasites develop normally only in 4th and 5th instar caterpillars. The parasitized caterpillar spins its cocoon inside the carob pod before being killed by the parasite. The fully grown maggot leaves the host and pupates inside its cocoon. Adult longevity is dependent upon the presence of carbohydrate in the diet. Maximal male and female longevity (50% survival of 21 and 17.5 days respectively) was reached on a carbohydrate diet and water, at 26°C and 55% R.H. Newly emerged females readily mate with one or two-day old males. The average fecundity of a female is 202 eggs, deposited during 13.6 days, after an incubation period of 6.9 days. Superparasitism is common in nature but only one maggot is successful in completing its development.     

Biology of the flea beetle,Altica carduorum [Col.: Chrysomelidae] on Canada thistle (Cirsium arvense) in South Dakota

A laboratory colony of 50 adults ofAltica carduorum Guérin-Méneville was established at South Dakota State University. Beetles reared in this colony had an average preoviposition period of 7 days when exposed to a regular cycle of 16 hr of light (24°C) and 8 hr of darkness (12.7°C). The laboratory reared females, whose longevity averaged 100 days, laid an average of 259.3±9.7 eggs. High temperatures and/or low RH are limiting factors to beetle survival. In the field eggs were laid throughout June on the underside of leaves along the edges of the veins. Adults fed throughout the summer and then over-wintered in the soil. Some of these beetles emerged the following spring and laid viable eggs. Factors limiting establishment in South Dakota, however, were high temperatures, low humidities, and the predators,Lebia viridis Say andHarpalus pennsylvanicus Degeer.A. carduorum originates from the Swiss Rhône valley where there is a relatively “continental” climate, but is limited to special habitats where comparatively high humidity occurs. South Dakota climate is characterized by cold winters, and hot, dry summers, therefore establishment would be most difficult.     

Longevity and reproductive rate ofPatasson lameerei [Hym.: Mymaridae], a parasitoid ofSitona spp. [Col.: Curculionidae] eggs

Patasson lameerei DeBauche produced an average of 28.5 offspring under 2 temperature regimes usingSitona hispidulus (Fabricius) eggs as hosts. Although its fecundity was not affected by the temperature regimes,P. lameerei lived significantly longer at 6.7/18.3°C than at 21.1°C. When ample hosts were available,P. lameerei produced more offspring during the 1st few hours of its adult life than during any other comparable period. When the parasitoids were denied access to host eggs for 1,2, or 3 days after emergence, they still produced similar numbers of offspring during their 1st 24 h exposure to hosts.     

Biology ofIphiaulax kimballi [Hym.: Braconidae], a parasite ofDiatraea grandiosella [Lep.: Pyralidae]

Iphiaulax kimballi Kirkland is a gregarious ectoparasite of the mature larval stage ofDiatraea grandiosella Dyar in Mexico. The developmental rate from egg to adult is 16.3±1.0 (x±S.D.) at 29°C. The sex ratio is 1.7∶1 (♀∶♂) in the field. Following host paralysis the female deposits 63.5±2.1 eggs during der 28.6±6.4 day adult-life span; laying 4.6±3.1 eggs on each host. Females held at 10°C lived a maximum of 3 months.     

Mechanical transmission of beet yellows virus toChenopodium quinoa Willd. andChenopodium foliosum (Moench) Asch.

Beet yellows virus (BYV) was mechanically transmitted by sap from sugar-beet plants, infected with BYV, to the plants ofChenopodium quinoa Willd. and ofChenopodium foliosum (Moench) Asch. Mechanical transmission of BYV to the plants ofTetragonia expansa Murr. failed. Infectious material was homogenized in phosphate buffer with veronal and EDTA, pH 7–8. Experimental plants were darkened three days before infection and kept at a temperature of 5°C. Plants ofC. quinoa Willd. were decapitated. Back transmissions fromC. quinoa Willd. andC. foliosum (Moench) Asch. infected with BYV, to sugar-beet plants were carried out by the aveidMyzus persicae Sulz. These transmissions were positive. Filamentous particles of BYV, of an average length 1275 nm, were found in plants ofC. quinoa Willd. andC. Foliosum (Moench) Asch., infected with BYV.     

Behavior,net reproduction,longevity, and mummy-stage survival ofAphidius matricariae [Hym. Aphidiidae]

The courtship, mating and ovipositional behavior ofA. matricariae Haliday were studied. UsingMyzus persicae (Sulzer) as the host, the production of progeny per female parasite and survival from mummy stage to the adult were studied at constant temperatures of 10°, 12.8°, 15.6°, 18.3°, 21°, 24°, 26.7°, 29.5° and 32°C. The longevity of male and female parasites was determined at temperatures of 7°, 10°, 15.6°, 21°, 26.7°, 29.5° and 32°C. The greatest number of progeny (392) was produced at 21°C. The optimal temperatures for production of progeny and survival of the parasites during the mummy stage were from 12.8°C to 21°C. The longevity of male and female adult parasites decreased as temperatures increased and male parasites lived significantly (P<0.05) longer than females at 10° and 15.6°C.     

