Showing papers in "Journal of Economic Entomology in 1971"

Control of Chironomid Midges in Recreational Lakes

Abstract: Several commonly available and experimental insecticides were evaluated for control of chironomid midge larvae, Chironomus spp., Proclaideus spp., and Tanytarsus spp. in 2 recreational lakes. In Lake Calabasas, where the bottom has a thin layer of mud on a surface of cement, standard midge larvicides such as Abate® ( O, O -dimethyl phosphorothioate O, O -diester with 4,4′-thiodiphenol) and fenthion proved highly effective. Fenthion at 0.5 Ib per surface acre controlled the larvae for more than 7 weeks. At this rate of application very slight mortality of the mosquito fish Gambusia affinis (Baird & Girard) was observed. Abate at 0.75 pounds per acre controlled the midges for about 4–5 weeks and caused slight mortality of the fish. Dursban® ( O, O -diethyl O -(3,5,6-trichloro-2-pyridyl) phosphorothioate) at the rate of 0.2 Ib/acre yielded long-lasting control of midge larvae, the suppression lasting for almost 5 months. In Westlake (about 10 miles from Lake Calabasas), with a natural bottom, where small portions were treated, fenthion at 0.5 lb/acre yielded little or no control of the midge larvae. Abate at 0.5 pounds per acre produced similar results. Carbaryl at 0.5 and 1.0 pounds per acre yielded good control, but its longevity was for only 2-3 weeks. Dursban insecticide applied as granules or sprays at 0.2 pounds per acre yielded excellent control of midge larvae. The granular formulations produced better and longer-lasting larval control than an emulsifiable concentrate formulation. The latter formulation at 0.2 lb/acre or higher rate caused slight kill of blugill, Lepomis macrochirus Rafinesque; largemouth bass, Micropterus salmoides Lacepede; and black crappie, Pornoxis nigromaculatus (Le Sueur) in the lake. No mortality of fish was observed in plots treated with a granular formulation of Dursban at the same rate.

Determination of Sterile-Insect Competitiveness

Abstract: A method of determining a point estimate of competetiveness for sterilize insects is demonstrated. The method is independent of ratio of treated to normal insects used and can be determined from I ratio test provided the egg-hatch data are known for normal matings and matings between treated and normal insects.

Response of the Female Southern Green Stink Bug and Its Parasite, Trichopoda pennipes, to Male Stink Bug Pheromones

Abstract: Data are presented to support the theory that male Nezara viridula (L.) produce a pheromone that is highly attractive to females of the same species and to the tachinid parasite Trichopoda pennipes (F.). Laboratory studies with a “Y” tube olfactometer showed 60% of the virgin female stink bugs responding to the males within I hour. Virgin female stink bugs released in large outdoor screened cages were attracted to confined unmated male stink bugs. Field studies with sticky-board traps using caged male stink bugs as an attractant captured 1 ♂ and 4 ♀ stink bugs and 14♂ and 113 ♀ parasites within a 12• or 13-day exposure period. Dissections of the female stink bugs indicated they were young virgins and that the female parasites had mated. Female stink bugs, copulating-pairs and 5th-stage nymphs, were not so attractive to the female parasite as male stink bugs. Field collections of parasitized bugs had significantly higher numbers of tachinid eggs on the males. Parasitism of males in 2 experimental areas was 72.1 and 68.1% and for females in the same areas 68.1 and 38.5%.

Microencapsulation and Ultraviolet Protectants to Increase Sunlight Stability of an Insect Virus

Abstract: Technical preparations of Heliothis nucleopolyhedrosis virus were inactivated after exposure to either artificial or natural sunlight. The extent of inactivation increased as exposure time increased until a residual of 10-15% of the original viral activity remained. Inactivation under artificial sunlight closely approximated that of natural sunlight. Microencapsulation per se did not provide significant protection against sunlight unless UV-protectants were included. Nonencapsulated combinations of virus + carbon were as effective as encapsnlated combinations of virus + carbon.

