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Subterranean termite control methods using chitin synthesis inhibitors (CSIs) aim at eliminating colonies that feed upon a bait formulation. Several benzoylurea active ingredient formulations are currently commercially available as alternative termite management strategies to liquid termiticides. Individual workers need to molt on a regular basis and CSIs interfere with such molting process, allowing sufficient time for the acquisition of a colony-wide lethal dose prior to widespread mortality. As workers progressively die, the colony eventually collapses, leaving only soldiers and primary reproductives that starve to death. One common observation is that young workers often die early owing to their relatively short molting cycle. However, the absence of brood in dying colonies raises questions about the potential fate of eggs laid by the queen. This study aims to determine if CSI baits also terminate the ability of a colony to produce a new cohort of workers by disabling the ongoing brood development. Incipient termite colonies were used to test the impact of noviflumuron on the queen’s ability to lay eggs and on the eggs' ability to hatch. Our results showed that queens in colonies exposed to CSI not only initially laid less eggs than the control queens, but eggs also did not develop and were progressively cannibalized, eventually leading to colony establishment failure. This result implies that queens of mature colonies exposed to CSI would lose the ability to lay viable eggs as the colony collapses, leading to an absence of worker replacement, aiding in colony elimination.

The edible katydid, Ruspolia differens (Serville), is an economically and nutritionally important insect species that is common and widespread in Africa. Currently, there are aims to develop mass-rearing methods suitable for this species, but a critical first step would require a suitable oviposition medium to ensure economic and easy production of eggs with high hatchability. The objective of the present study was to determine the oviposition preference and egg hatchability in different oviposition media. Based on preliminary testing of a wide range of different materials, two oviposition media, namely, artificial (folded plastic cloth) and natural medium (leaf sheath of Pennisetum purpureum Schumach attached to a stem), were selected for a detailed experiment. A two-choice laboratory experiment was conducted in which R. differens females were able to select between the folded plastic cloth (one side covered with short fleece) and a leaf sheath of P. purpureum (wrapped in polyester fiber). The results show that R. differens laid almost three times more eggs on the plastic cloth (mean ± SE, 169.3 ± 18.0) than on the natural substrate, P. purpurem (69.0 ± 13.9). However, the hatchability (overall mean% ± SE, 56.5 ± 4.7) of eggs in the two media did not differ. Folded plastic cloth, therefore, provided a more effective medium for egg laying by R. differens, and is thus a promising oviposition medium for getting natural populations to start laying eggs in future mass rearing.

In this study, we examined the fecundity, survival, and adult longevity of Ephestia kuehniella (Zeller) at different temperatures (15, 17.5, 20, 22.5, 25, 27.5, and 30 °C), and developed a model of oviposition. The fecundity, survival, and adult longevity of E. kuehniella were affected by temperature. Longevity reduced from 15.7 d at 15 °C to 8.79 d at 30 °C. Total fecundity was lowest (160.54 eggs) at 30 °C and highest (351.75 eggs) at 25 °C. The relationship between temperature and total fecundity was described by a nonlinear function. Cumulative age-specific egg laying fitted well to the two-parameter Weibull equation and survival of adults fitted well to a reverse logistic curve. These three temperature-dependent attributes (age-specific cumulative egg laying, temperature-dependent total fecundity, and age-specific survival rate) were integrated into a model of oviposition. Simulation of oviposition using the model has the potential to be useful for predicting patterns of occurrence of E. kuehniella egg populations in stores.

Our objectives were to predict pheromone-trap catches and oviposition of blackheaded fireworm, Rhopobota naevana (Hubner), on commercial cranberry farms in Wisconsin, Washington, Oregon, and British Columbia and to model oviposition in Wisconsin. Real time, expressed as days after male moths were caught in traps, predicted the day of 50% catch better than degree-days in both growing regions. Weibull functions were used to model the cumulative percentage of male moths caught and cumulative percentage of eggs laid over time in a Wisconsin cranberry farm not treated with insecticides and the percentage of catch of male moths on insecticide-treated farms in Wisconsin and the Pacific Coast growing region. Insecticide treatments made the patterns of flight activity less predictable. However, characteristics of flight activity common to all regions indicated oviposition may occur during a 4-wk period after first catch.

