Population models for the Egyptian alfalfa weevil and alfalfa are reported, which compared favorably with field data. A mechanism for coupling the plant–herbivore trophic levels is suggested.

An intense forest fire destroyed a spruce (Picea spp.) stand in Agassiz Provincial Forest, Manitoba in May 1981. From 1 week following the fire, throughout the summer of 1981 and of 1982, carabid beetles were collected by pitfall trapping and standardized searches at weekly intervals. In all, 241 beetles of 24 species were collected. Agonum obsoletum Say and A. quadripunctatum De Geer were found; both species are known to be attracted to fires. A. quadripunctatum reproduced in the site in 1981 but there is no evidence that it did so in 1982. A. obsoletum was found in the study site only during the first 3 weeks after the fire. Evidence is presented to show that Harpalus laticeps LeConte is a characteristic species of forests after fire.

Agria [= Pseudosarcophaga] affinis (Fall.) and Aphaereta pallipes (Say) make an excellent host-parasitoid couple for a determination of effects of host diet on a parasitoid. The anatomy, life history, and behaviour of these insects have been described (Salkeld, 1959; Coppel et al., 1959). Moreover, A. affinis can be reared axenically on chemically defined diets and it is readily attacked in the laboratory by A. pallipes, a parasitoid of the onion maggot, Hylemya antiqua (Meig.). This parasitoid deposits eggs into the body cavity of its host and these increase in size: the duration of the egg stage depends on the age of the host larva when parasitized (Salkeld, 1959).

Feeding tests with the adults of Exeristes comstockii (Cress.) on chemically defined diets showed that, of ten B-vitamins omitted singly, only three, panthothenic acid, folic acid and thiamine, were needed for maximal egg production and maximal numbers of eggs contained in ovaries. Egg production on a diet with only these three vitamins was similar to that on a control with all B-vitamins, but egg viability was significantly lower. Addition of α-tocopherol did not increase fecundity or egg viability. Vitamin-starved females partly recovered ovarian function when fed tissues of Galleria mellonella L.

Recently, the light reactions of three species of tent caterpillars were described (3). The present paper contains a similar description of the responses of larvae of the spotless fall webworm, Hyphantria textor Harr. This species was chosen for comparative study because, like tent caterpillars, it is colonial through most of its larval stage, during which it forms extensive webs.

Larvae of all six instars were studied. Some of the behaviour described here was first observed during the summers of 1949-50 at Sault Ste. Marie, Ont. During July and August of 1953, several of the laboratory tests were repeated at Sault Ste. Marie, and, in addition, some new reactions were observed for the first time.

Spatial and temporal patterns of Dendroctonus frontalis emerging from loblolly pine, Pinus taeda, were studied. Daily emergence was measured at 1.5-m intervals along the infested bole on nine trees Emerging beetles from three of the trees were collected and their sex identified. Topological estimates of daily emergence on all trees were computed and the spatial and temporal patterns of emergence were described using three and five parameter models. Emergence followed the same general pattern at each of the 1.5-m sampling intervals. Peak density of emergence occurred at ca. 0.25 of the process time span (day 7) and declined thereafter. Emergence density was highest at the 3.5-m interval and tapered gradually towards the top of the tree and abruptly towards the bottom. The process took ca. 28 days for completion. Emergence partitioned by sex followed the same general pattern as observed for the combined sexes. The cumulative sex ratio of emerging beetles was essentially 1:1 at each height interval.

Since the curves at the various height intervals were similar, emergence was described as an average process for the entire tree. The essential features of the process were retained in the average analysis. A probability distribution function defined for emergence permits calculation of the distribution of beetles from host trees provided the cumulative density is known. A frequency histogram illustrating the range in observed emergence density over a three year period was also included.

Adult populations of D. frontalis available for colonization were interpreted as a single process “allocation.” The allocation process was defined by two components, re-emergence and emergence, and had the following characteristics: (1) it is continous for each tree in the infestation, (2) it is distinct for each tree, (3) it is bimodal in intensity, and (4) the components may operate together or independently. The allocation concept was used to interpret the manner in which D. frontalis infestations have been observed to develop.

Stained sections of female adult Platypus wilsoni Swaine showed that the punctures concentrated on the caudal half of the pronotum are fungus pits or mycangia. A fungus resembling Tuberculariella sp. was cultured from this area. Mycangia were not found in male adults.

