Pupal Parasitism Research Articles

Differential stratification, movement and parasitism of sexes of the bagworm, Thyridopteryx ephemeraeformis on redcedar

Abstract. 1. Male and female bagworm larvae develop and pupate at different heights on redcedar trees.2. Habitat segregation by height of male and female bagworms is apparent by the third instar, and results in part from differential movement of male and female larvae on redcedar foliage during their development. Females gradually ascend the crown, whereas males remain at the same height on the tree.3. Parasitism of male bagworm pupae was greater than for female pupae. Pupal parasitism is heaviest in the bottom of redcedar trees, where most male bagworms pupate.4. Several hypotheses are offered concerning the origin and maintenance of differential habitat utilization by male and female bagworms, despite apparently strong selection against males pupating low in the crowns of redcedar.

Ecology of Elasmopalpus lignosellus1 Parasite Complex on Peanuts in Texas2

Thirteen species of parasites were identified from Elasmopalpus lignosellus (Zeller) on peanuts in Texas. Means of 8.55, 5.21, and 4.98% parasitism were recorded from medium-larval, large-larval, and pupal stages, respectively, from 1975 to 1977. The dominant medium-larval parasite was Orgilus elasmopalpi Muesebeck (4.53% parasitism), followed by Apanteles sp. (1.46% parasitism), and Pristomerus spinator (F.) (0.73% parasitism). The dominant large-larval parasite was O. elasmopalpi (3.06% parasitism), with P. spinator (1.07% parasitism) second. The dominant pupal parasite was Invreia deceptor Grissell and Schauff (3.47% parasitism), with no pupal parasitism detected in the first generation. Parasites not previously reported from E. lignosellus include Orgilus nitidus Muesebeck, Macrocentrus sp., Agathis sp., and Geron aridus Painter. Parasitism was density independent and had little impact on E. lignosellus populations. Examination of all E. lignosellus parasite studies led to the conclusion that tachinid parasitism, an important component of E. lignosellus parasitism on many crops, is rare on peanuts. Restriction of tachinids from E. lignosellus parasites on peanuts is a result of larval behavior associated with plant growth form and larval feeding damage.

House Fly ( Musca domestica ) Control in Broiler-Breeder Poultry Houses by Pupal Parasites (Hymenoptera: Pteromalidae): Indigenous Parasite Species and Releases of Muscidifurax raptor1

Seven species of house fly pupal parasites, Spalangia cameroni Perkins, Muscidifurax raptor Girault and Sanders, S. endius Walker, S. nigroaenea Curtis, Pachycrepoideus vindemiae (Rondani), S, drosophilae Ashmead, and S. nigra Latreille, were recovered from fly pupae exposed in broiler-breeder poultry houses. S. cameroni and M. raptor ranked first and second, respectively, in overall relative abundance and together both species accounted for 91% of all parasites collected. Weekly sustained releases of an indigenous strain of M. raptor resulted in a significantly higher rate of house fly parasitism, concurrent with a significant reduction in the house fly population at the release farm in comparison to farms without parasite releases.

Observations on an Outbreak of the Palmerworm, Dichomeris ligulella Hüner, 1 in Southcentral Pennsylvania

The fifth reported epidemic of the palmerworm, Dichomeris ligulella Hubner (Lepidoptera: Gelechiidae), was studied in southcentral Pennsylvania in 1978. The influence of climate, larval and pupal parasitism, and disease was assessed with respect to population release and decline. Primary larval and pupal parasites included, respectively, one species of braconid wasp and two species of tachinid flies, and five species of ichneumonid wasps. All are new host records. Observations of larval and adult densities suggested that the outbreak palmerworm populations under study were limited primarily by adult mortality.