Boll weevils, Anthonomus grandis grandis Boheman, dipped into solutions containing 0.25-2.0% of CIBA-GEIGY’s CGA-184699 killed >40% after 1 wk. Feeding 0.25-1.5% of this material in the adult diet for 3 d produced mortality similar to that found in tests. Female boll weevils treated with this insect growth regulator by dipping or feeding and mated with untreated males resulted in 95-99% less egg laying compared with the control. Male boll weevils administered CGA-184699 by dipping or feeding and mated with untreated females produced 58.8-73.0% fewer eggs compared with the control. Egg hatch and adult emergence of the few eggs collected was reduced to virtually zero in dipping and feeding tests.

The problems of satisfactorily describing fruit fly host status for quarantine purposes are explored. A definition is provided based on the ability of a commodity to sustain fruit flies from the egg laying stage through to the next generation of reproducing adults. Experimental procedures required to determine host status for multivoltine fruit flies are described. These methods include both laboratory and field cage trials, field collection of fruit, and methods demonstrating fruit fly presence in a study area.

The activities of three avermectins and deltamethrin as oviposition suppressants were investigated with a laboratory bioassay in which gravid females of the blowfly Lucilia cuprina (Wiedemann) were exposed to treated oviposition targets. An easily comparable index of suppression, the oviposition suppression concentration (OSC), was defined. All four compounds were effective oviposition suppressants. The three avermectins had similar OSC50 values (approximately 13 ppm). Deltamethrin, with an OSC50 of 0.4 ppm, was the most potent suppressant. The avermectins all produced significant mortality in adults with suppressed oviposition, while deltamethrin did not cause an increase in deaths at concentrations giving up to 100% suppression of oviposition. The toxicities of all four compounds to adult females were similar when assessed by topical application.

One- to two-day-old Mexican fruit fly adults, Anastrepha ludens (Loew), were not deterred from feeding continuously or Jor periods of 1, 3, and 5 d on diet containing either 1 x 103 or 1 x 104 ppm cyromazine. Although flies behaved normally after feeding, egg production was significantly reduced. Cyromazine did not appear to affect males. Those females fed a single meal containing >1.5 x 103 ppm cyromazine had significantly fewer eggs compared with the control.

In a mark-release-recapture study, sheep wounds and rotted liver were used as attractants to study movements of the screwworm fly, Cochliomyia hominivorax (Coquerel), in a Costa Rican tropical wet forest in the wet season. When sites were monitored for less than 1 h, liver attracted between 3 and 12.2 times more flies of both sexes than did wounds, but proportionately fewer gravid and parous females. Only 24.6% of females marked at liver sites were recaptured; seldom (3.1%) did they visit sheep wounds. Females originally marked at sheep wounds remained at the study site longer, visited both sheep and liver sites, and greater than 50% were recaptured. Some females were observed for 16 d and one laid four clutches of eggs. Only 8% of the marked males were recaptured and none was recaptured less than 2 d later. Only a small proportion of the adult screwworms at a locality visited wounds on sentinel sheep; the majority of the adults were transient.

Colored, polyethylene plastic balls were modified to serve as oviposition devices for a laboratory strain of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), in the laboratory and the field. In outdoor field cages, large balls (100 mm diameter) yielded significantly more eggs than small balls (25 mm diameter) for all four colors tested (black, red, yellow, and blue). Blue and yellow balls yielded fewer eggs than black or red balls for small and medium (50 mm diameter) sizes, whereas numbers oviposited in black, red, and yellow spheres were not significantly different for numbers laid in the large size. Twice as many eggs were laid into large balls when guava juice was used as an attractant as compared with water. Large black or red balls with guava juice gave roughly as many eggs as did ‘Golden Delicious’ apples, and three times as many eggs as did ‘Red Delicious’ apples. Laboratory flies oviposited three times as many eggs into large yellow balls with guava juice as did wild flies reared in fruit.

