The effectiveness of freshly cracked grains (corn, wheat, and sorghum), rolled oats, and kibbled carobs in retaining adults of the flat grain beetle, Cryptolestes pusillus (Schonherr), red flour beetle, Tribolium castaneum (Herbst), and rice weevil, Sitophilus oryzae (L.), was evaluated in the laboratory. Cracked grains were also compared with a food-bait mixture (cracked corn and wheat, rolled oats, and kibbled carobs; 1:1:1:0.2 parts by weight), currently used for detecting stored-product beetles on farms and in country elevators in Kansas. Choice tests were performed in 41.5-cm diam wooden arenas using 5 g of one or more food materials in total darkness at 27-degrees-C and 45% RH. Each insect species was tested separately, and 80 adults of each species were exposed to the foods for 24 h. The number of adults retained in the foods was recorded. In two separate tests, the numbers of C. pusillus retained in cracked grains and rolled oats, and in cracked grains and food-bait mixture were not significantly different. Similar results were observed with T. castaneum. However, significantly more S. oryzae adults were retained in cracked corn and wheat than in cracked sorghum. Also, the numbers of S. oryzae retained in cracked corn, cracked wheat, and food-bait mixture were not significantly different. Kibbled carobs retained significantly fewer adults of all three species compared with cracked grains. The numbers of C. pusillus or T castaneum retained were not significantly different in food-bait mixture with and without the carobs. However, significantly more (1.4-fold) S. oryzae adults were retained in food-bait mixture with carobs than without carobs. These findings suggest that any of the cracked grains or rolled oats could be used as bait for detecting adults of C. pusillus or T castaneum, whereas cracked corn or cracked wheat could be used for detecting S. oryzae adults. The cracked grains can be potentially substituted for the currently used food-bait mixture. The performance of these cracked grains in detecting adults of the three insect species in the field remains to be tested.

Pitfall traps and grain samples taken with a vacuum probe provided data on insect infestation in farm-stored wheat in 26 Kansas counties. Insects were monitored at 65-d intervals from July 1986 through March 1987. Early detection when populations were low in July and March was accomplished best by pitfall traps. The traps detected insects in 61.5% of the bins of wheat within 1 mo of harvest. In September and November, > 95% of the bins were infested. More than half the bins contained Rhyzopertha dominica (F.), an especially damaging pest of Kansas farm-stored grain. Absence of insects in either traps or grain samples could not be interpreted as proof that grain was insect-free. Each method was a more efficient detector of infestations than the other in certain seasons and for certain insects. The center of the grain mass contained a significantly greater percentage of the total number of insects in grain samples from September to January and a significantly greater percentage of the trapped insects from July to March than other positions. Correlation coefficients relating the number of all insects in traps to the number in grain samples taken directly below the traps did not exceed 0.65 until March. In September and November, when insect populations were greatest, 25 insects were captured in traps for each insect in grain samples. In January, the ratio decreased to 9:1.

In the laboratory, cache materials from eastern woodrat nests were inoculated with lesser grain borer (Rhyzopertha dominica) adults and incubated for 3 months to observe survival and reproduction. Adults survived for more than 1 month on fruits of sandhill plum (Prunus angustifolia), chinkapin oak (Quercus muehlenbergii), hackberry (Celtis occidentalis), buckbrush (Symphoricarpus orbiculatus), and black walnut (Juglans nigra). Progeny were produced on acorns (husk damaged) and hackberry and buckbrush fruits. Wild populations of lesser grain borer were not observed emerging from any of the cache materials. The lesser grain borer, Rhyzopertha dominica (F.), is a specialized grain-feeding member of the family Bostrichidae, a woodboring group of insects. In recent studies on field biology in Kansas, adult beetles have been found flying in April and May at some distance from farm-stored grain (Wright, unpubl. data). The lesser grain borer has been collected in pheromone traps in many diverse habitats (Cogburn, 1988) and has been observed tunneling in various types of wood (Potter, 1935; Mathew, 1987). Other stored-product insects have been found in bee and wasp nests, bird and rodent nests, and other habitats (Linsley, 1944). Information on lesser grain borer field biology is minimal. We hypothesized that some sources of food or overwintering sites away from grains and animal feed may be present in the local habitat. materials and methods: Several kinds of fruits and seeds were collected from eastern woodrat, Neotoma floridana, nests near Manhattan, Kansas, during the winter of 1988-1989. The nests were located in wooded habitat adjacent to fallow fields. Other workers have found that small mammal caches are good sources of grains, seeds and fruits (Smith and Reichman, 1984). Caches of eastern woodrat removed from nests in December 1988 contained from 400 to 12,000 g of seeds, fruits and leaves (Wooster, pers. comm.). The cache materials were sorted by type and equilibrated in an environmental chamber at 28 ? 1?C and 65 ? 5% RH for 1 week. Twenty adult lesser grain borers (10 ? 10 days old) were added to each type of cache material in a glass jar with a screened lid. Each jar represented the total material from one woodrat nest with different quantities available per nest. Approximately 1 month later, each jar was checked for live and dead adults, signs of damage and reproduction. Any adults were removed when found. Dust from insect damage (which might include eggs or small larvae) was returned to the jar along with the cache material for another month. This procedure was repeated three times. At the final observation, nuts and seed pods were dissected and adults found were included in the data for the third month. results and discussion: Lesser grain borer adults were able to survive at least 1 month on five types of cache material (Table 1): fruits of sandhill plum (Prunus angustifolia Marsh.), chinkapin oak (Quercus muehlenbergii Eugelm.), hackberry (Celtis occidentalis L.), buckbrush (Symphoricarpus or biculatus Moench.) and fragrant sumac (Rhus arom?tica Ait.). On dried plum fruits with pits, adults survived for more than 1 month but no progeny were found. On plum pits only there was no survival. Adults survived on fruit of fragrant sumac through the first month, but no reproduction was observed. Chinkapin oak acorns (broken by woodrats) supported adults for 3 months. No larvae were observed outside of the husks. However, six new adults emerged in the second month. Acorn meats were extensively tunneled and full of frass and dust (Fig. 1). Other stored-grain insects have been reported to breed successfully in acorns (Joubert, 1966; Mills, 1989). Adult progeny emerged from hackberry (dried fruits with pits) in the second and third months. The number differed from one batch of material to the next (Table 1). Fruits from different caches were of various maturities. The less ripened fruits were not infested by lesser grain borer. Mature fruits 1 Kansas Agricultural Experiment Station Contribution No. 90-39-J. Accepted for publication 23 October 1989. This content downloaded from 207.46.13.120 on Wed, 14 Sep 2016 04:20:11 UTC All use subject to http://about.jstor.org/terms