Field Estimation of the Functional Response of Itoplectis behrensii1 , a Parasite of the California Oakworm, Phryganidia californica2

The functional response of ltoplectis behrensii (Cresson), an epidemic pupal parasite of Phryganidia californica Packard, was estimated from field data involving various host densities on the trunks of coast live oak, Quercus agrifolia Nee. Pupal hosts were detected as uniformly distributed on the trunk surface at high host densities using a nearest neighbor index of dispersion. The number of parasitized pupae were recorded at 3-4 day intervals throughout host pupation for 4 consecutive P. californica generations. A second degree polynomial curve was fitted to observed % parasitization at different host densities at 14 day intervals. Most generated curves were significant (at 5% level) to observed data. Minimum thresholds of parasite response were between 1 and 2 pupae/m2 of trunk surface. Optimum host densities ranged between 6.6-13.2 pupae/m2. Maximum parasitization ranged between 20.3 and 55.2%. Host densities beyond the optium range showed a decreasing rate of parasitization indicating inverse density dependence. Based on the estimated functional response, I. behrensii is more efficient at lower host densities between the minimum threshold and the optimim range.

Invasion and Establishment of House Fly, Musca Domestica (Diptera: Muscidae), Parasites (Hymenoptera: Pteromalidae) in New Caged-Layer Poultry Houses1

Muscidifurax raptor, Spalangia undescribed sp. near drosophilae, S. cameroni, Pachycrepoideus vindemiae and Nasonia vitripennis invaded manure at new caged-layer poultry houses near Raleigh, North Carolina within 8 weeks after the chickens were placed in the houses. After these houses were in operation for 16 weeks. Spatangia endius and S. nigroaenea were also recovered. Spatangia nigra was the only parasite species new to the collections at these houses during the 2nd year of operation (1978). During the 2-year stLJdy, M. raptor, P. vindemiae and S. cameroni ranked 1st, 2nd and 3rd, respectively, in relative abun, dance of all parasites collected. M. raptor and P. vindemiae were abundam from June through November. S. cameroni was prevalent in late summer and fall, while the other Spalangia species and N. vitripennis were most abundant during the summer. Weekly sustained releases of a Florida strain of S. endius did not increase house fly pupal parasitism at these poultry houses; only 3 specimens of S. endius were recovered during 3 months (August-October) of releases of 18,000 parasites per week.

Sustained Releases of Muscidifurax raptor (Hymenoptera: Pteromalidae) for House Fly ( Musca domestica ) Control in Two Types of Caged-Layer Poultry Houses 1

An indigenous strain of Muscidifurax raptor Girault and Sanders, a house fly pupal parasite, was mass-reared and released at 2 caged-layer poultry farms, one with narrow (California) houses and one with a high-rise house, from May through Nov. 1978. Weekly releases of 40,000 parasites in the narrow caged-layer houses resulted in a significant increase in the overall rate of parasitism of house fly pupae during the fly season in comparison to similar farms without releases; and a 2-fold increase in both the rate of parasitism and the proportion of M. raptor in the parasite population from that of the previous year; while parasitism rates and M. raptor populations remained essentially unchanged at farms receiving no parasite releases. In the high-rise house, weekly releases of 40,000 M. raptor resulted in a significant increase in the rate of parasitism of house fly pupae in the latter half of the fly season and a higher proportion of M. raptor in the parasite population in comparison to similar farms receiving no parasite releases. Concurrent with parasite releases, a reduction in the fly population occurred in the narrow caged-layer houses; however, no reduction was evident in the high-rise caged-layer house.

Interrelationship between Two Species of Muscoid Flies and the Pupal Parasite Spalangia Endius (Hymenoptera: Pteromalidae)

When Spalangia endius was exposed to pupal house flies. Musca domestica, at host-parasite ratios of 0.5:1 through 25:1, the percentage of parasitism decreased and the number of parasitized pupae increased as the ratio of pupae to parasites increased. There were significant differences in the number of pupae parasitized per adult wasp, and the number of progeny produced per adult wasp associated with the ratio of host to parasite. There was a significant difference in the number of pupae parasitized per adult wasp associated with age of pupae at ratios above 1:5. i.e., more for 1- and 2-day-old than 3-day-old pupae. When S. endius was offered a choice of pupae of the house fly or the stable fly, Stomoxys calcitrans, the percentage of parasitism was similar to that obtained when house fly pupae or stable fly pupae were exposed to the wasps.