Egg, nymphal, and adult populations of Empoasca fabae (Harris) were monitored in 2 fields in Montgomery Co., Va., during 1976 and 1977. Centigrade degree day (COD) accumulations for egg and nymphal development were related to alfalfa growth and harvest date. Effect of harvest on nymphal survival and subsequent buildup of potato leafhopper populations also were investigated. In general, development from egg to adult, using 136 CDD (base = 7.6°C) for egg hatch and 153 CDD (base = 9.4°C) for nymphal development, was longer than the period from adult immigration and egg laying in the field to harvest. Samples collected indicated that within 7–10 days after harvest the nymphal population was reduced by ca. 95% when alfalfa was cut to a 2–5 cm stubble height. However, when poor harvest practices or lodged alfalfa allowed alfalfa stubble containing leafy material or uncut stems to remain in the field survival of nymphs was much higher. Also, apparent in poorly harvested fields was an increase in the number of nymphs found on early regrowth alfalfa which is highly susceptible to potato leafhopper damage. Information is still needed that will relate population levels of potato leafhopper nymphs during the post harvest to regrowth period to action thresholds for insecticide application.

Simplified models of the dynamics of mosquito populations are reviewed and developed. Parameters used to develop the models include survival in the adult and immature stages, patterns of egg laying and number of eggs, development times, and population density curves. With this approach, it was possible to estimate growth rates of naturally-occurring populations of Culex pipiens quinquefasciatus Say and Anopheles albimanus Wiedemann when subjected to control by the release of sterile males. Maximum growth rates attained during release experiments were confirmed by independent biological evaluations.

Correlation between captures of cabbage maggot adults, Delia radicum (L.), on sticky boards and eggs deposited on rutabaga roots over two seasons was significant Correlation between egg numbers recovered from roots and subsequent damage was also high and significant. However, the relationship between flies captured on sticky boards and damage to roots was not clearly defined. Use of fly numbers recorded from sticky boards to predict damage cannot be fully supported from this investigation. Additional factors including oviposition behavior of females and mortality factors affecting eggs and larvae must be investigated before such a monitoring technique could provide accurate predictions.

It has not been possible to demonstrate an increase in oviposition rate in Tetranychus urticae Koch and T. telarius (L.) owing to DDT treatment. Treatments included direct application, holding on treated bean leaves, rearing on bean plants inserted in water containing DDT or combinations of such treatments. It was not possible to confirm a report that daughters of treated mites produced more eggs than did the parent females. A definite harmful effect is evidenced by early mortality, lowered oviposition rate, and restlessness. The harmful effect is intensified by high temperature.

In 1964, observations of Ostrinia nubilalis (Hubner) egg laying on corn indicated that larvae from the eggs laid after 70% tassel-height ratio had been reached were those most responsible for infestation of the cars of sweet corn. It was postulated that chemical control to prevent ear infestation would have to be applied sometime after this stage of development. Plot experiments conducted in 1967, 1968, and 1970, in which chemical sprays were applied at various times, indicated this hypothesis to be true. Generally, those sprays applied during the silking period were as effective, or more effective, than any others in reducing injury to sweet corn ears.

Field experiments were conducted at St. Luc, Quebec, from 1963 to 1965, to determine the relative effectiveness of 1, 2, 3, or 4 applications of DDT or carbaryl (Sevin®) in 2 commercial sweet corn fields. In all cases, the 1st application was made 5 days after the beginning of egg laying period and the others at weekly intervals, except for the single application of DDT or carbaryl, which was made 15 days after the 1st eggs were observed. In general, results were similar for the 3 years: the early variety was more infested than the late variety, DDT was slightly superior to carbaryl, the peak of egg laying always occurred between the 2nd and 3rd insecticide applications, and the date on which the single application was made varied each year from only 2 to 4 days from the date of maximum oviposition. The results of this 3-year study indicate that under the conditions of heavy infestations of the European corn borer, Ostrinia nubilalis (Hubner), in southwestern Quebec, 3 applications of either DDT or carbaryl would be recommendable for an early variety of sweet corn and 1 application for a late variety to obtain economical commercial control.