Sandflies and Tourism in Florida and the Bahamas and Caribbean Area

Abstract: A comprehensive discussion is presented of the relationship of sandflies to tourism in Florida and the Bahamas and Caribbean area Three species, Culicoides furens (Poey), C barbosai Wirth & Blanton, and Leptoconops becquaerti (Kieffer) are considered in detail as those most likely to be of economic significance The paper deals with the biology of the 3 species, with the realities of the sandfly problem as it affects tourism, and with the best-known control measures The intention throughout has been to place this whole subject in its proper perspective The primary purpose has been to help those concerned realize that sandflies present a serious threat for which there is rarely any easy, cheap, or fully effective remedy The authors advise that intending developers should fully investigate the sandfly situation before commencing their projects, since control measures forced upon them later may be very expensive

trans-Verbenol and Alpha-Pinene: Their Utility in Manipulation of the Mountain Pine Beetle

Abstract: Synthetic trans -verbenol containing 6% cis -verbenol and 1% unknowns combined with alpha-pinene was highly attractive to in-flight mountain pine beetle, Dendroctonus ponderosae Hopkins. Alpha-pinene was the most active of the terpenes tested with trans -verbenol. Myrcene showed intermediate activity, while limonene and 3-carene apparently were ineffective in eliciting a response. As behavior-regulating chemicals, trans -verbenol and alphapinene were effective in manipulating the host selection patterns of D. ponderosae . When 725 mature white pines, distributed over eight 40-acre plots in northern Idaho, were baited with the 2 materials, 133 or 18% were attacked heavily and subsequently killed. Beetle attacks were noted on an additional 15% of the baited trees, but these were aborted without tree mortality. Prior to baiting, all trees were sprayed to a height of about 20 ft with a 2.3% solution of lindane. The mortality of sprayed trees suggested that lindane was not effective under the conditions of this study. Only 21 of the estimated 7200 unbaited mature pines within the boundaries of the study plots were mass attacked, and 11 of these trees were within 10 to 15 ft of baited mass-attacked trees. Paperboard cylinders, about 8 ft × 10 in., covered with a tacky substance and baited with trans -verbenol and alpha-pinene appeared effective as a means of deadtrapping D. ponderosae . An abnormally high attack density could not be induced on a white pine baited with a massive amount of trans -verbenol and alpha-pinene.

Pheromone Studies of the Two spotted Spider Mite. 1. Evidence of a Sex Pheromone

Abstract: Male Tetranychus urticae Koch are attracted strongly to quiescent deutonymphs and will remain until emergence of the adult female, when mating occurs. In laboratory bioassays, males were attracted to 1.5 µliters of crude ether extract of quiescent deutonymphs containing 0.01 deutonymphs per ml of solvent. Male attraction varied over the range of concentrations tested. Strongest attraction occurred at 1.0 deutonymph equivalents per ml with decreased attraction at the higher and lower concentrations. Tests were conducted on detached hop leaf discs placed upon moist absorbent cotton. A clump of moistened finely ground polyvinylpyrrolidone powder served as the best of several tested substrates for the crude extract. Male attraction was measured as a percent of responses to treated sites and corrected for occasional visits to untreated check sites. Male response averaged 37.2% (range 0–73.6%) for 1.5 µliters of extract per test site. Further refinement in bioassay procedure s necessary to aid in the identification of the attractant.

Sticky Traps for Detection and Survey of Three Tephritids

Abstract: Five types of experimental sticky traps caught more native Mediterranean fruit flies (medflies), Ceratitis capitata (Wiedemann), than a standard 0.95-liter plastic trap when placed in cool leeward areas of Hawaii at an elevation of 366 m. A trap made of a rectangular board (hung vertically) covered with Stikem® and baited with 2 small separate squares of cane fiberboard impregnated with trimedlure or with a layer of trimedlure applied under the Stikem was the most effective. When the traps were placed at windward sea-level sites, 3 of the experimental traps were equal or superior to the standard in 5 tests made with released sterile medflies. Generally, the number of medflies caught was proportional to the rate of volatilization of the trimedlure. With melon flies, Dacus cucurbitae Coquillett, 3 of the experimental sticky traps (baited with cue-lure plus naled as the toxicant) caught more flies than the standard, but 2 (the coffee can and the V-shaped trap) were inferior. With a large population of oriental fruit flies, D. dorsalis Hendel, the same 2 traps and also the rectangular trap (baited with methyl cugenol plus naled) caught fewer flies than the standard, but two, the milk carton and the paired boards, caught as many as the standard.