Hymenopterous parasitoids of filth flies (Diptera: Muscidae) were surveyed during 2 years on dairy farms in Ontario and Quebec near Ottawa, Ontario, using freeze-killed sentinel house fly (Musca domestica L.) pupae and naturally occurring fly pupae collected on site. Musca domestica and Stomoxys calcitrans (L.) (stable fly) represented 98.3% of the natural fly hosts from which parasitoids emerged. Muscidifurax raptor Girault et Saunders, Nasonia vitripennis Walker, Pachycrepoideus vindemiae (Rondani), Spalangia cameroni Perkins, S. nigra Latreille, Trichomalopsis viridescens (Walsh), and Urolepis rufipes (Ashmead) (Pteromalidae) were recovered from both sentinel and natural fly pupae. Another eight species, S. drosophilae Ashmead, S. endius Walker, S. haematobiae Ashmead, S. nigroaenea Curtis, S. subpunctata Förster, Trichomalopsis dubia (Ashmead) (Pteromalidae), Aphaereta pallipes (Say) (Braconidae), and Phygadeuon ?fumator Gravenhörst (Ichneumonidae), were recovered only from natural pupae. Over the 2 years, M. raptor comprised 90.7% of emerged parasitoids from sentinel pupae but only 17.0% of emerged parasitoids from natural pupae. From natural pupae, S. cameroni, S. nigra, and S. nigroaenea collectively comprised 60.3% of emerged parasitoids; P. ?fumator comprised 13.5% and the remaining nine species 9.2%. The recoveries of S. endius and S. nigroaenea represent new distribution records for Canada, and several new host records are identified based on structure of the host fly puparium. The parasitoid fauna is compared with that known for western Canada, and recommendations are made for both regions concerning potential natural enemy enhancement for filth fly control.

Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), Palaearctic in origin, is thought to have been introduced into North America in the early 1800s. It is a major pest of spring wheat (Triticum aestivum Linnaeus (Poaceae)), durum wheat (T. durum Desfontaines), triticale (X-Triticosecale), and, to a lesser extent, spring rye (Secale cereale Linnaeus (Poaceae)) throughout the northern Great Plains. Climate is the principal factor regulating the distribution and abundance of most insects. A bioclimate simulation model was developed to explain the current distribution and abundance of S. mosellana. The current distribution for North America, Europe, and Asia was consistent with model projections. General circulation model scenarios (CSIRO-MK 3.0 and MIROC-H) for the 2030 and 2070 time periods were applied to the bioclimate simulation model of S. mosellana to assess the potential impact of changing climates on their distribution and relative abundance. Potential changes to relative abundance and distribution were most sensitive to time period, as opposed to climate change scenario. Differences between the MIROC-H and CSIRO-MK 3.0 models were restricted to particular regions in North America. The study found that the range and abundance of S. mosellana, and associated crop risk, was predicted to expand in a northerly direction and contract across the present southern limits.

Two opposing hypotheses are tested regarding the choice of oviposition sites by female Aedes togoi (Theobold) mosquitoes: (i) conspecific avoidance—females discriminate against sites harboring conspecifics to reduce intraspecific competition for their offspring and (ii) conspecific attraction—females prefer sites with conspecifics because their presence indicates suitable conditions for larvae. Under laboratory conditions, A. togoi females laid many more eggs on rearing water (LRW) containing conspecific larvae, their waste, bacteria, and food supplements than on rearing water alone (RM). In another experiment, females showed an oviposition preference for LRW sites that were devoid of A. togoi eggs compared with those harboring 50 (0.3 eggs/mL) conspecific eggs. Further, it was discovered that females laid their eggs at several sites rather than at a single suitable site. Possible reasons for such choices are discussed.

The influence of varietal differences in plants on infestation by aphids has received considerable attention in control studies. Painter (14), in 1941, concluded that the composition of the available food in the host plant plays possibly the most important role in determining the relative resistance to aphid attacks. In biological studies on Aphis rumicis L., Davidson (8) found that factors that influence the physiological activity of the plant affect also the progress of aphid infestation. The same author (6) also pointed out that aphids exhibit a wide range of fecundity on different hosts. “The sap of certain varieties of beans”, writes Davidson, “appears to have a direct inhibiting effect upon the reproductive capacity of the aphids, whereas that of other varieties seems to have the opposite effect.”