Tretamine at 20 mg/kg caused a slight decrease in the longevity of unmated males and females Oncopeltus fasciatus (Dallas), but the delayed toxic effect was greater at 40 mg/kg and severe at 80 mg/kg (median lifespan decrease from 80 to 20 days). Mating activity and egg laying also shortened the lifespan; at 20 mg/kg tretamine might have prolonged life by causing a decline in the sexual activity, but at 40 mg/kg it shortened the lifespan of sexually active insects, At 20 mg/kg immature males were rendered sterile and immature females infecund for about 2 weeks, but then they partially recovered; at 40 mg/kg the sterilant effect was nearly total and permanent. Females mated with tretamine-sterilized males laid eggs that were mostly fertile but failed to hatch. Treatment of mature females did not interfere with maturation of large oocytes and laying of mature eggs, but maturation of new oocytes was either greatly delayed or permanently blocked. Metepa sterilized at dosages about 8 times greater than tretamine, and its action differed in some ways. There was little reduction in longevity even at dosages causing total and permanent sterility. However, eggs laid by females mated with treated males had an abnormally low percent fertilization, suggesting either a low level of sperm transfer or a high level of sperm inactivation.

Soil and soil-water heating is likely to prove a limiting factor in the use of electromagnetic waves against soil infesting insects. Irradiation of foliage wall of the apple tree with ordinary white light in the amount of ten foot candles reduced fruit infestation by first brood codling moth 50%. Eggs are, however, frequently deposited in this intensity. Irradiation in the neighborhood of thirty foot candles seems likely to be required to prevent free oviposition. The violet end of the spectrum excites the moth to apparently normal oviposition. The red end tends to produce abnormal activity with some egg laying.

Cycloheximide and its acetate, acetoacetate, oxime, semicarbazone, and thiosemicarbazone derivatives were evaluated in the laboratory to ascertain their toxicity to and effects on the fecundity of the citrus red mite, Panonychus citri (McGregor), on citrus, and the Pacific mite, Tetranychus pacificus McGregor, on bean seedlings. Laboratory sprays of these compounds, in the order listed, produced injury to green lemon fruit at concentrations of 2, 0.5, 100, 40, 5, 10 ppm, respectively, and to bean seedlings at 100, 25, 1000, 100, 100, and 100 ppm, respectively. None of the compounds were highly effective in producing direct mortality to either mite species at concentrations which were nonphytotoxic. At concentrations of 10 ppm or above, spray applications of each compound, except the thiosemicarbazone, materially reduced the fecundity of both mite species. In field evaluation trials, the oxime was the only one of these compounds that showed promise for control of P. citri . Most effective control resulted when applications were made between the cycles of plant growth. When applications were made during the growth cycle, adult female mites moved onto new growth where egg laying returned to normal.

Six 500-watt lights were suspended directly over a block of fifteen trees consisting of several varieties of apples. The plot was flooded with light each evening for two and a half to three hours from April 26 to June 30,i.e., to the end of the first brood of codling moth. Temperature for the period was recorded and foot candle meter readings were made to ascertain light intensities. Comparing fruit of the same variety at the end of the test it was found that 21 per cent of the apples on check trees outside the test plot were moth attacked while only 14.5 per cent of the apples inside the test plot were so affected. Light of the intensity and quality used indicates a tendency to deter the codling moth in its egg laying habits.

In Dacus tryoni (Froggatt) no significant differences in radiation sensitivity were observed in 7 strains originating from Queensland and New South Wales. The most radiation-resistant physiological age of pupae extended over the last 3/10 of their development. A dose of 5 krad nearly sterilized both sexes within this period; doubling this dose prevented egg laying by treated females and permitted only 6 eggs per million to hatch and none to survive when irradiated males were mated with normal females. A dose of 10 krad given to fruit as a commodity treatment would provide adequate safeguards against the spread of this pest species.

During 1958 studies of the preferred feeding and egg-laying sites of the boll weevil ( Anthonomus grandis Boheman) were conducted at Stoneville, Miss. Females damaged the fruit of the cotton plant more than males. The preferred feeding and egg-laying sites were the squares on the upper half of the plants when the population was low. As the population increased, small bolls were damaged as well as squares; the damage was intensified on the upper portions of the plants and reached into the lower fruiting branches. Bolls from 1 to 19 days old were subject to weevil damage. Exposure of the cotton plant to feeding and egg laying by the boll weevil for 4 or 5 days resulted initially in increased square abscission and slightly reduced boll abscission. No difference occurred in total boll set for the entire season between the test and check plants.