An oviposition pheromone associated with the egg rafts of Culex tarsalis.

Abstract: The response of gravid mosquitoes, Culex tarsalis Coquillett, at 3 densities to egg rafts of their own species demonstrated an egg-associated pheromone which attracts females to oviposit. Olfactometer tests with this material showed significantly greater mosquito attraction to the oviposition pheromone than to distilled water. Gravid Culex pipiens pipiens L., and Aedes aegypti (L.), did not respond to the C. tarsalis pheromone, which fact indicates that it may be species specific. Preliminary analysis of this chemical indicates other solubility, a lipid nature, and low vapor pressure.

Suppression of Heliothis Populations with Glabrous Cotton Strains

Abstract: During 5 consecutive years of evaluating glabrous cotton strains in replicated field tests, oviposition of Heliothis spp. was reduced from 36% in 1966 to 80% in 1969. This reduced oviposition resulted in significantly fewer larvae and damaged fruiting forms. Glabrous cottons might therefore be used in conjunction with other methods of control.

Spider Populations in Alfalfa, with Notes on Spider Prey and Effect of Harvest

Abstract: The spider fauna of a Virginia alfalfa field was determined, and the seasonal occurrence of the 4 major species was plotted. Samples were taken with a D-Vac® sampler and a sweep net. Fourteen families were represented and comprised 75 genera and 112 identifiable species. Tetragnatha laboriosa Hentz, Pachygnatha tristriata Koch, Misumeuops asperatus (Hentz), and Oxyopes salticus Hentz were the most common. The effect of alfalfa harvest on numbers of spiders in the field was measured. The numbers of T. laboriosa, P. tristriata , and the family Lycosidae were not affected by the cutting process, but those of the Linyphiidae, Thomisidae, and Salticidae showed a definite response. Collections at intervals, over 24-hour periods, showed the effect of spider activity on sampling results. P. tristriata was far more active on the plant at night, and this was believed to be the result of a negative photo-orientation. T. laboriosa was collected during the periods of highest temperatures and lowest humidities. Feeding tests with 10 species belonging to 5 families were conducted in the laboratory. Although other factors were apparent, it appeared that size of prey, speed, and hardness of cuticle were the major criteria for determining whether a spider would feed on a certain insect.

Competitiveness of Gamma-Sterilized Males of the Mediterranean Fruit Fly: Effect of Irradiating Pupal or Adult Stage and of Irradiating Pupae in Nitrogen

Abstract: The sterilizing effect of 1-13 krad of gamma radiation given to 2- to 6-hr-old adults of Ceratitis capitata (Wiedemann) was established. Male sterility increased with increasing dose to reach 98 5% at 9 krad and 99.8% at 13 krad. The relationship between sterility and dose was similar to that found for males irradiated 2 days before eclosion. Above 3 krad, females produced eggs for 1 week, the number decreasing with increasing dose, and they then became infecund. When confined with untreated pairs in a 3: 1: 1: ratio, males treated With 5, 7, 9, or 11 krad 2 days before eclosion or as 2- to 6-hr-old adults reduced egg hatch to about the same extent. When males were irradiated in nitrogen 2 days before eclosion the gamma dose had to be increased by approximately 2.5 krad over that required in air to achieve a particular level of sterility. However, at the 98% level of male sterility, irradiation in nitrogen resulted in males which were 3 times more competitive than males irradiated in air.