Biotransformation of l-ornithine from l-arginine using whole-cell recombinant arginase

A recombinant arginase was generated for a whole-cell biotransformation system to convert l-arginine to l-ornithine in Escherichia coli. The gene ARG1 coding arginase from Bos taurus liver was synthesized and expressed in E. coli BL21 (DE3) via pETDuet-1. The recombinant arginase was used to catalyze l-arginine to l-ornithine and urea. The reaction was optimal at pH 9.5 and 37 °C. Manganese (10^?5 M) and Emulsifier OP-10 [0.033 % (v/v)] could promote arginase activity. In a scale up study, l-arginine conversion rate reached 98 % with a final concentration of 111.52 g l-ornithine/l.     

d-Tagatose production in the presence of borate by resting Lactococcus lactis cells harboring Bifidobacterium longum l-arabinose isomerase

Bifidobacterium longum NRRL B-41409 l-arabinose isomerase (l-AI) was overexpressed in Lactococcus lactis using a phosphate depletion inducible expression system. The resting L. lactis cells harboring the B. longum l-AI were used for production of d-tagatose from d-galactose in the presence of borate buffer. Multivariable analysis suggested that high pH, temperature and borate concentration favoured the conversion of d-galactose to d-tagatose. Almost quantitative conversion (92 %) was achieved at 20 g L^?1 substrate and at 37.5 °C after 5 days. The d-tagatose production rate of 185 g L^?1 day^?1 was obtained at 300 g L^?1 galactose, at 1.15 M borate, and at 41 °C during 10 days when the production medium was changed every 24 h. There was no significant loss in productivity during ten sequential 24 h batches. The initial d-tagatose production rate was 290 g L^?1 day^?1 under these conditions.     

Characterization of a recombinant l-fucose isomerase from Caldicellulosiruptor saccharolyticus that isomerizes l-fucose, d-arabinose, d-altrose, and l-galactose

A recombinant l-fucose isomerase from Caldicellulosiruptor saccharolyticus was purified as a single 68 kDa band with an activity of 76 U mg^?1. The molecular mass of the native enzyme was 204 kDa as a trimer. The maximum activity for l-fucose isomerization was at pH 7 and 75°C in the presence of 1 mM Mn²⁺. Its half-life at 70°C was 6.1 h. For aldose substrates, the enzyme displayed activity in decreasing order for l-fucose, with a k _cat of 11,910 min^?1 and a K _m of 140 mM, d-arabinose, d-altrose, and l-galactose. These aldoses were converted to the ketoses l-fuculose, d-ribulose, d-psicose, and l-tagatose, respectively, with 24, 24, 85, 55% conversion yields after 3 h.     

Development ofLydina polidoides [Diptera: Tachinidae] in relation to its hostChrysoteuchia topiaria [Lepidoptera: Pyralidae]

Lydina polidoides (Townsend) andChrysoteuchia topiaria Zeller were studied in the laboratory. The rate of development ofC. topiaria from eclosion to the diapausing prepupae was 55 days when larvae were exposed to long daylenghts (16 hr light, 8 hr dark) and 43 days when exposed to short daylengths (12 hr light 12 hr dark.) The same insects exposed to long days emerged as adults in 124 days, whereas those exposed to short days emerged in 156 days because short days prepared the prepupae for diapause but failed to maintain the diapause. When caterpillars (prepupae) ofC. topiaria parasitized by young larvae ofL. polidoides and non-parasitized caterpillars were removed from the field in January and exposed to long days at 21°C,C. topiaria emerged as adults in an average 55 days andL. polidoides in 106 days.Lydina polidoides is therefore univoltine andC. topiaria is probably the primary host of this Tachinid parasite.     

Indian species of the genusMirufens [Hym.: Trichogrammatidae]

An account is given of 4 new species ofMirufens Girault:M. brevifuniculata Khan & Shafee, M.albiscutellum Khan & Shafee,M. magniclavata Khan & Shafee andM. longiclavata Khan & Shafee. A key to Indian species of the genusMirufens is also provided.     