The effect of gamma radiation on boll weevil ( Anthonomus grandis Boheman) adults, pupae, and eggs was determined following exposure to cobalt60 Longevity and egg-laying capacity of reproducing weevils were drastically reduced at doses of 5,000 roentgens (r) or higher, whereas egg hatch was greatly reduced at doses as low as 2,500 r. Exposure of virgin males to 10,000 r resulted in transient sterility whereas 15,000 r produced permanent sterility. However, these doses resulted in very rapid mortality of both sexes. A ratio of 3.8:1:1 of sterilized males: normal males: normal females did not affect egg laying or hatch. There appeared to be little, if any, effect of adult boll weevil age on susceptibility to the lethal effects of gamma rays. Emergence of adults from prepupae, young, and old pupae exposed to 10,000 r was eliminated, greatly reduced, and unaffected, respectively. However, the lethal effects carried over because all of the adults died within 2 weeks. Exposure of eggs to 600 r did not affect hatch or subsequent development whereas 2,400 drastically reduced hatch and prevented subsequent development.

Experiments to study time of insecticide application in relation to control of the European corn borer ( Pyrausta nubilalis (Hbn.)) were carried out at Ankeny, Iowa, in 1951-56. Two applications of DDT gave significantly better borer control than one application in all experiments. Each year the best control was obtained following applications when egg laying was almost completed. The minimum points on regression curves represented the estimated optimum treatment dates. Criteria used for predicting time of insecticide application, as they existed on the dates of optimum treatment, were compared with the recommended or suggested criteria. In 5 out of 6 years the number of borer-degree days on the date of optimum treatment was below the suggested 1100, averaging about 900. A tassel bud-plant height ratio of 35 appeared to be more suitable than the recommended range of 30 to 50. Except for 1 year plants in plots with the best borer control were consistently taller than the recommended 35 inches. Plant height and unhatched egg masses were found to be unreliable. Data on moth emergence were consistent with recommendations; however, this criterion is unsuitable for use by the average grower. The recommendation to treat when 75% of the plants show evidence of recent feeding in the whorls was the most rapid and simple to use.

Various antibiotics and some other compounds were tested as insecticides and chemosterilants on adult female codling moths, Carpocapsa pomonella (L.). These were applied topically to the ventral abdomen or by injection with a microsyringe. Novobiocin was extremely toxic in several tests, killing all the moths treated with dilutions as low as 150 ppm. Egg laying was reduced significantly by a few antibiotics, but most of them had no effect on egg laying or on moth mortality.

So-called Pansy spot or thrips injury on apples is caused by the egg laying punctures of two species of thrips: Frankliniella occidentalis and Aeolothrips fasciatus . Injury of this character produced by thrips has been reported from most of the apple growing sections of the Pacific Northwest. In some instances the grade of the fruit has been lowered fully twenty per cent. Pansy spot derives its name from the shape of a discolored area which develops about the egg punctures. The color of this pansy shaped spot varies from white through various shades of pink. Egg laying begins shortly after bloom time, continuing until the fruit has reached the size of large walnuts. The life history of the insect in the orchard is not fully known. Sprays of oil and Black leaf applied while the trees were in full bloom showed that injury can be materially reduced but do not give complete control. The Black Leaf appears to be the active ingredient in bringing about this benefit.

A daily gain of 20 to 25 pounds of honey during a honey-flow is considered high for any colony of honeybees. Scientific data as to average nectar loads, number of trips per day, and the amount of water eliminated from nectar after it is brought into the hive indicate that a queenbee having an average daily egg-laying rate of less than 3,000 can produce enough workers to gather an excess of 25 pounds of nectar during anyone day. Consequently, recent scientific brood-rearing investigations were made on colonies having average queen bees, even though none of the latter were found to layover 3,000 eggs in twenty-four hours.

Studies made at the Wisconsin Experiment Station in 1924-1925 show variations, partly correlated to temperature, in the period from egg laying to capping of worker brood cells from less than 8 days to more than 11 days, majority being capped between the 8th and 9th days. Variations for complete development ranged from less than 19 7/8 days to more than 24 days. One set of experiments showed approximately 75 per cent of 4094 workers completing their development in less than 21¼ days. In another more definitely controlled set of 2602 individuals, 94 per cent emerged in less than 21 days with an average developmental period of approximately 20½ days.