Response of European Cherry Fruit Flies to Colored Rectangles

Abstract: When the response of Rhagoletis cerasi (L.) to 27 colors or shades of enamel paint was assayed under orchard conditions, more flies were captured on stickycoated rectangles painted yellow or dark tints of yellow than on any other. Daylight fluorescent yellow captured even more flies than yellow enamel. Evidence indicates that the flies’ response to yellow was one of positive attraction and true color discrimination. The biological basis of fly response to yellow may lie in the fact that yellow is the most intensely reflective color in the general part of the spectrum where green leaves (on which flies find food) reflect their most light, 500-600 mµ.

Laboratory testing of insecticides for control of the winter tick.

Abstract: Engorged female winter ticks, Dermacentor albipictus (Packard), were dipped in the laboratory in concentrations of 29 insecticides. Then the effects on the estimated reproduction (ER) were determined (ER = g eggs/g ♀ × % hatch of eggs × 20,000), and probit analysis was conducted with percent control of ER afforded by each insecticide. The results are presented in terms of concentrations of insecticides that inhibited the ER of the ticks (IC50 = concentration (%) that inhibited 50% of ER). For the 29 test insecticides, the IC50 values ranged from 0.00013% for isobenzan to 1.933% for ronnel.

Resistance to Aphis gossypii in Muskmelon

Abstract: Breeding line LJ 90234 muskmelon, Cucumis melo L ., was resistant to natural infestations of western biotypes of the melon aphid, Aphis gossypii Glover, in the field and to controlled infestation in the glasshouse. However, LJ 90234 was very susceptible to western flower thrips, Frankliniella occidentalis (Pergande). Muskmelons re sistant to southeastern biotypes of aphid were susceptible to the western biotype.

Competitiveness of gamma-sterilized males of the Mediterranean fruit fly.

Abstract: Male Ceratitis capitala (Weidemann) given gamma doses of 1–17 krad 2 days before adult eclosion were confined with untreated males and females in ratios of 5:1:1, 9:1:1, and 19:1:1. With the first 2 ratios, the egg hatch of treatments using 5-, 7-, 9-, or 11-krad-treated males was not significantly different despite an increase in male sterility from approximately 89 to more than 99%. In the 19:1:1 ratio experiment, the 7-krad treatment gave the lowest egg hatch, and it was significantly lower than that for the 11-krad treatment. Males irradiated with greater than 3 krad were less competitive than untreated males based on a comparison of observed and expected egg hatch. When the competitiveness of the irradiated males was quantified, it was clear that as the dose increased male competitiveness decreased.

Survival of Southern and Western Corn Rootworm Larvae in Relation to Soil Texture

Abstract: In laboratory and greenhouse experiments involving soil textures ranging from silty clay to loamy sand, survival of larvae of southern corn rootworm, Diabrotica undecimpunctata howardi Barber. and western corn rootworm, D. virgifera LeConte, increased as percentage clay content of the soils increased. Laboratory tests indicate that newly hatched corn rootworm larvae in petri dishes moved from sand to clay but with very little movement from clay soil to sandy soil. A greater tendency for desiccation is considered to be the mechanism involved in larval survival in relationship to soil textures.

A New Yeast Hydrolysate-Borax Bait for Trapping the Caribbean Fruit Fly

Abstract: In Florida, baits of 3% hydrolyzed torula yeast + 4% borax premixed in water in invaginated glass traps proved 2-40 times as attractive as the standard (pellets of enzymatic cottonseed hydrolysate + borax) in water as a bait for Anastrepha suspense (Loew). In 2- to 4-week surveys, it caught 5-6.8 times more flies than the standard, and in 1 month (March) it caught flies in 5 counties, where the standard did not catch any. The new bait could be used for 14 days without replenishment and was not less attractive than 0- to 1-day old baits until after the 10th day. Also, the new bait, like most protein hydrolysates, caught 2 or more times as many females as males. Traps containing the new bait were not competitive with one another for 5 days when they were used at a density of 10/acre, but some interaction occurred when they were used at a density of 25/acre. When the solid components of the bait were pelletized (1:1:33 ratio of yeast and borax) for convenience in handling, the catches were ⅓ less the 1st week; when the pellets were made up with a 1:2 ratio of yeast and borax, they were about 50% as effective. However, when the components were added dry (in loose form) to the trap before the water was added, the solution was as effective as the premixed solution.