The dogwood borer, Synanthedon scitula (Harris) (Lepidoptera: Sesiidae), has the broadest host range of the clearwing moths and is considered to be an economically important pest of many ornamental, fruit, and nut trees. Since the 1980s, dogwood borer has been recognized as an increasingly important, indirect pest of apple, Malus domestica Borkh. (Rosaceae), in eastern North America, owing mainly to increased plantings of apple on size-controlling rootstocks that promote the formation of adventitious root initials (burr knots) on the rootstock and scion. Burr knots appear to be preferred oviposition sites for dogwood borer females, although infestations can also be initiated in wounds, pruning cuts, and crotches on the branches and trunk. Larval feeding in burr knots does not adversely affect the growth and vigor of apple trees, but their mining outward from burr knots into vascular tissue can ultimately cause tree decline and death. Chlorpyrifos is the most effective insecticide for controlling dogwood borer. A supplemental label in the United States permits post-bloom, trunk drench applications of chlorpyrifos specifically for control of borers in apple, with several restrictions that preclude control of infestations higher in the tree. The ongoing review of pesticide tolerances dictated by the 1996 Food Quality Protection Act of the United States of America makes the long-term availability of this chemical uncertain. Cultural practices, such as deeper planting or berming, can reduce the likelihood of infestation of new apple plantings by dogwood borer, although they do not preclude infestations from developing above the graft union. This review and discussion is based on our contention that research toward the development of alternative, behaviorally based management strategies for dogwood borer in apple and other economically important host plants is warranted. Our review and synthesis of the dogwood borer literature revealed important gaps in knowledge about basic aspects of its biology that pertain directly to the development of alternative control tactics based on behavioral manipulation. There is considerable confusion surrounding the sex pheromone of dogwood borer and conflicting results on the response of males to isomers and blends of isomers of its purported pheromone. Studies using sex attractants to monitor its phenology in apple and non-apple habitats have yielded discrepant results and conclusions. Differences in the effectiveness of commercially available pheromone lures for trapping dogwood borer have been reported and the ability of pheromone traps to accurately reflect emergence or population density remains in question. Regardless of pronounced differences in the duration and modality of the seasonal flight of dogwood borer among different geographical regions within its range, the conclusion of univoltinism across most of its range has been perpetuated, based on extremely limited developmental data collected exclusively from individuals that developed on dogwood.

Field studies conducted in cherry orchards of the Willamette Valley, Oregon, indicate that diapausing pupae of the western cherry fruit fly, Rhagoletis indifferens Curran, overwinter in the soil at a depth of 1–4 in. Relatively very small numbers of pupae were collected from surface debris and soil samples taken at a depth of 6 in. and below. The number of flies emerging from different soil depths indicated that removal of the top 6 in. of soil caused a 99% reduction in adult emergence, while the removal of the top 1 in. of soil had no effect.

The New World species of the staphylinid subfamily Oxyporinae are revised. Only one genus, Oxyporus Fab., with two subgenera, is included in the subfamily. The genus Pseudoxyporus, described by Nakane and Sawada (1956), has been reduced to subgeneric rank. Sixteen species are included in the revision. Two new species, O. bierigi from Costa Rica and Panama, and O. balli from Mexico are described; two names are placed in synonymy [O. fasciatus Melsh. (= O. vittatus Grav.) and O. fenyesi Bernhauer (= O. mexicanus Fauvel)]; and two names are reduced to subspecific level [O. bicolor Fauvel (= O. vittatus bicolor) and O. austrinus Horn (= O. femoralis austrinus)]. All of the New World species and subspecies have been redescribed and illustrated, and a key has been included for the separation of all the taxa.

A survey of nine populations of the European earwig, Forficula auricularia L., species complex from eastern North America revealed the presence of the two sibling species recently identified as species A and B. A mitochondrial analysis, based on restriction polymorphism observed on the 16S rRNA and the cytochrome oxydase regions, proved to be a rapid method to identify and distinguish these two species. Furthermore, consistency between these mitochondrial data and a biological diagnosis, based on the dates and number of oviposition periods in each population, revealed that species A and B occupy different habitats. These observations are consistent with the hypothesis of multiple introductions of the two species on the Atlantic coast of North America, followed by a selection of the most adapted species to each habitat.

Amino acids, the main constituents of protein, are needed by animals for the synthesis of the new body tissue during growth and for the regeneration of old tissues in the adult. They take part in the formation of almost all substances in the body and perform an important function in many physiological processes. When these acids are not available to the animal in sufficient quantities, characteristic metabolic disturbances and pathological conditions result. Amino acids have a similar role in insect physiology and hence have an important bearing upon problems related to insect pathology, toxicology and ecology. Unfortunately, however, very few attempts have been made to investigate the importance of amino acids in the diet of insects.

