Development Rates for the Seed Maggots Delia platura and D. florilega (Diptera: Anthomyiidae)

Duration of immature stages of seedcorn maggots (SCM), Delia platura (Meigen), and bean seed maggots (BSM), D. florilega(Zetterstedt), was determined at eight constant temperatures from 5 to 40°C. No SCM or BSM survived to second instar at either 5 or 40°C. No BSM survived to the adult stage at 35°C. Duration of immature stages varied from 240 days at 10°C to 17 days at 35°C. A computer model developed using the SCM development rate data closely simulated SCM development in the field during the growing seaso

Emergence Patterns of the Seedcorn Maggot, Delia platura (Diptera: Anthomyiidae)

Time of emergence of seedcorn maggot (SCM), Delia platura (Meigen), adults that developed from eggs laid in field plots from May through October 1981, was determined during 1981, 1982, and 1983. Some SCM that developed from eggs laid as early as May 1981, overwintered, and the proportion of SCM overwintering increased when eggs were laid June to October. Adults emerged from overwintered pupae from April through October 1982, and in May and June 1983. Adults of the closely related bean seed maggot (BSM), D. florilega (Zetterstedt), also emerged in the plots, but in smaller numbers than SCM. BSM males emerged in 1981 only in plots planted during May 198

Development Rates for the Seed Maggots \u3ci\u3eDelia platura\u3c/i\u3e and \u3ci\u3eD. jlorilega\u3c/i\u3e (Diptera: Anthomyiidae)

Duration of immature stages of seedcorn maggots (SCM), Delia platura (Meigen), and bean seed maggots (BSM), D. florilega (Zetterstedt), was determined at eight constant temperatures from 5 to 40°C. No SCM or BSM survived to second instar at either 5 or 40°C. No BSM survived to the adult stage at 35°C. Duration of immature stages varied from 240 days at 10°C to 17 days at 35°C. A computer model developed using the SCM development rate data closely simulated SCM development in the field during the growing season

Detection of insect fragments in wheat flour by near-infrared spectroscopy

Insect fragments in commercial wheat flour are a major concern to the milling industry because consumers expect high quality and wholesome products at the retail level. Thus, the US Food and Drug Administration (FDA) has established a defect action level of 75 insect fragments per 50 g of flour. Millers routinely test their wheat flour to comply with this federal requirement and to deliver sound flour to their consumers. The current standard flotation method for detecting fragments in flour is expensive and labor intensive. Therefore, we examined the possible use of a rapid, near-infrared spectroscopy (NIRS) method for detecting insect fragments in wheat flour. We also compared the sensitivity and accuracy of the NIRS method with that of the current standard flotation method. Fragment counts with both techniques were significantly correlated with the actual number of fragments present in flour samples. However, the flotation method was more sensitive than the NIRS method with fragment counts below the FDA defect action level. We were unable to predict whether the number of fragments in a sample exceeded the FDA action level with our NIRS instrumentation. However, we were able to predict accurately whether flour samples contained less than or more than 130 fragments. Although current NIRS instruments are unable to detect insect fragments at the FDA action level, this method should be re-examined in the future because NIRS technology is rapidly improving

Identifying Stored-Grain Insects Using Near-Infrared Spectroscopy

Proper identification of insects in grain storage facilities is critical for predicting development of pest populations and for making management decisions. However, many stored-grain insect pests are difficult to identify, even for trained personnel. We examined the possibility that near-infrared (NIR) spectroscopy could be used for taxonomic purposes based on the premise that every species may have a unique chemical composition. Tests were conducted with 11 species of beetles commonly associated with stored grain. Spectra from individual insects were collected by using a near-infrared diode-array spectrometer. Calibrations were developed by using partial least squares analysis and neural networks. The neural networks calibration correctly identified .99% of test insects as primary or secondary pests and correctly identified .95% of test insects to genus. Evidence indicates that absorption characteristics of cuticular lipids may contribute to the classification of these species. We believe that this technology could be used for rapid, automated identification of many other organisms

Fitness costs of resistance to \u3ci\u3eBacillus thuringiensis\u3c/i\u3e in the Indianmeal moth, \u3ci\u3ePlodia interpunctella\u3c/i\u3e

Genetic changes in insects that result in insecticide resistance can also affect their fitness. Here, we report measurements of development time and survival of the Indianmeal moth, Plodia interpunctella (Hübner), to compare the relative fitness of Bacillus thuringiensis (Bt)-susceptible and -resistant colonies. Measurements of larval development time and survival indicated that a fitness cost was associated with resistance to Bt in some Bt-resistant colonies but not others. Comparisons of geographically different populations revealed inherent differences in development time and survival. In most cases, Bt-resistant moths suffered no disadvantage when feeding on a Bt-treated diet. In many cases, the development of Bt-resistant moths on Bt-treated diet was slower than the unselected moths on untreated diet, but it is unclear whether these differences would affect the successful mating of susceptible and resistant moths

VARIETAL RESISTANCE

Production of all classes of wheat grown in the United States totaled 2.5 billion bushels in 1997. Common wheat, Triticum aestivum L. subsp. aestivum, is the primary source of all wheat varieties grown in the United States, with over 200 varieties known and over 100 varieties cultivated. These 100 varieties constitute over 95% of all wheat cultivated in the United States. Five general wheat classes are predominant in the United States: hard red winter, hard red spring, soft red winter, white, and durum

Post-harvest entomology research in the United States Department of Agriculture–Agricultural Research Service

This is a review of current post-harvest entomology research conducted by the Agricultural Research Service, the research branch of the US Department of Agriculture. The review covers both durable and perishable commodities. Research on biochemistry, genetics, physiology, monitoring and control of insects infesting stored grain, dried fruits and nuts, and processed commodities is reviewed. Research on development of quarantine treatments, particularly for fruit flies, is also reviewed, including research on thermal and irradiation treatments and a discussion of risk management for quarantine pests. Two areas of research are covered more extensively: a project to map the genome of the red flour beetle, Tribolium castaneum, and the use of near-infrared spectroscopy for detection of hidden infestations in grain, quantification of insect fragments in food, determination of quality in dried fruits, identification of insect species and age-grading insects. Future research directions are identified

Post-harvest entomology research in the United States Department of Agriculture–Agricultural Research Service

This is a review of current post-harvest entomology research conducted by the Agricultural Research Service, the research branch of the US Department of Agriculture. The review covers both durable and perishable commodities. Research on biochemistry, genetics, physiology, monitoring and control of insects infesting stored grain, dried fruits and nuts, and processed commodities is reviewed. Research on development of quarantine treatments, particularly for fruit flies, is also reviewed, including research on thermal and irradiation treatments and a discussion of risk management for quarantine pests. Two areas of research are covered more extensively: a project to map the genome of the red flour beetle, Tribolium castaneum, and the use of near-infrared spectroscopy for detection of hidden infestations in grain, quantification of insect fragments in food, determination of quality in dried fruits, identification of insect species and age-grading insects. Future research directions are identified