Pheromone Studies of the Two spotted Spider Mite. 2. Behavioral Response of Males to Quiescent Deutonymphs

Abstract: Adult male Tetranychus urticae Koch were attracted to quiescent female deutonymphs with the onset of quiescence. The consistency of male attraction varied from 40–85% during the early part of the period and gradually increased to 80–100% prior to adult emergence. Average duration of the quiescent period was 40.4 hours at 24°C and 23.4 hours at 30°C. Occasional males were found that did not respond consistently to quiescent deutonymphs. The cause was not determined. Male attraction was greater at 30°C and 20–30% relative humidity than at 30°C and 90–95% relative humidity. Trials at 24°C and 20–30% relative humidity were intermediate. It was concluded that tests for bioassay of T. urlicae female sex pheromone could be conducted at 30°C and 20–30% relative humidity but should include sufficient replications to measure erratic male behavior.

Developmental Activities and Behavior of the Rice Weevil Inside Wheat Kernels

Abstract: Fifty-five wheat kernels infested by Sitophilus oryzae (L.) were X-rayed daily to study egg-to-adult development and behavior within the kernels. Enlarged photographic prints (2530) prepared from the radiographs were examined to determine larval instars. Larval-tunnel widths in the daily radiographs were measured, as were head-capsule widths of other larvae from dissected kernels. Four increases in tunnel width occurred, each followed by 1–4 days of static tunnel width (assumed to be time of molting). Four corresponding increases in width of the larval head capsule were observed confirming results obtained by radiographing. The mean tunnel widths for the 4 instars were 0.31, 0.51, 0.83, and 1.34 mm; the means for stadia 1 through 4 were 3.9, 5.4, 4.7, and 5.1 days, respectively. Prepupa, pupa, and pre-emerged adult stages averaged 1, 5.2, and 4.6 days, respectively. The mean life cycle (including 4 days for oviposition) was 37 days. Of 23 adults which developed, 12 had pupal chambers on 1 side of the kernel, with most or all tunneling on that side, 7 constructed pupal chambers parallel to the crease but occupied portions of both kernel halves, and 4 located pupal chambers diagonally across the crease.

Effect of Two Parasites, Anisopteromalus calandrae and Choetospila elegans upon Populations of the Maize Weevil Under Laboratory and Natural Conditions

Abstract: Anisopteromatus calandrae (Howard) and Choetospila eleegans Westwood were found to be natural parasites of the immature stages of the maize weevil, Sitophilus zeamaize Motschulsky, in weevil-infested corn at several locations in Louisiana. A. calandrae was found more frequently than C. elegans . In a period of 4 months, under laboratory conditions, the numbers of adult weevils produced when A. calandrae ami C. elegane were present were ca. 5 and 11 %, respectively, of the number produced in the absence of parasites. Under laboratory and outdoor environmental conditions, the mean weevil progeny in the A. calandrae treatment was less than ½ that produced in the control under both environmental conditions. C. elegans was less effective under both conditions but appeared to reduce weevil populations by ½ and ¼ under outdoor and under laboratory conditions, respectively. Reproduction by C. elegans was found to he arrhenotokous.

Feeding, Development, and Reproduction of Amblyseius largoensis on Various Food Substances

Abstract: Laboratory experiments were conducted on the reproduction and development of the predaceous mite Amblyseius largoensis Muma when offered various food substances. The young instars developed well and adults reproduced readily on Brevipalpus phoenicis (Geijskes), Eutetranychus orientalis (Klein), Tetranychus cinnabainus (Boisduval), on eggs of 2 moth species, Prays citri Milliere and Ectomyelois ceratoniae (Zeller), on nymphs and pupae of Retithrips syriacus Mayet, on a nematode, Panagrellus sp., and on the pollen of Carpobrotus acinaciformis (Mesembryanthemum) . Although A. largoensis developed on the honeydew of Planococcus citri (Risso) and Toxoptera aurantii (Fonscolombe), but poorly on Phyllocoptruta oleivora (Ashmead), reproduction was low on both P. citri honeydew and P. oleivora , and completely absent on T. aurantii honeydew. Similarly the predators succeeded in developing on scale crawlers of Aonidiella aurantii (Maskell) and Chrysomphalus aonidum (L.) and on pollen of citrus and Zea mays (corn); again, except for Z. mays , reproduction was low. In experiments on the effect of light on the rate of reproduction during mass rearing of the mites on Z. mays and C. acinaciformis , it was found that natural light produced the highest reproduction rate on both species. The possible significance of these responses is discussed in relation to the potential of A. largoensis to control citrus pests in the orchard.

