Showing papers on "Lepidoptera genitalia published in 1984"

An improved procedure for laboratory rearing of the corn earworm, Heliothis Zea (Lepidoptera:Noctuidae).

Abstract: An improved method for the laboratory rearing of the corn earworm. Heliothis IS described. The rearing medium is a modification of the commonly used wheat germ An oviposition chamber, a feeder for adults, and a simple and inexpensive contrnlled humidity chamber are described. The corn earworm, Heliothis zea (Boddie), is often used as a laboratory animal and is one of the most important insect pests in North America. The rearing procedure outlined below is based in part on the techniques of Berger (1963), Ignoffo (1965). and Young et al. (1976). The artificial diet used here is a lineal descendant of the wheat germ medium first developed by Adkisson et al. (1960) for rearing the pink bollworm, Pectinophora gossypiella (Saunders). This medium was subsequently modified for use with Heliothis zea by Vanderzant et al. (1962), Berger (1963), and Ignoffo (1966). We have made a few additional modifications, largely following Kogan and Parra's (1981) soybean looper diet. Up to now we have reared 34 sueeessive generations of H. zea using this procedure. PHYSICAL CONDITIONS DURING REARING The larvae are held in an environment chamber at 2SoC and a 16:8 light:dark photoperiod to prevent the induction of diapause. There is no need to control humidity externally because the larvae, confined in closed cups on a moist diet, are already in a sufficiently humid microenvironment. pupae, and adults are held in controlled humidity chambers (Fig. 1) in a rearing room at 2SoC and a 16:8 Jight:dark photoperiod. The relative humidity (Lh.) in the chamber is kept at about 70%. Maintenancc of a high r.h. is important becausc the insects otherwise desiccate and die prematurely. Adults in dry conditions, for example, often die without laying eggs. This problem is especially acute in northern climates where the r.h. may be as low as 1~20% in heated buildings in the winter. The humidity chamber (Fig. I) is 1.35 m tall by 1.47 m long by 0.54 m wide. It consists of a welded 3 cm angle-iron frame covered top and sides with transparent sheet plastic held on with masking tape. The underside of the chamber fits flush against the floor. The entire expanse of the front opens through two hinged doors. Three shelves of expanded metal, held by adjustable shelf brackets, permit the passage of air. Moisture is provided by a 38 by 49-cm plastic pan of deionized water in the bottom of the chamber with a small blower directed at its surface. The blower is clamped to one of two 1.3-cm diameter steel rods that extend from top to bottom in the middle of the ehamber. The percent r.h. is controlled by covering or uncovering two rows of 18 I.S-cm wide circular holes on each end of the plastic top. These holes are easily made with a heated cork borer. During the scotophase an \"artificial moon\" must be provided because the moths will neither mate nor lay eggs in complete darkness. The \"moon\" is a IS W light bulb in a IDepartment of Entomology, University of Illinois, Urbana, IL 61801. 1 Waldbauer et al.: An Improved Procedure for Laboratory Rearing of the Corn Earworm, Published by ValpoScholar, 1984 114 THE GREAT LAKES Er-.'TOMOLOGIST VoL 17, No.2

Trichoplusia ni (Lepidoptera: Noctuidae) Larval Development on Wild and Cultivated Plants

Abstract: Twenty-one plant families (44 species) were tested as suitable hosts for development of the cabbage looper, Trichoplusia ni (Hubner). Of these, 32 species supported development from fourth instar to adult. However, complete development (first instar to adult) occurred in only 15 species. Development from first or fourth instar to adult occurred on 20 hosts not previously reported; thus indicating survival on substitute hosts which could take place in the loss of their preferred cultivated hosts or if these host plants became undesirable.

Nestling foods of the savannah sparrow

Abstract: The diet of savannah sparrow (Passerculus sandwichensis) nestlings was monitored at Isle Verte, Quebec, during the 1980 breeding season. Adults carried exclusively arthropods to the nest. The main prey types found were Lepidoptera and Hymenoptera larvae, larval and adult Diptera and Homoptera. The proportion of different prey types in the diet varied during the season but there was no close relationship between temporal changes in the indices of prey abundance in the habitat and the type of prey chosen by the adult birds. Both the type and size of prey brought to the nest changed with the age and number of nestlings (aged 4–10 days). The proportion of Homoptera in the diet decreased sharply with age while that of Lepidoptera and Diptera increased. Adults feeding broods of four brought a larger proportion of large prey items (Lepidoptera and Hymenoptera larvae) than those feeding broods of a lesser size; to these they brought a larger proportion of smaller items such as Diptera and adult Lepidoptera. Males...