Effect of the Juvenile Hormone Analog Methoprene on Nasonia vitripennis1 When Administered Via a Host, Sarcophaga bullata2

Direct application of methoprene (Altosid SR-10®) to prepupae and pupae of Nasonia vitripennis (Walker) resulted in 100% mortality during the pupal stage. However, when the compound was administered by feeding it to its dipteran host, Sarcophaga bullata Parker, no effect on the parasite could be found. The number of wasps emerging from methoprene-treated hosts did not differ significantly from control hosts. Also, the fecundity of wasps reared on methoprene-treated hosts did not differ significantly from wasps reared on control hosts. As far as pupal parasites are concerned, it appears that methoprene is an ideal insect growth regulator for an integrated control program against Diptera breeding in livestock manure.

Larval and pupal parasites ofLymantria dispar and notes on parasites of otherLymantriidae [Lep.] in Poland 1975

Larvae and pupae ofLymantria dispar (L.) were collected periodically from infestations on Linden trees at Nieborow near Skierniewice and at Alexandrowa, south of Poznan, Poland during May–July 1975. The following parasites were recovered:Braconidae: Apanteles liparidis (Bouche),A. melanoscelus (Ratzeburg),A. porthetriaeMuesebeck,Meteorus pulchricornis (Wesmael);Ichneumonidae: Coccygomimus instigator (F.),Hyposoter tricoloripes (Viereck),Phobocampe n. sp.,P. disparis (Viereck);Tachinidae: Blepharipa pratensis (Meigen),Blondelia nigripes (Fallen),Carcelia separata (Rondani),Compsilura concinnata (Meigen),Parasetigena silvestris (Robineau-Desvoidy),Palexorista sp. Similar but less extensive collections were made of larvae ofOrgyia antiqua (L.). These yieldedApanteles sp.,A. melanoscelus, Tramosema rostrale (Brischke),Meloborus sp.,B. nigripes andP. silvestris; larvae ofLeucoma salicis (L.) yieldedA. melanoscelus andMeteorus versicolor (Wesmael). OnlyBlondelia sp. was recovered from the few larvae ofPorthesia similis (Fuessly) collected.

Sex ratio, pupal parasitism, and predation in two declining populations of the bagworm, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera: Psychidae)

Abstract. 1. Two populations of bagworms were censused in Ohio for 6 and 5 years respectively, to determine the influence of major pupal mortality factors. Bagworm densities declined from 2.3 bags per 30 cm of terminal branch to zero.2. No single key mortality factor was identified in population trends. Parasitic Hymenoptera were common but variable in effect. Avian predation may have been important in reducing one population, while the other was exterminated after a drastic change in sex ratio to favour males.

The Parasite Complex of the Forest Tent Caterpillar 1 in Northern Minnesota 2

The parasites of the forest tent caterpillar, Malacosoma disstria Hübner, were studied during the last 6 yr of the 1964–72 outbreak in northern Minnesota. Egg parasitism, only ca. 4–10%, involved 3 species: Telenomus clisiocampae Riley, Ooencyrtus clisiocampae (Ashmead), and Tetrastichus silvaticus Gahan. Twenty-five hymenopterous species and 13 dipterous species were reared from the larvae and pupae of the forest tent caterpillar. Six of the hymenopterous species were hyperparasites, while 6 of the dipterous species were scavengers. Rogas sp. was the only early larval parasite. The most abundant late larval parasites were Patelloa pachypyga (Aldrich and Webber), Leschenaultia exul (Townsend), Lespesia frenchii (Williston), and Trichonotus analis (Say). Pupal parasitism was highest on cocoons from the ground level and progressively lower in the shrub and crown levels. Pupal parasitism increased with age of the infestation until 1968, decreased significantly in 1969, then increased again until the population collapsed in 1972. Sarcophaga aldrichi Parker and tachina flies accounted for 98% of all parasitism in the late cocoon collection during 1967–71 except in 1970. S. aldrichi destroyed all other parasites in the pupae and became the over-whelmingly dominant parasite in pupae after the 1st year of heavy infestation. Itoplectis conquisitor (Say) was common during the 1st year of heavy infestation. Otherwise, ichneumon wasps were rare in the late cocoon collections except in areas at the edge of the outbreak. The biology and individual patterns of parasitism during the outbreak are discussed for the common parasites.