The Eleticinae are an archaic and in many respects primitive group of Meloidae found in South America (widespread), Africa (south of the Sahara Desert), and the Oriental Region (India to Thailand). They are, in general, poorly represented in collections, and very little is known definitely of their bionomics. On the basis of an analysis of adult anatomical characters the subfamily is defined in detail and is classified to the generic level in the present paper. Two tribes, seven subtribes, and 10 genera are recognized, keyed, and diagnosed. The tribe Spasticini is arranged as follows: Protomeloina Abdullah, transferred from the Meloinae and reduced to subtribal rank, with Protomeloe Abdullah; Spasticina Kaszab with Spastica Lacordaire; Xenospastina, new subtribe, with Xenospasta, new genus; and Anthicoxenina, new subtribe, with Anthicoxenus Fairmaire and Germain, formerly placed in the Anthicidae, and Iselma Haag-Rutenberg. The arrangement of the tribe Eleticini is: Eospastina, new subtribe, with Eospasta, new genus, and Serrospasta, new genus; Eleticina Wellman with Eletica Lacordaire (and including, as subgenera, Sibuteletica Pic, Meteletica Kaszab, and Proeletica Kaszab); and Ertlianina, new name for Ertliini Kaszab, with Ertliana Selander (= Steniselma Borchmann, new synonymy) and Ceriselma Borchmann, the latter elevated from subgeneric rank in Iselma. Species described as new are Protomeloe simplex (Argentina), Spastica minas (Brazil), Xenospasta flava (Colombia), and Serrospasta vittata (Colombia).

In the laboratory, females of Typhodromus tiliae Oudms., T.(N.) rhenanus Oudms., T. finlandicus Oudms., T. fallacis (Garm.), T. corticis Herb., and Phytoseius macropilis (Oudms.) were given various stages of the phytophagous mites Panonychus ulmi (Koch), Bryobia arborea M. & A., and Tetranychus telarius (L.), and Vasates schlechtendali (Nal.) to determine their ranges of feeding. The influence of these prey species on growth of phytoseiids and their ability to oviposit was not determined.

Even though Arabica coffee (Coffea arabica Linnaeus, Rubiaceae) can self-pollinate, bees are important pollinators, without which there is lower fruit quality and yield. We studied bee diversity in coffee agroecosystems in Costa Rica during two coffee flowering seasons (2005 and 2006). Malaise traps were used as a passive sampling method to collect bees during coffee blooms. We collected 1012 bee individuals from three different site types: nonagricultural fields and shaded and unshaded coffee farms. Unshaded coffee farms had significantly higher species richness (S) and number of bee individuals (n) than did the shaded coffee farms and nonagricultural sites. Overall bee diversity did not differ among site types but evenness (J′) was significantly lower in unshaded coffee farms. Using a more detailed community analysis, there was a significant association between functional groups and habitat type with more species and individuals of small-bodied ground-nesting bees (Lasioglossum (Dialictus) Robertson) associated with unshaded coffee farms. A large proportion (49%) of bees collected were of this subgenus, which was never before reported as common in coffee agroecosystems. Further studies should establish whether Dialictus is important in coffee pollination. We propose strategies involving conservation of native bees through simple habitat management for small-scale coffee farms that may improve crop quality and quantity.

Many problems in the management of renewable natural resources are extremum problems: we wish to maximize fish yield from a lake, tree yield from a forest, or minimize insect pest survival, for example. Such problems can be handled better by dynamic programming than classical analysis, because of the large number and the complex nature of constraints imposed on such systems. However, a priori arguments and analysis of biological time series show that such renewable natural resources do not constitute Markov processes, since state changes from t to t + 1 are dependent on the state: at t − 1 as well as the state at t. Therefore, before making a decision about the optimal strategy at t, we must explore the future consequences of the strategy at t + 1 and t + 2. This paper reports computer experiments on strategy evaluation procedures, using dynamic programming and modified dynamic programming with two-stage “look-ahead”. The data used to develop the model came from 60 years of observations on weather conditions and insect pest populations at Magdeburg, Germany. The general conclusion from this work is that the selection of most appropriate strategy for a biological management problem should he determined by the structure of the problem. Sometimes, “one-stage look-ahead” gave the lowest value for the criterion function, and sometimes “two-stage look-ahead” was optimal. The two types of programming always yielded lower cumulative defoliation than the method now used: killing as many pests as feasible whenever “pest” densities are reached.