Production and use of secretions passed by males at copulation in pieris protodice (lepidoptera, pieridae)

Abstract: During copulation in many species of insects the male passes to the female sizeable quantities of accessory gland secretions with the sperm (Thornhill and Alcock, 1983). Recently it has been shown in the Lepidoptera that these secretions may represent a nutrient investment by the male that is used by the female in the production of eggs and in somatic maintenance (Boggs and Gilbert, 1979; Boggs, 1981; Boggs and Watt, 1981; Goss, 1977; Greenfield, 1982). Typically these secretions are contained within a spermatophore with the sperm or they may be passed as loose secretion. The perspective that these secretions may constitute a nutrient investment by males has some important implications for how male and female lepidopterans should behave (Marshall, 1982; Rutowski, 1982; see also, Gwynne, 1982). In spite of recent interest in these secretions there are few studies of the patterns of their production and use within and between species of Lepidoptera (e.g., Boggs, 1981; Greenfield, 1982; Rutowski et al., 1983). This paper reports data on patterns of variation in the quantity of material passed to females during copulation by males of the checkered white butterfly (Pieris protodice Boisduval and LeConte) and the disappearance of these secretions from the female’s reproductive tract. The secretions are received by the female in the bursa copulatrix which in this butterfly species is composed of two sacs, the corpus bursa and the appendix bursa. These are connected in series with the appendix bursa being furthest from the copulatory opening. During copulation the appendix bursa is filled with a whitish fluid and the corpus bursa is filled with

Description of last-instar larvae of 22 species of north american spilomelini (lepidoptera: pyralidae: pyraustinae) with a key to species

Abstract: The last-instar larvae of 22 species of Spilomelini are described and illustrated Diagnostic characters are given, and a key included, for North American species

Intra- and Interspecific Relationships Among Some Parasites of Trichoplusia ni (Lepidoptera:Noctuidae)

Abstract: The common parasite species attacking Trichoplusia ni (Hubner) (Lepidoptera: Noctuidae) in southern California were investigated in the laboratory to demonstrate discriminatory abilities. Copidosoma truncatellum (Dalman) (Hymenoptera: Encyrtidae), a polyembryonic, egg-larval parasite, exhibited time-dependent, intraspecific discrimination. The solitary larval parasite, Microplitis brassicae Muesebeck (Hymenoptera: Ichneumonidae), discriminated between unparasitized hosts and those parasitized by Hyposoter exiguae (Viereck) (Hymenoptera: Ichneumonidae) or M. brassicae , but did not discriminate hosts containing C. truncatelium immatures. Multiple parasitization by these two species in hosts containing C. truncatellum resulted in successful development of C. truncatellum in most cases, with some hosts yielding M. brassicae or H. exiguae . In studies with Varia ruralis (Fallen) (Diptera: Tachinidae), the hymenopterous parasites had a competitive advantage when multiple parasitization occurred, but in the case of C. truncatellum, timing of parasitization by V. ruralis affected the results, with some 7- to 9-day-old hosts producing both C. truncatellum and V. ruralis .

Damage of Sunflower by the Southern Armyworm (Lepidoptera: Noctuidae)

Abstract: Spodoptera eridania (Cramer) occurred in economic infestations in ca. 50% of the 567 ha of sunflower planted in Alachua County, Florida in the fall of 1982. Outbreaks occurred in sunflower having dense stands of pigweed (Amaranthus sp.), a primary host. After consuming pigweed, the southern armyworm larvae moved en masse to the sunflower. Differences in seed yields from sunflower heads harvested from plants with 0, 50, and 100% defoliation caused by larval feeding were highly significant. Seed yields from plants showing 50 and 100% defoliation were reduced 45 and 98%, respectively, compared to plants showing little or no defoliation. The impact of native parasites on S. eridania populations in sunflower was negligible. Parasites recovered included Opion sp., Chelonus insularis Cresson, Meteorus autographae Muesebeck, and tachinids.

Laboratory biology of Meteorus autographae (Hymenoptera:Braconidae), an indigenous parasitoid of soybean looper (Lepidoptera:Noctuidae) larvae [Pseudoplusia includens].