Reproduction of Spalangia endius, Muscidifurax raptor and M. zaraptor on Fresh vs. Refrigerated Fly Hosts

A comparison of the suitability of fresh, 24- to 30-h-old, Musca domestica L. pupae and pupae which had been refrigerated at 10° C for 21 days for propagation of 3 pupal parasites, Spalangia endius Walker, Muscidifurax raptor Girault and Sanders, and M. zaraptor Kogan and Legner, showed that nonrefrigerated pupae were preferred. Estimates of the net reproductive rates were 12.5, 12.2, and 9.0% greater on fresh hosts for these 3 species, respectively. For practical mass production, these differences may not be important, as biomass of ensuing adult parasites was not significantly affected. Consideration of the intrinsic rate of natural increase for the 3 species indicated that only a small % of these parasites’ annual autumnal decline in parasitization activity can be attributed to the appearance of naturally cooled hosts. Parasite host destruction appeared largely uninfluenced by the refrigeration process.

A revision of Tachinaephagus Ashmead (Hymenoptera: Encyrtidae) with descriptions of four new species

AbstractThe encyrtid genus Tachinaephagus is revised, and a key to species presented. Four species are described and illustrated: T. stomoxicida sp. n., a very important parasite of Stomoxys nigra Macq. from Uganda and Mauritius; T. malayensis sp. n. from Malaysia; T. javensis sp. n. from Indonesia; and T. congoensis sp. n. from Zaïre. A lectotype is designated for T. zealandicus Ashm., the type-species of Tachinaephagus, and this genus as defined here is restricted to larval and pupal parasites of Diptera. Zeteticontus, which is superficially similar, is in fact distinct, and characters separating the two genera are tabulated.

Zur Parasitierung der Puppen von Forleule (Panolis flammea [Schiff.]), Kiefernspanner (Bupalus piniarius [L.]) und Heidel‐beerspanner (Boarmia bistortata [Goeze]) in bayerischen Kiefernwäldern1

AbstractOn the pupal parasites of the Pine Beauty (Panolis flammea [Schiff.]), the Pine Looper (Bupalus piniarius [L.]) and of Boarmia bistortata (Goeze) in Bavarian pine forestsIt was attempted to investigate, if economically indifferent hosts can be important as “reservoirs” of the parasites of dangerous pest insects and to get some insight into the cross‐relations between hosts and parasites in the pine forest. Some theoretical remarks on the biology of insect‐parasites (= parasitoids) are brought forward, especially a division of these into “idiophytic” species (consuming the host as it is when attacked) and “koinophytic” parasites (feeding for considerable time on the host when this itself is feeding). From these aspects the different species of the parasites and the parasite ranges of the hosts are discussed.The most important of the (idiophytic) pupal parasites are common to all three of the investigated hosts, but most of the (koinophytic) larval parasites are peculiar to one of them. ‐ In Panolis several pupal parasites are of approximately equal importance, whereas in the two Geometrids one of their pupal parasites is largely dominating, Rictichneumon pachymerus in the case of Boarmia, Cratichneumon nigritarius in that of Bupalus. ‐ As pupae of Boarmia are available almost throughout the year the idiophytic pupal parasites can follow an outbreak of this species, though their development is not synchronized with that of the host. With Panolis and Bupalus the idiophytic pupal parasites are usually predominating in periods of low host‐density. During outbreaks, however, they are often largely outnumbered by koinophytic parasites of the larvae, whose development is coordinated with that of the hosts. ‐ Boarmia bistortata can serve as a “parasite‐reservoir” of forest pests only in respect to idiophytic parasites. As such it may have some effect in preventing outbreaks of the pest, but can not have great influence on the termination of such an outbreak.

A Model to Simulate Control of House Flies 1 with a Pupal Parasite, Spalangia endius2

A model was developed that describes the interaction between a pest insect, the house fly, Musca domestica L., and a wasp, Spalangia endius Walker, a parasite of house fly pupae. The model is based on life history studies of both insects in the laboratory and in the field. With this model, densities of both insects can be simulated by computer techniques, and the degree of control of house flies that can be obtained by release of the parasite can be studied. The simulation is based principally upon 4 life history parameters: survival of adult females; survival of immature forms; developmental times for immature forms; and fecundity and egg-laying patterns of adult females. Simulations showed that high level control of house flies can be expected by the sustained release of the parasites, a result in agreement with the results of field tests. The simulations were therefore used to study the effects of varying the rate and pattern of parasite releases on house fly density reduction.