The period of emergence of either the fall or spring brood of Hessian flies, Phytophaga destructor Say, varies from year to year with bioclimatic conditions. On this account "fixed" or "approved" dates are unreliable and the seeding date each year should be correlated with the season and with the fall brood of flies. In Iowa, the flaxseed count has been the only constant and reliable factor to use in predicting accurately the actual f1y-free-date. One hundred or more flaxseeds were collected at each station each day (average about 1,000 per day at Monona county station) from old stubble dug up at random in heavily infested fields. These flaxseeds were then classified as parasitized, empty and viable. The viable flaxseeds were then dissected to determine the per cent of larvae, of pupae and of parasitized larvae. Hence, the flaxseed count gave the daily rate of transformation from the larva to the pupa and to the adult state, as well as the rate of approach of the fly-free-date. When this count yields very few pupae and only a small per cent of larvae in contrast to a large number of empty flaxseeds, it ;s proof that the actual fly-free-date is at hand and that the few remaining pupae will immediately issue as flies, lay their eggs and perish before wheat drilled at this time will come up. Thus it is possible to predict the f1y-free-date so that farmers can begin drilling wheat six or seven days before the end of the egg laying period of the fall brood of flies. The records of the Iowa Observation Stations for 1922 and 1923 are given in the form of a summary.

Because of extreme activity the numbers of grasshoppers, Acrididae, are hard to estimate. By aid of a field glass the observer can stand at some distance and count those in a given unit. Many units of ground should be so counted in a field before an estimate of the grasshoppers can be made. A knowledge of the egg laying habits is necessary before an estimate of the number of eggs in a locality can be made. Estimating the per cent of damage in a particular field is done by comparison of the amount of damaged seed in several small units with the undamaged seed. When making up a statement of the damage done by grasshoppers over a wide area, the entomologist should, when possible, compare the yield of damaged sections with the yield of localities where there were no grasshoppers but which had other limiting factors equal. A comparison of the yield during the grasshopper infestation with the yield in the same localities but in years when there were few, if any, grasshoppers can be made but before the entomologist can estimate the damage done by grasshoppers, he must know the action, during the years under comparison, of other limiting factors such as rainfall, temperature, sunshine, winds, and crop diseases.

The apple aphid, Aphis pomi De Geer, begins oviposition in early October. Termination of egg laying is usually brought about by weather extremes. Discussed are the environmental factors which determine egg densities indirectly by reducing the number of oviparous forms prior to oviposition and directly by reduction in the number of eggs after they are laid. The typical dispersion of eggs on infested shoots is described: egg densities found in decreasing numbers from the shoot tips.

A technique for collecting eggs of the sunflower moth, Homoeosoma electellum (Hulst), for artificially infesting sunflower, Helianthus annuus L., is described. Eggs laid on blue-green velour pads (0.95 by 0.95 cm) and stored in the refrigerator (4.4°C) for up to 7 days are used to infest plants with the desired number of larvae.

Several parameters of flight activity of the wireworm Melanotus communis (Gyllenhal), were measured in Florida sugar cane fields using blacklight traps. Seasonal flight activity of M. communis was greatest during May and June, with 88% of the annual total being caught during this period. Total number of eggs found in dissected females was greatest in June, indicating that June is probably the month of maximum oviposition. Significantly more M. communis were caught from sugar cane fields on muck soils than sugar cane fields on sandy soils. M. communis adults flew throughout the night and adult catches decreased with increasing trap height aboveground.

When pupae of Anthonomus grandis grandis Boheman were fumigated for 5 h in a circulating, saturated atmosphere of bisazir, 99% of the males were sterilized, and egg laying by treated females outcrossed with normal weevils was reduced by 90.6%. Sterile males transfered 11.8% more sperm than control males the 1st week post treatment but 42.6% less the 2nd week.

Overwintered Anthonomus grandis Boheman can be sterilized and egg laying can be greatly reduced in the laboratory by feeding them a diet containing busulfan (1,4-butanediol dimethanesulfonate). A feeding table designed to attract weevils as they emerged from hibernation quarters attracted a small percentage of the total overwintered weevils that were in the field on July 1.