Air-Borne Dispersal of Larvae of the Gypsy Moth and Its Influence on Concepts of Control

Abstract: Porthetria dispar (L.) disperses as an air-borne stadium I larva. A field study of dispersal from a dense population indicates that dispersal occurs throughout most of the duration of stadium I. Records taken at regular intervals during the day show that most dispersal occurs in late morning and closely coincides with activity of larvae. During the night, at low temperatures, or in periods of rain, larvae are inactive and few are dislodged even by strong winds. The long duration of hatch makes it difficult to prevent dispersal and get sufficient kill by a single application of a short-residual insecticide. Population management to maintain gypsy moth populations at densities too sparse to induce dispersal is suggested as an alternative method of control.

Fungus as Food for Some Stored-Product Insects

Abstract: Nine species of stored-product insects representing 8 genera in 6 families of Coleoptera and 1 genus of Psocoptera were exposed to 23 species of seed-borne fungi and 1 actinomycete cultures on potato-sugar agar in the laboratory. Some feeding by all 9 species was observed on Cladosporium cladosporioides (Fresenius) de Vries, Nigrospora sphaerica (Saccardo) Mason, and Alternaria alternata (Fries) Keissler. Most insects rejected Streptomyces griseus (Krainsky) Waksman and Henrici, Cochliobolus sativus (Ito and Kurib.) Drechsler ex Dastur, and Aspergilles spp. The granary weevil, Sitophilus granarius (L.); and the lesser grain borer, Rhyzopertha dominica (F.), fed lightly on a few but failed to reproduce on any microorganism. The psocid Lepinotus reticulatus (Enderlein) and the beetles Lathridius minutus (L.) and Microgramma arga (Reitter) were the most successful fungivores.

Quantitative Production and Processing of Tetranychid Mites for Large-Scale Testing or Predator Production

Abstract: Lima bean seeding held 7 days after planting at 27±2°C under fluorescent lights, were transferred to a greenhouse and infested with 0.24 g of Tetranychus pacificus McGregor eggs per 100 plants. Fourteen days later, the miles are washed from the leaves in a specially designed washer and collected on a series of graduated fine mesh screens. Recovery of mites during an 8-week period averaged 1.29 g or about 353,860 mites per 100 seedlings. Weekly production from 5000 plants averaged 64.4 g of mites and required about 12 man-hours per week for the entire process (planting, infesting, washing, collecting, weighing). The system was designed to be expanded readily without altering the basic program.

Comparative metabolism of carbaryl by resistant and susceptible strains of the cabbage looper.

Abstract: The in vivo and in vitro metabolism of carbaryl by susceptible, DDT-resistant, and parathion-resistant strains of Trichoplusia ni (Hubner) larvae was studied and respect compared. In each strain, maximum carbaryl-metabolizing activity was found in the fat body, and this activity was greatest in last larval stage and prepupal forms. Homogenate’s of gut and fat body tissues contained cytochrome P-450 and a mixed-function oxidate (s) which was inhibited by carbon monoxide and methylcnedioxy-phenyl synergists. Fat body from a parathion-resistant strain was 8 times and 4 times as active as fat body from a susceptible strain and a DDT-resistant strain, respectively. The in vivo half-lives of carbaryl in the susceptible. DDT-resistant, and parathion-resistant 1coopers were 13. 8, and 3 minutes. The major metabolite formed in vivo and in vitro by all strains was hydroxymethyl carbaryl.