Larval and Pupal Parasites of the Oak Leafroller, Archips semiferanus12

Parasitism of Archips semiferanus (Walker) larvae in Pennsylvania became appreciable in early June (18.0–63.1%), which coincides with the appearance of 5th instars. Dipteran parasitism of the larvae is major (16.9–57.7%), while hymenopteran parasitism is minor (1.1–5.4%). Conversely, dipteran parasitism of the pupae is minor (0.72–2.6%) and hymenopteran parasitism is major (3.5–32.3%). Twenty-two parasites have been recovered from larvae and pupae samples, 16 of which are new host records. The major larval parasite is Lypha setifacies (West) and the major pupal parasite is Itoplectis conquisitor (Say).

INFLUENCE OF RESISTANT AND SUSCEPTIBLE MAIZE INBRED LINES ON THE BIOLOGY OF THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS (LEPIDOPTERA: PYRALIDAE), AFTER NATURAL OVERWINTERING CONDITIONS IN SOUTHWESTERN QUEBEC

AbstractForty exotic maize inbred lines from 10 countries with known resistance or susceptibility to the European corn borer, Ostrinia nubilalis (Hübner), were used to study the effect of plant resistance on borer survival from natural overwintering conditions and particularly the fecundity of the female moth during the following summer. Also, additional information was obtained on different biological characters of the insect. Resistant and susceptible lines were grouped according to their leaf feeding ratings (antibiosis), per cent borer survival at pollination time or at harvest (tolerance). Each specimen observed was kept on the same plant tissue until pupation. The number of eggs and egg masses/female was significantly higher only when lines are grouped according to their leaf feeding ratings. No significant differences were obtained in most biological characters of borers fed on resistant or susceptible maize lines: spring pupation, pupal parasitism, mortality and weight, moth emergence and sex ratio.

Parasites, predators and other arthropods associated withMusca domestica and other flies breeding in bovine manure

The species of flies breeding in bovine manure, their parasites and predators as well as other associated arthropods in 3 localities in and near Bangalore are recoreded. The flies areMusca domestica L.,Musca pattoniAusten,Stomoxys calcitrans L.,Physiphora aenea F.,Physiphora demandata F.,Sargus metallinus F.,Sepsis thoracica R.-D.,Sepsis nitensWiedemann,Sphaerocera scabriculaHal, andLeptocera (Coproica) hirtulaRondani. Four species of hymenopterous pupal parasites of these flies have been obtained:Spalangia cameroniPerkins from pupae ofM. domestica, M. pattoni, S. calcitrans, P. aenea andP. demandata; Spalangia endiusWalker from pupae ofM. domestica, M. pattoni andS. calcitrans; Spalangia nigroaeneaCurtis from pupae ofM. domestica andS. calcitrans; andDirhinus trichiophthalmusMasi from pupae ofSargus metallinus F. Percentage parasitism of fly puparia in field samples was noted. Four species ofHister andAleochara puberulaKlug feeding on various immature stages ofM. domestica, 2 species of scarabaeid beetles, 2 species of ants and a pseudoscorpion were also found in the manure. The importance of biotic regulatory factors in the control of flies is discussed.

Biology and Behavior of the Spear-Marked Black Moth, Rheumaptera hastata, in Interior Alaska1

The spear-marked black moth, Rheumaptera hastata (L.), is a geometrid defoliator of birch in the northern United States, Canada, and Alaska. An outbreak occurred in interior Alaska from 1974-75 over an area of 2.7 million acres. Adult moths are black and white in color and emerge in early June from the overwintering pupal stage. Oviposition occurs in early June, and the larval stage extends from mid-June-mid-August. Pupation begins the latter part of July in the leaf litter. Pupal parasitism and several larval diseases accounted for a 90-95% decline in the population in August 1975.