Ovipositional and olfactory behavior of Bruchophagus roddi (Gussakovsky) was studied on resistant and susceptible alfalfa clones. Seed pods of the resistant clone were ovipositionally nonpreferred for 8 days (ages 10–18) vs. 2 days (ages 8–10) in the susceptible clone when caged with 2 ♀ /seed. At a density of 1 ♀/seed, 8-, to 10-day-old seed pods of the resistant clone were nonpreferred. An unidentified olfactory attractant, detected in 10-, to 14-day-old seed pods of the susceptible clone, probably mediated orientation to seed pods and initiation of egg laying.

Population studies of the white grub show that there are fewer grubs in certain legumes, indicating that adult beetles are plant selective in egg laying habits.

Egg laying by the two-spotted spider mite ( Tetranychus telarius (L.)) was strongly inhibited by cycloheximide (3-[2-(3,5-dimethyl-2-oxyeyclohexyl)-2-hydroxyethyl] glutarimide), an antibiotic useful against powdery mildew and some other fungous diseases. This inhibition occurred on peach, pear, apple, and rose leaves. The mites were also suppressed on apple leaves when cycloheximide was combined with Sevin® (1-naphthyl methylcarbamate). This antibiotic is systemic, and mites on potted peach trees were controlled by 25 to 200 p.p.m. for 2 to 6 weeks, the period of protection increasing with the concentration. Another antibiotic, cytovirin, a material extremely hazardous to handle, was about equal to cycloheximide in suppressing egg laying, but several other antibiotics, including derivatives of cycloheximide, showed much less or no activity. Both cycloheximide and cytovirin are phytotoxic at low concentrations. Pear seedlings were much more susceptible than apple and peach plants which were not injured in greenhouse tests by levels effective for the control of mites.

The spotted alfalfa aphid (Therioaphis maculata (Buckton)) has not previously been reported overwintering north of Kansas and the only report of egg laying was from California where all eggs produced were unviable. Observations are presented on the production of viable eggs by this species in a very limited area of Nebraska during the fall of 1960. These eggs hatched during April 1961.

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In 1961, coumaphos (Co-Ral®) 50% oral drench powder in capsules at dosages of from 0.5 to 25 mg/kg was fed to laying white leghorn hens for 7 or 10 days. Dosages over 5 mg/kg caused considerable loss of weight and reduction in egg laying. At the 25 mg/kg level, all birds died. Analyses of tissues from treated birds showed no residues in excess of 1 ppm (the established tolerance). However, residues up to 0.09 ppm were recovered from egg yolks. In 1962, colony houses, 10×12 ft, containing laying white leghorn hens were treated as follows: 2 houses received a 5% dust at the rate of 2 oz/30 ft2 of floor space; 2 houses were fogged, using a Halaby fogger, with a suspension of coumaphos 25% wettable powder at essentially the same dosage used in dusted houses. Less than 0.15 ppm coumaphos were found in liver and fat of the exposed birds. The dust application resulted in no detectable residues of coumaphos in egg yolks. In one instance, a marginal residue of 0.03 was found in eggs from birds exposed to fogging.

As the boll weevil ( Anthonomus grandis Boheman) removes its ovipositor from a puncture after egg deposition, a seal is formed over the opening. Counts were made of sealed and open punctures and eggs in cotton squares fed upon by weevils in the laboratory. A good correlation existed between sealed punctures and eggs. Regression analysis showed that as the number of punctures increased, the number of eggs recovered decreased. Counts of sealed punctures in squares required only about one-third the time necessary for dissection of eggs from squares.

Oxydemetonmethyl and Bidrin® (3-hydroxy- N, N -dimethyl- cis -crotonamide dimethyl phosphate) were sprayed on the leading shoots of young Sitka spruce, Picea sitchensis (Bong.) Carr., to determine their effects on Sitka-spruce weevil, Pissodes sitchensis Hopkins. Spring applications made after egg laying, but before the larvae caused appreciable damage, provided good control. Exploratory tests were made also with injected applications of oxydemetonmethyl, Bidrin, demeton, and schradan. Because of limited replication the results of the injection tests can be regarded only as tentative, but both oxydemetonmethyl and Bidrin appeared to provide a good measure of control.