Abstract: Certain biological characteristics of the parasitoid Meteorus autographae Muesebeck (Hymenoptera: Braconidae) were determined in the laboratory. Total developmental time from oviposition to emergence of adult M. autographae decreased with each successive increase in temperature (39.8 and 13.8 days at 16 and 27°C, respectively). Meteorus autographae parasitized and developed successfully in 1st through 5th instars of Pseudoplusia includens (Walker). Larvae of Trichoplusia ni (Hubner), Heliothis zea (Boddie), H. virescens (F.), Spodoptera frugiperda (J. E. Smith), S. exigua (Hubner), and Anticarsia gemmatalis Hubner also were suitable hosts for M. autographae. An average of 241.8 progeny were produced per female during her lifetime. Larvae of P. includens that were parasitized by M. autographae ceased feeding ca. 6 to 8 days after parasitization and consumed 78% less soybean foliage than nonparasitized larvae.

Growth and Refoliation of Koa Trees Infested by the Koa Moth, Scotorythra paludicola (Lepidoptera: Geometridae)

Abstract: Since the early 1900s, four major infestations of the koa moth, Scotorythra paludicola (Butler), have defoliated koa (Acacia koa Gray) stands on the island of Maui. After trees on 7564 ha of the Makawao Forest Reserve were damaged in 1977, a study was begun to determine growth and refoliation response of completely defoliated trees in a stand previously subjected to three different silvicultural treatments. Relative growth rates before defoliation ranged from 5.7 percent to 14.2 percent per year. Trees on thinned-and-fertilized plots showed significantly greater relative growth rates than control trees. The relative growth rates of trees on plots that were thinned only or fertilized only were not significantly different from those of the control trees. After defoliation, relative growth rates ranged from 1.1 percent to 4.3 percent with differences between treatments not significant. The 71 percent reduction in growth after defoliation was statistically significant. About one-third of the sample trees died within 20 months of defoliation. KOA (Acacia koa GRAY), AN ENDEMIC tropical hardwood, is the most valuable native timber species in Hawaii and ranks second only to ohia (Metrosideros polymorpha Gaud.) as the most abundant. The koa moth (Scotorythra paludicola Butler), endemic on the islands of Maui and Hawaii (Zimmerman 1958), is a koa defoliator. Since 1900, there have been five major outbreaks of the koa moth, four on Maui, and one on Hawaii (Swezey 1931, Fullaway 1946, Davis 1954). The most recent outbreak on Maui, in January 1977, affected 7564 ha, with total defoliation occurring on 1841 ha of koa in the Makawao Forest Reserve and the land of Halehaku (Figure 1) (Stein 1981). A less severe infestation (25 to 45 percent defoliation) was reported in 1973 (pers. comm., R. Hobdy, Hawaii Div. Forestry and Wildlife). This report evaluates the effect of complete defoliation of koa in a stand previously subjected to three silvicultural practices. 1 Manuscript accepted 12 April 1984. 2 U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station, Honolulu, Hawaii. Present address: U.S. Forest Service, P.O. Box 245, Berkeley, California 94701. 3 U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station, Honolulu, Hawaii 96813. MATERIALS AND METHODS The study area is located at the upper end of the Makawao Forest Reserve on the northeast flank of Haleakala, on Maui, Hawaii. The site is known locally as Borge Ridge. The study area is 730 m long, 245 m wide, varies from 1050to 1160-m elevation, and is located on a moderately shallow phase of the Olinda soil series. This reddish-brown loam is low in phosphorus, potassium, calcium, and magnesium, with a surface pH from 4.0 to 4.5. Annual rainfall averages 190 em, with a mean annual soil temperature of 21 0 C (Foote et al. 1972). The forest overstory is even-aged koa, the result of a fire in 1962 and subsequent regeneration. In 1968, the resulting koa stand contained an average of 6200 trees/ha. In 1973, the stand density was 2100 trees/ha. Foresters familiar with the development of the koa stand reported that height growth had stagnated and none of the trees had expressed dominance (Wesley Wong, pers. comm.). Data from a growth plot established by the Hawaii Division of Forestry and Wildlife in 1968 confirmed this assessment. The average diameter growth was 16mm/yr (±4 S.D.) for the period 1962 to 1968; 6 mm/yr (± 3 S.D.)

Effect of Aging on the Mating Competitiveness of Irradiated Male Greater Wax Moths (Lepidoptera: Pyralidae)

Abstract: Young adult Galleria mellonella (L.) males were exposed to either 0 or 20 rad of ionizing irradiation. Treated males competed with normal males for virgin females at 1, 8, and 15 days of age. Mating competitiveness decreased as irradiated males aged. A vigor-loss hypothesis is proposed. Additionally, an improved technique for obtaining substantial numbers of virgin adults is described.