The development and use of pitfall and probe traps for capture of insects in bulk-stored grain are outlined. Unbaited traps are effective in detecting infestations and they detect a large number of species compared with grain-sampling devices. The effectiveness of the traps is related to temperature, trapping period, and grain moisture content; and traps are less reliable for detecting insect species that are less mobile, have a nonuniform distribution in grain, feed within kernels, or can escape from the traps. Comparisons are given between effectiveness of probe traps and grain sampling for detecting insects, and experience using probe traps in stored grain is reported.

Sticky traps are highly useful for the detection of low-level insect populations which are otherwise difficult to detect in processed commodity storages. Even where insect populations may be moderately high, as in the storage of unprocessed agricultural commodities, they are useful for making management decisions on insecticidal treatments and safe storage periods. These traps enable warehousemen to locate infestations and take corrective action while the infestations are still small and before they spread to other commodities. Recently, these traps have been used to demonstrate monitoring of feral populations of stored-product insects in some climatic areas of the world. Feral populations likely serve as reservoirs of insects for infestation of stored commodities, a possibility of much significance for storage management.

Several experiments on the influence of resistant and susceptible maize on developmental parameters of Sitophilus zeamais Motsch. suggested that the procedure to determine the Dobie index of susceptibility could be shortened by replacing progeny yield with the number of eggs laid per sample and days to mid-emergence (DME) with days to first emergence (DFE). Before experimental validation of the modified index, assumptions regarding homogeneity of variances for DFE, DME and days to last emergence (DLE), degree of association between eggs laid per sample of grain and total progeny yield and between DFE and DME, and β-estimators of host suitability were proven. When compared to the Dobie index, the modified index extended the scale for rating resistance and magnified the differences among maize types. The new index could save time and resources for breeding programs.

Journal Article Development and Behavior of Immature Stages of the Maize Weevil (Coleoptera: Curculionidae) within Kernels of Resistant and Susceptible Maize Get access R. Urrelo, R. Urrelo 1 Department of Entomology, Kansas State University, Manhattan, Kansas 66506. 1Current address: Universidad Nacional Agraria de la Selva, Apartado 156, Tingo Maria, Peru. Search for other works by this author on: Oxford Academic Google Scholar V. F. Wright V. F. Wright Department of Entomology, Kansas State University, Manhattan, Kansas 66506. Search for other works by this author on: Oxford Academic Google Scholar Annals of the Entomological Society of America, Volume 82, Issue 6, 1 November 1989, Pages 712–716, https://doi.org/10.1093/aesa/82.6.712 Published: 01 November 1989 Article history Received: 01 February 1988 Accepted: 07 April 1989 Published: 01 November 1989

Journal Article Effects of Insect Infestation of Farm-Stored Wheat on Its Sale Price at Country and Terminal Elevators Get access Carl Reed, Carl Reed Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: Oxford Academic PubMed Google Scholar Valerie F. Wright, Valerie F. Wright Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: Oxford Academic PubMed Google Scholar John R. Pedersen, John R. Pedersen Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: Oxford Academic PubMed Google Scholar Kelli Anderson Kelli Anderson Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas 66506 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 82, Issue 4, 1 August 1989, Pages 1254–1261, https://doi.org/10.1093/jee/82.4.1254 Published: 01 August 1989 Article history Received: 11 July 1988 Accepted: 15 November 1988 Published: 01 August 1989

Topics covered at a round table discussion on stored-product entomology held at the 1982 North Central Branch Meeting of the Entomological Society of America are summarized. Areas addressed include education, research, extension, and international programs. It was concluded that more attention should be given to reducing losses in stored products.