Lethal temperatures of citrus blackflyAleurocanthus woglumi [Hom.: Aleyrodidae] and its parasite,Amitus hesperidum [Hym.: Platygasteridae]

Seasonally acclimatized citrus blackfly (CBF),Aleurocanthus woglumi Ashby, and its parasite,Amitus hesperidum Silv. were exposed to extreme temperatures for 3-hour periods and survivorship measured. In summer experiments, the LD₅₀ for CBF adults and 1st instar nymphs occurred between 40° and 45°C. The LD₅₀ forA. hesperidum adults occurred between 35° and 40°C and increased with decreased humidity, although some adults could continue to emerge from parasitized CBF up to 45°C. In winter experiments, the LD₅₀ for CBF eggs and adults occurred between ?5° and ?10°C and for other CBF stages between ?10° and ?15°C. The LD₅₀ for adultA. hesperidum, and survival and emergence of the parasites from CBF both occurred between ?10° and ?15°C. Comparing data from the 2 seasons shows that adults are the most temperature sensitive stage of CBF and the parasite is more temperature sensitive than CBF, especially at higher temperatures. Correlating lethal temperature data with field meteorological conditions shows that short-term temperature exposures cannot be expected to stop the potential spread of CBF orA. hesperidum through Florida.     

Mortality factors of satin moth,Leucoma salicis [Lep.: Lymantriidae], in aspen forests in Maine

Natural control agents of the satin moth,Leucoma salicis (L.) were examined in 2Populus grandidentata Michaux stands. Highest mortality occurred in overwintering larvae, with the causal agents 2 fungi,Paecilomyces sp. andHirsutella gigantea Petch, a factor causing death symptomatic of a pathogen, the parasiteEupteromalis hemipterus (Walker) and death from unknown causes. Mortality fromPaecilomyces sp. andE. hemipterus was reduced where overwintering sites were covered with burlap cloth. Parasites recovered from larvae and pupae included the braconidsApanteles melanoscelus (Ratzeburg) andMeteorus versicolor (Wesmeal), the ichneumonidCoccygomimus pedalis (Cresson), the tachinidsCompsilura concinnata (Meigen),Carcelia laxifrons Villeneuve,Tachinomyia variata Curran, and the sarcophagidsSarcophaga aldrichi Parker andAgria housei Shewell. Larval and pupal predators included the carabidCalosoma frigidum Kirby, pentatomids, and birds, particularly black-billed cuckoos,Coccyzus erythrophthaimus (Wilson). Eggs were parasitized by the scelionidTelenomus prob.californicus Ashmead and the trichogrammidTrichogramma minutum (Riley). Predators of adult satin moths included the hermit thrush,Hylocichla guttata (Pallas), and pentatomid bugs.     

A d-psicose 3-epimerase with neutral pH optimum from Clostridium bolteae for d-psicose production: cloning, expression, purification, and characterization

d-Tagatose 3-epimerase family enzymes can efficiently catalyze the epimerization of free keto-sugars, which could be used for d-psicose production from d-fructose. In previous studies, all optimum pH values of these enzymes were found to be alkaline. In this study, a d-psicose 3-epimerase (DPEase) with neutral pH optimum from Clostridium bolteae (ATCC BAA-613) was identified and characterized. The gene encoding the recombinant DPEase was cloned and expressed in Escherichia coli. In order to characterize the catalytic properties, the recombinant DPEase was purified to electrophoretic homogeneity using nickel-affinity chromatography. Ethylenediaminetetraacetic acid was shown to inhibit the enzyme activity completely; therefore, the enzyme was identified as a metalloprotein that exhibited the highest activity in the presence of Co²⁺. Although the DPEase demonstrated the most activity at a pH ranging from 6.5 to 7.5, it exhibited optimal activity at pH 7.0. The optimal temperature for the recombinant DPEase was 55 °C, and the half-life was 156 min at 55 °C. Using d-psicose as the substrate, the apparent K _m, k _cat, and catalytic efficiency (k _cat/K _m) were 27.4 mM, 49 s^?1, and 1.78 s^?1 mM^?1, respectively. Under the optimal conditions, the equilibrium ratio of d-fructose to d-psicose was 69:31. For high production of d-psicose, 216 g/L d-psicose could be produced with 28.8 % turnover yield at pH 6.5 and 55 °C. The recombinant DPEase exhibited weak-acid stability and thermostability and had a high affinity and turnover for the substrate d-fructose, indicating that the enzyme was a potential d-psicose producer for industrial production.     

Parasites ofColeophora laricella larvae in newfoundland [Lep.: Coleophoridae]

A total of 15 species of parasites have been reared from the larch casebearerColeophora laricella (Hübner), in Newfoundland, but only 2 species,Agathis pumila (Ratzeburg) andChrysocharis laricinellae (Ratzeburg), are common. Both of these species had been introduced in the late 1940's for the biological control of the casebearer. The chalcid,C. laricinellae, was the more common parasite till the early 1970's, but since then the braconid,A. pumila, has become the most dominant, parasitizing up to 80% of the host larvae. It appears thatA. pumila is the most promising biological control agent present in Newfoundland.