Cypermethrin was tested at nine dosages from 2 to 72 g AI/ha and at five temperatures from 15 °to 35 °C against second-instar nymphs of a non-diapause strain of the migratory grasshopper, Melanoplus sanguinipes (Fab.). At lower dosages, mortality increased with increasing temperatures from 15 °to 30 °C and then leveled off. At dosages of 12 g AI/ha or higher, mortality increased slightly with increasing temperature from 15 °to 20 °C, then declined at higher temperatures. Cypermethrin was about 2.2 times less toxic (LD50) at 35 °C than at 15 °or 20 °C and 70% of this reduction in toxicity occurred above 25 °C. Thus, the toxicity of cypermethrin was negatively correlated with temperature above 20 °C for nymphs of the migratory grasshopper.

Mites of the genus Trisetacus from North America are revised, and a key is presented for the 22 species recognized. A diagnosis and a review of host and distributional data are presented for each of these species. A comprehensive review of all nominate species and subspecies is included to facilitate appropriate usage of available names.

Conelet abortion in a jack pine, Pinus banksiana Lamb., seed orchard in Oneida County, Wisconsin was caused by Platylygus luridus (Reuter) (Hemiptera: Miridae) and ranged from 51% to 87% with the average 74.5% in 3 of 4 years. Adults preferred to feed on ovules in conelets and were 3 to 4 times more destructive than nymphs. When conelets were protected from this insect by coating the twig above and below the conelet with Tanglefoot®, abortion was below 11%. Other mirid adults including Phytocoris michiganae Knight, Pilophorus amoenus Uhler, Dichrooscytus suspectus Reuter, and Europiella n.sp. confined in cages with conelets did not induce abortion.

Platylygus luridus (Reuter) causes conelet abortion and reduces seed production in jack pine, Pinus banksiana Lamb., seed orchards in northern Wisconsin. One generation a year occurs and the insect overwinters as an egg that hatches during late May. The nymphs pass through 5 instars within 5 to 6 weeks. Adults were abundant during July and early August 1982. Eggs were laid singly within the phloem tissues of current year's shoots just below the bases of needle fascicles. The nymphs fed predominantly on the tender tissues of shoots or needles. The adults preferred to feed on ovules in the conelets, and conelet abortion resulted. About 74% of the total abortion occurred during adult feeding periods. Conditions favoring P. luridus population increases in the jack pine seed orchards included: densely planted seed orchards on high fertility sites; trees 6 to 10 years old with closed crowns or in shade; vigorously growing trees that were well watered and fertilized. Natural enemies included predators Deraeocoris albigulus, D. (possibly) laricicola, Evarcha nr. hoyi, and Misumenops asperatus.

The genus Porrhodites Kraatz is redescribed to include the Nearctic Paradeliphrum inflatum Hatch, as well as the Holarctic Porrhodites fenestralis (Zetterstedt). Orochares Kraatz is also redescribed to include Paradeliphrum (new synonymy). In addition to O. angustatus Erichson from Europe, O. japonicus Cameron from Japan and O. villiersi Jarrige from Iran, Orochares now includes two Nearctic species, Paradeliphrum tumidum Hatch from the Pacific Northwest and the new species O. suteri from Illinois and Wisconsin. Keys are provided to distinguish the North American species of each genus, and the major diagnostic characters of all included taxa are illustrated.

The smaller European elm bark beetle, Scolytus multistriatus (Marsham), had three distinct periods of adult flight annually in Georgia. Adults of the associated native elm bark beetle, Hylurgopinus rufipes Eichhoff, were trapped on elm logs during only one period in the spring, but some adults were reared from infested bolts in the fall. Seasonal abundance of the S. multistriatus parasite Spathius benefactor Matthews (Braconidae) showed little temporal relationship to its host. However, Entedon leucogramma Ratzeburg (Eulophidae) emergence was highly synchronized with S. multistriatus emergence. Scolytus multistriatus overwintered as fully developed larvae as in other parts of its range.

Three biological control methods were evaluated for the reduction of damage to chrysanthemums by the leafminer Liriomyza trifolii (Burgess). Yellow sticky boards trapped adults and reduced the damage by 50%, Afugan 30 EC effectively controlled the damage to chrysanthemums, and interplanting with field beans as a trap crop showed potential for reducing damage. A specific integrated pest management program can not be recommended as yet; more information is needed.

The presence of the fungus Phoma macdonaldii Boerema on the exocuticle of the adult stem weevil Apion occidentale Fall, was verified using isolation techniques and scanning electron microscopy. Pycnidiospores matching those of P. macdonaldii in size and shape were observed on the antennae, meso- and metathoracic legs of both field-collected and Phoma-incubated adults. Fungal hyphae were observed on the rostrum of both field-collected and laboratory-inoculated adults. Four percent of the weevils carried P. macdonaldii internally.

To our knowledge, reports of Betula spp. resistance against damage caused by the birch leafminer, Fenusa pusilla (Lepeletier), have not been published. Becker (1938), Friend (1933), and Johnson and Lyon (1976) stated that B. populifolia Marsh., B. papyrifera Marsh., and B. alba L. are the most commonly attacked species. Friend (1933) and Johnson and Lyon (1976) stated that B. lenta L., B. alleghaniensis Britt, and B. nigra L. have never been observed infested or are rarely fed upon.

Plant galls are growth deformities developed under the influence of parasitic insects. The process of differentiation of normal plant tissue into gall tissue has been examined by many authors (Kostoff and Kendall 1929; Rohfristch 1977; see also Mani 1964) but less effort has been made to study the effects of the gallmaker on plant tissues outside the vicinity of active gall formation. Negative effects on the overall growth of the host plant can be expected because the gall acts as an energy and nutrient sink (Palct 1972; Hartnett and Abrahamson 1979), which can cause abnormal patterns of resource allocation among plant organs.